Sample records for air mass flux

  1. Diode laser-based air mass flux sensor for subsonic aeropropulsion inlets

    NASA Astrophysics Data System (ADS)

    Miller, Michael F.; Kessler, William J.; Allen, Mark G.

    1996-08-01

    An optical air mass flux sensor based on a compact, room-temperature diode laser in a fiber-coupled delivery system has been tested on a full-scale gas turbine engine. The sensor is based on simultaneous measurements of O 2 density and Doppler-shifted velocity along a line of sight across the inlet duct. Extensive tests spanning engine power levels from idle to full afterburner demonstrate accuracy and precision of the order of 1 2 of full scale in density, velocity, and mass flux. The precision-limited velocity at atmospheric pressure was as low as 40 cm s. Multiple data-reduction procedures are quantitatively compared to suggest optimal strategies for flight sensor packages.

  2. Mass and Ozone Fluxes from the Lowermost Stratosphere

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.; Olsen, Mark A.

    2004-01-01

    Net mass flux from the stratosphere to the troposphere can be computed from the heating rate along the 380K isentropic surface and the time rate of change of the mass of the lowermost stratosphere (the region between the tropopause and the 380K isentrope). Given this net mass flux and the cross tropopause diabatic mass flux, the residual adiabatic mass flux across the tropopause can also be estimated. These fluxes have been computed using meteorological fields from a free-running general circulation model (FVGCM) and two assimilation data sets, FVDAS, and UKMO. The data sets tend to agree that the annual average net mass flux for the Northern Hemisphere is about 1P10 kg/s. There is less agreement on the southern Hemisphere flux that might be half as large. For all three data sets, the adiabatic mass flux is computed to be from the upper troposphere into the lowermost stratosphere. This flux will dilute air entering from higher stratospheric altitudes. The mass fluxes are convolved with ozone mixing ratios from the Goddard 3D CTM (which uses the FVGCM) to estimate the cross-tropopause transport of ozone. A relatively large adiabatic flux of tropospheric ozone from the tropical upper troposphere into the extratropical lowermost stratosphere dilutes the stratospheric air in the lowermost stratosphere. Thus, a significant fraction of any measured ozone STE may not be ozone produced in the higher Stratosphere. The results also illustrate that the annual cycle of ozone concentration in the lowermost stratosphere has as much of a role as the transport in the seasonal ozone flux cycle. This implies that a simplified calculation of ozone STE mass from air mass and a mean ozone mixing ratio may have a large uncertainty.

  3. Air-mass flux measurement system using Doppler-shifted filtered Rayleigh scattering

    NASA Technical Reports Server (NTRS)

    Shirley, John A.; Winter, Michael

    1993-01-01

    An optical system has been investigated to measure mass flux distributions in the inlet of a high speed air-breathing propulsion system. Rayleigh scattered light from air is proportional to the number density of molecules and hence can be used to ascertain the gas density in a calibrated system. Velocity field measurements are achieved by spectrally filtering the elastically-scattered Doppler-shifted light with an absorbing molecular filter. A novel anamorphic optical collection system is used which allows optical rays from different scattering angles, that have different Doppler shifts, to be recorded separately. This is shown to obviate the need to tune the laser through the absorption to determine velocities, while retaining the ability to make spatially-resolved measurements along a line. By properly selecting the laser tuning and filter parameters, simultaneous density measurements can be made. These properties are discussed in the paper and experiments demonstrating the velocimetry capability are described.

  4. Air sparging: Air-water mass transfer coefficients

    NASA Astrophysics Data System (ADS)

    Braida, Washington J.; Ong, Say Kee

    1998-12-01

    Experiments investigating the mass transfer of several dissolved volatile organic compounds (VOCs) across the air-water interface were conducted using a single-air- channel air-sparging system. Three different porous media were used in the study. Air velocities ranged from 0.2 cm s-1 to 2.5 cm s-1. The tortuosity factor for each porous medium and the air-water mass transfer coefficients were estimated by fitting experimental data to a one-dimensional diffusion model. The estimated mass transfer coefficients KG ranged from 1.79 × 10-3 cm min-1 to 3.85 × 10-2 cm min-1. The estimated lumped gas phase mass transfer coefficients KGa were found to be directly related to the air diffusivity of the VOC, air velocity, and particle size, and inversely related to the Henry's law constant of the VOCs. Of the four parameters investigated, the parameter that controlled or had a dominant effect on the lumped gas phase mass transfer coefficient was the air diffusivity of the VOC. Two empirical models were developed by correlating the Damkohler and the modified air phase Sherwood numbers with the air phase Peclet number, Henry's law constant, and the reduced mean particle size of porous media. The correlation developed in this study may be used to obtain better predictions of mass transfer fluxes for field conditions.

  5. Measurement of air and VOC vapor fluxes during gas-driven soil remediation: bench-scale experiments.

    PubMed

    Kim, Heonki; Kim, Taeyun; Shin, Seungyeop; Annable, Michael D

    2012-09-04

    In this laboratory study, an experimental method was developed for the quantitative analyses of gas fluxes in soil during advective air flow. One-dimensional column and two- and three-dimensional flow chamber models were used in this study. For the air flux measurement, n-octane vapor was used as a tracer, and it was introduced in the air flow entering the physical models. The tracer (n-octane) in the gas effluent from the models was captured for a finite period of time using a pack of activated carbon, which then was analyzed for the mass of n-octane. The air flux was calculated based on the mass of n-octane captured by the activated carbon and the inflow concentration. The measured air fluxes are in good agreement with the actual values for one- and two-dimensional model experiments. Using both the two- and three-dimensional models, the distribution of the air flux at the soil surface was measured. The distribution of the air flux was found to be affected by the depth of the saturated zone. The flux and flux distribution of a volatile contaminant (perchloroethene) was also measured by using the two-dimensional model. Quantitative information of both air and contaminant flux may be very beneficial for analyzing the performance of gas-driven subsurface remediation processes including soil vapor extraction and air sparging.

  6. Evaluation of Long-term Performance of Enhanced Anaerobic Source Zone Bioremediation using mass flux

    NASA Astrophysics Data System (ADS)

    Haluska, A.; Cho, J.; Hatzinger, P.; Annable, M. D.

    2017-12-01

    Chlorinated ethene DNAPL source zones in groundwater act as potential long term sources of contamination as they dissolve yielding concentrations well above MCLs, posing an on-going public health risk. Enhanced bioremediation has been applied to treat many source zones with significant promise, but long-term sustainability of this technology has not been thoroughly assessed. This study evaluated the long-term effectiveness of enhanced anaerobic source zone bioremediation at chloroethene contaminated sites to determine if the treatment prevented contaminant rebound and removed NAPL from the source zone. Long-term performance was evaluated based on achieving MCL-based contaminant mass fluxes in parent compound concentrations during different monitoring periods. Groundwater concertation versus time data was compiled for 6-sites and post-remedial contaminant mass flux data was then measured using passive flux meters at wells both within and down-gradient of the source zone. Post-remedial mass flux data was then combined with pre-remedial water quality data to estimate pre-remedial mass flux. This information was used to characterize a DNAPL dissolution source strength function, such as the Power Law Model and the Equilibrium Stream tube model. The six-sites characterized for this study were (1) Former Charleston Air Force Base, Charleston, SC; (2) Dover Air Force Base, Dover, DE; (3) Treasure Island Naval Station, San Francisco, CA; (4) Former Raritan Arsenal, Edison, NJ; (5) Naval Air Station, Jacksonville, FL; and, (6) Former Naval Air Station, Alameda, CA. Contaminant mass fluxes decreased for all the sites by the end of the post-treatment monitoring period and rebound was limited within the source zone. Post remedial source strength function estimates suggest that decreases in contaminant mass flux will continue to occur at these sites, but a mass flux based on MCL levels may never be exceeded. Thus, site clean-up goals should be evaluated as order

  7. Methods, fluxes and sources of gas phase alkyl nitrates in the coastal air.

    PubMed

    Dirtu, Alin C; Buczyńska, Anna J; Godoi, Ana F L; Favoreto, Rodrigo; Bencs, László; Potgieter-Vermaak, Sanja S; Godoi, Ricardo H M; Van Grieken, René; Van Vaeck, Luc

    2014-10-01

    The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3-C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO₂ levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor.

  8. Bivelocity hydrodynamics. Diffuse mass flux vs. diffuse volume flux

    NASA Astrophysics Data System (ADS)

    Brenner, Howard

    2013-02-01

    An intimate physical connection exists between a fluid’s mass and its volume, with the density ρ serving as a proportionality factor relating these two extensive thermodynamic properties when the fluid is homogeneous. This linkage has led to the erroneous belief among many researchers that a fluid’s diffusive (dissipative) mass flux and its diffusive volume flux counterpart, both occurring in inhomogeneous fluids undergoing transport are, in fact, synonymous. However, the existence of a truly dissipative mass flux (that is, a mass flux that is physically dissipative) has recently and convincingly been shown to be a physical impossibility [H.C. Öttinger, H. Struchtrup, M. Liu, On the impossibility of a dissipative contribution to the mass flux in hydrodynamics, Phys. Rev. E 80 (2009) 056303], owing, among other things, to its violation of the principle of angular momentum conservation. Unfortunately, as a consequence of the erroneous belief in the equality of the diffuse volume and mass fluxes (sans an algebraic sign), this has led many researchers to wrongly conclude that a diffuse volume flux is equally impossible. As a consequence, owing to the fundamental role played by the diffuse volume flux in the theory of bivelocity hydrodynamics [H. Brenner, Beyond Navier-Stokes, Int. J. Eng. Sci. 54 (2012) 67-98], many researchers have been led to falsely dismiss, without due consideration, the possibility of bivelocity hydrodynamics constituting a potentially viable physical theory, which it is believed to be. The present paper corrects this misconception by using a simple concrete example involving an isothermal rotating rigid-body fluid motion to clearly confirm that whereas a diffuse mass flux is indeed impossible, this fact does not exclude the possible existence of a diffuse volume flux and, concomitantly, the possibility that bivelocity hydrodynamics is indeed a potentially viable branch of fluid mechanics.

  9. Air-sea fluxes and satellite-based estimation of water masses formation

    NASA Astrophysics Data System (ADS)

    Sabia, Roberto; Klockmann, Marlene; Fernandez-Prieto, Diego; Donlon, Craig

    2015-04-01

    Recent work linking satellite-based measurements of sea surface salinity (SSS) and sea surface temperature (SST) with traditional physical oceanography has demonstrated the capability of generating routinely satellite-derived surface T-S diagrams [1] and analyze the distribution/dynamics of SSS and its relative surface density with respect to in-situ measurements. Even more recently [2,3], this framework has been extended by exploiting these T-S diagrams as a diagnostic tool to derive water masses formation rates and areas. A water mass describes a water body with physical properties distinct from the surrounding water, formed at the ocean surface under specific conditions which determine its temperature and salinity. The SST and SSS (and thus also density) at the ocean surface are largely determined by fluxes of heat and freshwater. The surface density flux is a function of the latter two and describes the change of the density of seawater at the surface. To obtain observations of water mass formation is of great interest, since they serve as indirect observations of the thermo-haline circulation. The SSS data which has become available through the SMOS [4] and Aquarius [5] satellite missions will provide the possibility of studying also the effect of temporally-varying SSS fields on water mass formation. In the present study, the formation of water masses as a function of SST and SSS is derived from the surface density flux by integrating the latter over a specific area and time period in bins of SST and SSS and then taking the derivative of the total density flux with respect to density. This study presents a test case using SMOS SSS, OSTIA SST, as well as Argo ISAS SST and SSS for comparison, heat fluxes from the NOCS Surface Flux Data Set v2.0, OAFlux evaporation and CMORPH precipitation. The study area, initially referred to the North Atlantic, is extended over two additional ocean basins and the study period covers the 2011-2012 timeframe. Yearly, seasonal

  10. Air-sea fluxes of momentum and mass in the presence of wind waves

    NASA Astrophysics Data System (ADS)

    Zülicke, Christoph

    2010-05-01

    An air-sea interaction model (ASIM) is developed including the effect of wind waves on momentum and mass transfer. This includes the derivation of profiles of dissipation rate, flow speed and concentration from a certain height to a certain depth. Simplified assumptions on the turbulent closure, skin - bulk matching and the spectral wave model allow for an analytic treatment. Particular emphasis was put on the inclusion of primary (gravity) waves and secondary (capillary-gravity) waves. The model was tuned to match wall-flow theory and data on wave height and slope. Growing waves reduce the air-side turbulent stress and lead to an increasing drag coefficient. In the sea, breaking waves inject turbulent kinetic energy and accelerate the transfer. Cross-reference with data on wave-related momentum and energy flux, dissipation rate and transfer velocity was sufficient. The evaluation of ASIM allowed for the analytical calculation of bulk formulae for the wind-dependent gas transfer velocity including information on the air-side momentum transfer (drag coefficient) and the sea-side gas transfer (Dalton number). The following regimes have been identified: the smooth waveless regime with a transfer velocity proportional to (wind) × (diffusion)2-3, the primary wave regime with a wind speed dependence proportional to (wind)1-4 × (diffusion)1-2-(waveage)1-4 and the secondary wave regime including a more-than-linear wind speed dependence like (wind)15-8 × (diffusion)1-2 × (waveage)5-8. These findings complete the current understanding of air-sea interaction for medium winds between 2 and 20 m s^-1.

  11. Air-sea heat flux control on the Yellow Sea Cold Water Mass intensity and implications for its prediction

    NASA Astrophysics Data System (ADS)

    Zhu, Junying; Shi, Jie; Guo, Xinyu; Gao, Huiwang; Yao, Xiaohong

    2018-01-01

    The Yellow Sea Cold Water Mass (YSCWM), which occurs during summer in the central Yellow Sea, plays an important role in the hydrodynamic field, nutrient cycle and biological species. Based on water temperature observations during the summer from 1978 to 1998 in the western Yellow Sea, five specific YSCWM years were identified, including two strong years (1984 and 1985), two weak years (1989 and 1995) and one normal year (1992). Using a three-dimensional hydrodynamic model, the YSCWM formation processes in these five years were simulated and compared with observations. In general, the YSCWM began forming in spring, matured in summer and gradually disappeared in autumn of every year. The 8 °C isotherm was used to indicate the YSCWM boundary. The modelled YSCWM areas in the two strong years were approximately two times larger than those in the two weak years. Based on the simulations in the weak year of 1995, ten numerical experiments were performed to quantify the key factors influencing the YSCWM intensity by changing the initial water condition in the previous autumn, air-sea heat flux, wind, evaporation, precipitation and sea level pressure to those in the strong year of 1984, respectively. The results showed that the air-sea heat flux was the dominant factor influencing the YSCWM intensity, which contributed about 80% of the differences of the YSCWM average water temperature at a depth of 50 m. In addition, the air-sea heat flux in the previous winter had a determining effect, contributing more than 50% of the differences between the strong and weak YSCWM years. Finally, a simple formula for predicting the YSCWM intensity was established by using the key influencing factors, i.e., the sea surface temperature before the cooling season and the air-sea heat flux during the cooling season from the previous December to the current February. With this formula, instead of a complicated numerical model, we were able to roughly predict the YSCWM intensity for the

  12. Sensing the flux of volatile chemicals through the air-water interface

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mackay, D.; Schroeder, W.H.; Ooijen, H. von

    1997-12-31

    There are several situations in which there is a need to assess the direction and magnitude of the flux across the air-water interface. Contaminants may be evaporating or absorbing in wastewater treatment systems in natural lake, river, estuarine and marine systems, and any attempt to compile a mass balance must include this process. In this study the authors review the theory underlying air-water exchange, then describe and discuss a sparging approach by which the direction and magnitude of the flux can be ascertained. The principle of the method is that a known flow rate of air is bubbled through themore » sparger and allowed to equilibrate with the water. The gas exiting the water surface is passed through a sorbent trap and later analyzed. The concentration, and hence the fugacity, of the contaminant in the sparged air can be deduced. In parallel, a similar flow of air from the atmosphere above the water is drawn through another sparger at a similar flow rate for a similar time and the trapped chemical analyzed giving the concentration and fugacity in the air. These data show the direction of air-water exchange (i.e. from high to low fugacity) and with information on the mass transfer coefficients and area, the flux. Successful tests were conducted of the system in a laboratory tank, in Lake Ontario and in Hamilton Harbour. Analyses of the traps showed a large number of peaks on the chromatogram many of which are believed to be of petroleum origin from fuels and vessel exhaust. The system will perform best under conditions where concentrations of specific contaminants are large, as occurs in waste water treatment systems. The approach has the potential to contribute to more accurate assessment of air-water fluxes. It avoids the problems of different analytical methodologies and the effect of sorption in the water column.« less

  13. Effect of radiator position and mass flux on the dryer room heat transfer rate

    NASA Astrophysics Data System (ADS)

    Mirmanto, M.; Sulistyowati, E. D.; Okariawan, I. D. K.

    A room radiator as usually used in cold countries, is actually able to be used as a heat source to dry goods, especially in the rainy season where the sun seldom shines due to much rain and cloud. Experiments to investigate effects of radiator position and mass flux on heat transfer rate were performed. This study is to determine the best position of the radiator and the optimum mass flux. The radiator used was a finned radiator made of copper pipes and aluminum fins with an overall dimension of 220 mm × 50 mm × 310 mm. The prototype room was constructed using plywood and wood frame with an overall size of 1000 mm × 1000 mm × 1000 mm. The working fluid was heated water flowing inside the radiator and air circulating naturally inside the prototype room. The nominal mass fluxes employed were 800, 900 and 1000 kg/m2 s. The water was kept at 80 °C at the radiator entrance, while the initial air temperature inside the prototype room was 30 °C. Three positions of the radiator were examined. The results show that the effect of the mass flux on the forced and free convection heat transfer rate is insignificant but the radiator position strongly affects the heat transfer rate for both forced and free convection.

  14. Sea-to-air flux of dimethyl sulfide in the South and North Pacific Ocean as measured by proton transfer reaction-mass spectrometry coupled with the gradient flux technique

    NASA Astrophysics Data System (ADS)

    Omori, Yuko; Tanimoto, Hiroshi; Inomata, Satoshi; Ikeda, Kohei; Iwata, Toru; Kameyama, Sohiko; Uematsu, Mitsuo; Gamo, Toshitaka; Ogawa, Hiroshi; Furuya, Ken

    2017-07-01

    Exchange of dimethyl sulfide (DMS) between the surface ocean and the lower atmosphere was examined by using proton transfer reaction-mass spectrometry coupled with the gradient flux (PTR-MS/GF) system. We deployed the PTR-MS/GF system and observed vertical gradients of atmospheric DMS just above the sea surface in the subtropical and transitional South Pacific Ocean and the subarctic North Pacific Ocean. In total, we obtained 370 in situ profiles, and of these we used 46 data sets to calculate the sea-to-air flux of DMS. The DMS flux determined was in the range from 1.9 to 31 μmol m-2 d-1 and increased with wind speed and biological activity, in reasonable accordance with previous observations in the open ocean. The gas transfer velocity of DMS derived from the PTR-MS/GF measurements was similar to either that of DMS determined by the eddy covariance technique or that of insoluble gases derived from the dual tracer experiments, depending on the observation sites located in different geographic regions. When atmospheric conditions were strongly stable during the daytime in the subtropical ocean, the PTR-MS/GF observations captured a daytime versus nighttime difference in DMS mixing ratios in the surface air overlying the ocean surface. The difference was mainly due to the sea-to-air DMS emissions and stable atmospheric conditions, thus affecting the gradient of DMS. This indicates that the DMS gradient is strongly controlled by diurnal variations in the vertical structure of the lower atmosphere above the ocean surface.

  15. Relationship between mass-flux reduction and source-zone mass removal: analysis of field data.

    PubMed

    Difilippo, Erica L; Brusseau, Mark L

    2008-05-26

    The magnitude of contaminant mass-flux reduction associated with a specific amount of contaminant mass removed is a key consideration for evaluating the effectiveness of a source-zone remediation effort. Thus, there is great interest in characterizing, estimating, and predicting relationships between mass-flux reduction and mass removal. Published data collected for several field studies were examined to evaluate relationships between mass-flux reduction and source-zone mass removal. The studies analyzed herein represent a variety of source-zone architectures, immiscible-liquid compositions, and implemented remediation technologies. There are two general approaches to characterizing the mass-flux-reduction/mass-removal relationship, end-point analysis and time-continuous analysis. End-point analysis, based on comparing masses and mass fluxes measured before and after a source-zone remediation effort, was conducted for 21 remediation projects. Mass removals were greater than 60% for all but three of the studies. Mass-flux reductions ranging from slightly less than to slightly greater than one-to-one were observed for the majority of the sites. However, these single-snapshot characterizations are limited in that the antecedent behavior is indeterminate. Time-continuous analysis, based on continuous monitoring of mass removal and mass flux, was performed for two sites, both for which data were obtained under water-flushing conditions. The reductions in mass flux were significantly different for the two sites (90% vs. approximately 8%) for similar mass removals ( approximately 40%). These results illustrate the dependence of the mass-flux-reduction/mass-removal relationship on source-zone architecture and associated mass-transfer processes. Minimal mass-flux reduction was observed for a system wherein mass removal was relatively efficient (ideal mass-transfer and displacement). Conversely, a significant degree of mass-flux reduction was observed for a site wherein mass

  16. Sea spray contributions to the air-sea fluxes at moderate and hurricane wind speeds

    NASA Astrophysics Data System (ADS)

    Mueller, J. A.; Veron, F.

    2009-12-01

    At sufficiently high wind speed conditions, the surface of the ocean separates to form a substantial number of sea spray drops, which can account for a significant fraction of the total air-sea surface area and thus make important contributions to the aggregate air-sea momentum, heat and mass fluxes. Although consensus around the qualitative impacts of these drops has been building in recent years, the quantification of their impacts has remained elusive. Ultimately, the spray-mediated fluxes depend on three controlling factors: the number and size of drops formed at the surface, the duration of suspension within the atmospheric marine boundary layer, and the rate of momentum, heat and mass transfer between the drops and the atmosphere. While the latter factor can be estimated from an established, physically-based theory, the estimates for the former two are not well established. Using a recent, physically-based model of the sea spray source function along with the results from Lagrangian stochastic simulations of individual drops, we estimate the aggregate spray-mediated fluxes, finding reasonable agreement with existing models and estimates within the empirical range of wind speed conditions. At high wind speed conditions that are outside the empirical range, however, we find somewhat lower spray-mediated fluxes than previously reported in the literature, raising new questions about the relative air-sea fluxes at high wind speeds as well as the development and sustainment of hurricanes.

  17. Seasonal Oxygen Supersaturation and Air-Sea Fluxes from Profiling Floats in the Pacific

    NASA Astrophysics Data System (ADS)

    Bushinsky, S. M.; Emerson, S. R.

    2016-02-01

    The Pacific Ocean is a heterogeneous basin that includes regions of strong CO2 fluxes to and from the atmosphere. The Kuroshio Extension (KE) is a current associated with the largest CO2 flux into the Pacific Ocean, which extends across the Pacific basin between the subarctic and subtropical regions. The relative importance of the biological and physical processes controlling this sink is uncertain. The stoichiometric relationship between O2 and dissolved inorganic carbon during photosynthesis and respiration may allow in situ O2 measurements to help determine the processes driving this large CO2 flux. In this study, we used Argo profiling floats with modified oxygen sensors to estimate O2 fluxes in several areas of the Pacific. In situ air calibrations of these sensors allowed us to accurately measure air-sea O2 differences, which largely control the flux of O2 to and from the atmosphere. In this way, we determine air-sea O2 fluxes from profiling floats, which previously did not measure O2 accurately enough to make these calculations. To characterize different areas within the KE, we separated O2 measurements from floats into 3 regions based on geographical position and temperature-salinity relationships: North KE, Central KE, and South KE. We then used these regions and floats in the Alaska Gyre and subtropical South Pacific gyre to develop seasonal climatologies of ΔO2 and air-sea flux. Mean annual air-sea oxygen fluxes (positive fluxes represent addition of O2 to the ocean) were calculated for the Alaska Gyre of -0.3 mol m-2 yr-1 (2012-2015), for the northern KE, central KE, and southern KE (2013-2015) of 6.8, 10.5, and 0.5 mol m-2 yr-1, respectively, and for the south subtropical Pacific (2014-2015) of 0.6 mol m-2 yr-1. The air-sea flux due to bubbles was greater than 50% of the total flux for winter months and essential for determining the magnitude and, in some cases, direction of the cumulative mean annual flux. Increases in solubility due to wintertime

  18. Measuring Convective Mass Fluxes Over Tropical Oceans

    NASA Astrophysics Data System (ADS)

    Raymond, David

    2017-04-01

    Deep convection forms the upward branches of all large-scale circulations in the tropics. Understanding what controls the form and intensity of vertical convective mass fluxes is thus key to understanding tropical weather and climate. These mass fluxes and the corresponding conditions supporting them have been measured by recent field programs (TPARC/TCS08, PREDICT, HS3) in tropical disturbances considered to be possible tropical storm precursors. In reality, this encompasses most strong convection in the tropics. The measurements were made with arrays of dropsondes deployed from high altitude. In some cases Doppler radar provided additional measurements. The results are in some ways surprising. Three factors were found to control the mass flux profiles, the strength of total surface heat fluxes, the column-integrated relative humidity, and the low to mid-tropospheric moist convective instability. The first two act as expected, with larger heat fluxes and higher humidity producing more precipitation and stronger lower tropospheric mass fluxes. However, unexpectedly, smaller (but still positive) convective instability produces more precipitation as well as more bottom-heavy convective mass flux profiles. Furthermore, the column humidity and the convective instability are anti-correlated, at least in the presence of strong convection. On spatial scales of a few hundred kilometers, the virtual temperature structure appears to be in dynamic balance with the pattern of potential vorticity. Since potential vorticity typically evolves on longer time scales than convection, the potential vorticity pattern plus the surface heat fluxes then become the immediate controlling factors for average convective properties. All measurements so far have taken place in regions with relatively flat sea surface temperature (SST) distributions. We are currently seeking funding for a measurement program in the tropical east Pacific, a region that exhibits strong SST gradients and

  19. Wintertime Air-Sea Gas Transfer Rates and Air Injection Fluxes at Station Papa in the NE Pacific

    NASA Astrophysics Data System (ADS)

    McNeil, C.; Steiner, N.; Vagle, S.

    2008-12-01

    In recent studies of air-sea fluxes of N2 and O2 in hurricanes, McNeil and D'Asaro (2007) used a simplified model formulation of air-sea gas flux to estimate simultaneous values of gas transfer rate, KT, and air injection flux, VT. The model assumes air-sea gas fluxes at high to extreme wind speeds can be explained by a combination of two processes: 1) air injection, by complete dissolution of small bubbles drawn down into the ocean boundary layer by turbulent currents, and 2) near-surface equilibration processes, such as occurs within whitecaps. This analysis technique relies on air-sea gas flux estimates for two gases, N2 and O2, to solve for the two model parameters, KT and VT. We present preliminary results of similar analysis of time series data collected during winter storms at Station Papa in the NE Pacific during 2003/2004. The data show a clear increase in KT and VT with increasing NCEP derived wind speeds and acoustically measured bubble penetration depth.

  20. Mass transfer inside a flux hood for the sampling of gaseous emissions from liquid surfaces - Experimental assessment and emission rate rescaling

    NASA Astrophysics Data System (ADS)

    Prata, Ademir A.; Lucernoni, Federico; Santos, Jane M.; Capelli, Laura; Sironi, Selena; Le-Minh, Nhat; Stuetz, Richard M.

    2018-04-01

    This study assesses the mass transfer of compounds inside the US EPA flux hood, one of the enclosure devices most commonly employed for the direct measurement of atmospheric emissions from liquid surfaces in wastewater treatment plants (WWTPs). Experiments comprised the evaporation of water and the volatilisation of a range of volatile organic compounds (VOCs). Special attention was given to the evaluation of the mass transfer coefficients in the microenvironment created by the flux hood and the effects of concentration build up in the hood's headspace. The VOCs emission rates and the water evaporation rates generally increased with the sweep air flow rate, as did the mass transfer coefficients for all compounds. The emission of compounds whose volatilisation is significantly influenced by the gas phase was greatly affected by concentration build up, whereas this effect was not significant for liquid phase-controlled compounds. The gas-film mass transfer coefficient (kG) estimated inside the US EPA flux hood was of the same order as the respective kG reported in the literature for wind tunnel-type devices, but the emission rates measured by the flux hood can be expected to be lower, due to the concentration build-up. Compared against an emission model for the passive surfaces in WWTPs, the mass transfer of acetic acid (representing a gas phase-dominated compound) inside the US EPA flux hood was equivalent to conditions of wind speeds at 10 m height (U10) of 0.27, 0.51 and 0.99 m s-1, respectively, for sweep air flow rates of 2, 5 and 10 L min-1. On the other hand, for higher wind speeds, the emission rates of gas phase-controlled compounds obtained with the flux hood can be considerably underestimated: for instance, at U10 = 5 m s-1, the emission rates of acetic acid inside the flux hood would be approximately 23, 12 and 6 times lower than the emission rates in the field, for sweep air flow rates of 2, 5 and 10 L min-1, respectively. A procedure is presented in

  1. Intercomparison of Air-Sea Fluxes in the Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Buckley, J.; Weller, R. A.; Farrar, J. T.; Tandon, A.

    2016-02-01

    Heat and momentum exchange between the air and sea in the Bay of Bengal is an important driver of atmospheric convection during the Asian Monsoon. Warm sea surface temperatures resulting from salinity stratified shallow mixed layers trigger widespread showers and thunderstorms. In this study, we compare atmospheric reanalysis flux products to air-sea flux values calculated from shipboard observations from four cruises and an air-sea flux mooring in the Bay of Bengal as part of the Air-Sea Interactions in the Northern Indian Ocean (ASIRI) experiment. Comparisons with months of mooring data show that most long timescale reanalysis error arises from the overestimation of longwave and shortwave radiation. Ship observations and select data from the air-sea flux mooring reveals significant errors on shorter timescales (2-4 weeks) which are greatly influenced by errors in shortwave radiation and latent and sensible heat. During these shorter periods, the reanalyses fail to properly show sharp decreases in air temperature, humidity, and shortwave radiation associated with mesoscale convective systems. Simulations with the Price-Weller-Pinkel (PWP) model show upper ocean mixing and deepening mixed layers during these events that effect the long term upper ocean stratification. Mesoscale convective systems associated with cloudy skies and cold and dry air can reduce net heat into the ocean for minutes to a few days, significantly effecting air-sea heat transfer, upper ocean stratification, and ocean surface temperature and salinity.

  2. On the physical air-sea fluxes for climate modeling

    NASA Astrophysics Data System (ADS)

    Bonekamp, J. G.

    2001-02-01

    At the sea surface, the atmosphere and the ocean exchange momentum, heat and freshwater. Mechanisms for the exchange are wind stress, turbulent mixing, radiation, evaporation and precipitation. These surface fluxes are characterized by a large spatial and temporal variability and play an important role in not only the mean atmospheric and oceanic circulation, but also in the generation and sustainment of coupled climate fluctuations such as the El Niño/La Niña phenomenon. Therefore, a good knowledge of air-sea fluxes is required for the understanding and prediction of climate changes. As part of long-term comprehensive atmospheric reanalyses with `Numerical Weather Prediction/Data assimilation' systems, data sets of global air-sea fluxes are generated. A good example is the 15-year atmospheric reanalysis of the European Centre for Medium--Range Weather Forecasts (ECMWF). Air-sea flux data sets from these reanalyses are very beneficial for climate research, because they combine a good spatial and temporal coverage with a homogeneous and consistent method of calculation. However, atmospheric reanalyses are still imperfect sources of flux information due to shortcomings in model variables, model parameterizations, assimilation methods, sampling of observations, and quality of observations. Therefore, assessments of the errors and the usefulness of air-sea flux data sets from atmospheric (re-)analyses are relevant contributions to the quantitative study of climate variability. Currently, much research is aimed at assessing the quality and usefulness of the reanalysed air-sea fluxes. Work in this thesis intends to contribute to this assessment. In particular, it attempts to answer three relevant questions. The first question is: What is the best parameterization of the momentum flux? A comparison is made of the wind stress parameterization of the ERA15 reanalysis, the currently generated ERA40 reanalysis and the wind stress measurements over the open ocean. The

  3. Surface Flux Modeling for Air Quality Applications

    EPA Science Inventory

    For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic c...

  4. Infrasound Waveform Inversion and Mass Flux Validation from Sakurajima Volcano, Japan

    NASA Astrophysics Data System (ADS)

    Fee, D.; Kim, K.; Yokoo, A.; Izbekov, P. E.; Lopez, T. M.; Prata, F.; Ahonen, P.; Kazahaya, R.; Nakamichi, H.; Iguchi, M.

    2015-12-01

    Recent advances in numerical wave propagation modeling and station coverage have permitted robust inversion of infrasound data from volcanic explosions. Complex topography and crater morphology have been shown to substantially affect the infrasound waveform, suggesting that homogeneous acoustic propagation assumptions are invalid. Infrasound waveform inversion provides an exciting tool to accurately characterize emission volume and mass flux from both volcanic and non-volcanic explosions. Mass flux, arguably the most sought-after parameter from a volcanic eruption, can be determined from the volume flux using infrasound waveform inversion if the volcanic flow is well-characterized. Thus far, infrasound-based volume and mass flux estimates have yet to be validated. In February 2015 we deployed six infrasound stations around the explosive Sakurajima Volcano, Japan for 8 days. Here we present our full waveform inversion method and volume and mass flux estimates of numerous high amplitude explosions using a high resolution DEM and 3-D Finite Difference Time Domain modeling. Application of this technique to volcanic eruptions may produce realistic estimates of mass flux and plume height necessary for volcanic hazard mitigation. Several ground-based instruments and methods are used to independently determine the volume, composition, and mass flux of individual volcanic explosions. Specifically, we use ground-based ash sampling, multispectral infrared imagery, UV spectrometry, and multigas data to estimate the plume composition and flux. Unique tiltmeter data from underground tunnels at Sakurajima also provides a way to estimate the volume and mass of each explosion. In this presentation we compare the volume and mass flux estimates derived from the different methods and discuss sources of error and future improvements.

  5. Mass, heat and freshwater fluxes in the South Indian Ocean

    NASA Technical Reports Server (NTRS)

    Fu, Lee-Lueng

    1986-01-01

    Six hydrographic sections were used to examine the circulation and property fluxes in the South Indian Ocean from 10 to 32 deg S. The calculations were made by applying an inverse method to the data. In the interior of the South Indian Ocean, the geostrophic flow is generally northward. At 18 deg S, the northward interior mass flux is balanced by the southward Ekman mass flux at the surface, whereas at 32 deg S the northward interior mass flux is balanced by the southward mass flux of the Agulhas Current. There is a weak, southward mass flux of 6 x 10 to the 9th kg/s in the Mozambique Channel. The rate of water exchange between the Pacific Ocean and the Indian Ocean is dependent on the choice of the initial reference level used in the inverse calculation. The choice of 1500 m, the depth of the deep oxygen minimum, has led to a flux of water from the Pacific Ocean to the Indian Ocean at a rate of 6.6 x 10 to the 9th kg/s. Heat flux calculations indicate that the Indian Ocean is exporting heat to the rest of the world's oceans at a rate of -0.69 x 10 to the 15th W at 18 deg S and -0.25 x 10 to the 15th W at 32 deg S (negative values being southward).

  6. Large-scale variability of wind erosion mass flux rates at Owens Lake 1. Vertical profiles of horizontal mass fluxes of wind-eroded particles with diameter greater than 50 μm

    USGS Publications Warehouse

    Gillette, Dale A.; Fryrear, D.W.; Xiao, Jing Bing; Stockton, Paul; Ono, Duane; Helm, Paula J.; Gill, Thomas E; Ley, Trevor

    1997-01-01

    A field experiment at Owens (dry) Lake, California, tested whether and how the relative profiles of airborne horizontal mass fluxes for >50-μm wind-eroded particles changed with friction velocity. The horizontal mass flux at almost all measured heights increased proportionally to the cube of friction velocity above an apparent threshold friction velocity for all sediment tested and increased with height except at one coarse-sand site where the relative horizontal mass flux profile did not change with friction velocity. Size distributions for long-time-averaged horizontal mass flux samples showed a saltation layer from the surface to a height between 30 and 50 cm, above which suspended particles dominate. Measurements from a large dust source area on a line parallel to the wind showed that even though the saltation flux reached equilibrium ∼650 m downwind of the starting point of erosion, weakly suspended particles were still input into the atmosphere 1567 m downwind of the starting point; thus the saltating fraction of the total mass flux decreased after 650 m. The scale length difference and ratio of 70/30 suspended mass flux to saltation mass flux at the farthest down wind sampling site confirm that suspended particles are very important for mass budgets in large source areas and that saltation mass flux can be a variable fraction of total horizontal mass flux for soils with a substantial fraction of <100-μm particles.

  7. Turbulent mass flux closure modeling for variable density turbulence in the wake of an air-entraining transom stern

    NASA Astrophysics Data System (ADS)

    Hendrickson, Kelli; Yue, Dick

    2016-11-01

    This work presents the development and a priori testing of closure models for the incompressible highly-variable density turbulent (IHVDT) flow in the near wake region of a transom stern. This complex, three-dimensional flow includes three regions with distinctly different flow behavior: (i) the convergent corner waves that originate from the body and collide on the ship center plane; (ii) the "rooster tail" that forms from the collision; and (iii) the diverging wave train. The characteristics of these regions involve violent free-surface flows and breaking waves with significant turbulent mass flux (TMF) at Atwood number At = (ρ2 -ρ1) / (ρ2 +ρ1) 1 for which there is little guidance in turbulence closure modeling for the momentum and scalar transport along the wake. Utilizing datasets from high-resolution simulations of the near wake of a canonical three-dimensional transom stern using conservative Volume-of-Fluid (cVOF), implicit Large Eddy Simulation (iLES), and Boundary Data Immersion Method (BDIM), we develop explicit algebraic turbulent mass flux closure models that incorporate the most relevant physical processes. Performance of these models in predicting the turbulent mass flux in all three regions of the wake will be presented. Office of Naval Research.

  8. Air-ice CO2 fluxes and pCO2 dynamics in the Arctic coastal area (Amundsen Gulf, Canada)

    NASA Astrophysics Data System (ADS)

    Geilfus, Nicolas-Xavier; Tison, Jean Louis; Carnat, Gauthier; Else, Brent; Borges, Alberto V.; Thomas, Helmuth; Shadwick, Elizabeth; Delille, Bruno

    2010-05-01

    Sea ice covers about 7% of the Earth surface at its maximum seasonal extent. For decades sea ice was assumed to be an impermeable and inert barrier for air - sea exchange of CO2 so that global climate models do not include CO2 exchange between the oceans and the atmosphere in the polar regions. However, uptake of atmospheric CO2 by sea ice cover was recently reported raising the need to further investigate pCO2 dynamics in the marine cryosphere realm and related air-ice CO2 fluxes. In addition, budget of CO2 fluxes are poorly constrained in high latitudes continental shelves [Borges et al., 2006]. We report measurements of air-ice CO2 fluxes above the Canadian continental shelf and compare them to previous measurements carried out in Antarctica. We carried out measurements of pCO2 within brines and bulk ice, and related air-ice CO2 fluxes (chamber method) in Antarctic first year pack ice ("Sea Ice Mass Balance in Antarctica -SIMBA" drifting station experiment September - October 2007) and in Arctic first year land fast ice ("Circumpolar Flaw Lead" - CFL, April - June 2008). These 2 experiments were carried out in contrasted sites. SIMBA was carried out on sea ice in early spring while CFL was carried out in from the middle of the winter to the late spring while sea ice was melting. Both in Arctic and Antarctic, no air-ice CO2 fluxes were detected when sea ice interface was below -10°C. Slightly above -10°C, fluxes toward the atmosphere were observed. In contrast, at -7°C fluxes from the atmosphere to the ice were significant. The pCO2 of the brine exhibits a same trend in both hemispheres with a strong decrease of the pCO2 anti-correlated with the increase of sea ice temperature. The pCO2 shifted from a large over-saturation at low temperature to a marked under-saturation at high temperature. These air-ice CO2 fluxes are partly controlled by the permeability of the air-ice interface, which depends of the temperature of this one. Moreover, air-ice CO2 fluxes are

  9. A microscale turbine driven by diffusive mass flux.

    PubMed

    Yang, Mingcheng; Liu, Rui; Ripoll, Marisol; Chen, Ke

    2015-10-07

    An external diffusive mass flux is shown to be able to generate a mechanical torque on a microscale object based on anisotropic diffusiophoresis. In light of this finding, we propose a theoretical prototype micro-turbine driven purely by diffusive mass flux, which is in strong contrast to conventional turbines driven by convective mass flows. The rotational velocity of the proposed turbine is determined by the external concentration gradient, the geometry and the diffusiophoretic properties of the turbine. This scenario is validated by performing computer simulations. Our finding thus provides a new type of chemo-mechanical response which could be used to exploit existing chemical energies at small scales.

  10. Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

    NASA Astrophysics Data System (ADS)

    Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

    2017-12-01

    This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

  11. The solar cycle variation of coronal mass ejections and the solar wind mass flux

    NASA Technical Reports Server (NTRS)

    Webb, David F.; Howard, Russell A.

    1994-01-01

    Coronal mass ejections (CMEs) are an important aspect of coronal physics and a potentially significant contributor to perturbations of the solar wind, such as its mass flux. Sufficient data on CMEs are now available to permit study of their longer-term occurrency patterns. Here we present the results of a study of CME occurrence rates over more than a complete 11-year solar sunspot cycle and a comparison of these rates with those of other activity related to CMEs and with the solar wind particle flux at 1 AU. The study includes an evaluation of correlations to the CME rates, which include instrument duty cycles, visibility functions, mass detection thresholds, and geometrical considerations. The main results are as follows: (1) The frequency of occurrence of CMEs tends to track the solar activity cycle in both amplitude and phase; (2) the CME rates from different instruments, when corrected for both duty cycles and visibility functions, are reasonably consistent; (3) considering only longer-term averages, no one class of solar activity is better correlated with CME rate than any other; (4) the ratio of the annualized CME to solar wind mass flux tends to track the solar cycle; and (5) near solar maximum, CMEs can provide a significant fraction (i.e., approximately equals 15%) of the average mass flux to the near-ecliptic solar wind.

  12. Effects of Heat Flux, Oxygen Concentration and Glass Fiber Volume Fraction on Pyrolysate Mass Flux from Composite Solids

    NASA Technical Reports Server (NTRS)

    Rich, D. B.; Lautenberger, C. W.; Yuan, Z.; Fernandez-Pello, A. C.

    2004-01-01

    Experimental work on the effects of heat flux, oxygen concentration and glass fiber volume fraction on pyrolysate mass flux from samples of polypropylene/glass fiber composite (PP/G) is underway. The research is conducted as part of a larger project to develop a test methodology for flammability of materials, particularly composites, in the microgravity and variable oxygen concentration environment of spacecraft and space structures. Samples of PP/G sized at 30 x 30 x 10 mm are flush mounted in a flow tunnel, which provides a flow of oxidizer over the surface of the samples at a fixed value of 1 m/s and oxygen concentrations varying between 18 and 30%. Each sample is exposed to a constant external radiant heat flux at a given value, which varies between tests from 10 to 24 kW/sq m. Continuous sample mass loss and surface temperature measurements are recorded for each test. Some tests are conducted with an igniter and some are not. In the former case, the research goal is to quantify the critical mass flux at ignition for the various environmental and material conditions described above. The later case generates a wider range of mass flux rates than those seen prior to ignition, providing an opportunity to examine the protective effects of blowing on oxidative pyrolysis and heating of the surface. Graphs of surface temperature and sample mass loss vs. time for samples of 30% PPG at oxygen concentrations of 18 and 21% are presented in the figures below. These figures give a clear indication of the lower pyrolysis rate and extended time to ignition that accompany a lower oxygen concentration. Analysis of the mass flux rate at the time of ignition gives good repeatability but requires further work to provide a clear indication of mass flux trends accompanying changes in environmental and material properties.

  13. Effects of Heat Flux, Oxygen Concentration and Glass Fiber Volume Fraction on Pyrolysate Mass Flux from Composite Solids

    NASA Technical Reports Server (NTRS)

    Rich, D. B.; Lautenberger, C. W.; Yuan, Z.; Fernandez-Pello, A. C.

    2004-01-01

    Experimental work on the effects of heat flux, oxygen concentration and glass fiber volume fraction on pyrolysate mass flux from samples of polypropylene/glass fiber composite (PP/G) is underway. The research is conducted as part of a larger project to develop a test methodology for flammability of materials, particularly composites, in the microgravity and variable oxygen concentration environment of spacecraft and space structures. Samples of PP/G sized at 30x30x10 mm are flush mounted in a flow tunnel, which provides a flow of oxidizer over the surface of the samples at a fixed value of 1 m/s and oxygen concentrations varying between 18 and 30%. Each sample is exposed to a constant external radiant heat flux at a given value, which varies between tests from 10 to 24 kW/m2. Continuous sample mass loss and surface temperature measurements are recorded for each test. Some tests are conducted with an igniter and some are not. In the former case, the research goal is to quantify the critical mass flux at ignition for the various environmental and material conditions described above. The later case generates a wider range of mass flux rates than those seen prior to ignition, providing an opportunity to examine the protective effects of blowing on oxidative pyrolysis and heating of the surface. Graphs of surface temperature and sample mass loss vs. time for samples of 30% PPG at oxygen concentrations of 18 and 21% are presented in the figures below. These figures give a clear indication of the lower pyrolysis rate and extended time to ignition that accompany a lower oxygen concentration. Analysis of the mass flux rate at the time of ignition gives good repeatability but requires further work to provide a clear indication of mass flux trends accompanying changes in environmental and material properties.

  14. Boundary layers at a dynamic interface: air-sea exchange of heat and mass

    NASA Astrophysics Data System (ADS)

    Szeri, Andrew

    2017-11-01

    Exchange of mass or heat across a turbulent liquid-gas interface is a problem of critical interest, especially in air-sea transfer of natural and man-made gases involved in climate change. The goal in this research area is to determine the gas flux from air to sea or vice versa. For sparingly soluble non-reactive gases, this is controlled by liquid phase turbulent velocity fluctuations that act on the thin species concentration boundary layer on the liquid side of the interface. If the fluctuations in surface-normal velocity and gas concentration differences are known, then it is possible to determine the turbulent contribution to the gas flux. However, there is no suitable fundamental direct approach in the general case where neither of these quantities can be easily measured. A new approach is presented to deduce key aspects about the near-surface turbulent motions from remote measurements, which allows one to determine the gas transfer velocity, or gas flux per unit area if overall concentration differences are known. The approach is illustrated with conceptual examples.

  15. Quantifying Particle Numbers and Mass Flux in Drifting Snow

    NASA Astrophysics Data System (ADS)

    Crivelli, Philip; Paterna, Enrico; Horender, Stefan; Lehning, Michael

    2016-12-01

    We compare two of the most common methods of quantifying mass flux, particle numbers and particle-size distribution for drifting snow events, the snow-particle counter (SPC), a laser-diode-based particle detector, and particle tracking velocimetry based on digital shadowgraphic imaging. The two methods were correlated for mass flux and particle number flux. For the SPC measurements, the device was calibrated by the manufacturer beforehand. The shadowgrapic imaging method measures particle size and velocity directly from consecutive images, and before each new test the image pixel length is newly calibrated. A calibration study with artificially scattered sand particles and glass beads provides suitable settings for the shadowgraphical imaging as well as obtaining a first correlation of the two methods in a controlled environment. In addition, using snow collected in trays during snowfall, several experiments were performed to observe drifting snow events in a cold wind tunnel. The results demonstrate a high correlation between the mass flux obtained for the calibration studies (r ≥slant 0.93) and good correlation for the drifting snow experiments (r ≥slant 0.81). The impact of measurement settings is discussed in order to reliably quantify particle numbers and mass flux in drifting snow. The study was designed and performed to optimize the settings of the digital shadowgraphic imaging system for both the acquisition and the processing of particles in a drifting snow event. Our results suggest that these optimal settings can be transferred to different imaging set-ups to investigate sediment transport processes.

  16. Methane flux across the air-water interface - Air velocity effects

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1983-01-01

    Methane loss to the atmosphere from flooded wetlands is influenced by the degree of supersaturation and wind stress at the water surface. Measurements in freshwater ponds in the St. Marks Wildlife Refuge, Florida, demonstrated that for the combined variability of CH4 concentrations in surface water and air velocity over the water surface, CH4 flux varied from 0.01 to 1.22 g/sq m/day. The liquid exchange coefficient for a two-layer model of the gas-liquid interface was calculated as 1.7 cm/h for CH4 at air velocity of zero and as 1.1 + 1.2 v to the 1.96th power cm/h for air velocities from 1.4 to 3.5 m/s and water temperatures of 20 C.

  17. Quantifying energy and mass transfer in crop canopies: sensors for measurement of temperature and air velocity

    NASA Technical Reports Server (NTRS)

    Bugbee, B.; Monje, O.; Tanner, B.

    1996-01-01

    Here we report on the in situ performance of inexpensive, miniature sensors that have increased our ability to measure mass and energy fluxes from plant canopies in controlled environments: 1. Surface temperature. Canopy temperature measurements indicate changes in stomatal aperture and thus latent and sensible heat fluxes. Infrared transducers from two manufacturers (Exergen Corporation, Newton, MA; and Everest Interscience, Tucson, AZ, USA) have recently become available. Transducer accuracy matched that of a more expensive hand-held infrared thermometer. 2. Air velocity varies above and within plant canopies and is an important component in mass and energy transfer models. We tested commercially-available needle, heat-transfer anemometers (1 x 50 mm cylinder) that consist of a fine-wire thermocouple and a heater inside a hypodermic needle. The needle is heated and wind speed determined from the temperature rise above ambient. These sensors are particularly useful in measuring the low wind speeds found within plant canopies. 3. Accurate measurements of air temperature adjacent to plant leaves facilitates transport phenomena modeling. We quantified the effect of radiation and air velocity on temperature rise in thermocouples from 10 to 500 micrometers. At high radiation loads and low wind speeds, temperature errors were as large as 7 degrees C above air temperature.

  18. Characterising terrestrial influences on Antarctic air masses using Radon-222 measurements at King George Island

    NASA Astrophysics Data System (ADS)

    Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.

    2014-09-01

    We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late-summer to 44 mBq m-3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47-53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

  19. Characterising terrestrial influences on Antarctic air masses using radon-222 measurements at King George Island

    NASA Astrophysics Data System (ADS)

    Chambers, S. D.; Hong, S.-B.; Williams, A. G.; Crawford, J.; Griffiths, A. D.; Park, S.-J.

    2014-05-01

    We report on one year of high precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m-3 in late summer to 44 mBq m-3 in late-winter and early-spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m-3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47-53° S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

  20. Traveling-wave device with mass flux suppression

    DOEpatents

    Swift, Gregory W.; Backhaus, Scott N.; Gardner, David L.

    2000-01-01

    A traveling-wave device is provided with the conventional moving pistons eliminated. Acoustic energy circulates in a direction through a fluid within a torus. A side branch may be connected to the torus for transferring acoustic energy into or out of the torus. A regenerator is located in the torus with a first heat exchanger located on a first side of the regenerator downstream of the regenerator relative to the direction of the circulating acoustic energy; and a second heat exchanger located on an upstream side of the regenerator. The improvement is a mass flux suppressor located in the torus to minimize time-averaged mass flux of the fluid. In one embodiment, the device further includes a thermal buffer column in the torus to thermally isolate the heat exchanger that is at the operating temperature of the device.

  1. Flux-Rope Structure of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Nieves-Chinchilla, T.; Hidalgo, M.; Zhang, J.; Riley, P.; van Driel-Gesztelyi, L.; Mandrini, C. H.

    2013-01-01

    This Topical Issue (TI) of Solar Physics, devoted to the study of flux-rope structure in coronal mass ejections (CMEs), is based on two Coordinated Data Analysis Workshops (CDAWs) held in 2010 (20-23 September in Dan Diego, California, USA) and 2011 (5-9 September in Alcala, Spain). The primary purpose of the CDAWs was to address the question whether all CMEs have a flux rope structure. Each CDAW was attended by about 50 scientists interested in the origin, propagation, and interplanetary manifestation of CME phenomena.

  2. Air Pressure Controlled Mass Measurement System

    NASA Astrophysics Data System (ADS)

    Zhong, Ruilin; Wang, Jian; Cai, Changqing; Yao, Hong; Ding, Jin'an; Zhang, Yue; Wang, Xiaolei

    Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

  3. Validation of two innovative methods to measure contaminant mass flux in groundwater

    NASA Astrophysics Data System (ADS)

    Goltz, Mark N.; Close, Murray E.; Yoon, Hyouk; Huang, Junqi; Flintoft, Mark J.; Kim, Sehjong; Enfield, Carl

    2009-04-01

    The ability to quantify the mass flux of a groundwater contaminant that is leaching from a source area is critical to enable us to: (1) evaluate the risk posed by the contamination source and prioritize cleanup, (2) evaluate the effectiveness of source remediation technologies or natural attenuation processes, and (3) quantify a source term for use in models that may be applied to predict maximum contaminant concentrations in downstream wells. Recently, a number of new methods have been developed and subsequently applied to measure contaminant mass flux in groundwater in the field. However, none of these methods has been validated at larger than the laboratory-scale through a comparison of measured mass flux and a known flux that has been introduced into flowing groundwater. A couple of innovative flux measurement methods, the tandem circulation well (TCW) and modified integral pumping test (MIPT) methods, have recently been proposed. The TCW method can measure mass flux integrated over a large subsurface volume without extracting water. The TCW method may be implemented using two different techniques. One technique, the multi-dipole technique, is relatively simple and inexpensive, only requiring measurement of heads, while the second technique requires conducting a tracer test. The MIPT method is an easily implemented method of obtaining volume-integrated flux measurements. In the current study, flux measurements obtained using these two methods are compared with known mass fluxes in a three-dimensional, artificial aquifer. Experiments in the artificial aquifer show that the TCW multi-dipole and tracer test techniques accurately estimated flux, within 2% and 16%, respectively; although the good results obtained using the multi-dipole technique may be fortuitous. The MIPT method was not as accurate as the TCW method, underestimating flux by as much as 70%. MIPT method inaccuracies may be due to the fact that the method assumptions (two-dimensional steady

  4. Ocean Winds and Turbulent Air-Sea Fluxes Inferred From Remote Sensing

    NASA Technical Reports Server (NTRS)

    Bourassa, Mark A.; Gille, Sarah T.; Jackson, Daren L.; Roberts, J. Brent; Wick, Gary A.

    2010-01-01

    Air-sea turbulent fluxes determine the exchange of momentum, heat, freshwater, and gas between the atmosphere and ocean. These exchange processes are critical to a broad range of research questions spanning length scales from meters to thousands of kilometers and time scales from hours to decades. Examples are discussed (section 2). The estimation of surface turbulent fluxes from satellite is challenging and fraught with considerable errors (section 3); however, recent developments in retrievals (section 3) will greatly reduce these errors. Goals for the future observing system are summarized in section 4. Surface fluxes are defined as the rate per unit area at which something (e.g., momentum, energy, moisture, or CO Z ) is transferred across the air/sea interface. Wind- and buoyancy-driven surface fluxes are called surface turbulent fluxes because the mixing and transport are due to turbulence. Examples of nonturbulent processes are radiative fluxes (e.g., solar radiation) and precipitation (Schmitt et al., 2010). Turbulent fluxes are strongly dependent on wind speed; therefore, observations of wind speed are critical for the calculation of all turbulent surface fluxes. Wind stress, the vertical transport of horizontal momentum, also depends on wind direction. Stress is very important for many ocean processes, including upper ocean currents (Dohan and Maximenko, 2010) and deep ocean currents (Lee et al., 2010). On short time scales, this horizontal transport is usually small compared to surface fluxes. For long-term processes, transport can be very important but again is usually small compared to surface fluxes.

  5. Mass fluxes of organic pollutants between groundwater, streambed sediments and surface water

    NASA Astrophysics Data System (ADS)

    Schirmer, Mario; Kalbus, Edda; Schmidt, Christian

    2010-05-01

    Rivers and groundwater are commonly hydraulically connected and thus also pollutants migrate between one and the other. Particularly in small lowland streams, pollutant transport by discharging groundwater can deteriorate the surface water quality. Moreover, in urban and industrial areas streambed sediments are often polluted with a variety of organic and inorganic substances. For planning measures to improve surface water quality or to mitigate pollutant migration, it is an essential prerequisite to understand pollutant pathways and mass fluxes between the stream, the streambed sediment and the connected aquifer. We present methodological approaches and results of a study conducted at a small man-made stream located in the industrial area of Bitterfeld-Wolfen, Germany. This site is characterized by a diffuse groundwater contamination with a variety of aliphatic and aromatic organic substances. The underlying approach of this study was to quantify the mass fluxes between the aquifer, the streambed and the stream by combining high-resolution with integral monitoring approaches. Magnitudes and pattern of water fluxes were obtained by mapping streambed temperatures. The method was applied to a reach of 280 m in length. The mass fluxes from the aquifer towards the stream were estimated by combining the water fluxes with representative, average pollutant concentrations. The concentrations were obtained from an integral pumping test with four simultaneously pumped wells operated for the period of five days. For monochlorobenzene (MCB), the main groundwater pollutant at the site, the resulting average mass flux from the aquifer towards the stream was estimated to 724 µg/m²/d. Mass flux calculations with average aqueous concentrations of MCB in the streambed were found to be higher than those originating from the aquifer. Consequently, the streambed sediments represent a secondary pollutant source for the surface water. Pollutant concentrations in the streambed were

  6. Mass flux in the ecliptic plane and near the Sun deduced from Doppler scintillation

    NASA Technical Reports Server (NTRS)

    Woo, Richard; Gazis, Paul R.

    1994-01-01

    During the late declining phase of the solar cycle, the tilt of the solar magnetic dipole with respect to the Sun's rotation axis leads to large-scale organization of the solar wind, such that alternating regions of high- and low-speed solar wind are observed in the ecliptic plane. In this paper, we use Doppler scintillation measurements to investigate mass flux of these two types of solar wind in the ecliptic plane and inside 0.3 AU, where in situ measurements have not been possible. To the extent that Doppler scintillation reflects mass flux, we find that mass flux in high-speed streams: (1) is lower (by a factor of approximately 2.2) than the mass flux of the average solar wind in the heliocentric distance range of 0.3-0.5 AU; (2) is lower still (by as much as a factor of about 4) than the mass flux of the slow solar wind associated with the streamer belt; and (3) appears to grow with heliocentric distance. These Doppler scintillation results are consistent with the equator to pole decrease in mass flux observed in earlier spectral broadening measurements, and with trends and differences between high- and low-speed solar wind observed by in situ measurements in the range of 0.3-0.1 AU. The mass flux results suggest that the solar wind flow in high-speed streams is convergent towards the ecliptic near the Sun, becoming less convergent and approaching radial with increasing heliocentric distance beyond 0.3 AU. The variability of mass flux observed within equatorial and polar high-speed streams close to the Sun is strikingly low. This low variability implies that, as Ulysses currently ascends to higher latitudes and spends more time in the south polar high-speed stream after crossing the heliocentric current sheet, it can expect to observe a marked decrease in variations of both mass flux and solar wind speed, a trend that appears to have started already.

  7. Characteristics of vertical air motion in isolated convective clouds

    DOE PAGES

    Yang, Jing; Wang, Zhien; Heymsfield, Andrew J.; ...

    2016-08-11

    The vertical velocity and air mass flux in isolated convective clouds are statistically analyzed using aircraft in situ data collected from three field campaigns: High-Plains Cumulus (HiCu) conducted over the midlatitude High Plains, COnvective Precipitation Experiment (COPE) conducted in a midlatitude coastal area, and Ice in Clouds Experiment-Tropical (ICE-T) conducted over a tropical ocean. The results show that small-scale updrafts and downdrafts (<  500 m in diameter) are frequently observed in the three field campaigns, and they make important contributions to the total air mass flux. The probability density functions (PDFs) and profiles of the observed vertical velocity are provided. The PDFsmore » are exponentially distributed. The updrafts generally strengthen with height. Relatively strong updrafts (>  20 m s −1) were sampled in COPE and ICE-T. The observed downdrafts are stronger in HiCu and COPE than in ICE-T. The PDFs of the air mass flux are exponentially distributed as well. The observed maximum air mass flux in updrafts is of the order 10 4 kg m −1 s −1. The observed air mass flux in the downdrafts is typically a few times smaller in magnitude than that in the updrafts. Since this study only deals with isolated convective clouds, and there are many limitations and sampling issues in aircraft in situ measurements, more observations are needed to better explore the vertical air motion in convective clouds.« less

  8. Evapotranspiration: Mass balance measurements compared with flux estimation methods

    USDA-ARS?s Scientific Manuscript database

    Evapotranspiration (ET) may be measured by mass balance methods and estimated by flux sensing methods. The mass balance methods are typically restricted in terms of the area that can be represented (e.g., surface area of weighing lysimeter (LYS) or equivalent representative area of neutron probe (NP...

  9. Updated stomatal flux and flux-effect models for wheat for quantifying effects of ozone on grain yield, grain mass and protein yield.

    PubMed

    Grünhage, Ludger; Pleijel, Håkan; Mills, Gina; Bender, Jürgen; Danielsson, Helena; Lehmann, Yvonne; Castell, Jean-Francois; Bethenod, Olivier

    2012-06-01

    Field measurements and open-top chamber experiments using nine current European winter wheat cultivars provided a data set that was used to revise and improve the parameterisation of a stomatal conductance model for wheat, including a revised value for maximum stomatal conductance and new functions for phenology and soil moisture. For the calculation of stomatal conductance for ozone a diffusivity ratio between O(3) and H(2)O in air of 0.663 was applied, based on a critical review of the literature. By applying the improved parameterisation for stomatal conductance, new flux-effect relationships for grain yield, grain mass and protein yield were developed for use in ozone risk assessments including effects on food security. An example of application of the flux model at the local scale in Germany shows that negative effects of ozone on wheat grain yield were likely each year and on protein yield in most years since the mid 1980s. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Critical Heat Flux Phenomena at HighPressure & Low Mass Fluxes: NEUP Final Report Part I: Experiments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Corradini, Michael; Wu, Qiao

    2015-04-30

    This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embeddedmore » in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.« less

  11. The Influence of Air-Sea Fluxes on Atmospheric Aerosols During the Summer Monsoon Over the Tropical Indian Ocean

    NASA Astrophysics Data System (ADS)

    Zavarsky, Alex; Booge, Dennis; Fiehn, Alina; Krüger, Kirstin; Atlas, Elliot; Marandino, Christa

    2018-01-01

    During the summer monsoon, the western tropical Indian Ocean is predicted to be a hot spot for dimethylsulfide emissions, the major marine sulfur source to the atmosphere, and an important aerosol precursor. Other aerosol relevant fluxes, such as isoprene and sea spray, should also be enhanced, due to the steady strong winds during the monsoon. Marine air masses dominate the area during the summer monsoon, excluding the influence of continentally derived pollutants. During the SO234-2/235 cruise in the western tropical Indian Ocean from July to August 2014, directly measured eddy covariance DMS fluxes confirm that the area is a large source of sulfur to the atmosphere (cruise average 9.1 μmol m-2 d-1). The directly measured fluxes, as well as computed isoprene and sea spray fluxes, were combined with FLEXPART backward and forward trajectories to track the emissions in space and time. The fluxes show a significant positive correlation with aerosol data from the Terra and Suomi-NPP satellites, indicating a local influence of marine emissions on atmospheric aerosol numbers.

  12. Variability of the gaseous elemental mercury sea-air flux of the Baltic Sea.

    PubMed

    Kuss, Joachim; Schneider, Bernd

    2007-12-01

    The importance of the sea as a sink for atmospheric mercury has been established quantitatively through models based on wet and dry deposition data, but little is known about the release of mercury from sea areas. The concentration of elemental mercury (Hg0) in sea surface water and in the marine atmosphere of the Baltic Sea was measured at high spatial resolution in February, April, July, and November 2006. Wind-speed records and the gas-exchange transfer velocity were then used to calculate Hg0 sea-air fluxes on the basis of Hg0 sea-air concentration differences. Our results show that the spatial resolution of the surface water Hg0 data can be significantly improved by continuous measurements of Hg0 in air equilibrated with water instead of quantitative extraction of Hg0 from seawater samples. A spatial and highly seasonal variability of the Hg0 sea-air flux was thus determined. In winter, the flux was low and changed in direction. In summer, a strong emission flux of up to 150 ng m(-2) day(-1) in the central Baltic Sea was recorded. The total emission of Hg0 from the studied area (235000 km2) was 4300 +/- 1600 kg in 2006 and exceeded deposition estimates.

  13. Direct control of air gap flux in permanent magnet machines

    DOEpatents

    Hsu, John S.

    2000-01-01

    A method and apparatus for field weakening in PM machines uses field weakening coils (35, 44, 45, 71, 72) to produce flux in one or more stators (34, 49, 63, 64), including a flux which counters flux normally produced in air gaps between the stator(s) (34, 49, 63, 64) and the rotor (20, 21, 41, 61) which carries the PM poles. Several modes of operation are introduced depending on the magnitude and polarity of current in the field weakening coils (35, 44, 45, 71, 72). The invention is particularly useful for, but not limited to, the electric vehicle drives and PM generators.

  14. Mass flux measurements at active lava lakes: Implications for magma recycling

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.; Flynn, Luke P.; Rothery, David A.; Oppenheimer, Clive; Sherman, Sarah B.

    1999-04-01

    Remotely sensed and field data can be used to estimate heat and mass fluxes at active lava lakes. Here we use a three thermal component pixel model with three bands of Landsat thematic mapper (TM) data to constrain the thermal structure of, and flux from, active lava lakes. Our approach considers that a subpixel lake is surrounded by ground at ambient temperatures and that the surface of the lake is composed of crusted and/or molten material. We then use TM band 6 (10.42-12.42 μm) with bands 3 (0.63-0.69 μm) or 4 (0.76-0.90 μm) and 5 (1.55-1.75 μm) or 7 (2.08-2.35 μm), along with field data (e.g., lava lake area), to place limits on the size and temperature of each thermal component. Previous attempts to achieve this have used two bands of TM data with a two-component thermal model. Using our model results with further field data (e.g., petrological data) for lava lakes at Erebus, Erta 'Ale, and Pu'u 'O'o, we calculate combined radiative and convective fluxes of 11-20, 14-27 and 368-373 MW, respectively. These yield mass fluxes, of 30-76, 44-104 and 1553-2079 kg s-1, respectively. We also identify a hot volcanic feature at Nyiragongo during 1987 from which a combined radiative and convective flux of 0.2-0.6 MW implies a mass flux of 1-2 kg s-1. We use our mass flux estimates to constrain circulation rates in each reservoir-conduit-lake system and consider four models whereby circulation results in intrusion within or beneath the volcano (leading to endogenous or cryptic growth) and/or magma mixing in the reservoir (leading to recycling). We suggest that the presence of lava lakes does not necessarily imply endogenous or cryptic growth: lava lakes could be symptomatic of magma recycling in supraliquidus reservoirs.

  15. Kinetic energy flux budget across air-sea interface

    NASA Astrophysics Data System (ADS)

    Fan, Yalin; Hwang, Paul

    2017-12-01

    The kinetic energy (KE) fluxes into subsurface currents (EFc) is an important boundary condition for ocean circulation models. Traditionally, numerical models assume the KE flux from wind (EFair) is identical to EFc, that is, no net KE is gained (or lost) by surface waves. This assumption, however, is invalid when the surface wave field is not fully developed, and acquires KE when it grows in space or time. In this study, numerical experiments are performed to investigate the KE flux budget across the air-sea interface under both uniform and idealized tropical cyclone (TC) winds. The wave fields are simulated using the WAVEWATCH III model under different wind forcing. The difference between EFair and EFc is estimated using an air-sea KE budget model. To address the uncertainty of these estimates resides in the variation of source functions, two source function packages are used for this study: the ST4 source package (Ardhuin et al, 2010), and the ST6 source package (Babanin, 2011). The modeled EFc is significantly reduced relative to EFair under growing seas for both the uniform and TC experiments. The reduction can be as large as 20%, and the variation of this ratio is highly dependent on the choice of source function for the wave model. Normalized EFc are found to be consistent with analytical expressions by Hwang and Sletten (2008) and Hwang and Walsh (2016) and field observations by Terray et al. (1996) and Drennan et al. (1996), while the scatters are more widely in the TC cases due to the complexity of the associated wave field. The waves may even give up KE to subsurface currents in the left rear quadrant of fast moving storms. Our results also suggest that the normalized KE fluxes may depend on both wave age and friction velocity (u*).

  16. Spatio-temporal visualization of air-sea CO2 flux and carbon budget using volume rendering

    NASA Astrophysics Data System (ADS)

    Du, Zhenhong; Fang, Lei; Bai, Yan; Zhang, Feng; Liu, Renyi

    2015-04-01

    This paper presents a novel visualization method to show the spatio-temporal dynamics of carbon sinks and sources, and carbon fluxes in the ocean carbon cycle. The air-sea carbon budget and its process of accumulation are demonstrated in the spatial dimension, while the distribution pattern and variation of CO2 flux are expressed by color changes. In this way, we unite spatial and temporal characteristics of satellite data through visualization. A GPU-based direct volume rendering technique using half-angle slicing is adopted to dynamically visualize the released or absorbed CO2 gas with shadow effects. A data model is designed to generate four-dimensional (4D) data from satellite-derived air-sea CO2 flux products, and an out-of-core scheduling strategy is also proposed for on-the-fly rendering of time series of satellite data. The presented 4D visualization method is implemented on graphics cards with vertex, geometry and fragment shaders. It provides a visually realistic simulation and user interaction for real-time rendering. This approach has been integrated into the Information System of Ocean Satellite Monitoring for Air-sea CO2 Flux (IssCO2) for the research and assessment of air-sea CO2 flux in the China Seas.

  17. Boundary layers at a dynamic interface: Air-sea exchange of heat and mass

    NASA Astrophysics Data System (ADS)

    Szeri, Andrew J.

    2017-04-01

    Exchange of mass or heat across a turbulent liquid-gas interface is a problem of critical interest, especially in air-sea transfer of natural and anthropogenic gases involved in the study of climate. The goal in this research area is to determine the gas flux from air to sea or vice versa. For sparingly soluble nonreactive gases, this is controlled by liquid phase turbulent velocity fluctuations that act on the thin species concentration boundary layer on the liquid side of the interface. If the fluctuations in surface-normal velocity w' and gas concentration c' are known, then it is possible to determine the turbulent contribution to the gas flux. However, there is no suitable fundamental direct approach in the general case where neither w' nor c' can be easily measured. A new approach is presented to deduce key aspects about the near-surface turbulent motions from measurements that can be taken by an infrared (IR) camera. An equation is derived with inputs being the surface temperature and heat flux, and a solution method developed for the surface-normal strain experienced over time by boundary layers at the interface. Because the thermal and concentration boundary layers experience the same near-surface fluid motions, the solution for the surface-normal strain determines the gas flux or gas transfer velocity. Examples illustrate the approach in the cases of complete surface renewal, partial surface renewal, and insolation. The prospects for use of the approach in flows characterized by sheared interfaces or rapid boundary layer straining are explored.

  18. Effect of air gap variation on the performance of single stator single rotor axial flux permanent magnet generator

    NASA Astrophysics Data System (ADS)

    Kasim, Muhammad; Irasari, Pudji; Hikmawan, M. Fathul; Widiyanto, Puji; Wirtayasa, Ketut

    2017-02-01

    The axial flux permanent magnet generator (AFPMG) has been widely used especially for electricity generation. The effect of the air gap variation on the characteristic and performances of single rotor - single stator AFPMG has been described in this paper. Effect of air gap length on the magnetic flux distribution, starting torque and MMF has been investigated. The two dimensional finite element magnetic method has been deployed to model and simulated the characteristics of the machine which is based on the Maxwell equation. The analysis has been done for two different air gap lengths which were 2 mm and 4 mm using 2D FEMM 4.2 software at no load condition. The increasing of air gap length reduces the air-gap flux density. For air gap 2 mm, the maximum value of the flux density was 1.04 T while 0.73 T occured for air gap 4 mm.. Based on the experiment result, the increasing air gap also reduced the starting torque of the machine with 39.2 Nm for air gap 2 mm and this value decreased into 34.2 Nm when the air gap increased to 4 mm. Meanwhile, the MMF that was generated by AFPMG decreased around 22% at 50 Hz due to the reduction of magnetic flux induced on stator windings. Overall, the research result showed that the variation of air gap has significant effect on the machine characteristics.

  19. Mesoscale Convective Mass Fluxes in the Eastern Pacific

    NASA Astrophysics Data System (ADS)

    Lopez-Carrillo, C.; Raymond, D. J.

    2002-12-01

    In this paper, mesoscale characteristics of convective mass fluxes observed during EPIC-2001 are presented. The fluxes are synthesized from radial velocities collected with the Doppler radar mounted on the tail of the NOAA WP3-43 aircraft. Nine of the ten ITCZ-missions in which this aircraft participated were analyzed. The target area for all these missions is a rectangular box extending from 8N to 12N and from 93W to 97W. The aircraft observed this area roughly from 10:30 am to 3:30 pm local time while flying a lawn-mower pattern.

  20. Multiple-Point Mass Flux Measurement System Using Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mielke, Amy F.; Elam, Kristie A.; Clem, Michelle M.

    2009-01-01

    A multiple-point Rayleigh scattering diagnostic is being developed to provide mass flux measurements in gas flows. Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous density, temperature, and velocity measurements. Rayleigh scattered light from a focused 18 Watt continuous-wave laser beam is directly imaged through a solid Fabry-Perot etalon onto a CCD detector which permits spectral analysis of the light. The spatial resolution of the measurements is governed by the locations of interference fringes, which can be changed by altering the etalon characteristics. A prototype system has been used to acquire data in a Mach 0.56 flow to demonstrate feasibility of using this system to provide mass flux measurements. Estimates of measurement uncertainty and recommendations for system improvements are presented

  1. Mass Fluxes of Ice and Oxygen Across the Entire Lid of Lake Vostok from Observations of Englacial Radiowave Attenuation

    NASA Astrophysics Data System (ADS)

    Winebrenner, D. P.; Kintner, P. M. S.; MacGregor, J. A.

    2017-12-01

    Over deep Antarctic subglacial lakes, spatially varying ice thickness and the pressure-dependent melting point of ice result in areas of melting and accretion at the ice-water interface, i.e., the lake lid. These ice mass fluxes drive lake circulation and, because basal Antarctic ice contains air-clathrate, affect the input of oxygen to the lake, with implications for subglacial life. Inferences of melting and accretion from radar-layer tracking and geodesy are limited in spatial coverage and resolution. Here we develop a new method to estimate rates of accretion, melting, and the resulting oxygen input at a lake lid, using airborne radar data over Lake Vostok together with ice-temperature and chemistry data from the Vostok ice core. Because the lake lid is a coherent reflector of known reflectivity (at our radar frequency), we can infer depth-averaged radiowave attenuation in the ice, with spatial resolution 1 km along flight lines. Spatial variation in attenuation depends mostly on variation in ice temperature near the lid, which in turn varies strongly with ice mass flux at the lid. We model ice temperature versus depth with ice mass flux as a parameter, thus linking that flux to (observed) depth-averaged attenuation. The resulting map of melt- and accretion-rates independently reproduces features known from earlier studies, but now covers the entire lid. We find that accretion is dominant when integrated over the lid, with an ice imbalance of 0.05 to 0.07 km3 a-1, which is robust against uncertainties.

  2. Does the Momentum Flux Generated by Gravitational Contraction Drive Asymptotic Giant Branch Mass Loss?

    NASA Astrophysics Data System (ADS)

    Lewis, B. M.

    1997-12-01

    Gravitational contraction always generates a radially directed momentum flow. A particularly simple example occurs in the electron-degenerate cores of asymptotic giant branch (AGB) stars, which contract steadily under the addition of helium ashes from shell hydrogen burning. The resulting momentum flux is quantified here. And since the cores of AGB stars lack efficient momentum-cancellation mechanisms, they can maintain equilibrium by exporting their excess momentum flux to the stellar envelope, which disposes of much of it in a low velocity wind. Gravitational contraction easily accounts for the momentum flux in the solar wind, as well as the flux required to lift mass into the dust formation zone of every AGB star, whereon radiation pressure continues its ejection as a low-velocity wind. This mechanism explains the dependence of the AGB mass-loss rate on core mass; its generalization to objects with angular momentum and/or strong magnetic fields suggests a novel explanation as to why most planetary nebulae and proto-planetary nebulae exhibit axial symmetry. Quasi-static contraction is inherently biased to the generation of the maximum possible momentum flux. Its formalism is, therefore, readily adapted to providing an upper limit to the momentum flux needed to sustain mass loss when this begins from a semicontinuous rather than an impulsive process.

  3. Seasonal Ventilation of the Stratosphere: Robust Diagnostics from One-Way Flux Distributions

    NASA Technical Reports Server (NTRS)

    Orbe, Clara; Holzer, Mark; Polvani, Lorenzo M.; Waugh, Darryn W.; Li, Feng; Oman, Luke D.; Newman, Paul A.

    2014-01-01

    We present an analysis of the seasonally varying ventilation of the stratosphere using one-way flux distributions. Robust transport diagnostics are computed using GEOSCCM subject to fixed present-day climate forcings. From the one-way flux, we determine the mass of the stratosphere that is in transit since entry through the tropical tropopause to its exit back into the troposphere, partitioned according to stratospheric residence time and exit location. The seasonalities of all diagnostics are quantified with respect to the month of year (a) when air enters the stratosphere, (b) when the mass of the stratosphere is partitioned, and (c) when air exits back into the troposphere. We find that the return flux, within 3 months since entry, depends strongly on when entry occurred: (34 +/- 10)% more of the air entering the stratosphere in July leaves poleward of 45 deg N compared to air that enters in January. The month of year when the air mass is partitioned is also found to be important: The stratosphere contains about six times more air of tropical origin during late summer and early fall that will leave poleward of 45 deg within 6 months since entering the stratosphere compared to during late winter to late spring. When the entire mass of the air that entered the stratosphere at the tropics regardless of its residence time is considered, we find that (51 +/- 1)% and (39 +/- 2)% will leave poleward of 10 deg in the Northern Hemisphere (NH) and Southern Hemisphere (SH), respectively.

  4. Extreme air-sea surface turbulent fluxes in mid latitudes - estimation, origins and mechanisms

    NASA Astrophysics Data System (ADS)

    Gulev, Sergey; Natalia, Tilinina

    2014-05-01

    Extreme turbulent heat fluxes in the North Atlantic and North Pacific mid latitudes were estimated from the modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA-25) for the period from 1979 onwards. We used direct surface turbulent flux output as well as reanalysis state variables from which fluxes have been computed using COARE-3 bulk algorithm. For estimation of extreme flux values we analyzed surface flux probability density distribution which was approximated by Modified Fisher-Tippett distribution. In all reanalyses extreme turbulent heat fluxes amount to 1500-2000 W/m2 (for the 99th percentile) and can exceed 2000 W/m2 for higher percentiles in the western boundary current extension (WBCE) regions. Different reanalyses show significantly different shape of MFT distribution, implying considerable differences in the estimates of extreme fluxes. The highest extreme turbulent latent heat fluxes are diagnosed in NCEP-DOE, ERA-Interim and NCEP-CFSR reanalyses with the smallest being in MERRA. These differences may not necessarily reflect the differences in mean values. Analysis shows that differences in statistical properties of the state variables are the major source of differences in the shape of PDF of fluxes and in the estimates of extreme fluxes while the contribution of computational schemes used in different reanalyses is minor. The strongest differences in the characteristics of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the WBCE extension regions and high latitudes. In the next instance we analyzed the mechanisms responsible for forming surface turbulent fluxes and their potential role in changes of midlatitudinal heat balance. Midlatitudinal cyclones were considered as the major mechanism responsible for extreme turbulent fluxes which are typically occur during the cold air outbreaks in the rear parts of cyclones when atmospheric conditions

  5. Mass and heat transfer model of Tubular Solar Still

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ahsan, Amimul; Fukuhara, Teruyuki

    2010-07-15

    In this paper, a new mass and heat transfer model of a Tubular Solar Still (TSS) was proposed incorporating various mass and heat transfer coefficients taking account of the humid air properties inside the still. The heat balance of the humid air and the mass balance of the water vapor in the humid air were formulized for the first time. As a result, the proposed model enabled to calculate the diurnal variations of the temperature, water vapor density and relative humidity of the humid air, and to predict the hourly condensation flux besides the temperatures of the water, cover andmore » trough, and the hourly evaporation flux. The validity of the proposed model was verified using the field experimental results carried out in Fukui, Japan and Muscat, Oman in 2008. The diurnal variations of the calculated temperatures and water vapor densities had a good agreement with the observed ones. Furthermore, the proposed model can predict the daily and hourly production flux precisely. (author)« less

  6. Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables

    USGS Publications Warehouse

    Eckley, Chris S.; Tate, Michael T.; Lin, Che-Jen; Gustin, Mae S.; Dent, Stephen; Eagles-Smith, Collin A.; Lutz, Michelle A; Wickland, Kimberly; Wang, Bronwen; Gray, John E.; Edwards, Grant; Krabbenhoft, David P.; Smith, David

    2016-01-01

    Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of existing Hg flux data collected using the dynamic flux chamber (DFC) approach from almost a thousand locations was created for the Western North America region. Statistical analysis was performed on the data to identify the important variables controlling Hg fluxes and to allow spatiotemporal scaling. The results indicated that most of the variability in soil-air Hg fluxes could be explained by variations in soil-Hg concentrations, solar radiation, and soil moisture. This analysis also identified that variations in DFC methodological approaches were detectable among the field studies, with the chamber material and sampling flushing flow rate influencing the magnitude of calculated emissions. The spatiotemporal scaling of soil-air Hg fluxes identified that the largest emissions occurred from irrigated agricultural landscapes in California. Vegetation was shown to have a large impact on surface-air Hg fluxes due to both a reduction in solar radiation reaching the soil as well as from direct uptake of Hg in foliage. Despite high soil Hg emissions from some forested and other heavily vegetated regions, the net ecosystem flux (soil flux + vegetation uptake) was low. Conversely, sparsely vegetated regions showed larger net ecosystem emissions, which were similar in magnitude to atmospheric Hg deposition (except for the Mediterranean California region where soil emissions were higher). The net ecosystem flux results highlight the important role of landscape characteristics in effecting the balance between Hg sequestration and (re-)emission to the atmosphere.

  7. Surface-Air Mercury Fluxes Across Western North America: A Synthesis of Spatial Trends and Controlling Variables.

    NASA Astrophysics Data System (ADS)

    Eckley, C.; Tate, M.; Lin, C. J.; Gustin, M. S.; Dent, S.; Eagles-Smith, C.; Lutz, M.; Wickland, K.; Wang, B.; Gray, J.; Edwards, G. C.; Krabbenhoft, D. P.; Smith, D. B.

    2016-12-01

    Mercury (Hg) emission and deposition can occur to and from soils and are an important component of the global atmospheric Hg budget. This presentation focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of existing Hg flux data collected using the dynamic flux chamber (DFC) approach from almost a thousand locations was created for the Western North America region. Statistical analysis was performed on the data to identify the important variables controlling Hg fluxes and to allow spatiotemporal scaling. The results indicated that most of the variability in soil-air Hg fluxes could be explained by variations in soil-Hg concentrations, solar radiation, and soil moisture. This analysis also identified that variations in DFC methodological approaches were detectable among the field studies, with the chamber material and sampling flushing flow rate influencing the magnitude of calculated emissions. The spatiotemporal scaling of soil-air Hg fluxes identified that the largest emissions occurred from irrigated agricultural landscapes in California. Vegetation was shown to have a large impact on surface-air Hg fluxes due to both a reduction in solar radiation reaching the soil as well as from direct uptake of Hg in foliage. Despite high soil Hg emissions from some forested and other heavily vegetated regions, the net ecosystem flux (soil flux + vegetation uptake) was low. Conversely, sparsely vegetated regions showed larger net ecosystem emissions, which were similar in magnitude to atmospheric Hg deposition (except for the Mediterranean California region where soil emissions were higher). The net ecosystem flux results highlight the important role of landscape characteristics in effecting the balance between Hg sequestration and (re-)emission to the atmosphere.

  8. The Effective Mass of a Ball in the Air

    ERIC Educational Resources Information Center

    Messer, J.; Pantaleone, J.

    2010-01-01

    The air surrounding a projectile affects the projectile's motion in three very different ways: the drag force, the buoyant force, and the added mass. The added mass is an increase in the projectile's inertia from the motion of the air around it. Here we experimentally measure the added mass of a spherical projectile in air. The results agree well…

  9. Mass Flux Measurements of Arsenic in Groundwater (Battelle Conference)

    EPA Science Inventory

    Concentration trends of arsenic are typically used to evaluate the performance of remediation efforts designed to mitigate arsenic contamination in groundwater. A complementary approach would be to track changes in mass flux of the contaminant through the subsurface, for exampl...

  10. Development and evaluation of an ammonia bidirectional flux parameterization for air quality models

    NASA Astrophysics Data System (ADS)

    Pleim, Jonathan E.; Bash, Jesse O.; Walker, John T.; Cooter, Ellen J.

    2013-05-01

    is an important contributor to particulate matter in the atmosphere and can significantly impact terrestrial and aquatic ecosystems. Surface exchange between the atmosphere and biosphere is a key part of the ammonia cycle. New modeling techniques are being developed for use in air quality models that replace current ammonia emissions from fertilized crops and ammonia dry deposition with a bidirectional surface flux model including linkage to a detailed biogeochemical and farm management model. Recent field studies involving surface flux measurements over crops that predominate in North America have been crucial for extending earlier bidirectional flux models toward more realistic treatment of NH3 fluxes for croplands. Comparisons of the ammonia bidirection flux algorithm to both lightly fertilized soybeans and heavily fertilized corn demonstrate that the model can capture the magnitude and dynamics of observed ammonia fluxes, both net deposition and evasion, over a range of conditions with overall biases on the order of the uncertainty of the measurements. However, successful application to the field experiment in heavily fertilized corn required substantial modification of the model to include new parameterizations for in-soil diffusion resistance, ground quasi-laminar boundary layer resistance, and revised cuticular resistance that is dependent on in-canopy NH3 concentration and RH at the leaf surface. This new bidirectional flux algorithm has been incorporated in an air quality modeling system, which also includes an implementation of a soil nitrification model.

  11. Estimating ocean-air heat fluxes during cold air outbreaks by satellite

    NASA Technical Reports Server (NTRS)

    Chou, S. H.; Atlas, D.

    1981-01-01

    Nomograms of mean column heating due to surface sensible and latent heat fluxes were developed. Mean sensible heating of the cloud free region is related to the cloud free path (CFP, the distance from the shore to the first cloud formation) and the difference between land air and sea surface temperatures, theta sub 1 and theta sub 0, respectively. Mean latent heating is related to the CFP and the difference between land air and sea surface humidities q sub 1 and q sub 0 respectively. Results are also applicable to any path within the cloud free region. Corresponding heat fluxes may be obtained by multiplying the mean heating by the mean wind speed in the boundary layer. The sensible heating estimated by the present method is found to be in good agreement with that computed from the bulk transfer formula. The sensitivity of the solutions to the variations in the initial coastal soundings and large scale subsidence is also investigated. The results are not sensitive to divergence but are affected by the initial lapse rate of potential temperature; the greater the stability, the smaller the heating, other things being equal. Unless one knows the lapse rate at the shore, this requires another independent measurement. For this purpose the downwind slope of the square of the boundary layer height is used, the mean value of which is also directly proportional to the mean sensible heating. The height of the boundary layer should be measurable by future spaceborn lidar systems.

  12. Modeling and experimental design for metabolic flux analysis of lysine-producing Corynebacteria by mass spectrometry.

    PubMed

    Wittmann, C; Heinzle, E

    2001-04-01

    Experimental design of (13)C-tracer studies for metabolic flux analysis with mass spectrometric determination of labeling patterns was performed for the central metabolism of Corynebacterium glutamicum comprising various flux scenarios. Ratio measurement of mass isotopomer pools of Corynebacterium products lysine, alanine, and trehalose is sufficient to quantify the flux partitioning ratios (i) between glycolysis and pentose phosphate pathways (Phi(PPP)), (ii) between the split pathways in the lysine biosynthesis (Phi(DH)), (iii) at the pyruvate node (Phi(PC)), and reversibilities of (iv) glucose 6-phosphate isomerase (zeta(PGI)), (v) at the pyruvate node (zeta(PC/PEPCK)), and (vi) of transaldolase and transketolases in the PPP. Weighted sensitivities for flux parameters were derived from partial derivatives to quantitatively evaluate experimental approaches and predict precision for estimated flux parameters. Deviation of intensity ratios from ideal values of 1 was used as weighting function. Weighted flux sensitivities can be used to identify optimal type and degree of tracer labeling or potential intensity ratios to be measured. Experimental design for lysine-producing strain C. glutamicum MH 20-22B (Marx et al., Biotechnol. Bioeng. 49, 111-129, 1996) and various potential mutants with different alterations in the flux pattern showed that specific tracer labelings are optimal to quantify a certain flux parameter uninfluenced by the overall flux situation. Identified substrates of choice are [1-(13)C]glucose for the estimation of Phi(PPP) and zeta(PGI) and a 1 : 1 mixture of [U-(12)C/U-(13)C]glucose for the determination of zeta(PC/PEPCK). Phi(PC) can be quantified by feeding [4-(13)C]glucose or [U-(12)C/U-(13)C]glucose (1 : 1), whereas Phi(DH) is accessible via [4-(13)C]glucose. The sensitivity for the quantification of a certain flux parameter can be influenced by superposition through other flux parameters in the network, but substrate and measured mass

  13. Motion-Correlated Flow Distortion and Wave-Induced Biases in Air-Sea Flux Measurements From Ships

    NASA Astrophysics Data System (ADS)

    Prytherch, J.; Yelland, M. J.; Brooks, I. M.; Tupman, D. J.; Pascal, R. W.; Moat, B. I.; Norris, S. J.

    2016-02-01

    Direct measurements of the turbulent air-sea fluxes of momentum, heat, moisture and gases are often made using sensors mounted on ships. Ship-based turbulent wind measurements are corrected for platform motion using well established techniques, but biases at scales associated with wave and platform motion are often still apparent in the flux measurements. It has been uncertain whether this signal is due to time-varying distortion of the air flow over the platform, or to wind-wave interactions impacting the turbulence. Methods for removing such motion-scale biases from scalar measurements have previously been published but their application to momentum flux measurements remains controversial. Here we use eddy covariance momentum flux measurements obtained onboard RRS James Clark Ross as part of the Waves, Aerosol and Gas Exchange Study (WAGES), a programme of near-continuous measurements using the autonomous AutoFlux system (Yelland et al., 2009). Measurements were made in 2013 in locations throughout the North and South Atlantic, the Southern Ocean and the Arctic Ocean, at latitudes ranging from 62°S to 75°N. We show that the measured motion-scale bias has a dependence on the horizontal ship velocity, and that a correction for it reduces the dependence of the measured momentum flux on the orientation of the ship to the wind. We conclude that the bias is due to experimental error, and that time-varying motion-dependent flow distortion is the likely source. Yelland, M., Pascal, R., Taylor, P. and Moat, B.: AutoFlux: an autonomous system for the direct measurement of the air-sea fluxes of CO2, heat and momentum. J. Operation. Oceanogr., 15-23, doi:10.1080/1755876X.2009.11020105, 2009.

  14. Oxygen in the Southern Ocean From Argo Floats: Determination of Processes Driving Air-Sea Fluxes

    NASA Astrophysics Data System (ADS)

    Bushinsky, Seth M.; Gray, Alison R.; Johnson, Kenneth S.; Sarmiento, Jorge L.

    2017-11-01

    The Southern Ocean is of outsized significance to the global oxygen and carbon cycles with relatively poor measurement coverage due to harsh winters and seasonal ice cover. In this study, we use recent advances in the parameterization of air-sea oxygen fluxes to analyze 9 years of oxygen data from a recalibrated Argo oxygen data set and from air-calibrated oxygen floats deployed as part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project. From this combined data set of 150 floats, we find a total Southern Ocean oxygen sink of -183 ± 80 Tmol yr-1 (positive to the atmosphere), greater than prior estimates. The uptake occurs primarily in the Polar-Frontal Antarctic Zone (PAZ, -94 ± 30 Tmol O2 yr-1) and Seasonal Ice Zone (SIZ, -111 ± 9.3 Tmol O2 yr-1). This flux is driven by wintertime ventilation, with a large portion of the flux in the SIZ passing through regions with fractional sea ice. The Subtropical Zone (STZ) is seasonally driven by thermal fluxes and exhibits a net outgassing of 47 ± 29 Tmol O2 yr-1 that is likely driven by biological production. The Subantarctic Zone (SAZ) uptake is -25 ± 12 Tmol O2 yr-1. Total oxygen fluxes were separated into a thermal and nonthermal component. The nonthermal flux is correlated with net primary production and mixed layer depth in the STZ, SAZ, and PAZ, but not in the SIZ where seasonal sea ice slows the air-sea gas flux response to the entrainment of deep, low-oxygen waters.

  15. Converting from 3.6 and 4.5 μm Fluxes to Stellar Mass

    NASA Astrophysics Data System (ADS)

    Eskew, Michael; Zaritsky, Dennis; Meidt, Sharon

    2012-06-01

    We use high spatial resolution maps of stellar mass and infrared flux of the Large Magellanic Cloud (LMC) to calibrate a conversion between 3.6 and 4.5 μm fluxes and stellar mass, M * = 105.65 F 2.85 3.6 F -1.85 4.5(D/0.05)2 M ⊙, where fluxes are in Jy and D is the luminosity distance to the source in Mpc, and to provide an approximate empirical estimate of the fractional internal uncertainty in M * of 0.3\\sqrt{N/10^6}, where N is the number of stars in the region. We find evidence that young stars and hot dust contaminate the measurements, but attempts to remove this contamination using data that are far superior to what are generally available for unresolved galaxies resulted in marginal gains in accuracy. The scatter among mass estimates for regions in the LMC is comparable to that found by previous investigators when modeling composite populations, and so we conclude that our simple conversion is as precise as possible for the data and models currently available. Our results allow for a reasonably bottom-heavy initial mass function, such as Salpeter or heavier, and moderately disfavor lighter versions such as a diet-Salpeter or Chabrier initial mass function.

  16. The Effect of Breaking Waves on CO_2 Air-Sea Fluxes in the Coastal Zone

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Loza, Lucía; Ocampo-Torres, Francisco J.; García-Nava, Héctor

    2018-03-01

    The influence of wave-associated parameters controlling turbulent CO_2 fluxes through the air-sea interface is investigated in a coastal region. A full year of high-quality data of direct estimates of air-sea CO_2 fluxes based on eddy-covariance measurements is presented. The study area located in Todos Santos Bay, Baja California, Mexico, is a net sink of CO_2 with a mean flux of -1.3 μmol m^{-2}s^{-1} (-41.6 mol m^{-2}yr^{-1} ). The results of a quantile-regression analysis computed between the CO_2 flux and, (1) wind speed, (2) significant wave height, (3) wave steepness, and (4) water temperature, suggest that the significant wave height is the most correlated parameter with the magnitude of the flux but the behaviour of the relation varies along the probability distribution function, with the slopes of the regression lines presenting both positive and negative values. These results imply that the presence of surface waves in coastal areas is the key factor that promotes the increase of the flux from and into the ocean. Further analysis suggests that the local characteristics of the aqueous and atmospheric layers might determine the direction of the flux.

  17. A flux-gradient system for simultaneous measurement of the CH4, CO2, and H2O fluxes at a lake-air interface.

    PubMed

    Xiao, Wei; Liu, Shoudong; Li, Hanchao; Xiao, Qitao; Wang, Wei; Hu, Zhenghua; Hu, Cheng; Gao, Yunqiu; Shen, Jing; Zhao, Xiaoyan; Zhang, Mi; Lee, Xuhui

    2014-12-16

    Inland lakes play important roles in water and greenhouse gas cycling in the environment. This study aims to test the performance of a flux-gradient system for simultaneous measurement of the fluxes of water vapor, CO2, and CH4 at a lake-air interface. The concentration gradients over the water surface were measured with an analyzer based on the wavelength-scanned cavity ring-down spectroscopy technology, and the eddy diffusivity was measured with a sonic anemometer. Results of a zero-gradient test indicate a flux measurement precision of 4.8 W m(-2) for water vapor, 0.010 mg m(-2) s(-1) for CO2, and 0.029 μg m(-2) s(-1) for CH4. During the 620 day measurement period, 97%, 69%, and 67% of H2O, CO2, and CH4 hourly fluxes were higher in magnitude than the measurement precision, which confirms that the flux-gradient system had adequate precision for the measurement of the lake-air exchanges. This study illustrates four strengths of the flux-gradient method: (1) the ability to simultaneously measure the flux of H2O, CO2, and CH4; (2) negligibly small density corrections; (3) the ability to resolve small CH4 gradient and flux; and (4) continuous and noninvasive operation. The annual mean CH4 flux (1.8 g CH4 m(-2) year(-1)) at this hypereutrophic lake was close to the median value for inland lakes in the world (1.6 g CH4 m(-2) year(-1)). The system has adequate precision for CH4 flux for broad applications but requires further improvement to resolve small CO2 flux in many lakes.

  18. PVDF flux/mass/velocity/trajectory systems and their applications in space

    NASA Technical Reports Server (NTRS)

    Tuzzolino, Anthony J.

    1994-01-01

    The current status of the University of Chicago Polyvinylidene Fluoride (PVDF) flux/mass/velocity/trajectory instrumentation is summarized. The particle response and thermal stability characteristics of pure PVDF and PVDF copolymer sensors are described, as well as the characteristics of specially constructed two-dimensional position-sensing PVDF sensors. The performance of high-flux systems and of velocity/trajectory systems using these sensors is discussed, and the objectives and designs of a PVDF velocity/trajectory dust instrument for launch on the Advanced Research and Global Observation Satellite (ARGOS) in 1995 and of a high-flux dust instrument for launch on the Cassini spacecraft to Saturn in 1997 are summarized.

  19. Measurements and Modeling of Turbulent Fluxes during Persistent Cold Air Pool Events in Salt Lake Valley, Utah

    NASA Astrophysics Data System (ADS)

    Ivey, C. E.; Sun, X.; Holmes, H.

    2017-12-01

    Land surface processes are important in meteorology and climate research since they control the partitioning of surface energy and water exchange at the earth's surface. The surface layer is coupled to the planetary boundary layer (PBL) by surface fluxes, which serve as sinks or sources of energy, moisture, momentum, and atmospheric pollutants. Quantifying the surface heat and momentum fluxes at the land-atmosphere interface, especially for different surface land cover types, is important because they can further influence the atmospheric dynamics, vertical mixing, and transport processes that impact local, regional, and global climate. A cold air pool (CAP) forms when a topographic depression (i.e., valley) fills with cold air, where the air in the stagnant layer is colder than the air aloft. Insufficient surface heating, which is not able to sufficiently erode the temperature inversion that forms during the nighttime stable boundary layer, can lead to the formation of persistent CAPs during wintertime. These persistent CAPs can last for days, or even weeks, and are associated with increased air pollution concentrations. Thus, realistic simulations of the land-atmosphere exchange are meaningful to achieve improved predictions of the accumulation, transport, and dispersion of air pollution concentrations. The focus of this presentation is on observations and modeling results using turbulence data collected in Salt Lake Valley, Utah during the 2010-2011 wintertime Persistent Cold Air Pool Study (PCAPS). Turbulent fluxes and the surface energy balance over seven land use types are quantified. The urban site has an energy balance ratio (EBR) larger than one (1.276). Negative Bowen ratio (-0.070) is found at the cropland site. In addition to turbulence observations, half-hourly WRF simulated net radiation, latent heat, sensible heat, ground heat fluxes during one persistent CAP event are evaluated using the PCAPS observations. The results show that sensible and latent

  20. Inter-annual variability of air mass and acidified pollutants transboundary exchange in the north-eastern part of the EANET region

    NASA Astrophysics Data System (ADS)

    Gromov, Sergey A.; Trifonova-Yakovleva, Alisa; Gromov, Sergey S.

    2016-04-01

    Anthropogenic emissions, be it exhaust gases or aerosols, stem from multitude of sources and may survive long-range transport within the air masses they were emitted into. So they follow regional and global transport pathways varying under different climatological regimes. Transboundary transfer of pollutants occurs this way and has a significant impact on the ecological situation of the territories neighbouring those of emission sources, as found in a few earlier studies examining the environmental monitoring data [1]. In this study, we employ a relatively facile though robust technique for estimating the transboundary air and concomitant pollutant fluxes using actual or climatological meteorological and air pollution monitoring data. Practically, we assume pollutant transfer being proportional to the horizontal transport of air enclosed in the lower troposphere and to the concentration of the pollutant of interest. The horizontal transport, in turn, is estimated using the mean layer wind direction and strength, or their descriptive statistics at the individual transects of the boundary of interest. The domain of our interest is the segment of Russian continental border in East Asia spanning from 88° E (southern Middle Siberia) to 135° E (Far East at Pacific shore). The data on atmospheric pollutants concentration are available from the Russian monitoring sites of the region-wide Acid Deposition Monitoring Network in East Asia (EANET, http://www.eanet.asia/) Mondy (Baikal area) and Primorskaya (near Vladivostok). The data comprises multi-year continuous measurement of gas-phase and particulate species abundances in air with at least biweekly sampling rate starting from 2000. In the first phase of our study, we used climatological dataset on winds derived from the aerological soundings at Russian stations along the continental border for the 10-year period (1961-1970) by the Research Institute of Hydrometeorological Information - World Data Centre (RIHMI-WDC) [3

  1. IN SITU OXIDATION AND ASSOCIATED MASS-FLUX-REDUCTION/MASS-REMOVAL BEHAVIOR FOR SYSTEMS WITH ORGANIC LIQUID LOCATED IN LOWER-PERMEABILITY SEDIMENTS

    PubMed Central

    Marble, Justin C.; Carroll, Kenneth C.; Janousek, Hilary; Brusseau, Mark L.

    2010-01-01

    The effectiveness of permanganate for in situ chemical oxidation of organic liquid (trichloroethene) trapped in lower-permeability (K) zones located within a higher-permeability matrix was examined in a series of flow-cell experiments. The permanganate solution was applied in both continuous and pulsed-injection modes. Manganese-oxide precipitation, as confirmed by use of SEM-EDS, occurred within, adjacent to, and downgradient of the lower-K zones, reflective of trichloroethene oxidation. During flow interruptions, precipitate formed within the surrounding higher-permeability matrix, indicating diffusive flux of aqueous-phase trichloroethene from the lower-K zones. The impact of permanganate treatment on mass flux behavior was examined by conducting water floods after permanganate injection. The results were compared to those of water-flood control experiments. The amount of water flushing required for complete contaminant mass removal was reduced for all permanganate treatments for which complete removal was characterized. However, the nature of the mass-flux-reduction/mass-removal relationship observed during water flooding varied as a function of the specific permanganate treatment. PMID:20685008

  2. Sensitivity of Global Sea-Air CO2 Flux to Gas Transfer Algorithms, Climatological Wind Speeds, and Variability of Sea Surface Temperature and Salinity

    NASA Technical Reports Server (NTRS)

    McClain, Charles R.; Signorini, Sergio

    2002-01-01

    Sensitivity analyses of sea-air CO2 flux to gas transfer algorithms, climatological wind speeds, sea surface temperatures (SST) and salinity (SSS) were conducted for the global oceans and selected regional domains. Large uncertainties in the global sea-air flux estimates are identified due to different gas transfer algorithms, global climatological wind speeds, and seasonal SST and SSS data. The global sea-air flux ranges from -0.57 to -2.27 Gt/yr, depending on the combination of gas transfer algorithms and global climatological wind speeds used. Different combinations of SST and SSS global fields resulted in changes as large as 35% on the oceans global sea-air flux. An error as small as plus or minus 0.2 in SSS translates into a plus or minus 43% deviation on the mean global CO2 flux. This result emphasizes the need for highly accurate satellite SSS observations for the development of remote sensing sea-air flux algorithms.

  3. Detection of air-gap eccentricity and broken-rotor bar conditions in a squirrel-cage induction motor using the radial flux sensor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hwang, Don-Ha; Woo, Byung-Chul; Sun, Jong-Ho

    2008-04-01

    A new method for detecting eccentricity and broken rotor bar conditions in a squirrel-cage induction motor is proposed. Air-gap flux variation analysis is done using search coils, which are inserted at stator slots. Using this method, the leakage flux in radial direction can be directly detected. Using finite element method, the air-gap flux variation is accurately modeled and analyzed. From the results of the simulation, a motor under normal condition shows maximum magnetic flux density of 1.3 T. On the other hand, the eccentric air-gap condition displays about 1.1 T at 60 deg. and 1.6 T at 240 deg. Amore » difference of flux density is 0.5 T in the abnormal condition, whereas no difference is detected in the normal motor. In the broken rotor bar conditions, the flux densities at 65 deg. and 155 deg. are about 0.4 T and 0.8 T, respectively. These simulation results are coincided with those of experiment. Consequently, the measurement of the magnetic flux at air gap is one of effective ways to discriminate the faulted conditions of the eccentricity and broken rotor bars.« less

  4. Air-water gas exchange and CO2 flux in a mangrove-dominated estuary

    USGS Publications Warehouse

    Ho, David T.; Ferrón, Sara; Engel, Victor C.; Larsen, Laurel G.; Barr, Jordan G.

    2014-01-01

    Mangrove forests are highly productive ecosystems, but the fate of mangrove-derived carbon remains uncertain. Part of that uncertainty stems from the fact that gas transfer velocities in mangrove-surrounded waters are not well determined, leading to uncertainty in air-water CO2 fluxes. Two SF6 tracer release experiments were conducted to determine gas transfer velocities (k(600) = 8.3 ± 0.4 and 8.1 ± 0.6 cm h−1), along with simultaneous measurements of pCO2 to determine the air-water CO2 fluxes from Shark River, Florida (232.11 ± 23.69 and 171.13 ± 20.28 mmol C m−2 d−1), an estuary within the largest contiguous mangrove forest in North America. The gas transfer velocity results are consistent with turbulent kinetic energy dissipation measurements, indicating a higher rate of turbulence and gas exchange than predicted by commonly used wind speed/gas exchange parameterizations. The results have important implications for carbon fluxes in mangrove ecosystems.

  5. Impact of current speed on mass flux to a model flexible seagrass blade

    NASA Astrophysics Data System (ADS)

    Lei, Jiarui; Nepf, Heidi

    2016-07-01

    Seagrass and other freshwater macrophytes can acquire nutrients from surrounding water through their blades. This flux may depend on the current speed (U), which can influence both the posture of flexible blades (reconfiguration) and the thickness of the flux-limiting diffusive layer. The impact of current speed (U) on mass flux to flexible blades of model seagrass was studied through a combination of laboratory flume experiments, numerical modeling and theory. Model seagrass blades were constructed from low-density polyethylene (LDPE), and 1, 2-dichlorobenzene was used as a tracer chemical. The tracer mass accumulation in the blades was measured at different unidirectional current speeds. A numerical model was used to estimate the transfer velocity (K) by fitting the measured mass uptake to a one-dimensional diffusion model. The measured transfer velocity was compared to predictions based on laminar and turbulent boundary layers developing over a flat plate parallel to flow, for which K∝U0.5 and ∝U, respectively. The degree of blade reconfiguration depended on the dimensionless Cauchy number, Ca, which is a function of both the blade stiffness and flow velocity. For large Ca, the majority of the blade was parallel to the flow, and the measured transfer velocity agreed with laminar boundary layer theory, K∝U0.5. For small Ca, the model blades remained upright, and the flux to the blade was diminished relative to the flat-plate model. A meadow-scale analysis suggests that the mass exchange at the blade scale may control the uptake at the meadow scale.

  6. Significance of groundwater flux on contaminant concentration and mass discharge in the nonaqueous phase liquid (NAPL) contaminated zone.

    PubMed

    Zhu, Jianting; Sun, Dongmin

    2016-09-01

    Groundwater flowing through residual nonaqueous phase liquid (NAPL) source zone will cause NAPL dissolution and generate large contaminant plume. The use of contaminant mass discharge (CMD) measurements in addition to NAPL aqueous phase concentration to characterize site conditions and assess remediation performance is becoming popular. In this study, we developed new and generic numerical models to investigate the significance of groundwater flux temporal variations on the NAPL source dynamics. The developed models can accommodate any temporal variations of groundwater flux in the source zone. We examined the various features of groundwater flux using a few selected functional forms of linear increase/decrease, gradual smooth increase/decrease, and periodic fluctuations with a general trend. Groundwater flux temporal variations have more pronounced effects on the contaminant mass discharge dynamics than the aqueous concentration. If the groundwater flux initially increases, then the reduction in contaminant mass discharge (CMDR) vs. NAPL mass reduction (MR) relationship is mainly downward concave. If the groundwater flux initially decreases, then CMDR vs. MR relationship is mainly upward convex. If the groundwater flux variations are periodic, the CMDR vs. MR relationship tends to also have periodic variations ranging from upward convex to downward concave. Eventually, however, the CMDR vs. MR relationship approaches 1:1 when majority of the NAPL mass becomes depleted. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Three dimensional rotating flow of Powell-Eyring nanofluid with non-Fourier's heat flux and non-Fick's mass flux theory

    NASA Astrophysics Data System (ADS)

    Ibrahim, Wubshet

    2018-03-01

    This article numerically examines three dimensional boundary layer flow of a rotating Powell-Eyring nanofluid. In modeling heat transfer processes, non-Fourier heat flux theory and for mass transfer non-Fick's mass flux theory are employed. This theory is recently re-initiated and it becomes the active research area to resolves some drawback associated with the famous Fourier heat flux and mass flux theory. The mathematical model of the flow problem is a system of non-linear partial differential equations which are obtained using the boundary layer analysis. The non-linear partial differential equations have been transformed into non-linear high order ordinary differential equations using similarity transformation. Employing bvp4c algorithm from matlab software routine, the numerical solution of the transformed ordinary differential equations is obtained. The governing equations are constrained by parameters such as rotation parameter λ , the non-Newtonian parameter N, dimensionless thermal relaxation and concentration relaxation parameters δt and δc . The impacts of these parameters have been discussed thoroughly and illustrated using graphs and tables. The findings show that thermal relaxation time δt reduces the thermal and concentration boundary layer thickness. Further, the results reveal that the rotational parameter λ has the effect of decreasing the velocity boundary layer thickness in both x and y directions. Further examination pinpoints that the skin friction coefficient along x-axis is an increasing and skin friction coefficient along y-axis is a decreasing function of rotation parameter λ . Furthermore, the non-Newtonian fluid parameter N has the characteristic of reducing the amount of local Nusselt numbers -f″ (0) and -g″ (0) both in x and y -directions.

  8. The effect on empirical atmospheric modeling of the mass-flux as an independent parameter. [in sun and Be stars

    NASA Technical Reports Server (NTRS)

    Thomas, R. N.

    1982-01-01

    Observational data on atmospheric structure and mass fluxes from the sun and Be stars are applied to test the adequacy of the original Parker 'hot corona' approach to predicting atmospheric structure and the size of the mass flux from only the radiative and nonradiative energy fluxes, and from gravity, and imposing the condition that thermal and escape points must coincide. Observations do not support this latter condition. It is concluded that the Parker approach is an asymptotic approximation to the very low mass flux limit in a nonvariable stellar atmosphere.

  9. Atmospheric deposition and air-sea gas exchange fluxes of DDT and HCH in the Yangtze River Estuary, East China Sea

    NASA Astrophysics Data System (ADS)

    Li, Zhongxia; Lin, Tian; Li, Yuanyuan; Jiang, Yuqing; Guo, Zhigang

    2017-07-01

    The Yangtze River Estuary (YRE) is strongly influenced by the Yangtze River and lies on the pathway of the East Asian Monsoon. This study examined atmospheric deposition and air-sea gas exchange fluxes of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) to determine whether the YRE is a sink or source of selected pesticides at the air-water interface under the influences of river input and atmospheric transport. The air-sea gas exchange of DDT was characterized by net volatilization with a marked difference in its fluxes between summer (140 ng/m2/d) and the other three seasons (12 ng/m2/d), possibly due to the high surface seawater temperatures and larger riverine input in summer. However, there was no obvious seasonal variation in the atmospheric HCH deposition, and the air-sea gas exchange reached equilibrium because of low HCH levels in the air and seawater after the long-term banning of HCH and the degradation. The gas exchange flux of HCH was comparable to the dry and wet deposition fluxes at the air-water interface. This suggests that the influences from the Yangtze River input and East Asian continental outflow on the fate of HCH in the YRE were limited. The gas exchange flux of DDT was about fivefold higher than the total dry and wet deposition fluxes. DDT residues in agricultural soil transported by enhanced riverine runoff were responsible for sustaining such a high net volatilization in summer. Moreover, our results indicated that there were fresh sources of DDT from the local environment to sustain net volatilization throughout the year.

  10. Mass analysis addition to the Differential Ion Flux Probe (DIFP) study

    NASA Technical Reports Server (NTRS)

    Wright, K. H., Jr.; Jolley, Richard

    1994-01-01

    The objective of this study is to develop a technique to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The approach, conducted in conjunction with current MSFC activities, is to extend the capabilities of the Differential Ion Flux Probe (DIFP) to include a high throughput mass measurement that does not require either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This will significantly reduce the complexity and expense of instrument fabrication, testing, and integration of flight hardware compared to classical mass analyzers. The feasibility of the enhanced DIFP has been verified by using breadboard test models in a controlled plasma environment. The ability to manipulate particles through the instrument regardless of incident angle, energy, or ionic component has been amply demonstrated. The energy analysis mode is differential and leads directly to a time-of-flight mass measurement. With the new design, the DIFP will separate multiple ion streams and analyze each stream independently for ion flux intensity, velocity (including direction of motion), mass, and temperature (or energy distribution). In particular, such an instrument will be invaluable on follow-on electrodynamic TSS missions and, possibly, for environmental monitoring on the space station.

  11. Solid He: Progress, Status, and Outlook for Mass Flux Measurements

    NASA Astrophysics Data System (ADS)

    Hallock, R. B.

    2015-07-01

    After a brief introduction, what is provided there is brief summary of work with solid He done at the University of Massachusetts Amherst and an outlook for future work. What is presented here is based on a presentation made at the Quantum Gases Fluids and Solids Workshop in Sao Paulo, Brazil in August of 2014. Our work with solid He is aimed at the question: Can a sample cell filled with solid He support a mass flux through the cell? The answer, as will be shown here, is yes. Evidence for this from several types of experiments will be reviewed. There will be an emphasis on more recent work, work that explores how the flux observed depends on temperature and on the He impurity level. The behavior observed suggests that solid He may be an example of a material that demonstrates Bosonic Luttinger liquid behavior. The normalized He flux has a universal temperature dependence. The presence of He at different impurity levels shows that the He blocks the flux at a characteristic temperature. The behavior appears to be consistent with the cores of dislocations as the entity that carries the flux, but it is clear that more work needs to be done to fully understand solid He.

  12. Air-sea exchange fluxes of synthetic polycyclic musks in the North Sea and the Arctic.

    PubMed

    Xie, Zhiyong; Ebinghaus, Ralf; Temme, Christian; Heemken, Olaf; Ruck, Wolfgang

    2007-08-15

    Synthetic polycyclic musk fragrances Galaxolide (HHCB) and Tonalide (AHTN) were measured simultaneously in air and seawater in the Arctic and the North Sea and in the rural air of northern Germany. Median concentrations of gas-phase HHCB and AHTN were 4 and 18 pg m(-3) in the Arctic, 28 and 18 pg m(-3) in the North Sea, and 71 and 21 pg m(-3) in northern Germany, respectively. Various ratios of HHCB/AHTN implied that HHCB is quickly removed by atmospheric degradation, while AHTN is relatively persistent in the atmosphere. Dissolved concentrations ranged from 12 to 2030 pg L(-1) for HHCB and from below the method detection limit (3 pg L(-1)) to 965 pg L(-1) for AHTN with median values of 59 and 23 pg L(-1), respectively. The medians of volatilization fluxes for HHCB and AHTN were 27.2 and 14.2 ng m(-2) day(-1) and the depositional fluxes were 5.9 and 3.3 ng m(-2) day(-1), respectively, indicating water-to-air volatilization is a significant process to eliminate HHCB and AHTN from the North Sea. In the Arctic, deposition fluxes dominated the air-sea gas exchange of HHCB and AHTN, suggesting atmospheric input controls the levels of HHCB and AHTN in the polar region.

  13. "Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidrectional Ammonia Flux in CMAQ"

    EPA Science Inventory

    Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

  14. Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidirectional Ammonia Flux in CMAQ

    EPA Science Inventory

    Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

  15. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    NASA Astrophysics Data System (ADS)

    Marinov, I.; Gnanadesikan, A.

    2011-02-01

    The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

  16. Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

    NASA Astrophysics Data System (ADS)

    Marinov, I.; Gnanadesikan, A.

    2010-11-01

    The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation results in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

  17. Skyshine analysis using energy and angular dependent dose-contribution fluxes obtained from air-over-ground adjoint calculation.

    PubMed

    Uematsu, Mikio; Kurosawa, Masahiko

    2005-01-01

    A generalised and convenient skyshine dose analysis method has been developed based on forward-adjoint folding technique. In the method, the air penetration data were prepared by performing an adjoint DOT3.5 calculation with cylindrical air-over-ground geometry having an adjoint point source (importance of unit flux to dose rate at detection point) in the centre. The accuracy of the present method was certified by comparing with DOT3.5 forward calculation. The adjoint flux data can be used as generalised radiation skyshine data for all sorts of nuclear facilities. Moreover, the present method supplies plenty of energy-angular dependent contribution flux data, which will be useful for detailed shielding design of facilities.

  18. Optimizing laboratory-based radon flux measurements for sediments.

    PubMed

    Chanyotha, Supitcha; Kranrod, Chutima; Kritsananuwat, Rawiwan; Lane-Smith, Derek; Burnett, William C

    2016-07-01

    Radon flux via diffusion from sediments and other materials may be determined in the laboratory by circulating air through the sample and a radon detector in a closed loop. However, this approach is complicated by the necessity of having to determine the total air volume in the system and accounting for any small air leaks that can arise if using extended measurement periods. We designed a simple open-loop configuration that includes a measured mass of wet sediment and water inside a gas-tight reaction flask connected to a drying system and a radon-in-air analyzer. Ambient air flows through two charcoal columns before entering the reaction vessel to eliminate incoming radon. After traveling through the reaction flask, the air passes the drier and the radon analyzer and is then vented. After some time, the radon activity will reach a steady state depending upon the airflow rate. With this approach, the radon flux via diffusion is simply the product of the steady-state radon activity (Bq/m(3)) multiplied by the airflow rate (mL/min). We demonstrated that this setup could produce good results for materials that produce relatively high radon fluxes. We also show that a modified closed system approach, including radon removal of the incoming air by charcoal filtration in a bypass, can produce very good results including samples with very low emission rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Possible Lack of Low-Mass Meteoroids in the Earth's Meteoroid Flux Due to Space Erosion?

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    2017-01-01

    The Earth's cumulative meteoroid flux, as found by Halliday et al. (1996), may have a shallower slope for meteoroid masses in the range 0.1-2.5 kg compared to those with masses greater than 2.5 kg when plotted on a log flux vs. log mass graph. This would indicate a lack of low-mass objects. While others such as Ceplecha (1992) find no shallow slope, there may be a reason for a lack of 0.1-2.5 kg meteoroids which supports Halliday et al.'s finding. Simple models show that a few centimeters of space erosion in stony meteoroids can reproduce the bend in Halliday et al.'s curve at approximately 2.5 kg and give the shallower slope.

  20. Supersonic Mass Flux Measurements via Tunable Diode Laser Absorption and Non-Uniform Flow Modeling

    NASA Technical Reports Server (NTRS)

    Chang, Leyen S.; Strand, Christopher L.; Jeffries, Jay B.; Hanson, Ronald K.; Diskin, Glenn S.; Gaffney, Richard L.; Capriotti, Diego P.

    2011-01-01

    Measurements of mass flux are obtained in a vitiated supersonic ground test facility using a sensor based on line-of-sight (LOS) diode laser absorption of water vapor. Mass flux is determined from the product of measured velocity and density. The relative Doppler shift of an absorption transition for beams directed upstream and downstream in the flow is used to measure velocity. Temperature is determined from the ratio of absorption signals of two transitions (lambda(sub 1)=1349 nm and lambda(sub 2)=1341.5 nm) and is coupled with a facility pressure measurement to obtain density. The sensor exploits wavelength-modulation spectroscopy with second-harmonic detection (WMS-2f) for large signal-to-noise ratios and normalization with the 1f signal for rejection of non-absorption related transmission fluctuations. The sensor line-of-sight is translated both vertically and horizontally across the test section for spatially-resolved measurements. Time-resolved measurements of mass flux are used to assess the stability of flow conditions produced by the facility. Measurements of mass flux are within 1.5% of the value obtained using a facility predictive code. The distortion of the WMS lineshape caused by boundary layers along the laser line-of-sight is examined and the subsequent effect on the measured velocity is discussed. A method for correcting measured velocities for flow non-uniformities is introduced and application of this correction brings measured velocities within 4 m/s of the predicted value in a 1630 m/s flow.

  1. Ionisation in turbulent magnetic molecular clouds. I. Effect on density and mass-to-flux ratio structures

    NASA Astrophysics Data System (ADS)

    Bailey, Nicole D.; Basu, Shantanu; Caselli, Paola

    2017-05-01

    Context. Previous studies show that the physical structures and kinematics of a region depend significantly on the ionisation fraction. These studies have only considered these effects in non-ideal magnetohydrodynamic simulations with microturbulence. The next logical step is to explore the effects of turbulence on ionised magnetic molecular clouds and then compare model predictions with observations to assess the importance of turbulence in the dynamical evolution of molecular clouds. Aims: In this paper, we extend our previous studies of the effect of ionisation fractions on star formation to clouds that include both non-ideal magnetohydrodynamics and turbulence. We aim to quantify the importance of a treatment of the ionisation fraction in turbulent magnetised media and investigate the effect of the turbulence on shaping the clouds and filaments before star formation sets in. In particular, here we investigate how the structure, mass and width of filamentary structures depend on the amount of turbulence in ionised media and the initial mass-to-flux ratio. Methods: To determine the effects of turbulence and mass-to-flux ratio on the evolution of non-ideal magnetised clouds with varying ionisation profiles, we have run two sets of simulations. The first set assumes different initial turbulent Mach values for a fixed initial mass-to-flux ratio. The second set assumes different initial mass-to-flux ratio values for a fixed initial turbulent Mach number. Both sets explore the effect of using one of two ionisation profiles: step-like (SL) or cosmic ray only (CR-only). We compare the resulting density and mass-to-flux ratio structures both qualitatively and quantitatively via filament and core masses and filament fitting techniques (Gaussian and Plummer profiles). Results: We find that even with almost no turbulence, filamentary structure still exists although at lower density contours. Comparison of simulations shows that for turbulent Mach numbers above 2, there is

  2. Air-water CO2 Fluxes In Seasonal Hypoxia-influenced Green Bay, Lake Michigan

    NASA Astrophysics Data System (ADS)

    Lin, P.; Klump, J. V.; Guo, L.

    2016-02-01

    Increasing anthropogenic nutrient enrichment has led to seasonal hypoxia in Green Bay, the largest freshwater estuary in the Laurentian Great Lakes, but change in carbon dynamics associated with the development of hypoxia remains poorly understood. Variations in alkalinity, abundance of carbon species, and air-water CO2 fluxes were quantified under contrasting hypoxic conditions during summer 2014. Green Bay was characterized with high pH (average 8.62 ± 0.16 in August), high DIC concentrations (2113 - 3213 µmol/kg) and high pCO2 in the water column. pCO2 was mostly >700 µatm in June, resulting in a net CO2 source to the air, while pCO2 was mostly <650 µatm in August when hypoxic conditions occurred in Green Bay. In central Green Bay, pCO2 was the highest during both sampling months, accompanying by low dissolved oxygen (DO) and lower pH in the water column. In August, pCO2 was inversely correlated with DOC concentration and increased with DOC/DOP ratio, suggesting a control by organic matter on air-water CO2 dynamics and consumption of DO in Green Bay. Positive CO2 fluxes to the atmosphere during August were only observed in northern bay but a CO2 sink was found in southern Green Bay ( 40% of study area) with high biological production and terrestrial DOM. Daily CO2 flux ranged from 10.9 to 48.5 mmol-C m-2 d-1 in June with an average of 18.29 ± 7.44 mmol-C m-2 d-1, whereas it varied from 1.82 ± 1.18 mmol m-2 d-1 in the north to -2.05 ± 1.89 mmol m-2 d-1 in the south of Green Bay in August. Even though strong biological production reduced the CO2 emission, daily CO2 fluxes from Green Bay to the air were as high as 7.4 × 107 mole-C in June and 4.6 × 106 mole-C in August, suggesting a significant role of high-DIC lakes in global CO2 budget and cycling.

  3. Mean and turbulent mass flux measurements in an idealised street network.

    PubMed

    Carpentieri, Matteo; Robins, Alan G; Hayden, Paul; Santi, Edoardo

    2018-03-01

    Pollutant mass fluxes are rarely measured in the laboratory, especially their turbulent component. They play a major role in the dispersion of gases in urban areas and modern mathematical models often attempt some sort of parametrisation. An experimental technique to measure mean and turbulent fluxes in an idealised urban array was developed and applied to improve our understanding of how the fluxes are distributed in a dense street canyon network. As expected, horizontal advective scalar fluxes were found to be dominant compared with the turbulent components. This is an important result because it reduces the complexity in developing parametrisations for street network models. On the other hand, vertical mean and turbulent fluxes appear to be approximately of the same order of magnitude. Building height variability does not appear to affect the exchange process significantly, while the presence of isolated taller buildings upwind of the area of interest does. One of the most interesting results, again, is the fact that even very simple and regular geometries lead to complex advective patterns at intersections: parametrisations derived from measurements in simpler geometries are unlikely to capture the full complexity of a real urban area. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. In Situ NAPL Modification for Contaminant Source-Zone Passivation, Mass Flux Reduction, and Remediation

    NASA Astrophysics Data System (ADS)

    Mateas, D. J.; Tick, G.; Carroll, K. C.

    2016-12-01

    A remediation method was developed to reduce the aqueous solubility and mass-flux of target NAPL contaminants through the in-situ creation of a NAPL mixture source-zone. This method was tested in the laboratory using equilibrium batch tests and two-dimensional flow-cell experiments. The creation of two different NAPL mixture source zones were tested in which 1) volumes of relatively insoluble n-hexadecane (HEX) or vegetable oil (VO) were injected into a trichloroethene (TCE) contaminant source-zone; and 2) pre-determined HEX-TCE and VO-TCE mixture ratio source zones were emplaced into the flow cell prior to water flushing. NAPL-aqueous phase batch tests were conducted prior to the flow-cell experiments to evaluate the effects of various NAPL mixture ratios on equilibrium aqueous-phase concentrations of TCE and toluene (TOL) and to design optimal NAPL (HEX or VO) injection volumes for the flow-cell experiments. Uniform NAPL mixture source-zones were able to quickly decrease contaminant mass-flux, as demonstrated by the emplaced source-zone experiments. The success of the HEX and VO injections to also decrease mass flux was dependent on the ability of these injectants to homogeneously mix with TCE source-zone. Upon injection, both HEX and VO migrated away from the source-zone, to some extent. However, the lack of a steady-state dissolution phase and the inefficient mass-flux-reduction/mass-removal behavior produced after VO injection suggest that VO was more effective than HEX for mixing and partitioning within the source-zone region to form a more homogeneous NAPL mixture with TCE. VO appears to be a promising source-zone injectant-NAPL due to its negligible long-term toxicity and lower mobilization potential.

  5. A representation for the turbulent mass flux contribution to Reynolds-stress and two-equation closures for compressible turbulence

    NASA Technical Reports Server (NTRS)

    Ristorcelli, J. R.

    1993-01-01

    The turbulent mass flux, or equivalently the fluctuating Favre velocity mean, appears in the first and second moment equations of compressible kappa-epsilon and Reynolds stress closures. Mathematically it is the difference between the unweighted and density-weighted averages of the velocity field and is therefore a measure of the effects of compressibility through variations in density. It appears to be fundamental to an inhomogeneous compressible turbulence, in which it characterizes the effects of the mean density gradients, in the same way the anisotropy tensor characterizes the effects of the mean velocity gradients. An evolution equation for the turbulent mass flux is derived. A truncation of this equation produces an algebraic expression for the mass flux. The mass flux is found to be proportional to the mean density gradients with a tensor eddy-viscosity that depends on both the mean deformation and the Reynolds stresses. The model is tested in a wall bounded DNS at Mach 4.5 with notable results.

  6. Mass Transfer in a Nanoscale Material Enhanced by an Opposing Flux

    NASA Astrophysics Data System (ADS)

    Chmelik, Christian; Bux, Helge; Caro, Jürgen; Heinke, Lars; Hibbe, Florian; Titze, Tobias; Kärger, Jörg

    2010-02-01

    Diffusion is known to be quantified by measuring the rate of molecular fluxes in the direction of falling concentration. In contrast with intuition, considering methanol diffusion in a novel type of nanoporous material (MOF ZIF-8), this rate has now been found to be enhanced rather than slowed down by an opposing flux of labeled molecules. In terms of the key quantities of random particle movement, this result means that the self-diffusivity exceeds the transport diffusivity. It is rationalized by considering the strong intermolecular interaction and the dominating role of intercage hopping in mass transfer in the systems under study.

  7. Condensation heat transfer and pressure drop of R-410A in a 7.0 mm O.D. microfin tube at low mass fluxes

    NASA Astrophysics Data System (ADS)

    Kim, Nae-Hyun

    2016-12-01

    R-410A condensation heat transfer and pressure drop data are provided for a 7.0 mm O.D. microfin tube at low mass fluxes (50-250 kg/m2 s). The heat transfer coefficient of the microfin tube shows a minimum behavior with the mass flux. At a low mass flux, where flow pattern is stratified, condensation induced by surface tension by microfins overwhelms condensation induced by shear, and the heat transfer coefficient decreases as mass flux increases. At a high mass flux, where flow pattern is annular, condensation induced by shear governs the heat transfer, and the heat transfer coefficient increases as mass flux increases. The pressure drop of the microfin tube is larger than that of the smooth tube at the annular flow regime. On the contrary, the pressure drop of the smooth tube is larger than that of the microfin tube at the stratified flow regime.

  8. The influence of continental air masses on the aerosols and nutrients deposition over the western North Pacific

    NASA Astrophysics Data System (ADS)

    Fu, Jiangping; Wang, Bo; Chen, Ying; Ma, Qingwei

    2018-01-01

    The air masses transported from East Asia have a strong impact on the aerosol properties and deposition in the marine boundary layer of the western North Pacific (WNP) during winter and spring. We joined a cruise between 17 Mar. and 22 Apr. 2014 and investigated the changes of aerosol composition and size distribution over the remote WNP and marginal seas. Although the secondary aerosol species (SO42-, NO3- and NH4+) in remote WNP were influenced significantly by the continental transport, NH4+ concentrations were lower than 2.7 μg m-3 in most sampling days and not correlated with non-sea-salt (nss)-SO42- suggesting that the ocean could be a primary source of NH4+. Moderate Cl- depletion (23%) was observed in remote WNP, and the inverse relationship between Cl- depletion percentages and nss-K+ in aerosols suggested that the transport of biomass burning smoke from East Asia might be a vital extra source of Cl-. Both Asian dust and haze events were encountered during the cruise. Asian dust carried large amounts of crustal elements such as Al and Ti to the WNP, and the dusty Fe deposition may double its background concentration in seawater. Differently, a dramatic increase of dry deposition flux of dissolved particulate inorganic nitrogen was observed during the haze event. Our study reveals that the transport of different continental air masses may have distinct biogeochemical impacts on the WNP by increasing the fluxes of different nutrient elements and potentially changing the nutrient stoichiometry.

  9. A Mass-Flux Scheme View of a High-Resolution Simulation of a Transition from Shallow to Deep Cumulus Convection.

    NASA Astrophysics Data System (ADS)

    Kuang, Zhiming; Bretherton, Christopher S.

    2006-07-01

    In this paper, an idealized, high-resolution simulation of a gradually forced transition from shallow, nonprecipitating to deep, precipitating cumulus convection is described; how the cloud and transport statistics evolve as the convection deepens is explored; and the collected statistics are used to evaluate assumptions in current cumulus schemes. The statistical analysis methodologies that are used do not require tracing the history of individual clouds or air parcels; instead they rely on probing the ensemble characteristics of cumulus convection in the large model dataset. They appear to be an attractive way for analyzing outputs from cloud-resolving numerical experiments. Throughout the simulation, it is found that 1) the initial thermodynamic properties of the updrafts at the cloud base have rather tight distributions; 2) contrary to the assumption made in many cumulus schemes, nearly undiluted air parcels are too infrequent to be relevant to any stage of the simulated convection; and 3) a simple model with a spectrum of entraining plumes appears to reproduce most features of the cloudy updrafts, but significantly overpredicts the mass flux as the updrafts approach their levels of zero buoyancy. A buoyancy-sorting model was suggested as a potential remedy. The organized circulations of cold pools seem to create clouds with larger-sized bases and may correspondingly contribute to their smaller lateral entrainment rates. Our results do not support a mass-flux closure based solely on convective available potential energy (CAPE), and are in general agreement with a convective inhibition (CIN)-based closure. The general similarity in the ensemble characteristics of shallow and deep convection and the continuous evolution of the thermodynamic structure during the transition provide justification for developing a single unified cumulus parameterization that encompasses both shallow and deep convection.


  10. Effect of gas mass flux on cryogenic liquid jet breakup

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1992-01-01

    A scattered-light scanning instrument developed at NASA Lewis Research Center was used to measure the characteristic drop size of clouds of liquid nitrogen droplets. The instrument was calibrated with suspensions of monosized polystyrene spheres. In this investigation of the mechanism of liquid nitrogen jet disintegration in a high-velocity gas flow, the Sauter mean diameter, D32, was found to vary inversely with the nitrogen gas mass flux raised to the power 1.33. Values of D32 varied from 5 to 25 microns and the mass flux exponent of 1.33 agrees well with theory for liquid jet breakup in high-velocity gas flows. The loss of very small droplets due to the high vaporization rate of liquid nitrogen was avoided by sampling the spray very close to the atomizer, i.e., 1.3 cm downstream of the nozzle orifice. The presence of high velocity and thermal gradients in the gas phase also made sampling of the particles difficult. As a result, it was necessary to correct the measurements for background noise produced by both highly turbulent gas flows and thermally induced density gradients in the gas phase.

  11. Effects of cold front passage on turbulent fluxes over a large inland water

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Liu, H.

    2011-12-01

    Turbulent fluxes of sensible and latent heat over a large inland water in southern USA were measured using the eddy covariance method through the year of 2008. In addition, net radiation, air temperatures and relative humidity, and water temperature in different depths were also measured. The specific objective of this study is to examine effects of a cold front passage on the surface energy fluxes. For the typical cold front event selected from April 11 to 14, air temperature decreased by 16°C, while surface temperature only dropped 6°C. Atmospheric vapor pressure decreased by 1.6 kPa, while that in the water-air interface dropped 0.7 kPa. The behavior difference in the water-air interface was caused by the passage of cold, dry air masses immediately behind the cold front. During the cold front event, sensible heat and latent heat flux increased by 171 W m-2 and 284 W m-2, respectively. Linear aggression analysis showed that the sensible heat flux was proportional to the product of wind speed and the temperature gradient of water-air interface, with a correlation coefficient of 0.95. Latent heat flux was proportional to the product of wind speed and vapor pressure difference between the water surface and overlaying atmosphere, with a correlation coefficient of 0.81. Also, the correlations between both fluxes and the wind speed were weak. This result indicated that the strong wind associated with the cold front event contributed to the turbulent mixing, which indirectly enhanced surface energy exchange between the water surface and the atmosphere. The relationship between the water heat storage energy and turbulent fluxes was also examined.

  12. Use of a numerical simulation approach to improve the estimation of air-water exchange fluxes of polycyclic aromatic hydrocarbons in a coastal zone.

    PubMed

    Lai, I-Chien; Lee, Chon-Lin; Ko, Fung-Chi; Lin, Ju-Chieh; Huang, Hu-Ching; Shiu, Ruei-Feng

    2017-07-15

    The air-water exchange is important for determining the transport, fate, and chemical loading of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere and in aquatic systems. Investigations of PAH air-water exchange are mostly based on observational data obtained using complicated field sampling processes. This study proposes a new approach to improve the estimation of long-term PAH air-water exchange fluxes by using a multivariate regression model to simulate hourly gaseous PAH concentrations. Model performance analysis and the benefits from this approach indicate its effectiveness at improving the flux estimations and at decreasing the field sampling difficulty. The proposed GIS mapping approach is useful for box model establishment and is tested for visualization of the spatiotemporal variations of air-water exchange fluxes in a coastal zone. The air-water exchange fluxes illustrated by contour maps suggest that the atmospheric PAHs might have greater impacts on offshore sites than on the coastal area in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. ERUPTING FILAMENTS WITH LARGE ENCLOSING FLUX TUBES AS SOURCES OF HIGH-MASS THREE-PART CMEs, AND ERUPTING FILAMENTS IN THE ABSENCE OF ENCLOSING FLUX TUBES AS SOURCES OF LOW-MASS UNSTRUCTURED CMEs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hutton, Joe; Morgan, Huw, E-mail: joh9@aber.ac.uk

    2015-11-01

    The 3-part appearance of many coronal mass ejections (CMEs) arising from erupting filaments emerges from a large magnetic flux tube structure, consistent with the form of the erupting filament system. Other CMEs arising from erupting filaments lack a clear 3-part structure and reasons for this have not been researched in detail. This paper aims to further establish the link between CME structure and the structure of the erupting filament system and to investigate whether CMEs which lack a 3-part structure have different eruption characteristics. A survey is made of 221 near-limb filament eruptions observed from 2013 May 03 to 2014more » June 30 by Extreme UltraViolet (EUV) imagers and coronagraphs. Ninety-two filament eruptions are associated with 3-part structured CMEs, 41 eruptions are associated with unstructured CMEs. The remaining 88 are categorized as failed eruptions. For 34% of the 3-part CMEs, processing applied to EUV images reveals the erupting front edge is a pre-existing loop structure surrounding the filament, which subsequently erupts with the filament to form the leading bright front edge of the CME. This connection is confirmed by a flux-rope density model. Furthermore, the unstructured CMEs have a narrower distribution of mass compared to structured CMEs, with total mass comparable to the mass of 3-part CME cores. This study supports the interpretation of 3-part CME leading fronts as the outer boundaries of a large pre-existing flux tube. Unstructured (non 3-part) CMEs are a different family to structured CMEs, arising from the eruption of filaments which are compact flux tubes in the absence of a large system of enclosing closed field.« less

  14. CLIVAR-GSOP/GODAE Ocean Synthesis Inter-Comparison of Global Air-Sea Fluxes From Ocean and Coupled Reanalyses

    NASA Astrophysics Data System (ADS)

    Valdivieso, Maria

    2014-05-01

    The GODAE OceanView and CLIVAR-GSOP ocean synthesis program has been assessing the degree of consistency between global air-sea flux data sets obtained from ocean or coupled reanalyses (Valdivieso et al., 2014). So far, fifteen global air-sea heat flux products obtained from ocean or coupled reanalyses have been examined: seven are from low-resolution ocean reanalyses (BOM PEODAS, ECMWF ORAS4, JMA/MRI MOVEG2, JMA/MRI MOVECORE, Hamburg Univ. GECCO2, JPL ECCOv4, and NCEP GODAS), five are from eddy-permitting ocean reanalyses developed as part of the EU GMES MyOcean program (Mercator GLORYS2v1, Reading Univ. UR025.3, UR025.4, UKMO GloSea5, and CMCC C-GLORS), and the remaining three are couple reanalyses based on coupled climate models (JMA/MRI MOVE-C, GFDL ECDA and NCEP CFSR). The global heat closure in the products over the period 1993-2009 spanned by all data sets is presented in comparison with observational and atmospheric reanalysis estimates. Then, global maps of ensemble spread in the seasonal cycle, and of the Signal to Noise Ratio of interannual flux variability over the 17-yr common period are shown to illustrate the consistency between the products. We have also studied regional variability in the products, particularly at the OceanSITES project locations (such as, for instance, the TAO/TRITON and PIRATA arrays in the Tropical Pacific and Atlantic, respectively). Comparisons are being made with other products such as OAFlux latent and sensible heat fluxes (Yu et al., 2008) combined with ISCCP satellite-based radiation (Zhang et al., 2004), the ship-based NOC2.0 product (Berry and Kent, 2009), the Large and Yeager (2009) hybrid flux dataset CORE.2, and two atmospheric reanalysis products, the ECMWF ERA-Interim reanalysis (referred to as ERAi, Dee et al., 2011) and the NCEP/DOE reanalysis R2 (referred to as NCEP-R2, Kanamitsu et al., 2002). Preliminary comparisons with the observational flux products from OceanSITES are also underway. References Berry, D

  15. Multi-Scale Modeling and the Eddy-Diffusivity/Mass-Flux (EDMF) Parameterization

    NASA Astrophysics Data System (ADS)

    Teixeira, J.

    2015-12-01

    Turbulence and convection play a fundamental role in many key weather and climate science topics. Unfortunately, current atmospheric models cannot explicitly resolve most turbulent and convective flow. Because of this fact, turbulence and convection in the atmosphere has to be parameterized - i.e. equations describing the dynamical evolution of the statistical properties of turbulence and convection motions have to be devised. Recently a variety of different models have been developed that attempt at simulating the atmosphere using variable resolution. A key problem however is that parameterizations are in general not explicitly aware of the resolution - the scale awareness problem. In this context, we will present and discuss a specific approach, the Eddy-Diffusivity/Mass-Flux (EDMF) parameterization, that not only is in itself a multi-scale parameterization but it is also particularly well suited to deal with the scale-awareness problems that plague current variable-resolution models. It does so by representing small-scale turbulence using a classic Eddy-Diffusivity (ED) method, and the larger-scale (boundary layer and tropospheric-scale) eddies as a variety of plumes using the Mass-Flux (MF) concept.

  16. The Transport of Plasma and Magnetic Flux in Giant Planet Magnetospheres

    NASA Astrophysics Data System (ADS)

    Russell, C. T.

    2013-05-01

    Both Jupiter and Saturn have moons that add significant quantities of neutrals and/or dust beyond geosynchronous orbit. This material becomes charged and interacts with the planetary plasma that is "orbiting" the planets at near corotational speeds, driven by the planetary ionospheres. Since this speed is greater than the keplerian orbital speed at these distances, the net force on the newly added charged mass is outward. The charged material is held in place by the magnetic field which stretches to the amount needed to balance centripetal and centrifugal forces. The currents involved in this process close in the ionosphere which is an imperfect conductor and the feet of the field lines hence slip poleward and the material near the equator moves outward. This motion allows the magnetosphere to divest itself of the added mass by transferring it to the magnetotail. The magnetotail in turn can rid itself of the newly added mass by the process of reconnection, interior to the region of added mass, freeing an island of magnetized plasma which then moves down the magnetotail no longer connected to the magnetosphere. This maintains a quasi-stationary conservation of mass in the magnetosphere with roughly constant mass and "periodic" disturbances. However, there is one other steady state the magnetosphere needs to maintain. It needs to replace the mass loaded flux tubes with emptied flux tubes. Thus the "emptied" flux tubes in the tail must move inward against the outgoing mass-loaded flux tubes. That they are buoyant is a help in this regard but it appears also to be helpful if the returning flux separates into thin flux tubes, just like air bubbles rising in a container with a leak in the bottom. In this way the magnetospheres of Jupiter and Saturn maintain their dynamic, steady-state convection patterns.

  17. Observed Screen (Air) and GCM Surface/Screen Temperatures: Implications for Outgoing Longwave Fluxes at the Surface.

    NASA Astrophysics Data System (ADS)

    Garratt, J. R.

    1995-05-01

    There is direct evidence that excess net radiation calculated in general circulation models at continental surfaces [of about 11-17 W m2 (20%-27%) on an annual ~1 is not only due to overestimates in annual incoming shortwave fluxes [of 9-18 W m2 (6%-9%)], but also to underestimates in outgoing longwave fluxes. The bias in the outgoing longwave flux is deduced from a comparison of screen-air temperature observations, available as a global climatology of mean monthly values, and model-calculated surface and screen-air temperatures. An underestimate in the screen temperature computed in general circulation models over continents, of about 3 K on an annual basis, implies an underestimate in the outgoing longwave flux, averaged in six models under study, of 11-15 W m2 (3%-4%). For a set of 22 inland stations studied previously, the residual bias on an annual basis (the residual is the net radiation minus incoming shortwave plus outgoing longwave) varies between 18 and 23 W m2 for the models considered. Additional biases in one or both of the reflected shortwave and incoming longwave components cannot be ruled out.

  18. Simulations of Emerging Magnetic Flux. II. The Formation of Unstable Coronal Flux Ropes and the Initiation of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Leake, James E.; Linton, Mark G.; Antiochos, Spiro K.

    2014-01-01

    We present results from three-dimensional magnetohydrodynamic simulations of the emergence of a twisted convection zone flux tube into a pre-existing coronal dipole field. As in previous simulations, following the partial emergence of the sub-surface flux into the corona, a combination of vortical motions and internal magnetic reconnection forms a coronal flux rope. Then, in the simulations presented here, external reconnection between the emerging field and the pre-existing dipole coronal field allows further expansion of the coronal flux rope into the corona. After sufficient expansion, internal reconnection occurs beneath the coronal flux rope axis, and the flux rope erupts up to the top boundary of the simulation domain (approximately 36 Mm above the surface).We find that the presence of a pre-existing field, orientated in a direction to facilitate reconnection with the emerging field, is vital to the fast rise of the coronal flux rope. The simulations shown in this paper are able to self-consistently create many of the surface and coronal signatures used by coronal mass ejection (CME) models. These signatures include surface shearing and rotational motions, quadrupolar geometry above the surface, central sheared arcades reconnecting with oppositely orientated overlying dipole fields, the formation of coronal flux ropes underlying potential coronal field, and internal reconnection which resembles the classical flare reconnection scenario. This suggests that proposed mechanisms for the initiation of a CME, such as "magnetic breakout," are operating during the emergence of new active regions.

  19. An assessment of TropFlux and NCEP air-sea fluxes on ROMS simulations over the Bay of Bengal region

    NASA Astrophysics Data System (ADS)

    Dey, Dipanjan; Sil, Sourav; Jana, Sudip; Pramanik, Saikat; Pandey, P. C.

    2017-12-01

    This study presents an assessment of the TropFlux and the National Centers for Environmental Prediction (NCEP) reanalysis air-sea fluxes in simulating the surface and subsurface oceanic parameters over the Bay of Bengal (BoB) region during 2002-2014 using the Regional Ocean Modelling System (ROMS). The assessment has been made by comparing the simulated fields with in-situ and satellite observations. The simulated surface and subsurface temperatures in the TropFlux forced experiment (TropFlux-E) show better agreement with the Research Moored Array for African-Asian-Australian Monsoon Analysis (RAMA) and Argo observations than the NCEP forced experiment (NCEP-E). The BoB domain averaged sea surface temperature (SST) simulated in the NCEP-E is consistently cooler than the satellite SST, with a root mean square error (RMSE) of 0.79 °C. Moreover, NCEP-E shows a limitation in simulating the observed seasonal cycle of the SST due to substantial underestimation of the pre-monsoon SST peak. These limitations are mostly due to the lower values of the NCEP net heat flux. The seasonal and interannual variations of SST in the TropFlux-E are better comparable to the observations with correlations and skills more than 0.80 and 0.90 respectively. However, SST is overestimated during summer monsoon periods mainly due to higher net heat flux. The superiority of TropFlux forcing over the NCEP reanalysis can also be seen when simulating the interannual variabilities of the magnitude and vertical extent of Wyrtki jets at two equatorial RAMA buoy locations. The jet is weaker in the NCEP-E relative to the TropFlux-E and observations. The simulated sea surface height anomalies (SSHA) from both the experiments are able to capture the regions of positive and negative SSHA with respect to satellite-derived altimeter data with better performance in the TropFlux-E. The speed of the westward propagating Rossby wave along 18°N in the TropFlux-E is found to be about 4.7 cm/s, which is close to

  20. Characterization of extreme air-sea turbulent fluxes

    NASA Astrophysics Data System (ADS)

    Gulev, Sergey; Belyaev, Konstantin

    2017-04-01

    Extreme ocean-atmosphere turbulent fluxes play a critical role in the convective processes in the mid and subpolar latitudes and may also affect a variety of atmospheric processes, such as generation and re-intensification of extreme cyclones in the areas of the mid latitude storm tracks. From the ocean dynamics perspective, specifically for quantifying extreme vertical mixing, characterization of the extreme fluxes requires, besides estimation of the extreme events, also consideration of the relative extremeness of surface fluxes and their timing, e.g. the duration of periods of high surface fluxes. In order to comprehensively characterize extreme turbulent fluxes at sea surface we propose a formalism based upon probability density distributions of surface turbulent fluxes and flux-related variables. Individual absolute flux extremes were derived using Modified Fisher-Tippett (MFT) distribution of turbulent fluxes. Then, we extend this distribution to the fractional distribution, characterizing the fraction of time-integrated turbulent heat flux provided by the fluxes exceeding a given percentile. Finally, we consider the time durations during which fluxes of a given intensity provide extreme accumulations of heat loss from the surface. For estimation of these characteristics of surface fluxes we use fluxes recomputed from the state variables available from modern era reanalyses (ERA-Interim, MERRA and CFSR) for the period from 1979 onwards. Applications of the formalism to the VOS (Voluntary Observing Ship) - based surface fluxes are also considered. We discuss application of the new metrics of mesoscale and synoptic variability of surface fluxes to the dynamics of mixed layer depth in the North Atlantic.

  1. Mass ablation and magnetic flux losses through a magnetized plasma-liner wall interface

    NASA Astrophysics Data System (ADS)

    García-Rubio, F.; Sanz, J.

    2017-07-01

    The understanding of energy and magnetic flux losses in a magnetized plasma medium confined by a cold wall is of great interest in the success of magnetized liner inertial fusion (MagLIF). In a MagLIF scheme, the fuel is magnetized and subsonically compressed by a cylindrical liner. Magnetic flux conservation is degraded by the presence of gradient-driven transport processes such as thermoelectric effects (Nernst) and magnetic field diffusion. In previous publications [Velikovich et al., Phys. Plasmas 22, 042702 (2015)], the evolution of a hot magnetized plasma in contact with a cold solid wall (liner) was studied using the classical collisional Braginskii's plasma transport equations in one dimension. The Nernst term degraded the magnetic flux conservation, while both thermal energy and magnetic flux losses were reduced with the electron Hall parameter ωeτe with a power-law asymptotic scaling (ωeτe)-1/2. In the analysis made in the present paper, we consider a similar situation, but with the liner being treated differently. Instead of a cold solid wall acting as a heat sink, we model the liner as a cold dense plasma with low thermal conduction (that could represent the cryogenic fuel layer added on the inner surface of the liner in a high-gain MagLIF configuration). Mass ablation comes into play, which adds notably differences to the previous analysis. The direction of the plasma motion is inverted, but the Nernst term still convects the magnetic field towards the liner. Magnetization suppresses the Nernst velocity and improves the magnetic flux conservation. Thermal energy in the hot plasma is lost in heating the ablated material. When the electron Hall parameter is large, mass ablation scales as (ωeτe)-3/10, while both the energy and magnetic flux losses are reduced with a power-law asymptotic scaling (ωeτe)-7/10.

  2. Air-sea heat exchange, an element of the water cycle

    NASA Technical Reports Server (NTRS)

    Chahine, M. T.

    1984-01-01

    The distribution and variation of water vapor, clouds and precipitation are examined. Principal driving forces for these distributions are energy exchange and evaporation at the air-sea interface, which are also important elements of air-sea interaction studies. The overall aim of air-sea interaction studies is to quantitatively determine mass, momentum and energy fluxes, with the goal of understanding the mechanisms controlling them. The results of general circulation simulations indicate that the atmosphere in mid-latitudes responds to changes in the oceanic surface conditions in the tropics. This correlation reflects the strong interaction between tropical and mid-latitude conditions caused by the transport of heat and momentum from the tropics. Studies of air-sea exchanges involve a large number of physica, chemical and dynamical processes including heat flux, radiation, sea-surface temperature, precipitation, winds and ocean currents. The fluxes of latent heat are studied and the potential use of satellite data in determining them evaluated. Alternative ways of inferring heat fluxes will be considered.

  3. Homologous and cannibalistic coronal mass ejections from twisted magnetic flux rope simulations

    NASA Astrophysics Data System (ADS)

    Chatterjee, Piyali; Fan, Yuhong

    We present results from magnetohydrodynamic simulations of the development of homologous sequence of coronal mass ejections (CMEs) and demonstrate their so-called cannibalistic behavior. These CMEs originate from the repeated formations and partial eruptions of kink unstable flux ropes as a result of continued emergence of a twisted flux rope across the lower boundary into a pre-existing coronal potential arcade field. Our simulation shows that a CME erupting into the open magnetic field created by a preceding CME has a higher speed. The second of the three successive CMEs in one of the simulations is cannibalistic, catching up and merging with the first into a single fast CME before exiting the domain. All the CMEs including the leading merged CME, attained speeds of about 1000 km s-1 as they exit the domain. The reformation of a twisted flux rope after each CME eruption during the sustained flux emergence can naturally explain the X-ray observations of repeated reformations of sigmoids and "sigmoid-under-cusp" configurations at a low-coronal source of homologous CMEs. We also investigate the initiation mechanism and ejecta topology of these energetic CMEs as a function of the twist parameter of the flux rope.

  4. Critical mass flux for flaming ignition of dead, dry wood as a function of exernal radiant heat flux

    Treesearch

    Sara McAllister; Mark Finney; Jack Cohen

    2010-01-01

    Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion - that a sufficient amount of pyrolysis gases must be...

  5. The OceanFlux Greenhouse Gases methodology for deriving a sea surface climatology of CO2 fugacity in support of air-sea gas flux studies

    NASA Astrophysics Data System (ADS)

    Goddijn-Murphy, L. M.; Woolf, D. K.; Land, P. E.; Shutler, J. D.; Donlon, C.

    2015-07-01

    Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean CO2 Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. As fCO2 is highly sensitive to temperature, the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrently with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air-sea CO2 fluxes, it is therefore desirable to calculate fCO2 valid for a more consistent and averaged SST. This paper presents the OceanFlux Greenhouse Gases methodology for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using monthly composite SST data on a 1° × 1° grid from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010, including the prediction errors of fCO2 produced by the spatial interpolation technique. The partial pressure of CO2 (pCO2) is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air-sea CO2 flux, and hence the presented fCO2 distributions can be used in air-sea gas flux calculations together with climatologies of other climate variables.

  6. An Integrated Approach to Estimate Instantaneous Near-Surface Air Temperature and Sensible Heat Flux Fields during the SEMAPHORE Experiment.

    NASA Astrophysics Data System (ADS)

    Bourras, Denis; Eymard, Laurence; Liu, W. Timothy; Dupuis, Hélène

    2002-03-01

    A new technique was developed to retrieve near-surface instantaneous air temperatures and turbulent sensible heat fluxes using satellite data during the Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, which was conducted in 1993 under mainly anticyclonic conditions. The method is based on a regional, horizontal atmospheric temperature advection model whose inputs are wind vectors, sea surface temperature fields, air temperatures around the region under study, and several constants derived from in situ measurements. The intrinsic rms error of the method is 0.7°C in terms of air temperature and 9 W m2 for the fluxes, both at 0.16° × 0.16° and 1.125° × 1.125° resolution. The retrieved air temperature and flux horizontal structures are in good agreement with fields from two operational general circulation models. The application to SEMAPHORE data involves the First European Remote Sensing Satellite (ERS-1) wind fields, Advanced Very High Resolution Radiometer (AVHRR) SST fields, and European Centre for Medium-Range Weather Forecasts (ECMWF) air temperature boundary conditions. The rms errors obtained by comparing the estimations with research vessel measurements are 0.3°C and 5 W m2.

  7. Subtropical air masses over eastern Canada: Their links to extreme precipitation

    NASA Astrophysics Data System (ADS)

    Gyakum, John; Wood, Alice; Milrad, Shawn; Atallah, Eyad

    2017-04-01

    We investigate extremely warm, moist air masses with an analysis of 850-hPa equivalent potential temperature (θe) extremes at Montreal, Quebec. The utility of using this metric is that it represents the thermodynamic property of air that ascends during a precipitation event. We produce an analysis of the 40 most extreme cases of positive θe, 10 for each season, based upon standardized anomalies from the 33-year climatology. The analysis shows the cases to be characterized by air masses with distinct subtropical traits for all seasons: reduced static stability, anomalously high precipitable water, and anomalously elevated dynamic tropopause heights. Persistent, slow moving upper- and lower-level features were essential in the build up of high- θe air encompassing much of eastern Canada. The trajectory analysis also showed anticyclonic curvature to all paths in all seasons, implying that the subtropical anticyclone is crucial in the transport of high- θe air. These atmospheric rivers during the winter are characterized by trajectories from the subtropical North Atlantic, and over the Gulf Stream current, northward into Montreal. In contrast, the summer anticyclonic trajectories are primarily continental, traveling from Texas north-northeastward into the Great Lakes, and then eastward into Montreal. The role of the air mass in modulating the strength of a precipitation event is addressed with an analysis of the expression, P = RD, where P is the total precipitation, and R is the precipitation rate, averaged through the duration, D, of the event. Though appearing simple, this expression includes R, (assumed to be same as condensation, with an efficiency of 1), which may be expressed as the product of vertical motion and the change of saturation mixing ratio following a moist adiabat, through the troposphere. This expression for R includes the essential ingredients of lift, air mass temperature, and static stability (implicit in vertical motion). We use this

  8. Comparison of Sea-Air CO2 Flux Estimates Using Satellite-Based Versus Mooring Wind Speed Data

    NASA Astrophysics Data System (ADS)

    Sutton, A. J.; Sabine, C. L.; Feely, R. A.; Wanninkhof, R. H.

    2016-12-01

    The global ocean is a major sink of anthropogenic CO2, absorbing approximately 27% of CO2 emissions since the beginning of the industrial revolution. Any variation or change in the ocean CO2 sink has implications for future climate. Observations of sea-air CO2 flux have relied primarily on ship-based underway measurements of partial pressure of CO2 (pCO2) combined with satellite, model, or multi-platform wind products. Direct measurements of ΔpCO2 (seawater - air pCO2) and wind speed from moored platforms now allow for high-resolution CO2 flux time series. Here we present a comparison of CO2 flux calculated from moored ΔpCO2 measured on four moorings in different biomes of the Pacific Ocean in combination with: 1) Cross-Calibrated Multi-Platform (CCMP) winds or 2) wind speed measurements made on ocean reference moorings excluded from the CCMP dataset. Preliminary results show using CCMP winds overestimates CO2 flux on average by 5% at the Kuroshio Extension Observatory, Ocean Station Papa, WHOI Hawaii Ocean Timeseries Station, and Stratus. In general, CO2 flux seasonality follows patterns of seawater pCO2 and SST with periods of CO2 outgassing during summer and CO2 uptake during winter at these locations. Any offsets or seasonal biases in CCMP winds could impact global ocean sink estimates using this data product. Here we present patterns and trends between the two CO2 flux estimates and discuss the potential implications for tracking variability and change in global ocean CO2 uptake.

  9. Measurement uncertainties in quantifying aeolian mass flux: evidence from wind tunnel and field site data

    PubMed Central

    Keijsers, Joep G.S.; Maroulis, Jerry; Visser, Saskia M.

    2014-01-01

    Aeolian sediment traps are widely used to estimate the total volume of wind-driven sediment transport, but also to study the vertical mass distribution of a saltating sand cloud. The reliability of sediment flux estimations from such measurements are dependent upon the specific configuration of the measurement compartments and the analysis approach used. In this study, we analyse the uncertainty of these measurements by investigating the vertical cumulative distribution and relative sediment flux derived from both wind tunnel and field studies. Vertical flux data was examined using existing data in combination with a newly acquired dataset; comprising meteorological data and sediment fluxes from six different events, using three customized catchers at Ameland beaches in northern Netherlands. Fast-temporal data collected in a wind tunnel shows that the median transport height has a scattered pattern between impact and fluid threshold, that increases linearly with shear velocities above the fluid threshold. For finer sediment, a larger proportion was transported closer to the surface compared to coarser sediment fractions. It was also shown that errors originating from the distribution of sampling compartments, specifically the location of the lowest sediment trap relative to the surface, can be identified using the relative sediment flux. In the field, surface conditions such as surface moisture, surface crusts or frozen surfaces have a more pronounced but localized effect than shear velocity. Uncertainty in aeolian mass flux estimates can be reduced by placing multiple compartments in closer proximity to the surface. PMID:25071984

  10. Climate change impacts on sea-air fluxes of CO2 in three Arctic seas: a sensitivity study using Earth observation

    NASA Astrophysics Data System (ADS)

    Land, P. E.; Shutler, J. D.; Cowling, R. D.; Woolf, D. K.; Walker, P.; Findlay, H. S.; Upstill-Goddard, R. C.; Donlon, C. J.

    2013-12-01

    We applied coincident Earth observation data collected during 2008 and 2009 from multiple sensors (RA2, AATSR and MERIS, mounted on the European Space Agency satellite Envisat) to characterise environmental conditions and integrated sea-air fluxes of CO2 in three Arctic seas (Greenland, Barents, Kara). We assessed net CO2 sink sensitivity due to changes in temperature, salinity and sea ice duration arising from future climate scenarios. During the study period the Greenland and Barents seas were net sinks for atmospheric CO2, with integrated sea-air fluxes of -36 ± 14 and -11 ± 5 Tg C yr-1, respectively, and the Kara Sea was a weak net CO2 source with an integrated sea-air flux of +2.2 ± 1.4 Tg C yr-1. The combined integrated CO2 sea-air flux from all three was -45 ± 18 Tg C yr-1. In a sensitivity analysis we varied temperature, salinity and sea ice duration. Variations in temperature and salinity led to modification of the transfer velocity, solubility and partial pressure of CO2 taking into account the resultant variations in alkalinity and dissolved organic carbon (DOC). Our results showed that warming had a strong positive effect on the annual integrated sea-air flux of CO2 (i.e. reducing the sink), freshening had a strong negative effect and reduced sea ice duration had a small but measurable positive effect. In the climate change scenario examined, the effects of warming in just over a decade of climate change up to 2020 outweighed the combined effects of freshening and reduced sea ice duration. Collectively these effects gave an integrated sea-air flux change of +4.0 Tg C in the Greenland Sea, +6.0 Tg C in the Barents Sea and +1.7 Tg C in the Kara Sea, reducing the Greenland and Barents sinks by 11% and 53%, respectively, and increasing the weak Kara Sea source by 81%. Overall, the regional integrated flux changed by +11.7 Tg C, which is a 26% reduction in the regional sink. In terms of CO2 sink strength, we conclude that the Barents Sea is the most

  11. Settlement with Amherst, Mass., Company Reduces Emissions to Air

    EPA Pesticide Factsheets

    Under the terms of a recent settlement with the U.S. Environmental Protection Agency (EPA), John S. Lane and Son, Inc. (JS Lane), a sand and gravel company in Amherst, Mass., has taken steps to reduce air pollution, as required by the Clean Air Act (CAA).

  12. Grazing-induced BVOC fluxes from a managed grassland

    NASA Astrophysics Data System (ADS)

    Mozaffar, Ahsan; Schoon, Niels; Bachy, Aurelie; Digrado, Anthony; Heinesch, Bernard; Aubinet, Marc; Fauconnier, Marie-laure; Delaplace, Pierre; Dujardin, Patrick; Amelynck, Crist

    2017-04-01

    Grassland ecosystems cover one fourth of the Earth's land surface and are both sources and sinks of Biogenic Volatile Organic Compounds (BVOCs) which play an important role in atmospheric chemistry and air pollution. The use of grassland for cattle breeding is a common practice in many parts of the world. As it has been widely demonstrated that plants emit large bursts of BVOCs when they are mechanically damaged, grass tearing and trampling during grazing are expected to induce large BVOC emissions as well. Nevertheless, to the best of our knowledge, no study has been performed on BVOC fluxes from grazed grassland yet. Therefore investigations were performed using automated dynamic chambers in a managed grassland in Belgium over the 2015 and 2016 growing season. BVOC fluxes, together with carbon dioxide (CO2) and water vapor (H2O) fluxes from grazed and undisturbed grassland were followed simultaneously using PTR-MS (Proton Transfer Reaction-Mass Spectrometry) and a LI-840 non-dispersive IR gas analyzer. In addition, air in the chamber was sampled occasionally for GC-MS (Gas Chromatography-Mass Spectrometry) analysis to assist compound identification. Significant differences between grazed and undisturbed grassland patches were observed in terms of BVOC, CO2 and H2O vapor fluxes. Grazing by cows was found to result in enhanced emissions of several BVOCs such as methanol, acetaldehyde, acetone, acetic acid and Green Leaf Volatiles (GLVs), and induced BVOC emissions generally lasted for around 5 days following a grazing event. Quantitative data on the impact of grazing on BVOC, CO2 and H2O exchange between grassland and the atmosphere will be presented, and correlations between BVOC fluxes and environmental conditions will be discussed.

  13. Wind Tunnel Model Study of the Hot Exhaust Plume from the Compressor Research Facility at Wright-Patterson Air Force Base, Ohio

    DTIC Science & Technology

    1977-10-01

    PLUME FROM THE COMPRESSOR JtESEARCHJAC ILITY AT WRIGHT- /ATTERSON AIR FORCE JBASE, OHIO , r= mrm (.) Gary R./Ludwig 9. PERFORMING ORGANIZATION NAME... ms Mass flux of stack exhaust gas (slugs/sec) nrtfl Mass flux of ambient air and stack exhaust gas mixture st plume cross-section A (slugs/sec...the horizontal momentum flux in the ambient wind be the same in the model as it is in full-scale. /»» Ms M i a. ’ ro P>"S P*» + ’f (3) where 0

  14. Air Mass Origin in the Arctic and its Response to Future Warming

    NASA Technical Reports Server (NTRS)

    Orbe, Clara; Newman, Paul A.; Waugh, Darryn W.; Holzer, Mark; Oman, Luke; Polvani, Lorenzo M.; Li, Feng

    2014-01-01

    We present the first climatology of air mass origin in the Arctic in terms of rigorously defined air mass fractions that partition air according to where it last contacted the planetary boundary layer (PBL). Results from a present-day climate integration of the GEOSCCM general circulation model reveal that the Arctic lower troposphere below 700 mb is dominated year round by air whose last PBL contact occurred poleward of 60degN, (Arctic air, or air of Arctic origin). By comparison, approx. 63% of the Arctic troposphere above 700 mb originates in the NH midlatitude PBL, (midlatitude air). Although seasonal changes in the total fraction of midlatitude air are small, there are dramatic changes in where that air last contacted the PBL, especially above 700 mb. Specifically, during winter air in the Arctic originates preferentially over the oceans, approx. 26% in the East Pacific, and approx. 20% in the Atlantic PBL. By comparison, during summer air in the Arctic last contacted the midlatitude PBL primarily over land, overwhelmingly so in Asia (approx. 40 %) and, to a lesser extent, in North America (approx. 24%). Seasonal changes in air-mass origin are interpreted in terms of seasonal variations in the large-scale ventilation of the midlatitude boundary layer and lower troposphere, namely changes in the midlatitude tropospheric jet and associated transient eddies during winter and large scale convective motions over midlatitudes during summer.

  15. Shifts in controls on the temporal coherence of throughfall chemical flux in Acadia National Park, Maine, USA

    USGS Publications Warehouse

    Nelson, Sarah J.; Webster, Katherine E.; Loftin, Cynthia S.; Weathers, Kathleen C.

    2013-01-01

    Major ion and mercury (Hg) inputs to terrestrial ecosystems include both wet and dry deposition (total deposition). Estimating total deposition to sensitive receptor sites is hampered by limited information regarding its spatial heterogeneity and seasonality. We used measurements of throughfall flux, which includes atmospheric inputs to forests and the net effects of canopy leaching or uptake, for ten major ions and Hg collected during 35 time periods in 1999–2005 at over 70 sites within Acadia National Park, Maine to (1) quantify coherence in temporal dynamics of seasonal throughfall deposition and (2) examine controls on these patterns at multiple scales. We quantified temporal coherence as the correlation between all possible site pairs for each solute on a seasonal basis. In the summer growing season and autumn, coherence among pairs of sites with similar vegetation was stronger than for site-pairs that differed in vegetation suggesting that interaction with the canopy and leaching of solutes differed in coniferous, deciduous, mixed, and shrub or open canopy sites. The spatial pattern in throughfall hydrologic inputs across Acadia National Park was more variable during the winter snow season, suggesting that snow re-distribution affects net hydrologic input, which consequently affects chemical flux. Sea-salt corrected calcium concentrations identified a shift in air mass sources from maritime in winter to the continental industrial corridor in summer. Our results suggest that the spatial pattern of throughfall hydrologic flux, dominant seasonal air mass source, and relationship with vegetation in winter differ from the spatial pattern of throughfall flux in these solutes in summer and autumn. The coherence approach applied here made clear the strong influence of spatial heterogeneity in throughfall hydrologic inputs and a maritime air mass source on winter patterns of throughfall flux. By contrast, vegetation type was the most important influence on

  16. On the importance of high-frequency air-temperature fluctuations for spectroscopic corrections of open-path carbon dioxide flux measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, Ivan; Helbig, Manuel; Sonnentag, Oliver

    2015-04-01

    A growing number of studies report systematic differences in CO2 flux estimates obtained with the two main types of gas analyzers: compared to eddy-covariance systems based on closed-path (CP) gas analyzers, systems with open-path (OP) gas analyzers systematically overestimate CO2 uptake during daytime periods with high positive sensible heat fluxes, while patterns for differences in nighttime CO2 exchange are less obvious. These biases have been shown to correlate with the sign and the magnitude of the sensible heat flux and to introduce large uncertainties when calculating annual CO2 budgets. In general, CP and OP gas analyzers commonly used to measure the CO2 density in the atmosphere operate on the principle of infrared light absorption approximated by Beer-Lambert's law. Non-dispersive interference-based optical filter elements are used to select spectral bands with strong attenuation of light transmission, characteristic to the gas of interest. The intensity of the light passing through the optical sensing path depends primarily on the amount of absorber gas in the measurement volume. Besides the density of the gas, barometric pressure and air temperature are additional factors affecting the strength and the half-width of the absorption lines. These so-called spectroscopic effects are accounted for by measuring barometric pressure and air temperature in the sensing path and scaling the light-intensity measurements before applying the calibration equation. This approach works well for CP gas analyzers with an intake tube that acts as a low-pass filter on fast air-temperature fluctuations. Low-frequency response temperature sensors in the measurement cell are therefore sufficient to account for spectroscopic temperature effects. In contrast, OP gas analyzers are exposed to high-frequency air-temperature fluctuations associated with the atmospheric surface-layer turbulent heat exchange. If not corrected adequately, these fast air-temperature variations can cause

  17. Experimental Determination of Air Density Using a 1 kg Mass Comparator in Vacuum

    NASA Astrophysics Data System (ADS)

    Gläser, M.; Schwartz, R.; Mecke, M.

    1991-01-01

    The density of ambient air has been determined by a straightforward experimental method. The apparent masses of two artefacts having about the same mass and surface, but different well-known volumes, have been compared by using a 1 kg balance in vacuum and in air. The differences of apparent masses and volumes yield the air density with a relative uncertainty (1σ) of 5 × 10-5. From measurements made using a third artefact, surface sorption effects caused by the change between vacuum and air conditions gave a coefficient of about 0,2 μg cm-2.

  18. Eddy covariance VOC emission and deposition fluxes above grassland using PTR-TOF

    NASA Astrophysics Data System (ADS)

    Ruuskanen, T. M.; Müller, M.; Schnitzhofer, R.; Karl, T.; Graus, M.; Bamberger, I.; Hörtnagl, L.; Brilli, F.; Wohlfahrt, G.; Hansel, A.

    2011-01-01

    Eddy covariance (EC) is the preferable technique for flux measurements since it is the only direct flux determination method. It requires a continuum of high time resolution measurements (e.g. 5-20 Hz). For volatile organic compounds (VOC) soft ionization via proton transfer reaction has proven to be a quantitative method for real time mass spectrometry; here we use a proton transfer reaction time of flight mass spectrometer (PTR-TOF) for 10 Hz EC measurements of full mass spectra up to m/z 315. The mass resolution of the PTR-TOF enabled the identification of chemical formulas and separation of oxygenated and hydrocarbon species exhibiting the same nominal mass. We determined 481 ion mass peaks from ambient air concentration above a managed, temperate mountain grassland in Neustift, Stubai Valley, Austria. During harvesting we found significant fluxes of 18 compounds distributed over 43 ions, including protonated parent compounds, as well as their isotopes and fragments and VOC-H+ - water clusters. The dominant BVOC fluxes were methanol, acetaldehyde, ethanol, hexenal and other C6 leaf wound compounds, acetone, acetic acid, monoterpenes and sequiterpenes. The smallest reliable fluxes we determined were less than 0.1 nmol m-2 s-1, as in the case of sesquiterpene emissions from freshly cut grass. Terpenoids, including mono- and sesquiterpenes, were also deposited to the grassland before and after the harvesting. During cutting, total VOC emission fluxes up to 200 nmolC m-2 s-1 were measured. Methanol emissions accounted for half of the emissions of oxygenated VOCs and a third of the carbon of all measured VOC emissions during harvesting.

  19. VOC Emission and Deposition Eddy Covariance Fluxes above Grassland using PTR-TOF

    NASA Astrophysics Data System (ADS)

    Ruuskanen, T. M.; Müller, M.; Schnitzhofer, R.; Karl, T.; Graus, M.; Bamberger, I.; Hörtnagl, L.; Brilli, F.; Wohlfahrt, G.; Hansel, A.

    2010-12-01

    Eddy covariance (EC) is the preferable technique for flux measurements since it is the only direct flux determination method. It requires a continuum of high time resolution measurements (e.g. 5-20 Hz). For volatile organic compounds (VOC) soft ionization via proton transfer reaction has proven to be a quantitative method for real time mass spectrometry; here we use a proton transfer reaction time of flight mass spectrometer (PTR-TOF) for 10 Hz EC measurements of full mass spectra up to m/z 315. The mass resolution of the PTR-TOF enabled the identification of chemical formulas and separation of oxygenated and hydrocarbon species exhibiting the same nominal mass. We determined 481 ion mass peaks from ambient air concentration above a managed, temperate mountain grassland in Neustift, Stubai Valley, Austria. During harvesting we found significant fluxes of 18 compounds distributed over 43 ions, including protonated parent compounds, as well as their isotopes and fragments and VOC-H+ - water clusters. The dominant BVOC fluxes were methanol, acetaldehyde, ethanol, hexenal and other C6 leaf wound compounds, acetone, acetic acid, monoterpenes and sequiterpenes. The smallest reliable fluxes we determined were less than 0.1 nmol m-2 s-1, as in the case of sesquiterpene emissions from freshly cut grass. Terpenoids, including mono- and sesquiterpenes, were also deposited to the grassland before and after the harvesting. During cutting, total VOC emission fluxes up to 200 nmolC m-2 s-1 were measured. Methanol emissions accounted for half of the emissions of oxygenated VOCs and a third of the carbon of all measured VOC emissions during harvesting.

  20. Eddy covariance VOC emission and deposition fluxes above grassland using PTR-TOF

    NASA Astrophysics Data System (ADS)

    Ruuskanen, T. M.; Müller, M.; Schnitzhofer, R.; Karl, T.; Graus, M.; Bamberger, I.; Hörtnagl, L.; Brilli, F.; Wohlfahrt, G.; Hansel, A.

    2010-09-01

    Eddy covariance (EC) is the preferable technique for flux measurements since it is the only direct flux determination method. It requires a continuum of high time resolution measurements (e.g. 5-20 Hz). For volatile organic compounds (VOC) soft ionization via proton transfer reaction has proven to be a quantitative method for real time mass spectrometry; here we use a proton transfer reaction time of flight mass spectrometer (PTR-TOF) for 10 Hz EC measurements of full mass spectra up to m/z 315. The mass resolution of the PTR-TOF enabled the identification of chemical formulas and separation of oxygenated and hydrocarbon species exhibiting the same nominal mass. We determined 481 ion mass peaks from ambient air concentration above a managed, temperate mountain grassland in Neustift, Stubai Valley, Austria. During harvesting we found significant fluxes of 18 compounds distributed over 43 ions, including protonated parent compounds, as well as their isotopes and fragments and VOC-H+-water clusters. The dominant BVOC fluxes were methanol, acetaldehyde, ethanol, hexenal and other C6 leaf wound compounds, acetone, acetic acid, monoterpenes and sequiterpenes. The smallest reliable fluxes we determined were less than 0.1 nmol m-2 s-1, as in the case of sesquiterpene emissions from freshly cut grass. Terpenoids, including mono- and sesquiterpenes, were also deposited to the grassland before and after the harvesting. During cutting, total VOC emission fluxes up to 200 nmol C m-2 s-1 were measured. Methanol emissions accounted for half of the emissions of oxygenated VOCs and a third of the carbon of all measured VOC emissions during harvesting.

  1. Modeling Energy and Mass Fluxes Over a Vineyard Using the Acasa Model

    NASA Astrophysics Data System (ADS)

    Marras, S.; Bellucco, V.; Pyles, D.; Falk, M.; Sirca, C.; Duce, P.; Snyder, R. L.; Paw U, K.; Spano, D.

    2012-12-01

    Energy and mass fluxes are widely monitored over natural ecosystems by the Eddy Covariance (EC) towers within the FLUXNET monitoring network. Only a few studies focused on EC measurements over tree crops and vines, and there is a lack of information useful to parameterize crop and flux models over such systems. The aim of this study was to improve our knowledge about the performance of the land surface model ACASA (Advanced Canopy-Atmosphere-Soil Algorithm) in estimating energy, water, and carbon fluxes over a typical Mediterranean vineyard located in Southern Sardinia (Italy). ACASA estimates turbulent fluxes per 20 canopy layers (10 layers within and 10 above the canopy) and 15 soil layers, using third-order closure equations. CO2 fluxes are estimated using a combination of Ball-Berry and Farquhar equations. The model parameters derived from literature, from a previous work conducted in Tuscany (Italy) and from direct measurements collected in the experimental site of this study. An Eddy Covariance measurement tower was installed to continuously monitor sensible and latent heat, and CO2 fluxes, in conjunction with a net radiometer, and soil heat flux plates from June 2009. A meteorological station was also set up for ancillary measurements. Model performance was evaluated by RMSE and linear regression statistics. Results for the energy balance components and CO2 exchanges will be presented. Detailed analysis was devoted to evaluate the model ability in estimating the vineyard evapotranspiration. This term of the energy balance is, in fact, important for farmers since they are mainly interested in quantify crop water requirements for a better irrigation management.

  2. An Explanation of the Very Low Radio Flux of Young Planet-mass Companions

    NASA Astrophysics Data System (ADS)

    Wu, Ya-Lin; Close, Laird M.; Eisner, Josh A.; Sheehan, Patrick D.

    2017-12-01

    We report Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum upper limits for five planetary-mass companions DH Tau B, CT Cha B, GSC 6214-210 B, 1RXS 1609 B, and GQ Lup B. Our survey, together with other ALMA studies, have yielded null results for disks around young planet-mass companions and placed stringent dust mass upper limits, typically less than 0.1 M ⊕, when assuming dust continuum is optically thin. Such low-mass gas/dust content can lead to a disk lifetime estimate (from accretion rates) much shorter than the age of the system. To alleviate this timescale discrepancy, we suggest that disks around wide companions might be very compact and optically thick in order to sustain a few Myr of accretion, yet have very weak (sub)millimeter flux so as to still be elusive to ALMA. Our order-of-magnitude estimate shows that compact optically thick disks might be smaller than 1000 R Jup and only emit ∼μJy of flux in the (sub)millimeter, but their average temperature can be higher than that of circumstellar disks. The high disk temperature could impede satellite formation, but it also suggests that mid- to far-infrared might be more favorable than radio wavelengths to characterize disk properties. Finally, the compact disk size might imply that dynamical encounters between the companion and the star, or any other scatterers in the system, play a role in the formation of planetary-mass companions.

  3. The correlation between HCN/H2O flux ratios and disk mass: evidence for protoplanet formation

    NASA Astrophysics Data System (ADS)

    Rose, Caitlin; Salyk, Colette

    2017-01-01

    We analyze hydrogen cyanide (HCN) and water vapor flux ratios in protoplanetary disks as a way to trace planet formation. Analyzing only disks in the Taurus molecular cloud, Najita et al. (2013) found a tentative correlation between protoplanetary disk mass and the HCN/H2O line flux ratio in Spitzer-IRS emission spectra. They interpret this correlation to be a consequence of more massive disks forming planetesimals more efficiently than smaller disks, as the formation of large planetesimals may lock up water ice in the cool outer disk region and prevent it from migrating, drying out the inner disk. The sequestering of water (and therefore oxygen) in the outer disk may also increase the carbon-to- oxygen ratio in the inner disk, leading to enhanced organic molecule (e.g. HCN) emission. To confirm this trend, we expand the Najita et al. sample by calculating HCN/H2O line flux ratios for 8 more sources with known disk masses from clusters besides Taurus. We find agreement with the Najita et al. trend, suggesting that this is a widespread phenomenon. In addition, we find HCN/H2O line flux ratios for 17 more sources that await disk mass measurements, which should become commonplace in the ALMA era. Finally, we investigate linear fits and outliers to this trend, and discuss possible causes.

  4. Critical mass flux for flaming ignition of wood as a function of external radiant heat flux and moisture content

    Treesearch

    S. McAllister; M. Finney; J. Cohen

    2011-01-01

    Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion - that a sufficient amount of pyrolysis gases must be...

  5. Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

    NASA Astrophysics Data System (ADS)

    Miller, L. A.; Papakyriakou, T. N.

    2015-12-01

    In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.

  6. The fabrication of plastic cages for suspension in mass air flow racks.

    PubMed

    Nielsen, F H; Bailey, B

    1979-08-01

    A cage for suspension in mass air flow racks was constructed of plastic and used to house rats. Little or no difficulty was encountered with the mass air flow rack-suspended cage system during the 4 years it was used for the study of trace elements.

  7. A Sensitivity Analysis of the Impact of Rain on Regional and Global Sea-Air Fluxes of CO2

    PubMed Central

    Shutler, J. D.; Land, P. E.; Woolf, D. K.; Quartly, G. D.

    2016-01-01

    The global oceans are considered a major sink of atmospheric carbon dioxide (CO2). Rain is known to alter the physical and chemical conditions at the sea surface, and thus influence the transfer of CO2 between the ocean and atmosphere. It can influence gas exchange through enhanced gas transfer velocity, the direct export of carbon from the atmosphere to the ocean, by altering the sea skin temperature, and through surface layer dilution. However, to date, very few studies quantifying these effects on global net sea-air fluxes exist. Here, we include terms for the enhanced gas transfer velocity and the direct export of carbon in calculations of the global net sea-air fluxes, using a 7-year time series of monthly global climate quality satellite remote sensing observations, model and in-situ data. The use of a non-linear relationship between the effects of rain and wind significantly reduces the estimated impact of rain-induced surface turbulence on the rate of sea-air gas transfer, when compared to a linear relationship. Nevertheless, globally, the rain enhanced gas transfer and rain induced direct export increase the estimated annual oceanic integrated net sink of CO2 by up to 6%. Regionally, the variations can be larger, with rain increasing the estimated annual net sink in the Pacific Ocean by up to 15% and altering monthly net flux by > ± 50%. Based on these analyses, the impacts of rain should be included in the uncertainty analysis of studies that estimate net sea-air fluxes of CO2 as the rain can have a considerable impact, dependent upon the region and timescale. PMID:27673683

  8. The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident Flux

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, Geoffrey W.; Rowe, Jason F.; Howard, Andrew W.; Isaacson, Howard; Fortney, Jonathan J.; Miller, Neil; Demory, Brice-Olivier; Fischer, Debra A.; Adams, Elisabeth R.; Dupree, Andrea K.; Howell, Steve B.; Kolbl, Rea; Johnson, John Asher; Horch, Elliott P.; Everett, Mark E.; Fabrycky, Daniel C.; Seager, Sara

    2013-05-01

    We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like inflated hot Jupiters. KOI-94 also hosts at least three smaller transiting planets, all of which were detected by the Kepler mission. With 26 radial velocities of KOI-94 from the W. M. Keck Observatory and a simultaneous fit to the Kepler light curve, we measure the mass of the giant planet and determine that it is not inflated. Support for the planetary interpretation of the other three candidates comes from gravitational interactions through transit timing variations, the statistical robustness of multi-planet systems against false positives, and several lines of evidence that no other star resides within the photometric aperture. We report the properties of KOI-94b (M P = 10.5 ± 4.6 M ⊕, R P = 1.71 ± 0.16 R ⊕, P = 3.74 days), KOI-94c (M P = 15.6^{+5.7}_{-15.6} M ⊕, R P = 4.32 ± 0.41 R ⊕, P = 10.4 days), KOI-94d (M P = 106 ± 11 M ⊕, R P = 11.27 ± 1.06 R ⊕, P = 22.3 days), and KOI-94e (M P = 35^{+18}_{-28} M ⊕, R P = 6.56 ± 0.62 R ⊕, P = 54.3 days). The radial velocity analyses of KOI-94b and KOI-94e offer marginal (>2σ) mass detections, whereas the observations of KOI-94c offer only an upper limit to its mass. Using the KOI-94 system and other planets with published values for both mass and radius (138 exoplanets total, including 35 with M P < 150 M ⊕), we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to 13 Jupiter masses: (R P/R ⊕) = 1.78(M P/M ⊕)0.53(F/erg s-1 cm-2)-0.03 for M P < 150 M ⊕, and R P/R ⊕ = 2.45(M P/M ⊕)-0.039(F/erg s-1 cm-2)0.094 for M P > 150 M ⊕. These equations can be used to predict the radius or mass of a planet. Based in part on observations obtained at the W. M. Keck Observatory, which is

  9. Spatial distirbution of Antarctic mass flux due to iceberg transport

    NASA Astrophysics Data System (ADS)

    Comeau, Darin; Hunke, Elizabeth; Turner, Adrian

    Under a changing climate that sees amplified warming in the polar regions, the stability of the West Antarctic ice sheet and its impact on sea level rise is of great importance. Icebergs are at the interface of the land-ice, ocean, and sea ice systems, and represent approximately half of the mass flux from the Antarctic ice sheet to the ocean. Calved icebergs transport freshwater away from the coast and exchange heat with the ocean, thereby affecting stratification and circulation, with subsequent indirect thermodynamic effects to the sea ice system. Icebergs also dynamically interact with surrounding sea ice pack, as well as serving as nutrient sources for biogeochemical activity. The spatial pattern of these fluxes transported from the continent to the ocean is generally poorly represented in current global climate models. We are implementing an iceberg model into the new Accelerated Climate Model for Energy (ACME) within the MPAS-Seaice model, which uses a variable resolution, unstructured grid framework. This capability will allow for full coupling with the land ice model to inform calving fluxes, and the ocean model for freshwater and heat exchange, giving a complete representation of the iceberg lifecycle and increasing the fidelity of ACME southern cryosphere simulations.

  10. Normalized vertical ice mass flux profiles from vertically pointing 8-mm-wavelength Doppler radar

    NASA Technical Reports Server (NTRS)

    Orr, Brad W.; Kropfli, Robert A.

    1993-01-01

    During the FIRE 2 (First International Satellite Cloud Climatology Project Regional Experiment) project, NOAA's Wave Propagation Laboratory (WPL) operated its 8-mm wavelength Doppler radar extensively in the vertically pointing mode. This allowed for the calculation of a number of important cirrus cloud parameters, including cloud boundary statistics, cloud particle characteristic sizes and concentrations, and ice mass content (imc). The flux of imc, or, alternatively, ice mass flux (imf), is also an important parameter of a cirrus cloud system. Ice mass flux is important in the vertical redistribution of water substance and thus, in part, determines the cloud evolution. It is important for the development of cloud parameterizations to be able to define the essential physical characteristics of large populations of clouds in the simplest possible way. One method would be to normalize profiles of observed cloud properties, such as those mentioned above, in ways similar to those used in the convective boundary layer. The height then scales from 0.0 at cloud base to 1.0 at cloud top, and the measured cloud parameter scales by its maximum value so that all normalized profiles have 1.0 as their maximum value. The goal is that there will be a 'universal' shape to profiles of the normalized data. This idea was applied to estimates of imf calculated from data obtained by the WPL cloud radar during FIRE II. Other quantities such as median particle diameter, concentration, and ice mass content can also be estimated with this radar, and we expect to also examine normalized profiles of these quantities in time for the 1993 FIRE II meeting.

  11. A Comparison of the Red Green Blue Air Mass Imagery and Hyperspectral Infrared Retrieved Profiles

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Folmer, Michael; Dunion, Jason

    2014-01-01

    The Red Green Blue (RGB) Air Mass imagery is derived from multiple channels or paired channel differences. Multiple channel products typically provide additional information than a single channel can provide alone. The RGB Air Mass imagery simplifies the interpretation of temperature and moisture characteristics of air masses surrounding synoptic and mesoscale features. Despite the ease of interpretation of multiple channel products, the combination of channels and channel differences means the resulting product does not represent a quantity or physical parameter such as brightness temperature in conventional single channel satellite imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles of temperature, moisture, and ozone can provide insight about the air mass represented on the RGB Air Mass product and provide confidence in the product and representation of air masses despite the lack of a quantity to reference for interpretation. This study focuses on RGB Air Mass analysis of Hurricane Sandy as it moved north along the U.S. East Coast, while transitioning to a hybrid extratropical storm. Soundings and total column ozone retrievals were analyzed using data from the Cross-track Infrared and Advanced Technology Microwave Sounder Suite (CrIMSS) on the Suomi National Polar Orbiting Partnership satellite and the Atmospheric Infrared Sounder (AIRS) on the National Aeronautics and Space Administration Aqua satellite along with dropsondes that were collected from National Oceanic and Atmospheric Administration and Air Force research aircraft. By comparing these datasets to the RGB Air Mass, it is possible to capture quantitative information that could help in analyzing the synoptic environment enough to diagnose the onset of extratropical transition. This was done by identifying any stratospheric air intrusions (SAIs) that existed in the vicinity of Sandy as the wind

  12. The initiation of coronal mass ejections by newly emerging magnetic flux

    NASA Technical Reports Server (NTRS)

    Feynman, J.; Martin, S. F.

    1995-01-01

    We present observational evidence that eruptions of quiescent filaments and associated coronal mass ejections (CMEs) occur as a consequence of the destabilization of large-scale coronal arcades due to interactions between these structures and new and growing active regions. Both statistical and case studies have been carried out. In a case study of a 'bulge' observed by the High-Altitude Observatory Solar Maximum Mission coronagraph, the high-resolution magnetograms from the Big Bear Solar Observatory show newly emerging and rapidly changing flux in the magnetic fields that apparently underlie the bugle. For other case studies and in the statistical work the eruption of major quiescent filaments was taken as a proxy for CME eruption. We have found that two thirds of the quiescent-filament-associated CMEs occurred after substantial amounts of new magnetic flux emerged in the vicinity of the filament. In addition, in a study of all major quiescent filaments and active regions appearing in a 2-month period we found that 17 of the 22 filaments that were associated with new active regions erupted and 26 of the 31 filaments that were not associated with new flux did not erupt. In all cases in which the new flux was oriented favorably for reconnection with the preexisting large-scale coronal arcades; the filament was observed to erupt. The appearance of the new flux in the form of new active regions begins a few days before the eruption and typically is still occurring at the time of the eruption. A CME initiation scenario taking account of these observational results is proposed.

  13. Determining Mass and Persistence of a Reactive Brominated-Solvent DNAPL Source Using Mass Depletion-Mass Flux Reduction Relationships During Pumping

    NASA Astrophysics Data System (ADS)

    Johnston, C. D.; Davis, G. B.; Bastow, T.; Annable, M. D.; Trefry, M. G.; Furness, A.; Geste, Y.; Woodbury, R.; Rhodes, S.

    2011-12-01

    Measures of the source mass and depletion characteristics of recalcitrant dense non-aqueous phase liquid (DNAPL) contaminants are critical elements for assessing performance of remediation efforts. This is in addition to understanding the relationships between source mass depletion and changes to dissolved contaminant concentration and mass flux in groundwater. Here we present results of applying analytical source-depletion concepts to pumping from within the DNAPL source zone of a 10-m thick heterogeneous layered aquifer to estimate the original source mass and characterise the time trajectory of source depletion and mass flux in groundwater. The multi-component, reactive DNAPL source consisted of the brominated solvent tetrabromoethane (TBA) and its transformation products (mostly tribromoethene - TriBE). Coring and multi-level groundwater sampling indicated the DNAPL to be mainly in lower-permeability layers, suggesting the source had already undergone appreciable depletion. Four simplified source dissolution models (exponential, power function, error function and rational mass) were able to describe the concentration history of the total molar concentration of brominated organics in extracted groundwater during 285 days of pumping. Approximately 152 kg of brominated compounds were extracted. The lack of significant kinetic mass transfer limitations in pumped concentrations was notable. This was despite the heterogeneous layering in the aquifer and distribution of DNAPL. There was little to choose between the model fits to pumped concentration time series. The variance of groundwater velocities in the aquifer determined during a partitioning inter-well tracer test (PITT) were used to parameterise the models. However, the models were found to be relatively insensitive to this parameter. All models indicated an initial source mass around 250 kg which compared favourably to an estimate of 220 kg derived from the PITT. The extrapolated concentrations from the

  14. Flow boiling heat transfer of R134a and R404A in a microfin tube at low mass fluxes and low heat fluxes

    NASA Astrophysics Data System (ADS)

    Spindler, Klaus; Müller-Steinhagen, Hans

    2009-05-01

    An experimental investigation of flow boiling heat transfer in a commercially available microfin tube with 9.52 mm outer diameter has been carried out. The microfin tube is made of copper with a total fin number of 55 and a helix angle of 15°. The fin height is 0.24 mm and the inner tube diameter at fin root is 8.95 mm. The test tube is 1 m long and is electrically heated. The experiments have been performed at saturation temperatures between 0 and -20°C. The mass flux was varied between 25 and 150 kg/m2s, the heat flux from 15,000 W/m2 down to 1,000 W/m2. All measurements have been performed at constant inlet vapour quality ranging from 0.1 to 0.7. The measured heat transfer coefficients range from 1,300 to 15,700 W/m2K for R134a and from 912 to 11,451 W/m2K for R404A. The mean heat transfer coefficient of R134a is in average 1.5 times higher than for R404A. The mean heat transfer coefficient has been compared with the correlations by Koyama et al. and by Kandlikar. The deviations are within ±30% and ±15%, respectively. The influence of the mass flux on the heat transfer is most significant between 25 and 62.5 kg/m2s, where the flow pattern changes from stratified wavy flow to almost annular flow. This flow pattern transition is shifted to lower mass fluxes for the microfin tube compared to the smooth tube.

  15. Flux rope evolution in interplanetary coronal mass ejections: the 13 May 2005 event

    NASA Astrophysics Data System (ADS)

    Manchester, W. B., IV; van der Holst, B.; Lavraud, B.

    2014-06-01

    Coronal mass ejections (CMEs) are a dramatic manifestation of solar activity that release vast amounts of plasma into the heliosphere, and have many effects on the interplanetary medium and on planetary atmospheres, and are the major driver of space weather. CMEs occur with the formation and expulsion of large-scale magnetic flux ropes from the solar corona, which are routinely observed in interplanetary space. Simulating and predicting the structure and dynamics of these interplanetary CME magnetic fields are essential to the progress of heliospheric science and space weather prediction. We discuss the simulation of the 13 May 2005 CME event in which we follow the propagation of a flux rope from the solar corona to beyond Earth orbit. In simulating this event, we find that the magnetic flux rope reconnects with the interplanetary magnetic field, to evolve to an open configuration and later reconnects to reform a twisted structure sunward of the original rope. Observations of the 13 May 2005 CME magnetic field near Earth suggest that such a rearrangement of magnetic flux by reconnection may have occurred.

  16. Methanethiol Concentrations and Sea-Air Fluxes in the Subarctic NE Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Kiene, R. P.; Williams, T. E.; Esson, K.; Tortell, P. D.; Dacey, J. W. H.

    2017-12-01

    Exchange of volatile organic sulfur from the ocean to the atmosphere impacts the global sulfur cycle and the climate system and is thought to occur mainly via the gas dimethylsulfide (DMS). DMS is produced during degradation of the abundant phytoplankton osmolyte dimethylsulfoniopropionate (DMSP) but bacteria can also convert dissolved DMSP into the sulfur gas methanethiol (MeSH). MeSH has been difficult to measure in seawater because of its high chemical and biological reactivity and, thus, information on MeSH concentrations, distribution and sea-air fluxes is limited. We measured MeSH in the northeast subarctic Pacific Ocean in July 2016, along transects with strong phytoplankton abundance gradients. Water samples obtained with Niskin bottles were analyzed for MeSH by purge-and-trap gas chromatography. Depth profiles showed that MeSH concentrations were high near the surface and declined with depth. Surface waters (5 m depth) had an average MeSH concentration of 0.75 nM with concentrations reaching up to 3nM. MeSH concentrations were correlated (r = 0.47) with microbial turnover of dissolved DMSP which ranged up to 236 nM per day. MeSH was also correlated with total DMSP (r = 0.93) and dissolved DMS (r = 0.63), supporting the conclusion that DMSP was a major precursor of MeSH. Surface water MeSH:DMS concentration ratios averaged 0.19 and ranged up to 0.50 indicating that MeSH was a significant fraction of the volatile sulfur pool in surface waters. Sea-air fluxes of MeSH averaged 15% of the combined DMS+MeSH flux, therefore MeSH contributed an important fraction of the sulfur emitted to the atmosphere from the subarctic NE Pacific Ocean.

  17. 13C labeling analysis of sugars by high resolution-mass spectrometry for metabolic flux analysis.

    PubMed

    Acket, Sébastien; Degournay, Anthony; Merlier, Franck; Thomasset, Brigitte

    2017-06-15

    Metabolic flux analysis is particularly complex in plant cells because of highly compartmented metabolism. Analysis of free sugars is interesting because it provides data to define fluxes around hexose, pentose, and triose phosphate pools in different compartment. In this work, we present a method to analyze the isotopomer distribution of free sugars labeled with carbon 13 using a liquid chromatography-high resolution mass spectrometry, without derivatized procedure, adapted for Metabolic flux analysis. Our results showed a good sensitivity, reproducibility and better accuracy to determine isotopic enrichments of free sugars compared to our previous methods [5, 6]. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. OGLE-2012-bLG-0950Lb: the First Planet Mass Measurement From Only Microlens Parallax and Lens Flux

    NASA Technical Reports Server (NTRS)

    Koshimoto, N.; Udalski, A.; Beaulieu, J. P.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Rattenbury, N.; Fukui, A.; Bhattacharya, A.; Suzuki, D.

    2016-01-01

    We report the discovery of a microlensing planet OGLE-2012-BLG-0950Lb with a planet/host mass ratio Periapsis Approx. = 2 x10(exp. -4). A long term distortion detected in both MOA and OGLE light curve can be explained by themicrolens parallax due to the Earths orbital motion around the Sun. Although the finite source effect is not detected, we obtain the lens flux by the high resolution Keck AO observation. Combining the microlens parallax and the lens flux reveal the nature of the lens: a planet with mass of M(sub p) = 35(+17/-)M compared to Earth is orbiting around an M-dwarf with mass of M(sub host) = 0.56(+0.12/-0.16) M compared to the Sun with a planet-host projected separation of r1 = 2.7(+0.6/-0.7) au located at Luminosity Distance = 3.0(+0.8/-1.1) kpc from us. This is the first mass measurement from only microlens parallax and the lens flux without the finite source effect. In the coming space observation-era with Spitzer, K2, Euclid, and WFIRST, we expect many such events for which we will not be able to measure any finite source effect. This work demonstrates an ability of mass measurements in such events.

  19. Water vapor mass balance method for determining air infiltration rates in houses

    Treesearch

    David R. DeWalle; Gordon M. Heisler

    1980-01-01

    A water vapor mass balance technique that includes the use of common humidity-control equipment can be used to determine average air infiltration rates in buildings. Only measurements of the humidity inside and outside the home, the mass of vapor exchanged by a humidifier/dehumidifier, and the volume of interior air space are needed. This method gives results that...

  20. EVALUATION OF MASS FLUX TO AND FROM GROUND WATER USING A VERTICAL FLUX MODEL (VFLUX): APPLICATION TO THE SOIL VACUUM EXTRACTION CLOSURE PROBLEM

    EPA Science Inventory

    Site closure for soil vacuum extraction (SVE) application typically requires attainment of specified soil concentration standards based on the premise that mass flux from the vadose zone to ground water not result in levels exceeding maximum contaminant levels (MCLSs). Unfortuna...

  1. Experimental evaluation of refrigerant mass charge and ambient air temperature effects on performance of air-conditioning systems

    NASA Astrophysics Data System (ADS)

    Deymi-Dashtebayaz, Mahdi; Farahnak, Mehdi; Moraffa, Mojtaba; Ghalami, Arash; Mohammadi, Nima

    2018-03-01

    In this paper the effects of refrigerant charge amount and ambient air temperature on performance and thermodynamic condition of refrigerating cycle in the split type air-conditioner have been investigated. Optimum mass charge is the point at which the energy efficiency ratio (EER) of refrigeration cycle becomes the maximum. Experiments have been conducted over a range of refrigerant mass charge from 540 to 840 g and a range of ambient temperature from 27 to 45 °C, in a 12,000 Btu/h split air-conditioner as case study. The various parameters have been considered to evaluate the cooling rate, energy efficiency ratio (EER), mass charge effect and thermodynamic cycle of refrigeration system with R22 refrigerant gas. Results confirmed that the lack of appropriate refrigerant mass charge causes the refrigeration system not to reach its maximum cooling capacity. The highest cooling capacity achieved was 3.2 kW (11,000 Btu/h). The optimum mass charge and corresponding EER of studied system have been obtained about 640 g and 2.5, respectively. Also, it is observed that EER decreases by 30% as ambient temperature increases from 27 °C to 45 °C. By optimization of the refrigerant mass charge in refrigerating systems, about 785 GWh per year of electric energy can be saved in Iran's residential sector.

  2. Response of air-sea carbon fluxes and climate to orbital forcing changes in the Community Climate System Model

    NASA Astrophysics Data System (ADS)

    Jochum, M.; Peacock, S.; Moore, K.; Lindsay, K.

    2010-07-01

    A global general circulation model coupled to an ocean ecosystem model is used to quantify the response of carbon fluxes and climate to changes in orbital forcing. Compared to the present-day simulation, the simulation with the Earth's orbital parameters from 115,000 years ago features significantly cooler northern high latitudes but only moderately cooler southern high latitudes. This asymmetry is explained by a 30% reduction of the strength of the Atlantic Meridional Overturning Circulation that is caused by an increased Arctic sea ice export and a resulting freshening of the North Atlantic. The strong northern high-latitude cooling and the direct insolation induced tropical warming lead to global shifts in precipitation and winds to the order of 10%-20%. These climate shifts lead to regional differences in air-sea carbon fluxes of the same order. However, the differences in global net air-sea carbon fluxes are small, which is due to several effects, two of which stand out: first, colder sea surface temperature leads to a more effective solubility pump but also to increased sea ice concentration which blocks air-sea exchange, and second, the weakening of Southern Ocean winds that is predicted by some idealized studies occurs only in part of the basin, and is compensated by stronger winds in other parts.

  3. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  4. The mass and speed dependence of meteor air plasma temperatures.

    PubMed

    Jenniskens, Peter; Laux, Christophe O; Wilson, Michael A; Schaller, Emily L

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  5. Enhanced Ahead-of-Eye TC Coastal Ocean Cooling Processes and their Impact on Air-Sea Heat Fluxes and Storm Intensity

    NASA Astrophysics Data System (ADS)

    Seroka, G. N.; Miles, T. N.; Glenn, S. M.; Xu, Y.; Forney, R.; Roarty, H.; Schofield, O.; Kohut, J. T.

    2016-02-01

    Any landfalling tropical cyclone (TC) must first traverse the coastal ocean. TC research, however, has focused over the deep ocean, where TCs typically spend the vast majority of their lifetime. This paper will show that the ocean's response to TCs can be different between deep and shallow water, and that the additional shallow water processes must be included in coupled models for accurate air-sea flux treatment and TC intensity prediction. The authors will present newly observed coastal ocean processes that occurred in response to Hurricane Irene (2011), due to the presence of a coastline, an ocean bottom, and highly stratified conditions. These newly observed processes led to enhanced ahead-of-eye SST cooling that significantly impacted air-sea heat fluxes and Irene's operationally over-predicted storm intensity. Using semi-idealized modeling, we find that in shallow water in Irene, only 6% of cooling due to air-sea heat fluxes, 17% of cooling due to 1D vertical mixing, and 50% of cooling due to all processes (1D mixing, air-sea heat fluxes, upwelling, and advection) occurred ahead-of-eye—consistent with previous studies. Observations from an underwater glider and buoys, however, indicated 75-100% of total SST cooling over the continental shelf was ahead-of-eye. Thus, the new coastal ocean cooling processes found in this study must occur almost completely ahead-of-eye. We show that Irene's intense cooling was not captured by basic satellite SST products and coupled ocean-atmosphere hurricane models, and that including the cooling in WRF modeling mitigated the high bias in model predictions. Finally, we provide evidence that this SST cooling—not track, wind shear, or dry air intrusion—was the key missing contribution to Irene's decay just prior to NJ landfall. Ongoing work is exploring the use of coupled WRF-ROMS modeling in the coastal zone.

  6. Estimation of air-to-grass mass interception factors for iodine.

    PubMed

    Karunakara, N; Ujwal, P; Yashodhara, I; Sudeep Kumara, K; Mohan, M P; Bhaskar Shenoy, K; Geetha, P V; Dileep, B N; James, Joshi P; Ravi, P M

    2018-06-01

    Air-to-grass mass interception factors for radionuclide are important basic input parameter for the estimation of radiation dose to the public around a nuclear power plant. In this paper, we present the determination of air-to- grass mass interception factors for iodine using a 2 m × 2 m × 2 m (l × b × h) size environmental chamber. The temperature, humidity, and rainfall inside the environmental chamber was controlled to required values to simulate different environmental conditions. Grass (Pennisetum purpureum, Schum), grown in pots, was kept inside the environmental chamber and stable iodine in elemental form was sublimed quickly inside the chamber to simulate an accidental release of iodine to the environment. The concentration of iodine in the air was measured periodically by drawing air through a bubbling setup, containing 1% sodium carbonate solution. The mass interception factor for dry deposition varied in the range of 0.25-7.7 m 2  kg -1 with mean value of 2.2 m 2  kg -1 with respect to fresh weight of grass, and that due to wet deposition varied in the range of 0.6-4.8 m 2  kg -1 with mean value of 2.3 m 2  kg -1 . The mass interception factor was inversely correlated with the total iodine deposited through dry deposition as well as with the rainfall. Copyright © 2017. Published by Elsevier Ltd.

  7. Heat flux microsensor measurements

    NASA Technical Reports Server (NTRS)

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-01-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  8. Fluxes of biogenic volatile organic compounds measured and modelled above a Norway spruce forest

    NASA Astrophysics Data System (ADS)

    Juráň, Stanislav; Fares, Silvano; Pallozzi, Emanuele; Guidolotti, Gabriele; Savi, Flavia; Alivernini, Alessandro; Calfapietra, Carlo; Večeřová, Kristýna; Křůmal, Kamil; Večeřa, Zbyněk; Cudlín, Pavel; Urban, Otmar

    2016-04-01

    Fluxes of biogenic volatile organic compounds (BVOCs) were investigated at Norway spruce forest at Bílý Kříž in Beskydy Mountains of the Czech Republic during the summer 2014. A proton-transfer-reaction-time-of-flight mass spectrometer (PTR-TOF-MS, Ionicon Analytik, Austria) has been coupled with eddy-covariance system. Additionally, Inverse Lagrangian Transport Model has been used to derive fluxes from concentration gradient of various monoterpenes previously absorbed into n-heptane by wet effluent diffusion denuder with consequent quantification by gas chromatography with mass spectrometry detection. Modelled data cover each one day of three years with different climatic conditions and previous precipitation patterns. Model MEGAN was run to cover all dataset with monoterpene fluxes and measured basal emission factor. Highest fluxes measured by eddy-covariance were recorded during the noon hours, represented particularly by monoterpenes and isoprene. Inverse Lagrangian Transport Model suggests most abundant monoterpene fluxes being α- and β-pinene. Principal component analysis revealed dependencies of individual monoterpene fluxes on air temperature and particularly global radiation; however, these dependencies were monoterpene specific. Relationships of monoterpene fluxes with CO2 flux and relative air humidity were found to be negative. MEGAN model correlated to eddy-covariance PTR-TOF-MS measurement evince particular differences, which will be shown and discussed. Bi-directional fluxes of oxygenated short-chain volatiles (methanol, formaldehyde, acetone, acetaldehyde, formic acid, acetic acid, methyl vinyl ketone, methacrolein, and methyl ethyl ketone) were recorded by PTR-TOF-MS. Volatiles of anthropogenic origin as benzene and toluene were likely transported from the most benzene polluted region in Europe - Ostrava city and adjacent part of Poland around Katowice, where metallurgical and coal mining industries are located. Those were accumulated during

  9. BOREAS AFM-2 King Air 1994 Aircraft Flux and Moving Window Data

    NASA Technical Reports Server (NTRS)

    Kelly, Robert D.; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS AFM-2 team collected pass-by-pass fluxes (and many other statistics) for a large number of level (constant altitude), straight-line passes used in a variety of flight patterns. The data were collected by the University of Wyoming King Air in 1994 BOREAS IFCs 1-3. Most of these data were collected at 60-70 m above ground level, but a significant number of passes were also flown at various levels in the planetary boundary layer, up to about the inversion height. This documentation concerns only the data from the straight and level passes that are presented as original (over the NSA and SSA) and moving window values (over the Transect). Another archive of King Air data is also available, containing data from all the soundings flown by the King Air 1994 IFCs 1-3. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  10. Novel model of stator design to reduce the mass of superconducting generators

    NASA Astrophysics Data System (ADS)

    Kails, Kevin; Li, Quan; Mueller, Markus

    2018-05-01

    High temperature superconductors (HTS), with much higher current density than conventional copper wires, make it feasible to develop very powerful and compact power generators. Thus, they are considered as one promising solution for large (10 + MW) direct-drive offshore wind turbines due to their low tower head mass. However, most HTS generator designs are based on a radial topology, which requires an excessive amount of HTS material and suffers from cooling and reliability issues. Axial flux machines on the other hand offer higher torque/volume ratios than the radial machines, which makes them an attractive option where space and transportation becomes an issue. However, their disadvantage is heavy structural mass. In this paper a novel stator design is introduced for HTS axial flux machines which enables a reduction in their structural mass. The stator is for the first time designed with a 45° angle that deviates the air gap closing forces into the vertical direction reducing the axial forces. The reduced axial forces improve the structural stability and consequently simplify their structural design. The novel methodology was then validated through an existing design of the HTS axial flux machine achieving a ∼10% mass reduction from 126 tonnes down to 115 tonnes. In addition, the air gap flux density increases due to the new claw pole shapes improving its power density from 53.19 to 61.90 W kg‑1. It is expected that the HTS axial flux machines designed with the new methodology offer a competitive advantage over other proposed superconducting generator designs in terms of cost, reliability and power density.

  11. Mass Flux of ZnSe by Physical Vapor Transport

    NASA Technical Reports Server (NTRS)

    Sha, Yi-Gao; Su, Ching-Hua; Palosz, W.; Volz, M. P.; Gillies, D. C.; Szofran, F. R.; Lehoczky, S. L.; Liu, Hao-Chieh; Brebrick, R. F.

    1995-01-01

    Mass fluxes of ZnSe by physical vapor transport (PVT) were measured in the temperature range of 1050 to 1160 C using an in-situ dynamic technique. The starting materials were either baked out or distilled under vacuum to obtain near-congruently subliming compositions. Using an optical absorption technique Zn and Se, were found to be the dominant vapor species. Partial pressures of Zn and Se, over the starting materials at temperatures between 960 and 1140 C were obtained by measuring the optical densities of the vapor phase at the wavelengths of 2138, 3405, 3508, 3613, and 3792 A. The amount and composition of the residual gas inside the experimental ampoules were measured after the run using a total pressure gauge. For the first time, the experimentally determined partial pressures of Zn and Se, and the amount and composition of the residual gas were used in a one-dimensional diffusion limited analysis of the mass transport rates for a PVT system. Reasonable agreement between the experimental and theoretical results was observed.

  12. Video Meteor Fluxes

    NASA Technical Reports Server (NTRS)

    Campbell-Brown, M. D.; Braid, D.

    2011-01-01

    The flux of meteoroids, or number of meteoroids per unit area per unit time, is critical for calibrating models of meteoroid stream formation and for estimating the hazard to spacecraft from shower and sporadic meteors. Although observations of meteors in the millimetre to centimetre size range are common, flux measurements (particularly for sporadic meteors, which make up the majority of meteoroid flux) are less so. It is necessary to know the collecting area and collection time for a given set of observations, and to correct for observing biases and the sensitivity of the system. Previous measurements of sporadic fluxes are summarized in Figure 1; the values are given as a total number of meteoroids striking the earth in one year to a given limiting mass. The Gr n et al. (1985) flux model is included in the figure for reference. Fluxes for sporadic meteoroids impacting the Earth have been calculated for objects in the centimeter size range using Super-Schmidt observations (Hawkins & Upton, 1958); this study used about 300 meteors, and used only the physical area of overlap of the cameras at 90 km to calculate the flux, corrected for angular speed of meteors, since a large angular speed reduces the maximum brightness of the meteor on the film, and radiant elevation, which takes into account the geometric reduction in flux when the meteors are not perpendicular to the horizontal. They bring up corrections for both partial trails (which tends to increase the collecting area) and incomplete overlap at heights other than 90 km (which tends to decrease it) as effects that will affect the flux, but estimated that the two effects cancelled one another. Halliday et al. (1984) calculated the flux of meteorite-dropping fireballs with fragment masses greater than 50 g, over the physical area of sky accessible to the MORP fireball cameras, counting only observations in clear weather. In the micron size range, LDEF measurements of small craters on spacecraft have been used to

  13. Dusty air masses transport between Amazon Basin and Caribbean Islands

    NASA Astrophysics Data System (ADS)

    Euphrasie-Clotilde, Lovely; Molinie, Jack; Prospero, Joseph; Feuillard, Tony; Brute, Francenor; Jeannot, Alexis

    2015-04-01

    Depend on the month, African desert dust affect different parts of the North Atlantic Ocean. From December to April, Saharan dust outbreaks are often reported over the amazon basin and from May to November over the Caribbean islands and the southern regions of USA. This annual oscillation of Saharan dust presence, related to the ITCZ position, is perturbed some time, during March. Indeed, over Guadeloupe, the air quality network observed between 2007 and 2012 several dust events during March. In this paper, using HISPLIT back trajectories, we analyzed air masses trajectories for March dust events observed in Guadeloupe, from 2007 to 2012.We observed that the high pressure positions over the Atlantic Ocean allow the transport of dusty air masses from southern region of West Africa to the Caribbean Sea with a path crossing close to coastal region of French Guyana. Complementary investigations including the relationship between PM10 concentrations recorded in two sites Pointe-a-Pitre in the Caribbean, and Cayenne in French Guyana, have been done. Moreover we focus on the mean delay observed between the times arrival. All the results show a link between pathway of dusty air masses present over amazon basin and over the Caribbean region during several event of March. The next step will be the comparison of mineral dust composition for this particular month.

  14. IS FLUX ROPE A NECESSARY CONDITION FOR THE PROGENITOR OF CORONAL MASS EJECTIONS?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ouyang, Y.; Yang, K.; Chen, P. F., E-mail: chenpf@nju.edu.cn

    2015-12-10

    A magnetic flux rope structure is believed to exist in most coronal mass ejections (CMEs). However, it has been long debated whether the flux rope exists before eruption or if it is formed during eruption via magnetic reconnection. The controversy has continued because of our lack of routine measurements of the magnetic field in the pre-eruption structure, such as solar filaments. However, recently an indirect method was proposed to infer the magnetic field configuration based on the sign of helicity and the bearing direction of the filament barbs. In this paper, we apply this method to two erupting filament events, one onmore » 2014 September 2 and the other on 2011 March 7, and find that the first filament is supported by a magnetic flux rope and the second filament is supported by a sheared arcade, i.e., the first one is an inverse-polarity filament and the second one is a normal-polarity filament. With the identification of the magnetic configurations in these two filaments, we stress that a flux rope is not a necessary condition for the pre-CME structure.« less

  15. Hard X-ray Flux from Low-Mass Stars in the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    Caramazza, M.; Drake, J. J.; Micela, G.; Flaccomio, E.

    2009-05-01

    We investigate the X-ray emission in the 20-40 keV band expected from the flaring low-mass stellar population in Cygnus OB2 assuming that the observed soft X-ray emission is due to a superposition of flares and that the ratio of hard X-ray to soft X-ray emission is described by a scaling found for solar flares by Isola and co-workers. We estimate a low-mass stellar hard X-ray flux in the 20-40 keV band in the range ~7×1031-7×1033 erg/s and speculate the limit of this values. Hard X-ray emission could lie at a level not much below the current observed flux upper limits for Cygnus OB2. Simbol-X, with its broad energy band (10-100 keV) and its sensitivity should be able to detect this emission and would provide insights into the hard X-ray production of flares on pre-main sequence stars.

  16. Influence of the relative optical air mass on ultraviolet erythemal irradiance

    NASA Astrophysics Data System (ADS)

    Antón, M.; Serrano, A.; Cancillo, M. L.; García, J. A.

    2009-12-01

    The main objective of this article is to analyze the relationship between the transmissivity for ultraviolet erythemal irradiance (UVER) and the relative optical air mass at Badajoz (Southwestern Spain). Thus, a power expression between both variables is developed, which analyses in detail how atmospheric transmission is influenced by the total ozone column (TOC) and the atmospheric clearness. The period of analysis extends from 2001 to 2005. The experimental results indicate that clearness conditions play an important role in the relationship between UVER transmissivity and the relative optical air mass, while the effect of TOC is much smaller for this data set. In addition, the results show that UVER transmissivity is more sensitive to changes in atmospheric clearness than to TOC variability. Changes in TOC values higher than 15% cause UVER trasnmissivity to vary between 14% and 22%, while changes between cloud-free and overcast conditions produce variations in UVER transmissivity between 68% and 74% depending on the relative optical air mass.

  17. Defining Winter and Identifying Synoptic Air Mass Change in the Northeast and Northern Plains U.S. since 1950

    NASA Astrophysics Data System (ADS)

    Chapman, C. J.; Pennington, D.; Beitscher, M. R.; Godek, M. L.

    2017-12-01

    Understanding and forecasting the characteristics of winter weather change in the northern U.S. is vital to regional economy, agriculture, tourism and resident life. This is especially true in the Northeast and Northern Plains where substantial changes to the winter season have already been documented in the atmospheric science and biological literature. As there is no single established definition of `winter', this research attempts to identify the winter season in both regions utilizing a synoptic climatological approach with air mass frequencies. The Spatial Synoptic Classification is used to determine the daily air mass/ weather type conditions since 1950 at 40 locations across the two regions. Annual frequencies are first computed as a baseline reference. Then winter air mass frequencies and departures from normal are calculated to define the season along with the statistical significance. Once the synoptic winter is established, long-term regional changes to the season and significance are explored. As evident global changes have occurred after 1975, an Early period of years prior to 1975 and a Late set for all years following this date are compared. Early and Late record synoptic changes are then examined to assess any thermal and moisture condition changes of the regional winter air masses over time. Cold to moderately dry air masses dominate annually in both regions. Northeast winters are also characterized by cold to moderate dry air masses, with coastal locations experiencing more Moist Polar types. The Northern Plains winters are dominated by cold, dry air masses in the east and cold to moderate dry air masses in the west. Prior to 1975, Northeast winters are defined by an increase in cooler and wetter air masses. Dry Tropical air masses only occur in this region after 1975. Northern Plains winters are also characterized by more cold, dry air masses prior to 1975. More Dry Moderate and Moist Moderate air masses have occurred since 1975. These results

  18. A New Framework to Compare Mass-Flux Schemes Within the AROME Numerical Weather Prediction Model

    NASA Astrophysics Data System (ADS)

    Riette, Sébastien; Lac, Christine

    2016-08-01

    In the Application of Research to Operations at Mesoscale (AROME) numerical weather forecast model used in operations at Météo-France, five mass-flux schemes are available to parametrize shallow convection at kilometre resolution. All but one are based on the eddy-diffusivity-mass-flux approach, and differ in entrainment/detrainment, the updraft vertical velocity equation and the closure assumption. The fifth is based on a more classical mass-flux approach. Screen-level scores obtained with these schemes show few discrepancies and are not sufficient to highlight behaviour differences. Here, we describe and use a new experimental framework, able to compare and discriminate among different schemes. For a year, daily forecast experiments were conducted over small domains centred on the five French metropolitan radio-sounding locations. Cloud base, planetary boundary-layer height and normalized vertical profiles of specific humidity, potential temperature, wind speed and cloud condensate were compared with observations, and with each other. The framework allowed the behaviour of the different schemes in and above the boundary layer to be characterized. In particular, the impact of the entrainment/detrainment formulation, closure assumption and cloud scheme were clearly visible. Differences mainly concerned the transport intensity thus allowing schemes to be separated into two groups, with stronger or weaker updrafts. In the AROME model (with all interactions and the possible existence of compensating errors), evaluation diagnostics gave the advantage to the first group.

  19. Accounting for observational uncertainties in the evaluation of low latitude turbulent air-sea fluxes simulated in a suite of IPSL model versions

    NASA Astrophysics Data System (ADS)

    Servonnat, Jerome; Braconnot, Pascale; Gainusa-Bogdan, Alina

    2015-04-01

    Turbulent momentum and heat (sensible and latent) fluxes at the air-sea interface are key components of the whole energetic of the Earth's climate and their good representation in climate models is of prime importance. In this work, we use the methodology developed by Braconnot & Frankignoul (1993) to perform a Hotelling T2 test on spatio-temporal fields (annual cycles). This statistic provides a quantitative measure accounting for an estimate of the observational uncertainty for the evaluation of low-latitude turbulent air-sea fluxes in a suite of IPSL model versions. The spread within the observational ensemble of turbulent flux data products assembled by Gainusa-Bogdan et al (submitted) is used as an estimate of the observational uncertainty for the different turbulent fluxes. The methodology holds on a selection of a small number of dominating variability patterns (EOFs) that are common to both the model and the observations for the comparison. Consequently it focuses on the large-scale variability patterns and avoids the possibly noisy smaller scales. The results show that different versions of the IPSL couple model share common large scale model biases, but also that there the skill on sea surface temperature is not necessarily directly related to the skill in the representation of the different turbulent fluxes. Despite the large error bars on the observations the test clearly distinguish the different merits of the different model version. The analyses of the common EOF patterns and related time series provide guidance on the major differences with the observations. This work is a first attempt to use such statistic on the evaluation of the spatio-temporal variability of the turbulent fluxes, accounting for an observational uncertainty, and represents an efficient tool for systematic evaluation of simulated air-seafluxes, considering both the fluxes and the related atmospheric variables. References Braconnot, P., and C. Frankignoul (1993), Testing Model

  20. Diffusive flux of PAHs across sediment-water and water-air interfaces at urban superfund sites.

    PubMed

    Minick, D James; Anderson, Kim A

    2017-09-01

    Superfund sites may be a source of polycyclic aromatic hydrocarbons (PAHs) to the surrounding environment. These sites can also act as PAH sinks from present-day anthropogenic activities, especially in urban locations. Understanding PAH transport across environmental compartments helps to define the relative contributions of these sources and is therefore important for informing remedial and management decisions. In the present study, paired passive samplers were co-deployed at sediment-water and water-air interfaces within the Portland Harbor Superfund Site and the McCormick and Baxter Superfund Site. These sites, located along the Willamette River (Portland, OR, USA), have PAH contamination from both legacy and modern sources. Diffusive flux calculations indicate that the Willamette River acts predominantly as a sink for low molecular weight PAHs from both the sediment and the air. The sediment was also predominantly a source of 4- and 5-ring PAHs to the river, and the river was a source of these same PAHs to the air, indicating that legacy pollution may be contributing to PAH exposure for residents of the Portland urban center. At the remediated McCormick and Baxter Superfund Site, flux measurements highlight locations within the sand and rock sediment cap where contaminant breakthrough is occurring. Environ Toxicol Chem 2017;36:2281-2289. © 2017 SETAC. © 2017 SETAC.

  1. Winter air-mass-based synoptic climatological approach and hospital admissions for myocardial infarction in Florence, Italy.

    PubMed

    Morabito, Marco; Crisci, Alfonso; Grifoni, Daniele; Orlandini, Simone; Cecchi, Lorenzo; Bacci, Laura; Modesti, Pietro Amedeo; Gensini, Gian Franco; Maracchi, Giampiero

    2006-09-01

    The aim of this study was to evaluate the relationship between the risk of hospital admission for myocardial infarction (MI) and the daily weather conditions during the winters of 1998-2003, according to an air-mass-based synoptic climatological approach. The effects of time lag and 2-day sequences with specific air mass types were also investigated. Studies concerning the relationship between atmospheric conditions and human health need to take into consideration simultaneous effects of many weather variables. At the moment few studies have surveyed these effects on hospitalizations for MI. Analyses were concentrated on winter, when the maximum peak of hospitalization occurred. An objective daily air mass classification by means of statistical analyses based on ground meteorological data was carried out. A comparison between air mass classification and hospital admissions was made by the calculation of a MI admission index, and to detect significant relationships the Mann-Whitney U test, the analysis of variance, and the Bonferroni test were used. Significant increases in hospital admissions for MI were evident 24h after a day characterized by an anticyclonic continental air mass and 6 days after a day characterized by a cyclonic air mass. Increased risk of hospitalization was found even when specific 2-day air mass sequences occurred. These results represent an important step in identifying reliable linkages between weather and health.

  2. DNAPL REMOVAL MECHANISMS AND MASS TRANSFER CHARACTERISTICS DURING COSOLVENT-AIR FLOODING

    EPA Science Inventory

    The concurrent injection of cosolvent and air, a cosolvent-air (CA) flood was recently suggested for a dense nonaqueous phase liquid (DNAPL) remediation technology. The objectives of this study were to elucidate the DNAPL removal mechanisms of the CA flood and to quantify mass t...

  3. The Use of Red Green Blue (RGB) Air Mass Imagery to Investigate the Role of Stratospheric Air in a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Molthan, Andrew; Jedlovec, Gary

    2013-01-01

    AIRS ozone and model PV analysis confirm the stratospheric air in RGB Air Mass imagery. Trajectories confirm winds south of the low were distinct from CCB driven winds. Cross sections connect the tropopause fold, downward motion, and high nearsurface winds. Comparison to conceptual models show Shapiro-Keyser features and sting jet characteristics were observed in a storm that impacted the U.S. East Coast. RGB Air Mass imagery can be used to identify stratospheric air and regions susceptible to tropopause folding and attendant non-convective winds.

  4. Trace gases and air mass origin at Kaashidhoo, Indian Ocean

    NASA Astrophysics Data System (ADS)

    Lobert, Jürgen M.; Harris, Joyce M.

    2002-10-01

    Carbon monoxide (CO) was measured at the Kaashidhoo Climate Observatory (KCO, Republic of Maldives) between February 1998 and March 2000 to assess the regional pollution of the remote atmosphere in the northern Indian Ocean. CO showed a distinct annual cycle with maximum daily mixing ratios of around 240 parts per billion (ppb), a seasonal difference of about 200 ppb, and high variability during the dry seasons. Detailed air mass trajectory analysis for 1998, 1999, and 2000 was used to identify source regions and to associate them with various levels of pollution encountered at KCO. We conclude that most significant changes in local pollution throughout the year are caused by changes in air masses. Air at KCO generally originated from three main regions with decreasing pollution: India and southeast Asia, the Arabian Sea, and the Southern Hemisphere. We show that isentropic air mass trajectories can be used to predict CO pollution levels at KCO to a certain extent and vice versa. Nitrous oxide, CFC-11, CFC-12, CCI4, and SF6 were measured during the Indian Ocean Experiment (February to March 1999) to support pollution analysis and to confirm that India is the main source for heavy pollution measured at KCO. Correlations between CO and other gases and aerosol properties measured at the surface illustrate that CO may also be used as a proxy for aerosol loading and general pollution at the surface.

  5. Mass transfer and benzene removal from air using latex rubber tubing and a hollow-fiber membrane module.

    PubMed

    Fitch, Mark; Neeman, Jeffrey; England, Ellen

    2003-03-01

    A dense-phase latex rubber tube and a polyporous propylene hollow-fiber membrane module (HFMM) were investigated for control of benzene-contaminated gas streams. The abiotic mass flux observed through the latex tube was 3.9 13 mg/(min.m(2)) for 150 ppm of benzene at various gas and liquid flow rates, while a 100-fold lower mass flux was observed in the HFMM. After seeding with an aromatic-degrading culture enriched from activated sludge, the observed removal was 80% of 150 ppm, corresponding to a mass flux of 45 mg/(min.m(2)). The observed mass flux through the HFMM during biofiltration also rose, to 0.4 mg/(min.m(2)). Because the HFMM had a 50-fold higher surface area than the latex tube, the observed benzene removal was 99.8%. Compared to conventional biofilters, the two reactors had modest elimination capacities, 2.5 18 g/(m(3).h) in the latex tube membrane bioreactor and 4.8 58 g/(m(3).h) in the HFMM. Although the HFMM had a higher elimination capacity, the gas-phase pressure drop was much greater.

  6. On the Influence of Air Mass Origin on Low-Cloud Properties in the Southeast Atlantic

    NASA Astrophysics Data System (ADS)

    Fuchs, Julia; Cermak, Jan; Andersen, Hendrik; Hollmann, Rainer; Schwarz, Katharina

    2017-10-01

    This study investigates the impact of air mass origin and dynamics on cloud property changes in the Southeast Atlantic (SEA) during the biomass burning season. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget and thus prominent in climate system research. In this study, the thermodynamically stable SEA stratocumulus cover is observed not only as the result of local environmental conditions but also as connected to large-scale meteorology by the often neglected but important role of spatial origins of air masses entering this region. In order to assess to what extent cloud properties are impacted by aerosol concentration, air mass history, and meteorology, a Hybrid Single-Particle Lagrangian Integrated Trajectory cluster analysis is conducted linking satellite observations of cloud properties (Spinning-Enhanced Visible and Infrared Imager), information on aerosol species (Monitoring Atmospheric Composition and Climate), and meteorological context (ERA-Interim reanalysis) to air mass clusters. It is found that a characteristic pattern of air mass origins connected to distinct synoptical conditions leads to marked cloud property changes in the southern part of the study area. Long-distance air masses are related to midlatitude weather disturbances that affect the cloud microphysics, especially in the southwestern subdomain of the study area. Changes in cloud effective radius are consistent with a boundary layer deepening and changes in lower tropospheric stability (LTS). In the southeastern subdomain cloud cover is controlled by a generally higher LTS, while air mass origin plays a minor role. This study leads to a better understanding of the dynamical drivers behind observed stratocumulus cloud properties in the SEA and frames potentially interesting conditions for aerosol-cloud interactions.

  7. Deriving a sea surface climatology of CO2 fugacity in support of air-sea gas flux studies

    NASA Astrophysics Data System (ADS)

    Goddijn-Murphy, L. M.; Woolf, D. K.; Land, P. E.; Shutler, J. D.; Donlon, C.

    2014-07-01

    Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean Carbon Dioxide (CO2) Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. fCO2 is highly sensitive to temperature and the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrent with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air-sea CO2 fluxes it is therefore desirable to calculate fCO2 valid for climate quality SST. This paper presents a method for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using climate quality SST data from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010. The partial pressure of CO2 (pCO2) is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air-sea CO2 flux, and hence the presented fCO2 distributions can be used in air-sea gas flux calculations together with climatologies of other climate variables.

  8. Balance Mass Flux and Velocity Across the Equilibrium Line in Ice Drainage Systems of Greenland

    NASA Technical Reports Server (NTRS)

    Zwally, H. Jay; Giovinetto, Mario B.; Koblinsky, Chester J. (Technical Monitor)

    2001-01-01

    Estimates of balance mass flux and the depth-averaged ice velocity through the cross-section aligned with the equilibrium line are produced for each of six drainage systems in Greenland. (The equilibrium line, which lies at approximately 1200 m elevation on the ice sheet, is the boundary between the area of net snow accumulation at higher elevations and the areas of net melting at lower elevations around the ice sheet.) Ice drainage divides and six major drainage systems are delineated using surface topography from ERS (European Remote Sensing) radar altimeter data. The net accumulation rate in the accumulation zone bounded by the equilibrium line is 399 Gt/yr and net ablation rate in the remaining area is 231 Gt/yr. (1 GigaTon of ice is 1090 kM(exp 3). The mean balance mass flux and depth-averaged ice velocity at the cross-section aligned with the modeled equilibrium line are 0.1011 Gt kM(exp -2)/yr and 0.111 km/yr, respectively, with little variation in these values from system to system. The ratio of the ice mass above the equilibrium line to the rate of mass output implies an effective exchange time of approximately 6000 years for total mass exchange. The range of exchange times, from a low of 3 ka in the SE drainage system to 14 ka in the NE, suggests a rank as to which regions of the ice sheet may respond more rapidly to climate fluctuations.

  9. Robustness analysis of an air heating plant and control law by using polynomial chaos

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Colón, Diego; Ferreira, Murillo A. S.; Bueno, Átila M.

    2014-12-10

    This paper presents a robustness analysis of an air heating plant with a multivariable closed-loop control law by using the polynomial chaos methodology (MPC). The plant consists of a PVC tube with a fan in the air input (that forces the air through the tube) and a mass flux sensor in the output. A heating resistance warms the air as it flows inside the tube, and a thermo-couple sensor measures the air temperature. The plant has thus two inputs (the fan's rotation intensity and heat generated by the resistance, both measured in percent of the maximum value) and two outputsmore » (air temperature and air mass flux, also in percent of the maximal value). The mathematical model is obtained by System Identification techniques. The mass flux sensor, which is nonlinear, is linearized and the delays in the transfer functions are properly approximated by non-minimum phase transfer functions. The resulting model is transformed to a state-space model, which is used for control design purposes. The multivariable robust control design techniques used is the LQG/LTR, and the controllers are validated in simulation software and in the real plant. Finally, the MPC is applied by considering some of the system's parameters as random variables (one at a time, and the system's stochastic differential equations are solved by expanding the solution (a stochastic process) in an orthogonal basis of polynomial functions of the basic random variables. This method transforms the stochastic equations in a set of deterministic differential equations, which can be solved by traditional numerical methods (That is the MPC). Statistical data for the system (like expected values and variances) are then calculated. The effects of randomness in the parameters are evaluated in the open-loop and closed-loop pole's positions.« less

  10. Stochastic Convection Parameterizations: The Eddy-Diffusivity/Mass-Flux (EDMF) Approach (Invited)

    NASA Astrophysics Data System (ADS)

    Teixeira, J.

    2013-12-01

    In this presentation it is argued that moist convection parameterizations need to be stochastic in order to be realistic - even in deterministic atmospheric prediction systems. A new unified convection and boundary layer parameterization (EDMF) that optimally combines the Eddy-Diffusivity (ED) approach for smaller-scale boundary layer mixing with the Mass-Flux (MF) approach for larger-scale plumes is discussed. It is argued that for realistic simulations stochastic methods have to be employed in this new unified EDMF. Positive results from the implementation of the EDMF approach in atmospheric models are presented.

  11. In situ stabilization of NAPL contaminant source-zones as a remediation technique to reduce mass discharge and flux to groundwater.

    PubMed

    Mateas, Douglas J; Tick, Geoffrey R; Carroll, Kenneth C

    2017-09-01

    Widely used flushing and in-situ destruction based remediation techniques (i.e. pump-and treat, enhanced-solubilization, and chemical oxidation/reduction) for sites contaminated by nonaqueous phase liquid (NAPL) contaminant sources have been shown to be ineffective at complete mass removal and reducing aqueous-phase contaminant of concern (COC) concentrations to levels suitable for site closure. A remediation method was developed to reduce the aqueous solubility and mass-flux of COCs within NAPL through the in-situ creation of a NAPL mixture source-zone. In contrast to remediation techniques that rely on the rapid removal of contaminant mass, this technique relies on the stabilization of difficult-to-access NAPL sources to reduce COC mass flux to groundwater. A specific amount (volume) of relatively insoluble n-hexadecane (HEXDEC) or vegetable oil (VO) was injected into a trichloroethene (TCE) contaminant source-zone through a bench-scale flow cell port (i.e. well) to form a NAPL mixture of targeted mole fraction (TCE:HEXDEC or TCE:VO). NAPL-aqueous phase batch tests were conducted prior to the flow-cell experiments to evaluate the effects of various NAPL mixture ratios on equilibrium aqueous-phase concentrations of TCE to design optimal NAPL (HEXDEC or VO) injection volumes for the flow-cell experiments. The NAPL-stabilization flow-cell experiments initiated and sustained significant reductions in COC concentration and mass flux due to a combination of both reduced relative permeability (increased NAPL-saturation) and via modification of NAPL composition (decreased TCE mole fraction). Variations in remediation performance (i.e. impacts on TCE concentration and mass flux reduction) between the different HEXDEC injection volumes were relatively minor, and therefore inconsistent with Raoult's Law predictions. This phenomenon likely resulted from non-uniform mixing of the injected HEXDEC with TCE in the source-zone. VO injection caused TCE concentrations and mass-flux

  12. Relationship between air mass type and emergency department visits for migraine headache across the Triangle region of North Carolina

    NASA Astrophysics Data System (ADS)

    Elcik, Christopher; Fuhrmann, Christopher M.; Mercer, Andrew E.; Davis, Robert E.

    2017-12-01

    An estimated 240 million people worldwide suffer from migraines. Because migraines are often debilitating, understanding the mechanisms that trigger them is crucial for effective prevention and treatment. Synoptic air mass types and emergency department (ED) visits for migraine headaches were examined over a 7-year period within a major metropolitan area of North Carolina to identify potential relationships between large-scale meteorological conditions and the incidence of migraine headaches. Barometric pressure changes associated with transitional air masses, or changing weather patterns, were also analyzed for potential relationships. Bootstrapping analysis revealed that tropical air masses (moist and dry) resulted in the greatest number of migraine ED visits over the study period, whereas polar air masses led to fewer. Moist polar air masses in particular were found to correspond with the fewest number of migraine ED visits. On transitional air mass days, the number of migraine ED visits fell between those of tropical air mass days and polar air mass days. Transitional days characterized by pressure increases exhibited a greater number of migraine ED visits than days characterized by pressure decreases. However, no relationship was found between migraine ED visits and the magnitude of barometric pressure changes associated with transitional air masses.

  13. Critical mass flux for flaming ignition of dead, dry wood as a function of external radiant heat flux and oxidizer flow velocity

    Treesearch

    Sara McAllister; Mark Finney; Jack Cohen

    2010-01-01

    Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion – that a sufficient amount of pyrolysis gases must be...

  14. Mass Flux in the Ancient Earth-Moon System and Benign Implications for the Origin of Life on Earth

    NASA Technical Reports Server (NTRS)

    Ryder, Graham

    2002-01-01

    The origin of life on Earth is commonly considered to have been negatively affected by intense impacting in the Hadean, with the potential for the repeated evaporation and sterilization of any ocean. The impact flux is based on scaling from the lunar crater density record, but that record has no tie to any absolute age determination for any identified stratigraphic unit older than approx. 3.9 Ga (Nectaris basin). The flux can be described in terms of mass accretion, and various independent means can be used to estimate the mass flux in different intervals. The critical interval is that between the end of essential crustal formation (approx. 4.4 Ga) and the oldest mare times (approx. 3.8 Ga). The masses of the basin-forming projectiles during Nectarian and early Imbrian times, when the last 15 of the approx.45 identified impact basins formed, can be reasonably estimated as minima. These in sum provide a minimum of 2 x 10(exp 21)g for the mass flux to the Moon during those times. If the interval was 80 million years (Nectaris 3.90 Ga, Orientale 3.82 Ga), then the flux was approx. 2 x 10(exp 13) g/yr over this period. This is higher by more than an order of magnitude than a flux curve that declines continuously and uniformly from lunar accretion to the rate inferred for the older mare plains. This rate cannot be extrapolated back increasingly into pre-Nectarian times, because the Moon would have added masses far in excess of itself in post-crust-formation time. Thus this episode was a distinct and cataclysmic set of events. There are approx. 30 pre-Nectarian basins, and they were probably part of the same cataclysm (starting at approx. 4.0 Ga?) because the crust is fairly intact, the meteoritic contamination of the pre-Nectarian crust is very low, impact melt rocks older than 3.92 Ga are virtually unknown, and ancient volcanic and plutonic rocks have survived this interval. The accretionary flux from approx. 4.4 to approx. 4.0 Ga was comparatively benign. When scaled

  15. Unsteady slip flow of Carreau nanofluid over a wedge with nonlinear radiation and new mass flux condition

    NASA Astrophysics Data System (ADS)

    Khan, M.; Azam, M.; Alshomrani, A. S.

    This article addresses a numerical investigation for the unsteady 2D slip flow of Carreau nanofluid past a static and/or moving wedge with the nonlinear radiation. A zero nanoparticle mass flux and convective boundary conditions are implemented. Further, the most recently devised model for nanofluid is adopted that incorporates the effects of Brownian motion and thermophoresis. A set of suitable transformation is demonstrated to alter the nonlinear partial differential equations into nonlinear ordinary differential equations and then tackled numerically by employing bvp4c in Matlab package. The numerical computations for the wall heat flux (Nusselt number) and wall mass flux (Sherwood number) are also performed. Effects of several controlling parameters on the velocity, temperature and nanoparticles concentration are explored and discussed in detail. Our study reveals that the temperature and the associated thermal boundary layer thickness are enhancing function of the temperature ratio parameter for both shear thickening and shear thinning fluids. Moreover, it is noticed that the velocity in case of moving wedge is higher than static wedge.

  16. Predicting the Turbulent Air-Sea Surface Fluxes, Including Spray Effects, from Weak to Strong Winds

    DTIC Science & Technology

    2012-09-30

    almost complete decoupling of the wind field from the sea surface . As a result of the weak surface stress, the flow becomes almost free from the...shore flow . In turn, wave growth and the associated surface roughness (z0) are limited. Consequently, the stability increases further in a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Predicting the Turbulent Air-Sea Surface Fluxes

  17. Effect of the fuel bias distribution in the primary air nozzle on the slagging near a swirl coal burner throat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lingyan Zeng; Zhengqi Li; Hong Cui

    2009-09-15

    Three-dimensional numerical simulations of slagging characteristics near the burner throat region were carried out for swirl coal combustion burners used in a 1025 tons/h boiler. The gas/particle two-phase numerical simulation results and the data measured by a particle-dynamics anemometer (PDA) show that the numeration model was reasonable. For the centrally fuel-rich swirl coal combustion burner, the coal particles move in the following way. The particles first flow into furnace with the primary air from the burner throat. After traversing a certain distance, they move back to the burner throat and then toward the furnace again. Thus, particle trajectories are extended.more » For the case with equal air mass fluxes in the inner and outer primary air/coal mixtures, as the ratio of the coal mass flux in the inner primary air/coal mixture to the total coal mass flux increased from 40 (the reference condition) to 50%, 50 to 70%, and 70 to 100%, the maximum number density declined by 22, 11, and 4%, respectively, relative to the reference condition. In addition, the sticking particle ratio declined by 13, 14, and 8%, respectively, compared to the reference condition. 22 refs., 12 figs., 3 tabs.« less

  18. Interannual variability of primary production and air-sea CO2 flux in the Atlantic and Indian sectors of the Southern Ocean.

    NASA Astrophysics Data System (ADS)

    Dufour, Carolina; Merlivat, Liliane; Le Sommer, Julien; Boutin, Jacqueline; Antoine, David

    2013-04-01

    As one of the major oceanic sinks of anthropogenic CO2, the Southern Ocean plays a critical role in the climate system. However, due to the scarcity of observations, little is known about physical and biological processes that control air-sea CO2 fluxes and how these processes might respond to climate change. It is well established that primary production is one of the major drivers of air-sea CO2 fluxes, consuming surface Dissolved Inorganic Carbon (DIC) during Summer. Southern Ocean primary production is though constrained by several limiting factors such as iron and light availability, which are both sensitive to mixed layer depth. Mixed layer depth is known to be affected by current changes in wind stress or freshwater fluxes over the Southern Ocean. But we still don't know how primary production may respond to anomalous mixed layer depth neither how physical processes may balance this response to set the seasonal cycle of air-sea CO2 fluxes. In this study, we investigate the impact of anomalous mixed layer depth on surface DIC in the Atlantic and Indian sectors of the Subantarctic zone of the Southern Ocean (60W-60E, 38S-55S) with a combination of in situ data, satellite data and model experiment. We use both a regional eddy permitting ocean biogeochemical model simulation based on NEMO-PISCES and data-based reconstruction of biogeochemical fields based on CARIOCA buoys and SeaWiFS data. A decomposition of the physical and biological processes driving the seasonal variability of surface DIC is performed with both the model data and observations. A good agreement is found between the model and the data for the amplitude of biological and air-sea flux contributions. The model data are further used to investigate the impact of winter and summer anomalies in mixed layer depth on surface DIC over the period 1990-2004. The relative changes of each physical and biological process contribution are quantified and discussed.

  19. Latitudinal variation of speed and mass flux in the acceleration region of the solar wind inferred from spectral broadening measurements

    NASA Technical Reports Server (NTRS)

    Woo, Richard; Goldstein, Richard M.

    1994-01-01

    Spectral broadening measurements conducted at S-band (13-cm wavelength) during solar minimum conditions in the heliocentric distance range of 3-8 R(sub O) by Mariner 4, Pioneer 10, Mariner 10, Helios 1, Helios 2, and Viking have been combined to reveal a factor of 2.6 reduction in bandwidth from equator to pole. Since spectral broadening bandwidth depends on electron density fluctuation and solar wind speed, and latitudinal variation of the former is available from coherence bandwidth measurements, the remote sensing spectral broadening measurements provide the first determination of the latitudinal variation of solar wind speed in the acceleration region. When combined with electron density measurements deduced from white-light coronagraphs, this result also leads to the first determination of the latitudinal variation of mass flux in the acceleration region. From equator to pole, solar wind speed increases by a factor of 2.2, while mass flux decreases by a factor of 2.3. These results are consistent with measurements of solar wind speed by multi-station intensity scintillation measurements, as well as measurements of mass flux inferred from Lyman alpha observations, both of which pertain to the solar wind beyond 0.5 AU. The spectral broadening observations, therefore, strengthen earlier conclusions about the latitudinal variation of solar wind speed and mass flux, and reinforce current solar coronal models and their implications for solar wind acceleration and solar wind modeling.

  20. Field Observations of Coastal Air-Sea Interaction

    NASA Astrophysics Data System (ADS)

    Ortiz-Suslow, D. G.; Haus, B. K.; Williams, N. J.; Graber, H. C.

    2016-12-01

    In the nearshore zone wind, waves, and currents generated from different forcing mechanisms converge in shallow water. This can profoundly affect the physical nature of the ocean surface, which can significantly modulate the exchange of momentum, heat, and mass across the air-sea interface. For decades, the focus of air-sea interaction research has been on the open ocean while the shallow water regime has been relatively under-explored. This bears implications for efforts to understand and model various coastal processes, such as mixing, surface transport, and air-sea gas flux. The results from a recent study conducted at the New River Inlet in North Carolina showed that directly measured air-sea flux parameters, such as the atmospheric drag coefficient, are strong functions of space as well as the ambient conditions (i.e. wind speed and direction). The drag is typically used to parameterize the wind stress magnitude. It is generally assumed that the wind direction is the direction of the atmospheric forcing (i.e. wind stress), however significant wind stress steering off of the azimuthal wind direction was observed and was found to be related to the horizontal surface current shear. The authors have just returned from a field campaign carried out within Monterey Bay in California. Surface observations made from two research vessels were complimented by an array of beach and inland flux stations, high-resolution wind forecasts, and satellite image acquisitions. This is a rich data set and several case studies will be analyzed to highlight the importance of various processes for understanding the air-sea fluxes. Preliminary findings show that interactions between the local wind-sea and the shoaling, incident swell can have a profound effect on the wind stress magnitude. The Monterey Bay coastline contains a variety of topographical features and the importance of land-air-sea interactions will also be investigated.

  1. On the evaluation of air mass factors for atmospheric near-ultraviolet and visible absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Perliski, Lori M.; Solomon, Susan

    1993-01-01

    The interpretation of UV-visible twilight absorption measurements of atmospheric chemical constituents is dependent on how well the optical path, or air mass factor, of light collected by the spectrometer is understood. A simple single scattering model and a Monte Carlo radiative transfer scheme have been developed to study the effects of multiple scattering, aerosol scattering, surface albedo and refraction on air mass factors for scattered light observations. At fairly short visible wavelengths (less than about 450 nm), stratospheric air mass factors are found to be relatively insensitive to multiple scattering, surface albedo and refraction, as well as aerosol scattering by background aerosols. Longer wavelengths display greater sensitivity to refraction and aerosol scattering. Tropospheric air mass factors are found to be highly dependent on aerosol scattering, surface albedo and, at long visible wavelengths (about 650 nm), refraction. Absorption measurements of NO2 and O4 are shown to support these conclusions.

  2. Development of a locally mass flux conservative computer code for calculating 3-D viscous flow in turbomachines

    NASA Technical Reports Server (NTRS)

    Walitt, L.

    1982-01-01

    The VANS successive approximation numerical method was extended to the computation of three dimensional, viscous, transonic flows in turbomachines. A cross-sectional computer code, which conserves mass flux at each point of the cross-sectional surface of computation was developed. In the VANS numerical method, the cross-sectional computation follows a blade-to-blade calculation. Numerical calculations were made for an axial annular turbine cascade and a transonic, centrifugal impeller with splitter vanes. The subsonic turbine cascade computation was generated in blade-to-blade surface to evaluate the accuracy of the blade-to-blade mode of marching. Calculated blade pressures at the hub, mid, and tip radii of the cascade agreed with corresponding measurements. The transonic impeller computation was conducted to test the newly developed locally mass flux conservative cross-sectional computer code. Both blade-to-blade and cross sectional modes of calculation were implemented for this problem. A triplet point shock structure was computed in the inducer region of the impeller. In addition, time-averaged shroud static pressures generally agreed with measured shroud pressures. It is concluded that the blade-to-blade computation produces a useful engineering flow field in regions of subsonic relative flow; and cross-sectional computation, with a locally mass flux conservative continuity equation, is required to compute the shock waves in regions of supersonic relative flow.

  3. Determination of local values of gas and liquid mass flux in highly loaded two-phase flow

    NASA Technical Reports Server (NTRS)

    Burick, R. J.; Scheuerman, C. H.; Falk, A. Y.

    1974-01-01

    A measurement system using a deceleration probe was designed for determining the local values of gas and liquid mass flux in various gas/liquid droplet sprayfields. The system was used to characterize two-phase flowfields generated by gas/liquid rocket-motor injectors. Measurements were made at static pressures up to 500 psia and injected mass flow ratios up to 20. The measurement system can also be used at higher pressures and in gas/solid flowfields.

  4. The impact of changing wind speeds on gas transfer and its effect on global air-sea CO2 fluxes

    NASA Astrophysics Data System (ADS)

    Wanninkhof, R.; Triñanes, J.

    2017-06-01

    An increase in global wind speeds over time is affecting the global uptake of CO2 by the ocean. We determine the impact of changing winds on gas transfer and CO2 uptake by using the recently updated, global high-resolution, cross-calibrated multiplatform wind product (CCMP-V2) and a fixed monthly pCO2 climatology. In particular, we assess global changes in the context of regional wind speed changes that are attributed to large-scale climate reorganizations. The impact of wind on global CO2 gas fluxes as determined by the bulk formula is dependent on several factors, including the functionality of the gas exchange-wind speed relationship and the regional and seasonal differences in the air-water partial pressure of CO2 gradient (ΔpCO2). The latter also controls the direction of the flux. Fluxes out of the ocean are influenced more by changes in the low-to-intermediate wind speed range, while ingassing is impacted more by changes in higher winds because of the regional correlations between wind and ΔpCO2. Gas exchange-wind speed parameterizations with a quadratic and third-order polynomial dependency on wind, each of which meets global constraints, are compared. The changes in air-sea CO2 fluxes resulting from wind speed trends are greatest in the equatorial Pacific and cause a 0.03-0.04 Pg C decade-1 increase in outgassing over the 27 year time span. This leads to a small overall decrease of 0.00 to 0.02 Pg C decade-1 in global net CO2 uptake, contrary to expectations that increasing winds increase net CO2 uptake.Plain Language SummaryThe effects of changing winds are isolated from the total change in trends in global <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span> over the last 27 years. The overall effect of increasing winds over time has a smaller impact than expected as the impact in regions of outgassing is greater than for the regions acting as a CO2 sink.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.478L..83L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.478L..83L"><span>Submillimetre <span class="hlt">flux</span> as a probe of molecular ISM <span class="hlt">mass</span> in high-z galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Lichen; Feldmann, Robert; Faucher-Giguère, Claude-André; Kereš, Dušan; Hopkins, Philip F.; Hayward, Christopher C.; Quataert, Eliot; Scoville, Nick Z.</p> <p>2018-07-01</p> <p>Recent long-wavelength observations on the thermal dust continuum suggest that the Rayleigh-Jeans tail can be used as a time-efficient quantitative probe of the dust and interstellar medium (ISM) <span class="hlt">mass</span> in high-z galaxies. We use high-resolution cosmological simulations from the Feedback in Realistic Environment (FIRE) project to analyse the dust emission of M* ≳ 1010 M⊙ galaxies at z= 2-4. Our simulations (MASSIVEFIRE) explicitly include various forms of stellar feedback, and they produce the stellar <span class="hlt">masses</span> and star formation rates of high-z galaxies in agreement with observations. Using radiative transfer modelling, we show that sub-millimetre (sub-mm) luminosity and molecular ISM <span class="hlt">mass</span> are tightly correlated and that the overall normalization is in quantitative agreement with observations. Notably, sub-mm luminosity traces molecular ISM <span class="hlt">mass</span> even during starburst episodes as dust <span class="hlt">mass</span> and <span class="hlt">mass</span>-weighted temperature evolve only moderately between z = 4 and z = 2, including during starbursts. Our finding supports the empirical approach of using broadband sub-mm <span class="hlt">flux</span> as a proxy for molecular gas content in high-z galaxies. We thus expect single-band sub-mm observations with ALMA to dramatically increase the sample size of high-z galaxies with reliable ISM <span class="hlt">masses</span> in the near future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.tmpL..76L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.tmpL..76L"><span>Submillimeter <span class="hlt">flux</span> as a probe of molecular ISM <span class="hlt">mass</span> in high-z galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Lichen; Feldmann, Robert; Faucher-Giguère, Claude-André; Kereš, Dušan; Hopkins, Philip F.; Hayward, Christopher C.; Quataert, Eliot; Scoville, Nick Z.</p> <p>2018-04-01</p> <p>Recent long wavelength observations on the thermal dust continuum suggest that the Rayleigh-Jeans (RJ) tail can be used as a time-efficient quantitative probe of the dust and ISM <span class="hlt">mass</span> in high-z galaxies. We use high-resolution cosmological simulations from the Feedback in Realistic Environment (FIRE) project to analyze the dust emission of M* ≳ 1010M⊙ galaxies at z = 2 - 4. Our simulations (MassiveFIRE) explicitly include various forms of stellar feedback, and they produce the stellar <span class="hlt">masses</span> and star formation rates of high-z galaxies in agreement with observations. Using radiative transfer modelling, we show that sub-millimeter (sub-mm) luminosity and molecular ISM <span class="hlt">mass</span> are tightly correlated and that the overall normalization is in quantitative agreement with observations. Notably, sub-mm luminosity traces molecular ISM <span class="hlt">mass</span> even during starburst episodes as dust <span class="hlt">mass</span> and <span class="hlt">mass</span>-weighted temperature evolve only moderately between z = 4 and z = 2, including during starbursts. Our finding supports the empirical approach of using broadband sub-mm <span class="hlt">flux</span> as a proxy for molecular gas content in high-z galaxies. We thus expect single-band sub-mm observations with ALMA to dramatically increase the sample size of high-z galaxies with reliable ISM <span class="hlt">masses</span> in the near future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A33K0351P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A33K0351P"><span>Signature of a Sudden Stratospheric Warming in the near-ground 7Be <span class="hlt">flux</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pacini, A. A.</p> <p>2015-12-01</p> <p>We present here a study of the impact of one Sudden Stratospheric Warming (SSW) upon the atmospheric vertical dynamics based on 7Be measurements in near ground <span class="hlt">air</span>, using both numerical and conceptual. In late September 2002, an unprecedented SSW event occurred in the southern hemisphere (SH), causing changes in the tropospheric circulation, ozone depletion and weakening of the polar jet in the mesosphere. There is an observational evidence suggesting that anomalies in the stratosphere play an important role in driving tropospheric weather producing tropospheric changes that can persists for up to 60 days in NH and up to about 90 days in the SH, as observed after the 2002 SSW (Thompson et al., 2005). Radioactive environmental techniques for tracing large-scale <span class="hlt">air-mass</span> transport have been applied in studies of atmospheric dynamics for decades and they are becoming more and more precise due to the improvement of the instrumental sensitivity and associated modeling. Temporal variations of the cosmogenic 7Be concentration in the near-surface atmosphere can provide information on the <span class="hlt">air</span> <span class="hlt">mass</span> dynamics, precipitation patterns, stratosphere-troposphere coupling and cosmic ray variations. The present study is based on an analysis of 7Be concentration measured in near-ground <span class="hlt">air</span> in the city of Angra dos Reis, Rio de Janeiro state, Brazil between 1987 and 2009. Using a simplified tropospheric 7Be model deposition based on a two-layer transport model, Pacini (2011) reported that the occurrence of strong downward <span class="hlt">air</span> <span class="hlt">flux</span> leave an imprint of the 3D motion of <span class="hlt">air</span> <span class="hlt">masses</span> to the near-ground <span class="hlt">air</span> 7Be data in the studied region. In this work, we have further developed the two-layer model by adding one more layer: the lower stratosphere (LS). In normal conditions, the contribution of the LS 7Be to the near-ground isotopic variability would be very small. On the other hand, stratospheric source can be crucial for the SSW event, indicating that a strong stratospheric <span class="hlt">air</span> intrusion</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AtmEn.178..255G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AtmEn.178..255G"><span>Particle growth in an isoprene-rich forest: Influences of urban, wildfire, and biogenic <span class="hlt">air</span> <span class="hlt">masses</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunsch, Matthew J.; Schmidt, Stephanie A.; Gardner, Daniel J.; Bondy, Amy L.; May, Nathaniel W.; Bertman, Steven B.; Pratt, Kerri A.; Ault, Andrew P.</p> <p>2018-04-01</p> <p>Growth of freshly nucleated particles is an important source of cloud condensation nuclei (CCN) and has been studied within a variety of environments around the world. However, there remains uncertainty regarding the sources of the precursor gases leading to particle growth, particularly in isoprene-rich forests. In this study, particle growth events were observed from the 14 total events (31% of days) during summer measurements (June 24 - August 2, 2014) at the Program for Research on Oxidants PHotochemistry, Emissions, and Transport (PROPHET) tower within the forested University of Michigan Biological Station located in northern Michigan. Growth events were observed within long-range transported <span class="hlt">air</span> <span class="hlt">masses</span> from urban areas, <span class="hlt">air</span> <span class="hlt">masses</span> impacted by wildfires, as well as stagnant, forested/regional <span class="hlt">air</span> <span class="hlt">masses</span>. Growth events observed during urban-influenced <span class="hlt">air</span> <span class="hlt">masses</span> were prevalent, with presumably high oxidant levels, and began midday during periods of high solar radiation. This suggests that increased oxidation of biogenic volatile organic compounds (BVOCs) likely contributed to the highest observed particle growth in this study (8 ± 2 nm h-1). Growth events during wildfire-influenced <span class="hlt">air</span> <span class="hlt">masses</span> were observed primarily at night and had slower growth rates (3 ± 1 nm h-1). These events were likely influenced by increased SO2, O3, and NO2 transported within the smoke plumes, suggesting a role of NO3 oxidation in the production of semi-volatile compounds. Forested/regional <span class="hlt">air</span> <span class="hlt">mass</span> growth events likely occurred due to the oxidation of regionally emitted BVOCs, including isoprene, monoterpenes, and sesquiterpenes, which facilitated multiday growth events also with slower rates (3 ± 2 nm h-1). Intense sulfur, carbon, and oxygen signals in individual particles down to 20 nm, analyzed by transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDX), suggest that H2SO4 and secondary organic aerosol contributed to particle growth. Overall, aerosol</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1344234-convective-cloud-vertical-velocity-mass-flux-characteristics-from-radar-wind-profiler-observations-during-goamazon2014-vertical-velocity-goamazon2014','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1344234-convective-cloud-vertical-velocity-mass-flux-characteristics-from-radar-wind-profiler-observations-during-goamazon2014-vertical-velocity-goamazon2014"><span>Convective cloud vertical velocity and <span class="hlt">mass-flux</span> characteristics from radar wind profiler observations during GoAmazon2014/5: VERTICAL VELOCITY GOAMAZON2014/5</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Giangrande, Scott E.; Toto, Tami; Jensen, Michael P.; ...</p> <p>2016-11-15</p> <p>A radar wind profiler data set collected during the 2 year Department of Energy Atmospheric Radiation Measurement Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) campaign is used to estimate convective cloud vertical velocity, area fraction, and <span class="hlt">mass</span> <span class="hlt">flux</span> profiles. Vertical velocity observations are presented using cumulative frequency histograms and weighted mean profiles to provide insights in a manner suitable for global climate model scale comparisons (spatial domains from 20 km to 60 km). Convective profile sensitivity to changes in environmental conditions and seasonal regime controls is also considered. Aggregate and ensemble average vertical velocity, convective area fraction, andmore » <span class="hlt">mass</span> <span class="hlt">flux</span> profiles, as well as magnitudes and relative profile behaviors, are found consistent with previous studies. Updrafts and downdrafts increase in magnitude with height to midlevels (6 to 10 km), with updraft area also increasing with height. Updraft <span class="hlt">mass</span> <span class="hlt">flux</span> profiles similarly increase with height, showing a peak in magnitude near 8 km. Downdrafts are observed to be most frequent below the freezing level, with downdraft area monotonically decreasing with height. Updraft and downdraft profile behaviors are further stratified according to environmental controls. These results indicate stronger vertical velocity profile behaviors under higher convective available potential energy and lower low-level moisture conditions. Sharp contrasts in convective area fraction and <span class="hlt">mass</span> <span class="hlt">flux</span> profiles are most pronounced when retrievals are segregated according to Amazonian wet and dry season conditions. During this deployment, wet season regimes favored higher domain <span class="hlt">mass</span> <span class="hlt">flux</span> profiles, attributed to more frequent convection that offsets weaker average convective cell vertical velocities.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110016051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110016051"><span>Progress on a Rayleigh Scattering <span class="hlt">Mass</span> <span class="hlt">Flux</span> Measurement Technique</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mielke-Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.; Hirt, Stefanie M.</p> <p>2010-01-01</p> <p>A Rayleigh scattering diagnostic has been developed to provide <span class="hlt">mass</span> <span class="hlt">flux</span> measurements in wind tunnel flows. Spectroscopic molecular Rayleigh scattering is an established flow diagnostic tool that has the ability to provide simultaneous density and velocity measurements in gaseous flows. Rayleigh scattered light from a focused 10 Watt continuous-wave laser beam is collected and fiber-optically transmitted to a solid Fabry-Perot etalon for spectral analysis. The circular interference pattern that contains the spectral information that is needed to determine the flow properties is imaged onto a CCD detector. Baseline measurements of density and velocity in the test section of the 15 cm x 15 cm Supersonic Wind Tunnel at NASA Glenn Research Center are presented as well as velocity measurements within a supersonic combustion ramjet engine isolator model installed in the tunnel test section.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..320..107G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..320..107G"><span><span class="hlt">Mass</span> and heat <span class="hlt">flux</span> balance of La Soufrière volcano (Guadeloupe) from aerial infrared thermal imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaudin, Damien; Beauducel, François; Coutant, Olivier; Delacourt, Christophe; Richon, Patrick; de Chabalier, Jean-Bernard; Hammouya, Gilbert</p> <p>2016-06-01</p> <p>La Soufrière of Guadeloupe is an active volcano of Lesser Antilles that is closely monitored due to a high eruptive hazard potential. Since 1992 it exhibits a medium-level but sustained background hydrothermal activity with low-energy and shallow seismicity, hot springs temperature increase and high <span class="hlt">flux</span> acidic gas fumaroles at the summit. The problem of estimating the heat balance and quantifying the evolution of hydrothermal activity has become a key challenge for surveillance. This work is the first attempt of a global mapping and quantification of La Soufrière thermal activity performed in February 2010 using aerial thermal infrared imagery. After instrument calibration and data processing, we present a global map of thermal anomalies allowing to spot the main active sites: the summit area (including the fumaroles of Tarissan Pit and South Crater), the Ty Fault fumarolic zone, and the hot springs located at the vicinity of the dome. In a second step, we deduce the <span class="hlt">mass</span> and the energy <span class="hlt">fluxes</span> released by the volcano. In particular, we propose a simple model of energy balance to estimate the <span class="hlt">mass</span> <span class="hlt">flux</span> of the summit fumaroles from their brightness temperature and size. In February 2010, Tarissan Pit had a 22.8 ± 8.1 kg s -1 <span class="hlt">flux</span> (1970 ± 704 tons day -1), while South Crater vents had a total of 19.5 ± 4.0 kg s -1 (1687 ± 348 tons day -1). Once converted into energy <span class="hlt">flux</span>, summit fumaroles represent 98% of the 106 ± 30 MW released by the volcano, the 2% remaining being split between the hot springs and the thermal anomalies at the summit and at the Ty Fault fumarolic zone. These values are in the high range of the previous estimations, highlighting the short-term variability of the expelled <span class="hlt">fluxes</span>. Such a heat <span class="hlt">flux</span> requires the cooling of 1500 m 3 of magma per day, in good agreement with previous geochemical studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615572B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615572B"><span>Towards Improved Estimates of Ocean Heat <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bentamy, Abderrahim; Hollman, Rainer; Kent, Elisabeth; Haines, Keith</p> <p>2014-05-01</p> <p>Recommendations and priorities for ocean heat <span class="hlt">flux</span> research are for instance outlined in recent CLIVAR and WCRP reports, eg. Yu et al (2013). Among these is the need for improving the accuracy, the consistency, and the spatial and temporal resolution of <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> over global as well as at region scales. To meet the main <span class="hlt">air</span>-sea <span class="hlt">flux</span> requirements, this study is aimed at obtaining and analyzing all the heat <span class="hlt">flux</span> components (latent, sensible and radiative) at the ocean surface over global oceans using multiple satellite sensor observations in combination with in-situ measurements and numerical model analyses. The <span class="hlt">fluxes</span> will be generated daily and monthly for the 20-year (1992-2011) period, between 80N and 80S and at 0.25deg resolution. Simultaneous estimates of all surface heat <span class="hlt">flux</span> terms have not yet been calculated at such large scale and long time period. Such an effort requires a wide range of expertise and data sources that only recently are becoming available. Needed are methods for integrating many data sources to calculate energy <span class="hlt">fluxes</span> (short-wave, long wave, sensible and latent heat) across the <span class="hlt">air</span>-sea interface. We have access to all the relevant, recently available satellite data to perform such computations. Yu, L., K. Haines, M. Bourassa, M. Cronin, S. Gulev, S. Josey, S. Kato, A. Kumar, T. Lee, D. Roemmich: Towards achieving global closure of ocean heat and freshwater budgets: Recommendations for advancing research in <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> through collaborative activities. INTERNATIONAL CLIVAR PROJECT OFFICE, 2013: International CLIVAR Publication Series No 189. http://www.clivar.org/sites/default/files/ICPO189_WHOI_<span class="hlt">fluxes</span>_workshop.pdf</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ResPh...8.1168H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...8.1168H"><span>Numerical study for peristalsis of Carreau-Yasuda nanomaterial with convective and zero <span class="hlt">mass</span> <span class="hlt">flux</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayat, T.; Ahmed, Bilal; Alsaedi, A.; Abbasi, F. M.</p> <p>2018-03-01</p> <p>The present communication investigates flow of Carreau-Yasuda nanofluid in presence of mixed convection and Hall current. Effects of viscous dissipation, Ohmic heating and convective conditions are addressed. In addition zero nanoparticle <span class="hlt">mass</span> <span class="hlt">flux</span> condition is imposed. Wave frame analysis is carried out. Coupled differential systems after long wavelength and low Reynolds number are numerically solved. Effects of different parameters on velocity, temperature and concentration are studied. Heat and <span class="hlt">mass</span> transfer rates are analyzed through tabular values. It is observed that concentration for thermophoresis and Brownian motion parameters has opposite effect. Further heat and <span class="hlt">mass</span> transfer rates at the upper wall enhances significantly when Hartman number increases and reverse situation is noticed for Hall parameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26930305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26930305"><span>Trends and sources vs <span class="hlt">air</span> <span class="hlt">mass</span> origins in a major city in South-western Europe: Implications for <span class="hlt">air</span> quality management.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernández-Camacho, R; de la Rosa, J D; Sánchez de la Campa, A M</p> <p>2016-05-15</p> <p>This study presents a 17-years <span class="hlt">air</span> quality database comprised of different parameters corresponding to the largest city in the south of Spain (Seville) where atmospheric pollution is frequently attributed to traffic emissions and is directly affected by Saharan dust outbreaks. We identify the PM10 contributions from both natural and anthropogenic sources in this area associated to different <span class="hlt">air</span> <span class="hlt">mass</span> origins. Hourly, daily and seasonal variation of PM10 and gaseous pollutant concentrations (CO, NO2 and SO2), all of them showing negative trends during the study period, point to the traffic as one of the main sources of <span class="hlt">air</span> pollution in Seville. Mineral dust, secondary inorganic compounds (SIC) and trace elements showed higher concentrations under North African (NAF) <span class="hlt">air</span> <span class="hlt">mass</span> origins than under Atlantic. We observe a decreasing trend in all chemical components of PM10 under both types of <span class="hlt">air</span> <span class="hlt">masses</span>, NAF and Atlantic. Principal component analysis using more frequent <span class="hlt">air</span> <span class="hlt">masses</span> in the area allows the identification of five PM10 sources: crustal, regional, marine, traffic and industrial. Natural sources play a more relevant role during NAF events (20.6 μg · m(-3)) than in Atlantic episodes (13.8 μg · m(-3)). The contribution of the anthropogenic sources under NAF doubles the one under Atlantic conditions (33.6 μg · m(-3) and 15.8 μg · m(-3), respectively). During Saharan dust outbreaks the frequent accumulation of local anthropogenic pollutants in the lower atmosphere results in poor <span class="hlt">air</span> quality and an increased risk of mortality. The results are relevant when analysing the impact of anthropogenic emissions on the exposed population in large cities. The increase in potentially toxic elements during Saharan dust outbreaks should also be taken into account when discounting the number of exceedances attributable to non-anthropogenic or natural origins. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2784W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2784W"><span>Sustained Observations of <span class="hlt">Air</span>-Sea <span class="hlt">Fluxes</span> and <span class="hlt">Air</span>-Sea Interaction at the Stratus Ocean Reference Station</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weller, Robert</p> <p>2014-05-01</p> <p>Since October 2000, a well-instrumented surface mooring has been maintained some 1,500 km west of the coast of northern Chile, roughly in the location of the climatological maximum in marine stratus clouds. Statistically significant increases in wind stress and decreases in annual net <span class="hlt">air</span>-sea heat <span class="hlt">flux</span> and in latent heat <span class="hlt">flux</span> have been observed. If the increased oceanic heat loss continues, the region will within the next decade change from one of net annual heat gain by the ocean to one of neat annual heat loss. Already, annual evaporation of about 1.5 m of sea water a year acts to make the warm, salty surface layer more dense. Of interest is examining whether or not increased oceanic heat loss has the potential to change the structure of the upper ocean and potentially remove the shallow warm, salty mixed layer that now buffers the atmosphere from the interior ocean. Insights into how that warm, shallow layer is formed and maintained come from looking at oceanic response to the atmosphere at diurnal tie scales. Restratification each spring and summer is found to depend upon the occurrence of events in which the trade winds decay, allowing diurnal warming in the near-surface ocean to occur, and when the winds return resulting in a net upward step in sea surface temperature. This process is proving hard to accurately model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1167255','SCIGOV-DOEDE'); return false;" href="https://www.osti.gov/servlets/purl/1167255"><span>CO2 CH4 <span class="hlt">flux</span> <span class="hlt">Air</span> temperature Soil temperature and Soil moisture, Barrow, Alaska 2013 ver. 1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Margaret Torn</p> <p>2015-01-14</p> <p>This dataset consists of field measurements of CO2 and CH4 <span class="hlt">flux</span>, as well as soil properties made during 2013 in Areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Included are i) measurements of CO2 and CH4 <span class="hlt">flux</span> made from June to September (ii) Calculation of corresponding Gross Primary Productivity (GPP) and CH4 exchange (transparent minus opaque) between atmosphere and the ecosystem (ii) Measurements of Los Gatos Research (LGR) chamber <span class="hlt">air</span> temperature made from June to September (ii) measurements of surface layer depth, type of surface layer, soil temperature and soil moisture from June to September.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.5861S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.5861S"><span>Gradient <span class="hlt">flux</span> measurements of sea-<span class="hlt">air</span> DMS transfer during the Surface Ocean Aerosol Production (SOAP) experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, Murray J.; Walker, Carolyn F.; Bell, Thomas G.; Harvey, Mike J.; Saltzman, Eric S.; Law, Cliff S.</p> <p>2018-04-01</p> <p>Direct measurements of marine dimethylsulfide (DMS) <span class="hlt">fluxes</span> are sparse, particularly in the Southern Ocean. The Surface Ocean Aerosol Production (SOAP) voyage in February-March 2012 examined the distribution and <span class="hlt">flux</span> of DMS in a biologically active frontal system in the southwest Pacific Ocean. Three distinct phytoplankton blooms were studied with oceanic DMS concentrations as high as 25 nmol L-1. Measurements of DMS <span class="hlt">fluxes</span> were made using two independent methods: the eddy covariance (EC) technique using atmospheric pressure chemical ionization-<span class="hlt">mass</span> spectrometry (API-CIMS) and the gradient <span class="hlt">flux</span> (GF) technique from an autonomous catamaran platform. Catamaran <span class="hlt">flux</span> measurements are relatively unaffected by airflow distortion and are made close to the water surface, where gas gradients are largest. <span class="hlt">Flux</span> measurements were complemented by near-surface hydrographic measurements to elucidate physical factors influencing DMS emission. Individual DMS <span class="hlt">fluxes</span> derived by EC showed significant scatter and, at times, consistent departures from the Coupled Ocean-Atmosphere Response Experiment gas transfer algorithm (COAREG). A direct comparison between the two <span class="hlt">flux</span> methods was carried out to separate instrumental effects from environmental effects and showed good agreement with a regression slope of 0.96 (r2 = 0.89). A period of abnormal downward atmospheric heat <span class="hlt">flux</span> enhanced near-surface ocean stratification and reduced turbulent exchange, during which GF and EC transfer velocities showed good agreement but modelled COAREG values were significantly higher. The transfer velocity derived from near-surface ocean turbulence measurements on a spar buoy compared well with the COAREG model in general but showed less variation. This first direct comparison between EC and GF <span class="hlt">fluxes</span> of DMS provides confidence in compilation of <span class="hlt">flux</span> estimates from both techniques, as well as in the stable periods when the observations are not well predicted by the COAREG model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12469825','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12469825"><span>Design and performance of a dynaniic gas <span class="hlt">flux</span> chamber.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reichman, Rivka; Rolston, Dennis E</p> <p>2002-01-01</p> <p>Chambers are commonly used to measure the emission of many trace gases and chemicals from soil. An aerodynamic (flow through) chamber was designed and fabricated to accurately measure the surface <span class="hlt">flux</span> of trace gases. Flow through the chamber was controlled with a small vacuum at the outlet. Due to the design using fans, a partition plate, and aerodynamic ends, <span class="hlt">air</span> is forced to sweep parallel and uniform over the entire soil surface. A fraction of the <span class="hlt">air</span> flowing inside the chamber is sampled in the outlet. The <span class="hlt">air</span> velocity inside the chamber is controlled by fan speed and outlet suction flow rate. The chamber design resulted in a uniform distribution of <span class="hlt">air</span> velocity at the soil surface. Steady state <span class="hlt">flux</span> was attained within 5 min when the outlet <span class="hlt">air</span> suction rate was 20 L/min or higher. For expected <span class="hlt">flux</span> rates, the presence of the chamber did not affect the measured <span class="hlt">fluxes</span> at outlet suction rates of around 20 L/min, except that the chamber caused some cooling of the surface in field experiments. Sensitive measurements of the pressure deficit across the soil layer in conjunction with measured <span class="hlt">fluxes</span> in the source box and chamber outlet show that the outflow rate must be controlled carefully to minimize errors in the <span class="hlt">flux</span> measurements. Both over- and underestimation of the <span class="hlt">fluxes</span> are possible if the outlet flow rate is not controlled carefully. For this design, the chamber accurately measured steady <span class="hlt">flux</span> at outlet <span class="hlt">air</span> suction rates of approximately 20 L/min when the pressure deficit within the chamber with respect to the ambient atmosphere ranged between 0.46 and 0.79 Pa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.1203W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.1203W"><span>Low-CCN concentration <span class="hlt">air</span> <span class="hlt">masses</span> over the eastern North Atlantic: Seasonality, meteorology, and drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wood, Robert; Stemmler, Jayson D.; Rémillard, Jasmine; Jefferson, Anne</p> <p>2017-01-01</p> <p>A 20 month cloud condensation nucleus concentration (NCCN) data set from Graciosa Island (39°N, 28°W) in the remote North Atlantic is used to characterize <span class="hlt">air</span> <span class="hlt">masses</span> with low cloud condensation nuclei (CCN) concentrations. Low-CCN events are defined as 6 h periods with mean NCCN<20 cm-3 (0.1% supersaturation). A total of 47 low-CCN events are identified. Surface, satellite, and reanalysis data are used to explore the meteorological and cloud context for low-CCN <span class="hlt">air</span> <span class="hlt">masses</span>. Low-CCN events occur in all seasons, but their frequency was 3 times higher in December-May than during June-November. Composites show that many of the low-CCN events had a common meteorological basis that involves southerly low-level flow and rather low wind speeds at Graciosa. Anomalously low pressure is situated to the west of Graciosa during these events, but back trajectories and lagged SLP composites indicate that low-CCN <span class="hlt">air</span> <span class="hlt">masses</span> often originate as cold <span class="hlt">air</span> outbreaks to the north and west of Graciosa. Low-CCN events were associated with low cloud droplet concentrations (Nd) at Graciosa, but liquid water path (LWP) during low-CCN events was not systematically different from that at other times. Satellite Nd and LWP estimates from MODIS collocated with Lagrangian back trajectories show systematically lower Nd and higher LWP several days prior to arrival at Graciosa, consistent with the hypothesis that observed low-CCN <span class="hlt">air</span> <span class="hlt">masses</span> are often formed by coalescence scavenging in thick warm clouds, often in cold <span class="hlt">air</span> outbreaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22004403-what-does-submillimeter-galaxy-selection-actually-select-dependence-submillimeter-flux-density-star-formation-rate-dust-mass','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22004403-what-does-submillimeter-galaxy-selection-actually-select-dependence-submillimeter-flux-density-star-formation-rate-dust-mass"><span>WHAT DOES A SUBMILLIMETER GALAXY SELECTION ACTUALLY SELECT? THE DEPENDENCE OF SUBMILLIMETER <span class="hlt">FLUX</span> DENSITY ON STAR FORMATION RATE AND DUST <span class="hlt">MASS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hayward, Christopher C.; Keres, Dusan; Jonsson, Patrik</p> <p>2011-12-20</p> <p>We perform three-dimensional dust radiative transfer (RT) calculations on hydrodynamic simulations of isolated and merging disk galaxies in order to quantitatively study the dependence of observed-frame submillimeter (submm) <span class="hlt">flux</span> density on galaxy properties. We find that submm <span class="hlt">flux</span> density and star formation rate (SFR) are related in dramatically different ways for quiescently star-forming galaxies and starbursts. Because the stars formed in the merger-induced starburst do not dominate the bolometric luminosity and the rapid drop in dust <span class="hlt">mass</span> and more compact geometry cause a sharp increase in dust temperature during the burst, starbursts are very inefficient at boosting submm <span class="hlt">flux</span> densitymore » (e.g., a {approx}> 16 Multiplication-Sign boost in SFR yields a {approx}< 2 Multiplication-Sign boost in submm <span class="hlt">flux</span> density). Moreover, the ratio of submm <span class="hlt">flux</span> density to SFR differs significantly between the two modes; thus one cannot assume that the galaxies with highest submm <span class="hlt">flux</span> density are necessarily those with the highest bolometric luminosity or SFR. These results have important consequences for the bright submillimeter-selected galaxy (SMG) population. Among them are: (1) The SMG population is heterogeneous. In addition to merger-driven starbursts, there is a subpopulation of galaxy pairs, where two disks undergoing a major merger but not yet strongly interacting are blended into one submm source because of the large ({approx}> 15'' or {approx}130 kpc at z = 2) beam of single-dish submm telescopes. (2) SMGs must be very massive (M{sub *} {approx}> 6 Multiplication-Sign 10{sup 10} M{sub Sun }). (3) The infall phase makes the SMG duty cycle a factor of a few greater than what is expected for a merger-driven starburst. Finally, we provide fitting functions for SCUBA and AzTEC submm <span class="hlt">flux</span> densities as a function of SFR and dust <span class="hlt">mass</span> and bolometric luminosity and dust <span class="hlt">mass</span>; these should be useful for calculating submm <span class="hlt">flux</span> density in semi-analytic models and</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ApJ...743..159H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ApJ...743..159H"><span>What Does a Submillimeter Galaxy Selection Actually Select? The Dependence of Submillimeter <span class="hlt">Flux</span> Density on Star Formation Rate and Dust <span class="hlt">Mass</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayward, Christopher C.; Kereš, Dušan; Jonsson, Patrik; Narayanan, Desika; Cox, T. J.; Hernquist, Lars</p> <p>2011-12-01</p> <p>We perform three-dimensional dust radiative transfer (RT) calculations on hydrodynamic simulations of isolated and merging disk galaxies in order to quantitatively study the dependence of observed-frame submillimeter (submm) <span class="hlt">flux</span> density on galaxy properties. We find that submm <span class="hlt">flux</span> density and star formation rate (SFR) are related in dramatically different ways for quiescently star-forming galaxies and starbursts. Because the stars formed in the merger-induced starburst do not dominate the bolometric luminosity and the rapid drop in dust <span class="hlt">mass</span> and more compact geometry cause a sharp increase in dust temperature during the burst, starbursts are very inefficient at boosting submm <span class="hlt">flux</span> density (e.g., a >~ 16 × boost in SFR yields a <~ 2 × boost in submm <span class="hlt">flux</span> density). Moreover, the ratio of submm <span class="hlt">flux</span> density to SFR differs significantly between the two modes; thus one cannot assume that the galaxies with highest submm <span class="hlt">flux</span> density are necessarily those with the highest bolometric luminosity or SFR. These results have important consequences for the bright submillimeter-selected galaxy (SMG) population. Among them are: (1) The SMG population is heterogeneous. In addition to merger-driven starbursts, there is a subpopulation of galaxy pairs, where two disks undergoing a major merger but not yet strongly interacting are blended into one submm source because of the large (gsim 15" or ~130 kpc at z = 2) beam of single-dish submm telescopes. (2) SMGs must be very massive (M sstarf >~ 6 × 1010 M ⊙). (3) The infall phase makes the SMG duty cycle a factor of a few greater than what is expected for a merger-driven starburst. Finally, we provide fitting functions for SCUBA and AzTEC submm <span class="hlt">flux</span> densities as a function of SFR and dust <span class="hlt">mass</span> and bolometric luminosity and dust <span class="hlt">mass</span>; these should be useful for calculating submm <span class="hlt">flux</span> density in semi-analytic models and cosmological simulations when performing full RT is computationally not feasible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HMT....52.2213B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HMT....52.2213B"><span>Influence of drying <span class="hlt">air</span> parameters on <span class="hlt">mass</span> transfer characteristics of apple slices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beigi, Mohsen</p> <p>2016-10-01</p> <p>To efficiently design both new drying process and equipment and/or to improve the existing systems, accurate values of <span class="hlt">mass</span> transfer characteristics are necessary. The present study aimed to investigate the influence of drying <span class="hlt">air</span> parameters (i.e. temperature, velocity and relative humidity) on effective diffusivity and convective <span class="hlt">mass</span> transfer coefficient of apple slices. The Dincer and Dost model was used to determine the <span class="hlt">mass</span> transfer characteristics. The obtained Biot number indicated that the moisture transfer in the apple slices was controlled by both internal and external resistance. The effective diffusivity and <span class="hlt">mass</span> transfer coefficient values obtained to be in the ranges of 7.13 × 10-11-7.66 × 10-10 and 1.46 × 10-7-3.39 × 10-7 m s-1, respectively and the both of them increased with increasing drying <span class="hlt">air</span> temperature and velocity, and decreasing relative humidity. The validation of the model showed that the model predicted the experimental drying curves of the samples with a good accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15279352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15279352"><span>Microbial <span class="hlt">air</span> quality in <span class="hlt">mass</span> transport buses and work-related illness among bus drivers of Bangkok <span class="hlt">Mass</span> Transit Authority.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan</p> <p>2004-06-01</p> <p>The <span class="hlt">air</span> quality in <span class="hlt">mass</span> transport buses, especially <span class="hlt">air</span>-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok <span class="hlt">Mass</span> Transit Authority were randomly selected to investigate for microbial <span class="hlt">air</span> quality. Nine <span class="hlt">air</span>-conditioned buses and 2-4 open-<span class="hlt">air</span> buses for each number of the bus (36 <span class="hlt">air</span>-conditioned buses and 12 open-<span class="hlt">air</span> buses) were included. Five points of in-bus <span class="hlt">air</span> samples in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 <span class="hlt">air</span> samples collected from <span class="hlt">air</span>-conditioned buses and open-<span class="hlt">air</span> buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results revealed that the mean +/- SD of bacterial counts in the studied open-<span class="hlt">air</span> buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied <span class="hlt">air</span>-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied <span class="hlt">air</span> samples were analyzed in detail, it was found that 33.33% of the <span class="hlt">air</span> samples from open-<span class="hlt">air</span> buses and 6.11% of <span class="hlt">air</span> samples from <span class="hlt">air</span>-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of <span class="hlt">air</span> samples from open-<span class="hlt">air</span> buses and 2.78% of <span class="hlt">air</span> samples from <span class="hlt">air</span>-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-<span class="hlt">air</span> bus drivers and 57.28% of <span class="hlt">air</span>-conditioned bus drivers had</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12214652','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12214652"><span>Exposure chamber measurements of <span class="hlt">mass</span> transfer and partitioning at the plant/<span class="hlt">air</span> interface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maddalena, Randy L; McKone, Thomas E; Kado, Norman Y</p> <p>2002-08-15</p> <p>Dynamic measures of <span class="hlt">air</span> and vegetation concentrations in an exposure chamber and a two-box <span class="hlt">mass</span> balance model are used to quantify factors that control the rate and extent of chemical partitioning between vegetation and the atmosphere. A continuous stirred flow-through exposure chamber was used to investigate the gas-phase transfer of pollutants between <span class="hlt">air</span> and plants. A probabilistic two-compartment <span class="hlt">mass</span> balance model of plant/<span class="hlt">air</span> exchange within the exposure chamber was developed and used with measured concentrations from the chamber to simultaneously evaluate partitioning (Kpa), overall <span class="hlt">mass</span> transfer across the plant/<span class="hlt">air</span> interface (Upa), and loss rates in the atmosphere (Ra) and aboveground vegetation (Rp). The approach is demonstrated using mature Capsicum annuum (bell pepper) plants exposed to phenanthrene (PH), anthracene (AN), fluoranthene (FL) and pyrene (PY). Measured values of log Kpa (V[<span class="hlt">air</span>]/V[fresh plant]) were 5.7, 5.7, 6.0, and 6.2 for PH, AN, FL, and PY, respectively. Values of Upa (m d(-1)) under the conditions of this study ranged from 42 for PH to 119 for FL. After correcting for wall effects, the estimated reaction half-lives in <span class="hlt">air</span> were 3, 9, and 25 h for AN, FL and PY. Reaction half-lives in the plant compartment were 17, 6, 17, and 5 d for PH, AN, FL, and PY, respectively. The combined use of exposure chamber measurements and models provides a robust tool for simultaneously measuring several different transfer factors that are important for modeling the uptake of pollutants into vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790008611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790008611"><span>A method of exploration of the atmosphere of Titan. [hot <span class="hlt">air</span> balloon heated by solar radiation or planetary thermal <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blamont, J.</p> <p>1978-01-01</p> <p>A hot-<span class="hlt">air</span> balloon, with the <span class="hlt">air</span> heated by natural sources, is described. Buoyancy is accomplished by either solar heating or by utilizing the IR thermal <span class="hlt">flux</span> of the planet to heat the gas in the balloon. Altitude control is provided by a valve which is opened and closed by a barometer. The balloon is made of an organic material which has to absorb radiant energy and to emit as little as possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24726518','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24726518"><span>PAH distribution and <span class="hlt">mass</span> <span class="hlt">fluxes</span> in the Three Gorges Reservoir after impoundment of the Three Gorges Dam.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deyerling, Dominik; Wang, Jingxian; Hu, Wei; Westrich, Bernhard; Peng, Chengrong; Bi, Yonghong; Henkelmann, Bernhard; Schramm, Karl-Werner</p> <p>2014-09-01</p> <p><span class="hlt">Mass</span> <span class="hlt">fluxes</span> of polycyclic aromatic hydrocarbons (PAHs) were calculated for the Three Gorges Reservoir (TGR) in China, based on concentration and discharge data from the Yangtze River. Virtual Organisms (VOs) have been applied during four campaigns in 2008, 2009 (twice) and 2011 at sampling sites distributed from Chongqing to Maoping. The total PAH <span class="hlt">mass</span> <span class="hlt">fluxes</span> ranged from 110 to 2,160 mg s(-1). Highest loads were determined at Chongqing with a decreasing trend towards Maoping in all four sampling campaigns. PAH remediation capacity of the TGR was found to be high as the <span class="hlt">mass</span> <span class="hlt">flux</span> reduced by more than half from upstream to downstream. Responsible processes are thought to be adsorption of PAH to suspended particles, dilution and degradation. Furthermore, the dependence of PAH concentration upon water depth was investigated at Maoping in front of the Three Gorges Dam. Although considerable differences could be revealed, there was no trend observable. Sampling of water with self-packed filter cartridges confirmed more homogenous PAH depth distribution. Moreover, PAH content of suspended particles was estimated from water concentrations gathered by VOs based on a water-particle separation model and subsequently compared to PAH concentration measured in water and in filter cartridges. It could be shown that the modeled data predicts the concentration caused by particle-bound PAHs to be about 6 times lower than PAHs dissolved in water. Besides, the model estimates the proportions of 5- and 6-ring PAHs being higher than in water phase. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26411341','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26411341"><span>Integrated, Step-Wise, <span class="hlt">Mass</span>-Isotopomeric <span class="hlt">Flux</span> Analysis of the TCA Cycle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alves, Tiago C; Pongratz, Rebecca L; Zhao, Xiaojian; Yarborough, Orlando; Sereda, Sam; Shirihai, Orian; Cline, Gary W; Mason, Graeme; Kibbey, Richard G</p> <p>2015-11-03</p> <p><span class="hlt">Mass</span> isotopomer multi-ordinate spectral analysis (MIMOSA) is a step-wise <span class="hlt">flux</span> analysis platform to measure discrete glycolytic and mitochondrial metabolic rates. Importantly, direct citrate synthesis rates were obtained by deconvolving the <span class="hlt">mass</span> spectra generated from [U-(13)C6]-D-glucose labeling for position-specific enrichments of mitochondrial acetyl-CoA, oxaloacetate, and citrate. Comprehensive steady-state and dynamic analyses of key metabolic rates (pyruvate dehydrogenase, β-oxidation, pyruvate carboxylase, isocitrate dehydrogenase, and PEP/pyruvate cycling) were calculated from the position-specific transfer of (13)C from sequential precursors to their products. Important limitations of previous techniques were identified. In INS-1 cells, citrate synthase rates correlated with both insulin secretion and oxygen consumption. Pyruvate carboxylase rates were substantially lower than previously reported but showed the highest fold change in response to glucose stimulation. In conclusion, MIMOSA measures key metabolic rates from the precursor/product position-specific transfer of (13)C-label between metabolites and has broad applicability to any glucose-oxidizing cell. Copyright © 2015 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030762','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030762"><span>Atmospheric bromine <span class="hlt">flux</span> from the coastal Abu Dhabi sabkhat: A ground-water <span class="hlt">mass</span>-balance investigation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wood, W.W.; Sanford, W.E.</p> <p>2007-01-01</p> <p>A solute <span class="hlt">mass</span>-balance study of ground water of the 3000 km2 coastal sabkhat (salt flats) of the Emirate of Abu Dhabi, United Arab Emirates, documents an annual bromide loss of approximately 255 metric tons (0.0032 Gmoles), or 85 kg/km2. This value is an order of magnitude greater than previously published direct measurements from the atmosphere over an evaporative environment of a salar in Bolivia. Laboratory evidence, consistent with published reports, suggests that this loss is by vapor transport to the atmosphere. If this bromine <span class="hlt">flux</span> to the atmosphere is representative of the total earth area of active salt flats then it is a significant, and generally under recognized, input to the global atmospheric bromide <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AMT.....9.5509Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AMT.....9.5509Y"><span>Comparison of two closed-path cavity-based spectrometers for measuring <span class="hlt">air</span>-water CO2 and CH4 <span class="hlt">fluxes</span> by eddy covariance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Mingxi; Prytherch, John; Kozlova, Elena; Yelland, Margaret J.; Parenkat Mony, Deepulal; Bell, Thomas G.</p> <p>2016-11-01</p> <p>In recent years several commercialised closed-path cavity-based spectroscopic instruments designed for eddy covariance <span class="hlt">flux</span> measurements of carbon dioxide (CO2), methane (CH4), and water vapour (H2O) have become available. Here we compare the performance of two leading models - the Picarro G2311-f and the Los Gatos Research (LGR) Fast Greenhouse Gas Analyzer (FGGA) at a coastal site. Both instruments can compute dry mixing ratios of CO2 and CH4 based on concurrently measured H2O, temperature, and pressure. Additionally, we used a high throughput Nafion dryer to physically remove H2O from the Picarro airstream. Observed <span class="hlt">air</span>-sea CO2 and CH4 <span class="hlt">fluxes</span> from these two analysers, averaging about 12 and 0.12 mmol m-2 day-1 respectively, agree within the measurement uncertainties. For the purpose of quantifying dry CO2 and CH4 <span class="hlt">fluxes</span> downstream of a long inlet, the numerical H2O corrections appear to be reasonably effective and lead to results that are comparable to physical removal of H2O with a Nafion dryer in the mean. We estimate the high-frequency attenuation of <span class="hlt">fluxes</span> in our closed-path set-up, which was relatively small ( ≤ 10 %) for CO2 and CH4 but very large for the more polar H2O. The Picarro showed significantly lower noise and <span class="hlt">flux</span> detection limits than the LGR. The hourly <span class="hlt">flux</span> detection limit for the Picarro was about 2 mmol m-2 day-1 for CO2 and 0.02 mmol m-2 day-1 for CH4. For the LGR these detection limits were about 8 and 0.05 mmol m-2 day-1. Using global maps of monthly mean <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> as reference, we estimate that the Picarro and LGR can resolve hourly CO2 <span class="hlt">fluxes</span> from roughly 40 and 4 % of the world's oceans respectively. Averaging over longer timescales would be required in regions with smaller <span class="hlt">fluxes</span>. Hourly <span class="hlt">flux</span> detection limits of CH4 from both instruments are generally higher than the expected emissions from the open ocean, though the signal to noise of this measurement may improve closer to the coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DyAtO..76...14S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DyAtO..76...14S"><span><span class="hlt">Air</span>-sea CO2 <span class="hlt">flux</span> pattern along the southern Bay of Bengal waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shanthi, R.; Poornima, D.; Naveen, M.; Thangaradjou, T.; Choudhury, S. B.; Rao, K. H.; Dadhwal, V. K.</p> <p>2016-12-01</p> <p>Physico-chemical observations made from January 2013 to March 2015 in coastal waters of the southwest Bay of Bengal show pronounced seasonal variation in physico-chemical parameters including total alkalinity (TA: 1927.390-4088.642 μmol kg-1), chlorophyll (0.13-19.41 μg l-1) and also calculated dissolved inorganic carbon (DIC: 1574.219-3790.954 μmol kg-1), partial pressure of carbon dioxide (pCO2: 155.520-1488.607 μatm) and <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> (FCO2: -4.808 to 11.255 mmol Cm-2 d-1). Most of the physical parameters are at their maximum during summer due to the increased solar radiation at cloud free conditions, less or no riverine inputs, and lack of vertical mixing of water column which leads to the lowest nutrients concentration, dissolved oxygen (DO), biological production, pCO2 and negative <span class="hlt">flux</span> of CO2 to the atmosphere. Chlorophyll and DO concentrations enhanced due to increased nutrients during premonsoon and monsoon season due to the vertical mixing of water column driven by the strong winds and external inputs at respective seasons. The constant positive loading of nutrients, TA, DIC, chlorophyll, pCO2 and FCO2 against atmospheric temperature (AT), lux, sea surface temperature (SST), pH and salinity observed in principal component analysis (PCA) suggested that physical and biological parameters play vital role in the seasonal distribution of pCO2 along the southwest Bay of Bengal. The annual variability of CO2 <span class="hlt">flux</span> clearly depicted that the southwest Bay of Bengal switch from sink (2013) to source status in the recent years (2014 and 2015) and it act as significant source of CO2 to the atmosphere with a mean <span class="hlt">flux</span> of 0.204 ± 1.449 mmol Cm-2 d-1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A13F2141B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A13F2141B"><span>Markers for Chinese and Korean <span class="hlt">Air</span> <span class="hlt">Masses</span>: Halocarbons and Other Trace Gases Measured During KORUS-AQ</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blake, N. J.; Blake, D. R.; Meinardi, S.; Simpson, I. J.; Hughes, S.; Barletta, B.; Fleming, L.; Vizenor, N.; Schroeder, J.; Emmons, L. K.; Knote, C. J.</p> <p>2017-12-01</p> <p>The UC-Irvine Whole <span class="hlt">Air</span> Sampler (WAS) collected a total of 2650 samples aboard the NASA DC-8 aircraft in support of the May-June 2016 field deployment phase of the KORUS-AQ mission: An International Cooperative <span class="hlt">Air</span> Quality Field Study in Korea. Here we employ our trace gas measurements, along with CAM-chem tracers and back-trajectories to identify source regions during KORUS-AQ, with a focus on <span class="hlt">air</span> <span class="hlt">masses</span> which indicate Chinese and/or Korean origin. During KORUS-AQ we flew mostly over and around the Korean Peninsula with the intent of characterising Korean sources, but Chinese influence was observed offshore near the surface of the West Sea during several KORUS-AQ flights - in accord with forecast predictions from CAM-chem model runs. Unlike previous missions in the Asian region such as TRACE-P (2001), we found that halon-1211 (H-1211) is no longer a useful indicator of <span class="hlt">air</span> <span class="hlt">masses</span> from China because of production decline. By contrast, mixing ratios of the long-lived halocarbons carbon tetrachloride (CCl4) and chlorofluorocarbon-113 (CFC-113) were more strongly enhanced in <span class="hlt">air</span> <span class="hlt">masses</span> intercepted from China compared to Korea. We will use these tracers, the shorter-lived halocarbons, dichloromethane (CH2Cl2) and methyl chloride (CH3Cl), as well as the sulfur gas carbonyl sulfide (COS) and others, to characterize different regional <span class="hlt">air</span> <span class="hlt">mass</span> origins and their sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3138023','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3138023"><span>Remediation of Chlorinated Solvent Plumes Using In-Situ <span class="hlt">Air</span> Sparging—A 2-D Laboratory Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Adams, Jeffrey A.; Reddy, Krishna R.; Tekola, Lue</p> <p>2011-01-01</p> <p>In-situ <span class="hlt">air</span> sparging has evolved as an innovative technique for soil and groundwater remediation impacted with volatile organic compounds (VOCs), including chlorinated solvents. These may exist as non-aqueous phase liquid (NAPL) or dissolved in groundwater. This study assessed: (1) how <span class="hlt">air</span> injection rate affects the <span class="hlt">mass</span> removal of dissolved phase contamination, (2) the effect of induced groundwater flow on <span class="hlt">mass</span> removal and <span class="hlt">air</span> distribution during <span class="hlt">air</span> injection, and (3) the effect of initial contaminant concentration on <span class="hlt">mass</span> removal. Dissolved-phase chlorinated solvents can be effectively removed through the use of <span class="hlt">air</span> sparging; however, rapid initial rates of contaminant removal are followed by a protracted period of lower removal rates, or a tailing effect. As the <span class="hlt">air</span> flow rate increases, the rate of contaminant removal also increases, especially during the initial stages of <span class="hlt">air</span> injection. Increased <span class="hlt">air</span> injection rates will increase the density of <span class="hlt">air</span> channel formation, resulting in a larger interfacial <span class="hlt">mass</span> transfer area through which the dissolved contaminant can partition into the vapor phase. In cases of groundwater flow, increased rates of <span class="hlt">air</span> injection lessened observed downward contaminant migration effect. The <span class="hlt">air</span> channel network and increased <span class="hlt">air</span> saturation reduced relative hydraulic conductivity, resulting in reduced groundwater flow and subsequent downgradient contaminant migration. Finally, when a higher initial TCE concentration was present, a slightly higher <span class="hlt">mass</span> removal rate was observed due to higher volatilization-induced concentration gradients and subsequent diffusive <span class="hlt">flux</span>. Once concentrations are reduced, a similar tailing effect occurs. PMID:21776228</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21776228','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21776228"><span>Remediation of chlorinated solvent plumes using in-situ <span class="hlt">air</span> sparging--a 2-D laboratory study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Adams, Jeffrey A; Reddy, Krishna R; Tekola, Lue</p> <p>2011-06-01</p> <p>In-situ <span class="hlt">air</span> sparging has evolved as an innovative technique for soil and groundwater remediation impacted with volatile organic compounds (VOCs), including chlorinated solvents. These may exist as non-aqueous phase liquid (NAPL) or dissolved in groundwater. This study assessed: (1) how <span class="hlt">air</span> injection rate affects the <span class="hlt">mass</span> removal of dissolved phase contamination, (2) the effect of induced groundwater flow on <span class="hlt">mass</span> removal and <span class="hlt">air</span> distribution during <span class="hlt">air</span> injection, and (3) the effect of initial contaminant concentration on <span class="hlt">mass</span> removal. Dissolved-phase chlorinated solvents can be effectively removed through the use of <span class="hlt">air</span> sparging; however, rapid initial rates of contaminant removal are followed by a protracted period of lower removal rates, or a tailing effect. As the <span class="hlt">air</span> flow rate increases, the rate of contaminant removal also increases, especially during the initial stages of <span class="hlt">air</span> injection. Increased <span class="hlt">air</span> injection rates will increase the density of <span class="hlt">air</span> channel formation, resulting in a larger interfacial <span class="hlt">mass</span> transfer area through which the dissolved contaminant can partition into the vapor phase. In cases of groundwater flow, increased rates of <span class="hlt">air</span> injection lessened observed downward contaminant migration effect. The <span class="hlt">air</span> channel network and increased <span class="hlt">air</span> saturation reduced relative hydraulic conductivity, resulting in reduced groundwater flow and subsequent downgradient contaminant migration. Finally, when a higher initial TCE concentration was present, a slightly higher <span class="hlt">mass</span> removal rate was observed due to higher volatilization-induced concentration gradients and subsequent diffusive <span class="hlt">flux</span>. Once concentrations are reduced, a similar tailing effect occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28402293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28402293"><span>Influence of relative <span class="hlt">air</span>/water flow velocity on oxygen <span class="hlt">mass</span> transfer in gravity sewers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carrera, Lucie; Springer, Fanny; Lipeme-Kouyi, Gislain; Buffiere, Pierre</p> <p>2017-04-01</p> <p>Problems related to hydrogen sulfide may be serious for both network stakeholders and the public in terms of health, sustainability of the sewer structure and urban comfort. H 2 S emission models are generally theoretical and simplified in terms of environmental conditions. Although <span class="hlt">air</span> transport characteristics in sewers must play a role in the fate of hydrogen sulfide, only a limited number of studies have investigated this issue. The aim of this study was to better understand H 2 S liquid to gas transfer by highlighting the link between the <span class="hlt">mass</span> transfer coefficient and the turbulence in the <span class="hlt">air</span> flow and the water flow. For experimental safety reasons, O 2 was taken as a model compound. The oxygen <span class="hlt">mass</span> transfer coefficients were obtained using a <span class="hlt">mass</span> balance in plug flow. The <span class="hlt">mass</span> transfer coefficient was not impacted by the range of the interface <span class="hlt">air</span>-flow velocity values tested (0.55-2.28 m·s -1 ) or the water velocity values (0.06-0.55 m·s -1 ). Using the ratio between k L,O 2 to k L,H 2 S , the H 2 S <span class="hlt">mass</span> transfer behavior in a gravity pipe in the same hydraulic conditions can be predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhRvD..58h4011F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhRvD..58h4011F"><span>Critical energy <span class="hlt">flux</span> and <span class="hlt">mass</span> in solvable theories of 2D dilaton gravity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fabbri, A.; Navarro-Salas, J.</p> <p>1998-10-01</p> <p>In this paper we address the issue of determining the semiclassical threshold for black hole formation in the context of a one-parameter family of theories which continuously interpolates between the RST and BPP models. We find that the results depend significantly on the initial static configuration of the spacetime geometry before the influx of matter is turned on. In some cases there is a critical energy density, given by the Hawking rate of evaporation, as well as a critical <span class="hlt">mass</span> mcr (eventually vanishing). In others there is neither mcr nor a critical <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940008316','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940008316"><span>Measuring surface <span class="hlt">fluxes</span> in CAPE</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kanemasu, E. T.; D-Shah, T.; Nie, Dalin</p> <p>1992-01-01</p> <p>Two stations (site 1612 and site 2008) were operated by the University of Georgia group from 6 July 1991 to 18 August 1991. The following data were collected continuously: surface energy <span class="hlt">fluxes</span> (i.e., net radiation, soil heat <span class="hlt">fluxes</span>, sensible heat <span class="hlt">flux</span> and latent heat <span class="hlt">flux</span>), <span class="hlt">air</span> temperature, vapor pressure, soil temperature (at 1 cm depth), and precipitation. Canopy reflectance and light interception data were taken three times at each site between 6 July and 18 August. Soil moisture content was measured twice at each site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=289282','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=289282"><span>Measurement of particulate matter emission <span class="hlt">fluxes</span> from a beef cattle feedlot using <span class="hlt">Flux</span>-gradient technique</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Data on <span class="hlt">air</span> emissions from open-lot beef cattle feedlots are limited. This research was conducted to determine PM10 emission <span class="hlt">fluxes</span> from a commercial beef cattle feedlot in Kansas using the <span class="hlt">flux</span>-gradient technique, a widely-used micrometeorological method for gaseous emissions from open sources. V...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15859112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15859112"><span>Measurement of the oxygen <span class="hlt">mass</span> transfer through the <span class="hlt">air</span>-water interface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mölder, Erik; Mashirin, Alelxei; Tenno, Toomas</p> <p>2005-01-01</p> <p>Gas <span class="hlt">mass</span> transfer through the liquid-gas interface has enormous importance in various natural and industrial processes. Surfactants or insoluble compounds adsorbed onto an interface will inhibit the gas <span class="hlt">mass</span> transfer through the liquid-gas surface. This study presents a technique for measuring the oxygen <span class="hlt">mass</span> transfer through the <span class="hlt">air</span>-water interface. Experimental data obtained with the measuring device were incorporated into a novel mathematical model, which allowed one to calculate diffusion conduction of liquid surface layer and oxygen <span class="hlt">mass</span> transfer coefficient in the liquid surface layer. A special measurement cell was constructed. The most important part of the measurement cell is a chamber containing the electrochemical oxygen sensor inside it. Gas exchange between the volume of the chamber and the external environment takes place only through the investigated surface layer. Investigated liquid was deoxygenated, which triggers the oxygen <span class="hlt">mass</span> transfer from the chamber through the liquid-<span class="hlt">air</span> interface into the liquid phase. The decrease of oxygen concentration in the cell during time was measured. By using this data it is possible to calculate diffusional parameters of the water surface layer. Diffusion conduction of oxygen through the <span class="hlt">air</span>-water surface layer of selected wastewaters was measured. The diffusion conduction of different wastewaters was about 3 to 6 times less than in the unpolluted water surface. It was observed that the dilution of wastewater does not have a significant impact on the oxygen diffusion conduction through the wastewater surface layer. This fact can be explained with the presence of the compounds with high surface activity in the wastewater. Surfactants achieved a maximum adsorption and, accordingly, the maximum decrease of oxygen permeability already at a very low concentration of surfactants in the solution. Oxygen <span class="hlt">mass</span> transfer coefficient of the surface layer of the water is found to be Ds/ls = 0.13 x 10(-3) x cm/s. A simple</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016490','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016490"><span>The Use of Red Green Blue <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery to Investigate the Role of Stratospheric <span class="hlt">Air</span> in a Non-Convective Wind Event</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, E. B.; Zavodsky, B. T.; Moltham, A. L.; Folmer, M. J.; Jedlovec, G. J.</p> <p>2014-01-01</p> <p>The investigation of non-convective winds associated with passing extratropical cyclones and the formation of the sting jet in North Atlantic cyclones that impact Europe has been gaining interest. Sting jet research has been limited to North Atlantic cyclones that impact Europe because it is known to occur in Shapiro-Keyser cyclones and theory suggests it does not occur in Norwegian type cyclones. The global distribution of sting jet cyclones is unknown and questions remain as to whether cyclones with Shapiro-Keyser characteristics that impact the United States develop features similar to the sting jet. Therefore unique National Aeronautics and Space Administration (NASA) products were used to analyze an event that impacted the Northeast United States on 09 February 2013. Moderate Resolution Imaging Spectroradiometer (MODIS) Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery and Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) ozone data were used in conjunction with NASA's global Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis and higher-resolution regional 13-km Rapid Refresh (RAP) data to analyze the role of stratospheric <span class="hlt">air</span> in producing high winds. The RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery and a new <span class="hlt">AIRS</span> ozone anomaly product were used to confirm the presence of stratospheric <span class="hlt">air</span>. Plan view and cross sectional plots of wind, potential vorticity, relative humidity, omega, and frontogenesis were used to analyze the relationship between stratospheric <span class="hlt">air</span> and high surface winds during the event. Additionally, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to plot trajectories to determine the role of the conveyor belts in producing the high winds. Analyses of new satellite products, such as the RGB <span class="hlt">Air</span> <span class="hlt">Mass</span> imagery, show the utility of future GOES-R products in forecasting non-convective wind events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Tensor&pg=4&id=EJ265056','ERIC'); return false;" href="https://eric.ed.gov/?q=Tensor&pg=4&id=EJ265056"><span>On the Tensorial Nature of <span class="hlt">Fluxes</span> in Continuous Media.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stokes, Vijay Kumar; Ramkrishna, Doraiswami</p> <p>1982-01-01</p> <p>Argues that <span class="hlt">mass</span> and energy <span class="hlt">fluxes</span> in a fluid are vectors. Topics include the stress tensor, theorem for tensor fields, <span class="hlt">mass</span> <span class="hlt">flux</span> as a vector, stress as a second order tensor, and energy <span class="hlt">flux</span> as a tensor. (SK)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880012242','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880012242"><span><span class="hlt">Mass</span>, heat and nutrient <span class="hlt">fluxes</span> in the Atlantic Ocean determined by inverse methods. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rintoul, Stephen Rich</p> <p>1988-01-01</p> <p>Inverse methods are applied to historical hydrographic data to address two aspects of the general circulation of the Atlantic Ocean. The method allows conservation statements for <span class="hlt">mass</span> and other properties, along with a variety of other constraints, to be combined in a dynamically consistent way to estimate the absolute velocity field and associated property transports. The method was first used to examine the exchange of <span class="hlt">mass</span> and heat between the South Atlantic and the neighboring ocean basins. The second problem addressed concerns the circulation and property <span class="hlt">fluxes</span> across the 24 and 36 deg N in the subtropical North Atlantic. Conservation statements are considered for the nutrients as well as <span class="hlt">mass</span>, and the nutrients are found to contribute significant information independent of temperature and salinity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A23A0183Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A23A0183Z"><span>An <span class="hlt">Air</span> <span class="hlt">Mass</span> Based Approach to the Establishment of Spring Season Synoptic Characteristics in the Northeast United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zander, R.; Messina, A.; Godek, M. L.</p> <p>2012-12-01</p> <p>The spring season is indicative of marked meteorological, ecological, and biological changes across the Northeast United States. The onset of spring coincides with distinct meteorological phenomena including an increase in severe weather events and snow meltwaters that can cause localized flooding and other costly damages. Increasing and variable springtime temperatures also influence Northeast tourist operations and agricultural productivity. Even with the vested interest of industry in the season and public awareness of the dynamic characteristics of spring, the definition of spring remains somewhat arbitrary. The primary goal of this research is to obtain a synoptic meteorological definition of the spring season through an assessment of <span class="hlt">air</span> <span class="hlt">mass</span> frequency over the past 60 years. A secondary goal examines the validity of recent speculations that the onset and termination of spring has changed in recent decades, particularly since 1975. The Spatial Synoptic Classification is utilized to define daily <span class="hlt">air</span> <span class="hlt">masses</span> over the region. Annual and seasonal baseline frequencies are identified and their differences are acquired to characterize the season. Seasonal frequency departures of the early and late segments of the period of record around 1975 are calculated and examined for practical and statistical significance. The daily boundaries of early and late spring are then isolated and frequencies are obtained for these periods. Boundary frequencies are assessed across the period of record to identify important changes in the season's initiation and termination through time. Results indicate that the Northeast spring season is dominated by dry <span class="hlt">air</span> <span class="hlt">masses</span>, mainly the Dry Moderate and Dry Polar types. Significant differences in seasonal <span class="hlt">air</span> <span class="hlt">mass</span> frequency are also observed through time. Prior to 1975, higher frequencies of polar <span class="hlt">air</span> <span class="hlt">mass</span> types are detected while after 1975 there is an increase in the frequencies of both moderate and tropical types. This finding is also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.1191B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.1191B"><span>Variations of the Electron <span class="hlt">Fluxes</span> in the Terrestrial Radiation Belts Due To the Impact of Corotating Interaction Regions and Interplanetary Coronal <span class="hlt">Mass</span> Ejections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benacquista, R.; Boscher, D.; Rochel, S.; Maget, V.</p> <p>2018-02-01</p> <p>In this paper, we study the variations of the radiation belts electron <span class="hlt">fluxes</span> induced by the interaction of two types of solar wind structures with the Earth magnetosphere: the corotating interaction regions and the interplanetary coronal <span class="hlt">mass</span> ejections. We use a statistical method based on the comparison of the preevent and postevent <span class="hlt">fluxes</span>. Applied to the National Oceanic and Atmospheric Administration-Polar Operational Environmental Satellites data, this gives us the opportunity to extend previous studies focused on relativistic electrons at geosynchronous orbit. We enlighten how corotating interaction regions and Interplanetary Coronal <span class="hlt">Mass</span> Ejections can impact differently the electron belts depending on the energy and the L shell. In addition, we provide a new insight concerning these variations by considering their amplitude. Finally, we show strong relations between the intensity of the magnetic storms related to the events and the variation of the <span class="hlt">flux</span>. These relations concern both the capacity of the events to increase the <span class="hlt">flux</span> and the deepness of these increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH52A..02V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH52A..02V"><span>Modeling Coronal <span class="hlt">Mass</span> Ejections with EUHFORIA: A Parameter Study of the Gibson-Low <span class="hlt">Flux</span> Rope Model using Multi-Viewpoint Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verbeke, C.; Asvestari, E.; Scolini, C.; Pomoell, J.; Poedts, S.; Kilpua, E.</p> <p>2017-12-01</p> <p>Coronal <span class="hlt">Mass</span> Ejections (CMEs) are one of the big influencers on the coronal and interplanetary dynamics. Understanding their origin and evolution from the Sun to the Earth is crucial in order to determine the impact on our Earth and society. One of the key parameters that determine the geo-effectiveness of the coronal <span class="hlt">mass</span> ejection is its internal magnetic configuration. We present a detailed parameter study of the Gibson-Low <span class="hlt">flux</span> rope model. We focus on changes in the input parameters and how these changes affect the characteristics of the CME at Earth. Recently, the Gibson-Low <span class="hlt">flux</span> rope model has been implemented into the inner heliosphere model EUHFORIA, a magnetohydrodynamics forecasting model of large-scale dynamics from 0.1 AU up to 2 AU. Coronagraph observations can be used to constrain the kinematics and morphology of the <span class="hlt">flux</span> rope. One of the key parameters, the magnetic field, is difficult to determine directly from observations. In this work, we approach the problem by conducting a parameter study in which <span class="hlt">flux</span> ropes with varying magnetic configurations are simulated. We then use the obtained dataset to look for signatures in imaging observations and in-situ observations in order to find an empirical way of constraining the parameters related to the magnetic field of the <span class="hlt">flux</span> rope. In particular, we focus on events observed by at least two spacecraft (STEREO + L1) in order to discuss the merits of using observations from multiple viewpoints in constraining the parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29780287','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29780287"><span>Forward Modeling of Coronal <span class="hlt">Mass</span> Ejection <span class="hlt">Flux</span> Ropes in the Inner Heliosphere with 3DCORE.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Möstl, C; Amerstorfer, T; Palmerio, E; Isavnin, A; Farrugia, C J; Lowder, C; Winslow, R M; Donnerer, J M; Kilpua, E K J; Boakes, P D</p> <p>2018-03-01</p> <p>Forecasting the geomagnetic effects of solar storms, known as coronal <span class="hlt">mass</span> ejections (CMEs), is currently severely limited by our inability to predict the magnetic field configuration in the CME magnetic core and by observational effects of a single spacecraft trajectory through its 3-D structure. CME magnetic <span class="hlt">flux</span> ropes can lead to continuous forcing of the energy input to the Earth's magnetosphere by strong and steady southward-pointing magnetic fields. Here we demonstrate in a proof-of-concept way a new approach to predict the southward field B z in a CME <span class="hlt">flux</span> rope. It combines a novel semiempirical model of CME <span class="hlt">flux</span> rope magnetic fields (Three-Dimensional Coronal ROpe Ejection) with solar observations and in situ magnetic field data from along the Sun-Earth line. These are provided here by the MESSENGER spacecraft for a CME event on 9-13 July 2013. Three-Dimensional Coronal ROpe Ejection is the first such model that contains the interplanetary propagation and evolution of a 3-D <span class="hlt">flux</span> rope magnetic field, the observation by a synthetic spacecraft, and the prediction of an index of geomagnetic activity. A counterclockwise rotation of the left-handed erupting CME <span class="hlt">flux</span> rope in the corona of 30° and a deflection angle of 20° is evident from comparison of solar and coronal observations. The calculated Dst matches reasonably the observed Dst minimum and its time evolution, but the results are highly sensitive to the CME axis orientation. We discuss assumptions and limitations of the method prototype and its potential for real time space weather forecasting and heliospheric data interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SpWea..16..216M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SpWea..16..216M"><span>Forward Modeling of Coronal <span class="hlt">Mass</span> Ejection <span class="hlt">Flux</span> Ropes in the Inner Heliosphere with 3DCORE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Möstl, C.; Amerstorfer, T.; Palmerio, E.; Isavnin, A.; Farrugia, C. J.; Lowder, C.; Winslow, R. M.; Donnerer, J. M.; Kilpua, E. K. J.; Boakes, P. D.</p> <p>2018-03-01</p> <p>Forecasting the geomagnetic effects of solar storms, known as coronal <span class="hlt">mass</span> ejections (CMEs), is currently severely limited by our inability to predict the magnetic field configuration in the CME magnetic core and by observational effects of a single spacecraft trajectory through its 3-D structure. CME magnetic <span class="hlt">flux</span> ropes can lead to continuous forcing of the energy input to the Earth's magnetosphere by strong and steady southward-pointing magnetic fields. Here we demonstrate in a proof-of-concept way a new approach to predict the southward field Bz in a CME <span class="hlt">flux</span> rope. It combines a novel semiempirical model of CME <span class="hlt">flux</span> rope magnetic fields (Three-Dimensional Coronal ROpe Ejection) with solar observations and in situ magnetic field data from along the Sun-Earth line. These are provided here by the MESSENGER spacecraft for a CME event on 9-13 July 2013. Three-Dimensional Coronal ROpe Ejection is the first such model that contains the interplanetary propagation and evolution of a 3-D <span class="hlt">flux</span> rope magnetic field, the observation by a synthetic spacecraft, and the prediction of an index of geomagnetic activity. A counterclockwise rotation of the left-handed erupting CME <span class="hlt">flux</span> rope in the corona of 30° and a deflection angle of 20° is evident from comparison of solar and coronal observations. The calculated Dst matches reasonably the observed Dst minimum and its time evolution, but the results are highly sensitive to the CME axis orientation. We discuss assumptions and limitations of the method prototype and its potential for real time space weather forecasting and heliospheric data interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663292-eruption-small-scale-emerging-flux-rope-driver-class-flare-coronal-mass-ejection','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663292-eruption-small-scale-emerging-flux-rope-driver-class-flare-coronal-mass-ejection"><span>The Eruption of a Small-scale Emerging <span class="hlt">Flux</span> Rope as the Driver of an M-class Flare and of a Coronal <span class="hlt">Mass</span> Ejection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yan, X. L.; Xue, Z. K.; Wang, J. C.</p> <p></p> <p>Solar flares and coronal <span class="hlt">mass</span> ejections are the most powerful explosions in the Sun. They are major sources of potentially destructive space weather conditions. However, the possible causes of their initiation remain controversial. Using high-resolution data observed by the New Solar Telescope of Big Bear Solar Observatory, supplemented by Solar Dynamics Observatory observations, we present unusual observations of a small-scale emerging <span class="hlt">flux</span> rope near a large sunspot, whose eruption produced an M-class flare and a coronal <span class="hlt">mass</span> ejection. The presence of the small-scale <span class="hlt">flux</span> rope was indicated by static nonlinear force-free field extrapolation as well as data-driven magnetohydrodynamics modeling ofmore » the dynamic evolution of the coronal three-dimensional magnetic field. During the emergence of the <span class="hlt">flux</span> rope, rotation of satellite sunspots at the footpoints of the <span class="hlt">flux</span> rope was observed. Meanwhile, the Lorentz force, magnetic energy, vertical current, and transverse fields were increasing during this phase. The free energy from the magnetic <span class="hlt">flux</span> emergence and twisting magnetic fields is sufficient to power the M-class flare. These observations present, for the first time, the complete process, from the emergence of the small-scale <span class="hlt">flux</span> rope, to the production of solar eruptions.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18676059','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18676059"><span>Investigation of surfactant-enhanced <span class="hlt">mass</span> removal and <span class="hlt">flux</span> reduction in 3D correlated permeability fields using magnetic resonance imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Changyong; Werth, Charles J; Webb, Andrew G</p> <p>2008-09-10</p> <p>Magnetic resonance imaging (MRI) was used to visualize the NAPL source zone architecture before and after surfactant-enhanced NAPL dissolution in three-dimensional (3D) heterogeneously packed flowcells characterized by different longitudinal correlation lengths: 2.1 cm (aquifer 1) and 1.1 cm (aquifer 2). Surfactant flowpaths were determined by imaging the breakthrough of a paramagnetic tracer (MnCl(2)) analyzed by the method of moments. In both experimental aquifers, preferential flow occurred in high permeability materials with low NAPL saturations, and NAPL was preferentially removed from the top of the aquifers with low saturation. Alternate flushing with water and two surfactant pulses (5-6 pore volumes each) resulted in approximately 63% of NAPL <span class="hlt">mass</span> removal from both aquifers. However, overall reduction in <span class="hlt">mass</span> <span class="hlt">flux</span> (<span class="hlt">Mass</span> <span class="hlt">Flux</span> 1) exiting the flowcell was lower in aquifer 2 (68%) than in aquifer 1 (81%), and local effluent concentrations were found to increase by as high as 120 times at local sampling ports from aquifer 2 after surfactant flushing. 3D MRI images of NAPL revealed that NAPL migrated downward and created additional NAPL source zones in previously uncontaminated areas at the bottom of the aquifers. The additional NAPL source zones were created in the direction transverse to flow in aquifer 2, which explains the higher <span class="hlt">mass</span> <span class="hlt">flux</span> relative to aquifer 1. Analysis using a total trapping number indicates that mobilization of NAPL trapped in the two coarsest sand fractions is possible when saturation is below 0.5 and 0.4, respectively. Results from this study highlight the potential impacts of porous media heterogeneity and NAPL source zone architecture on advanced in-situ flushing technologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/42116','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/42116"><span>How well can we measure the vertical wind speed? Implications for <span class="hlt">fluxes</span> of energy and <span class="hlt">mass</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>John Kochendorfer; Tilden P. Meyers; John Frank; William J. Massman; Mark W. Heuer</p> <p>2012-01-01</p> <p>Sonic anemometers are capable of measuring the wind speed in all three dimensions at high frequencies (10­50 Hz), and are relied upon to estimate eddy-covariance-based <span class="hlt">fluxes</span> of <span class="hlt">mass</span> and energy over a wide variety of surfaces and ecosystems. In this study, wind-velocity measurement errors from a three-dimensional sonic anemometer with a nonorthogonal transducer...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18540967','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18540967"><span>Foraging theory predicts predator-prey energy <span class="hlt">fluxes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brose, U; Ehnes, R B; Rall, B C; Vucic-Pestic, O; Berlow, E L; Scheu, S</p> <p>2008-09-01</p> <p>1. In natural communities, populations are linked by feeding interactions that make up complex food webs. The stability of these complex networks is critically dependent on the distribution of energy <span class="hlt">fluxes</span> across these feeding links. 2. In laboratory experiments with predatory beetles and spiders, we studied the allometric scaling (body-<span class="hlt">mass</span> dependence) of metabolism and per capita consumption at the level of predator individuals and per link energy <span class="hlt">fluxes</span> at the level of feeding links. 3. Despite clear power-law scaling of the metabolic and per capita consumption rates with predator body <span class="hlt">mass</span>, the per link predation rates on individual prey followed hump-shaped relationships with the predator-prey body <span class="hlt">mass</span> ratios. These results contrast with the current metabolic paradigm, and find better support in foraging theory. 4. This suggests that per link energy <span class="hlt">fluxes</span> from prey populations to predator individuals peak at intermediate body <span class="hlt">mass</span> ratios, and total energy <span class="hlt">fluxes</span> from prey to predator populations decrease monotonically with predator and prey <span class="hlt">mass</span>. Surprisingly, contrary to predictions of metabolic models, this suggests that for any prey species, the per link and total energy <span class="hlt">fluxes</span> to its largest predators are smaller than those to predators of intermediate body size. 5. An integration of metabolic and foraging theory may enable a quantitative and predictive understanding of energy <span class="hlt">flux</span> distributions in natural food webs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140005809','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140005809"><span>CO2 <span class="hlt">Flux</span> Estimation Errors Associated with Moist Atmospheric Processes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parazoo, N. C.; Denning, A. S.; Kawa, S. R.; Pawson, S.; Lokupitiya, R.</p> <p>2012-01-01</p> <p>Vertical transport by moist sub-grid scale processes such as deep convection is a well-known source of uncertainty in CO2 source/sink inversion. However, a dynamical link between vertical transport, satellite based retrievals of column mole fractions of CO2, and source/sink inversion has not yet been established. By using the same offline transport model with meteorological fields from slightly different data assimilation systems, we examine sensitivity of frontal CO2 transport and retrieved <span class="hlt">fluxes</span> to different parameterizations of sub-grid vertical transport. We find that frontal transport feeds off background vertical CO2 gradients, which are modulated by sub-grid vertical transport. The implication for source/sink estimation is two-fold. First, CO2 variations contained in moist poleward moving <span class="hlt">air</span> <span class="hlt">masses</span> are systematically different from variations in dry equatorward moving <span class="hlt">air</span>. Moist poleward transport is hidden from orbital sensors on satellites, causing a sampling bias, which leads directly to small but systematic <span class="hlt">flux</span> retrieval errors in northern mid-latitudes. Second, differences in the representation of moist sub-grid vertical transport in GEOS-4 and GEOS-5 meteorological fields cause differences in vertical gradients of CO2, which leads to systematic differences in moist poleward and dry equatorward CO2 transport and therefore the fraction of CO2 variations hidden in moist <span class="hlt">air</span> from satellites. As a result, sampling biases are amplified and regional scale <span class="hlt">flux</span> errors enhanced, most notably in Europe (0.43+/-0.35 PgC /yr). These results, cast from the perspective of moist frontal transport processes, support previous arguments that the vertical gradient of CO2 is a major source of uncertainty in source/sink inversion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.2671L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.2671L"><span>On the role of sea-state in bubble-mediated <span class="hlt">air</span>-sea gas <span class="hlt">flux</span> during a winter storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, Jun-Hong; Emerson, Steven R.; D'Asaro, Eric A.; McNeil, Craig L.; Harcourt, Ramsey R.; Sullivan, Peter P.; Yang, Bo; Cronin, Meghan F.</p> <p>2017-04-01</p> <p>Oceanic bubbles play an important role in the <span class="hlt">air</span>-sea exchange of weakly soluble gases at moderate to high wind speeds. A Lagrangian bubble model embedded in a large eddy simulation model is developed to study bubbles and their influence on dissolved gases in the upper ocean. The transient evolution of mixed-layer dissolved oxygen and nitrogen gases at Ocean Station Papa (50°N, 145°W) during a winter storm is reproduced with the model. Among different physical processes, gas bubbles are the most important in elevating dissolved gas concentrations during the storm, while atmospheric pressure governs the variability of gas saturation anomaly (the relative departure of dissolved gas concentration from the saturation concentration). For the same wind speed, bubble-mediated gas <span class="hlt">fluxes</span> are larger during rising wind with smaller wave age than during falling wind with larger wave age. Wave conditions are the primary cause for the bubble gas <span class="hlt">flux</span> difference: when wind strengthens, waves are less-developed with respect to wind, resulting in more frequent large breaking waves. Bubble generation in large breaking waves is favorable for a large bubble-mediated gas <span class="hlt">flux</span>. The wave-age dependence is not included in any existing bubble-mediated gas <span class="hlt">flux</span> parameterizations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26950394','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26950394"><span>Calculating <span class="hlt">flux</span> to predict future cave radon concentrations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rowberry, Matt D; Martí, Xavi; Frontera, Carlos; Van De Wiel, Marco J; Briestenský, Miloš</p> <p>2016-06-01</p> <p>Cave radon concentration measurements reflect the outcome of a perpetual competition which pitches <span class="hlt">flux</span> against ventilation and radioactive decay. The <span class="hlt">mass</span> balance equations used to model changes in radon concentration through time routinely treat <span class="hlt">flux</span> as a constant. This mathematical simplification is acceptable as a first order approximation despite the fact that it sidesteps an intrinsic geological problem: the majority of radon entering a cavity is exhaled as a result of advection along crustal discontinuities whose motions are inhomogeneous in both time and space. In this paper the dynamic nature of <span class="hlt">flux</span> is investigated and the results are used to predict cave radon concentration for successive iterations. The first part of our numerical modelling procedure focuses on calculating cave <span class="hlt">air</span> flow velocity while the second part isolates <span class="hlt">flux</span> in a <span class="hlt">mass</span> balance equation to simulate real time dependence among the variables. It is then possible to use this information to deliver an expression for computing cave radon concentration for successive iterations. The dynamic variables in the numerical model are represented by the outer temperature, the inner temperature, and the radon concentration while the static variables are represented by the radioactive decay constant and a range of parameters related to geometry of the cavity. Input data were recorded at Driny Cave in the Little Carpathians Mountains of western Slovakia. Here the cave passages have developed along splays of the NE-SW striking Smolenice Fault and a series of transverse faults striking NW-SE. Independent experimental observations of fault slip are provided by three permanently installed mechanical extensometers. Our numerical modelling has revealed four important <span class="hlt">flux</span> anomalies between January 2010 and August 2011. Each of these <span class="hlt">flux</span> anomalies was preceded by conspicuous fault slip anomalies. The mathematical procedure outlined in this paper will help to improve our understanding of radon migration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1791W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1791W"><span>Modelling storm development and the impact when introducing waves, sea spray and heat <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Lichuan; Rutgersson, Anna; Sahlée, Erik</p> <p>2015-04-01</p> <p>In high wind speed conditions, sea spray generated due to intensity breaking waves have big influence on the wind stress and heat <span class="hlt">fluxes</span>. Measurements show that drag coefficient will decrease in high wind speed. Sea spray generation function (SSGF), an important term of wind stress parameterization in high wind speed, usually treated as a function of wind speed/friction velocity. In this study, we introduce a wave state depended SSGG and wave age depended Charnock number into a high wind speed wind stress parameterization (Kudryavtsev et al., 2011; 2012). The proposed wind stress parameterization and sea spray heat <span class="hlt">fluxes</span> parameterization from Andreas et al., (2014) were applied to an atmosphere-wave coupled model to test on four storm cases. Compared with measurements from the FINO1 platform in the North Sea, the new wind stress parameterization can reduce the forecast errors of wind in high wind speed range, but not in low wind speed. Only sea spray impacted on wind stress, it will intensify the storms (minimum sea level pressure and maximum wind speed) and lower the <span class="hlt">air</span> temperature (increase the errors). Only the sea spray impacted on the heat <span class="hlt">fluxes</span>, it can improve the model performance on storm tracks and the <span class="hlt">air</span> temperature, but not change much in the storm intensity. If both of sea spray impacted on the wind stress and heat <span class="hlt">fluxes</span> are taken into account, it has the best performance in all the experiment for minimum sea level pressure and maximum wind speed and <span class="hlt">air</span> temperature. Andreas, E. L., Mahrt, L., and Vickers, D. (2014). An improved bulk <span class="hlt">air</span>-sea surface <span class="hlt">flux</span> algorithm, including spray-mediated transfer. Quarterly Journal of the Royal Meteorological Society. Kudryavtsev, V. and Makin, V. (2011). Impact of ocean spray on the dynamics of the marine atmospheric boundary layer. Boundary-layer meteorology, 140(3):383-410. Kudryavtsev, V., Makin, V., and S, Z. (2012). On the sea-surface drag and heat/<span class="hlt">mass</span> transfer at strong winds. Technical report, Royal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880025659&hterms=water+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Beffects','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880025659&hterms=water+effects&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Beffects"><span>Seasonal <span class="hlt">air</span> and water <span class="hlt">mass</span> redistribution effects on LAGEOS and Starlette</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gutierrez, Roberto; Wilson, Clark R.</p> <p>1987-01-01</p> <p>Zonal geopotential coefficients have been computed from average seasonal variations in global <span class="hlt">air</span> and water <span class="hlt">mass</span> distribution. These coefficients are used to predict the seasonal variations of LAGEOS' and Starlette's orbital node, the node residual, and the seasonal variation in the 3rd degree zonal coefficient for Starlette. A comparison of these predictions with the observed values indicates that <span class="hlt">air</span> pressure and, to a lesser extent, water storage may be responsible for a large portion of the currently unmodeled variation in the earth's gravity field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.655a2035D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.655a2035D"><span>Modelling heat and <span class="hlt">mass</span> transfer in a membrane-based <span class="hlt">air-to-air</span> enthalpy exchanger</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dugaria, S.; Moro, L.; Del, D., Col</p> <p>2015-11-01</p> <p>The diffusion of total energy recovery systems could lead to a significant reduction in the energy demand for building <span class="hlt">air</span>-conditioning. With these devices, sensible heat and humidity can be recovered in winter from the exhaust airstream, while, in summer, the incoming <span class="hlt">air</span> stream can be cooled and dehumidified by transferring the excess heat and moisture to the exhaust <span class="hlt">air</span> stream. Membrane based enthalpy exchangers are composed by different channels separated by semi-permeable membranes. The membrane allows moisture transfer under vapour pressure difference, or water concentration difference, between the two sides and, at the same time, it is ideally impermeable to <span class="hlt">air</span> and other contaminants present in exhaust <span class="hlt">air</span>. Heat transfer between the airstreams occurs through the membrane due to the temperature gradient. The aim of this work is to develop a detailed model of the coupled heat and <span class="hlt">mass</span> transfer mechanisms through the membrane between the two airstreams. After a review of the most relevant models published in the scientific literature, the governing equations are presented and some simplifying assumptions are analysed and discussed. As a result, a steady-state, two-dimensional finite difference numerical model is setup. The developed model is able to predict temperature and humidity evolution inside the channels. Sensible and latent heat transfer rate, as well as moisture transfer rate, are determined. A sensitive analysis is conducted in order to determine the more influential parameters on the thermal and vapour transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JCHyd.164..100J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JCHyd.164..100J"><span><span class="hlt">Mass</span> discharge assessment at a brominated DNAPL site: Effects of known DNAPL source <span class="hlt">mass</span> removal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnston, C. D.; Davis, G. B.; Bastow, T. P.; Woodbury, R. J.; Rao, P. S. C.; Annable, M. D.; Rhodes, S.</p> <p>2014-08-01</p> <p>Management and closure of contaminated sites is increasingly being proposed on the basis of <span class="hlt">mass</span> <span class="hlt">flux</span> of dissolved contaminants in groundwater. Better understanding of the links between source <span class="hlt">mass</span> removal and contaminant <span class="hlt">mass</span> <span class="hlt">fluxes</span> in groundwater would allow greater acceptance of this metric in dealing with contaminated sites. Our objectives here were to show how measurements of the distribution of contaminant <span class="hlt">mass</span> <span class="hlt">flux</span> and the overall <span class="hlt">mass</span> discharge emanating from the source under undisturbed groundwater conditions could be related to the processes and extent of source <span class="hlt">mass</span> depletion. In addition, these estimates of <span class="hlt">mass</span> discharge were sought in the application of agreed remediation targets set in terms of pumped groundwater quality from offsite wells. Results are reported from field studies conducted over a 5-year period at a brominated DNAPL (tetrabromoethane, TBA; and tribromoethene, TriBE) site located in suburban Perth, Western Australia. Groundwater <span class="hlt">fluxes</span> (qw; L3/L2/T) and <span class="hlt">mass</span> <span class="hlt">fluxes</span> (Jc; M/L2/T) of dissolved brominated compounds were simultaneously estimated by deploying Passive <span class="hlt">Flux</span> Meters (PFMs) in wells in a heterogeneous layered aquifer. PFMs were deployed in control plane (CP) wells immediately down-gradient of the source zone, before (2006) and after (2011) 69-85% of the source <span class="hlt">mass</span> was removed, mainly by groundwater pumping from the source zone. The high-resolution (26-cm depth interval) measures of qw and Jc along the source CP allowed investigation of the DNAPL source-zone architecture and impacts of source <span class="hlt">mass</span> removal. Comparable estimates of total <span class="hlt">mass</span> discharge (MD; M/T) across the source zone CP reduced from 104 g day- 1 to 24-31 g day- 1 (70-77% reductions). Importantly, this <span class="hlt">mass</span> discharge reduction was consistent with the estimated proportion of source <span class="hlt">mass</span> remaining at the site (15-31%). That is, a linear relationship between <span class="hlt">mass</span> discharge and source <span class="hlt">mass</span> is suggested. The spatial detail of groundwater and <span class="hlt">mass</span> <span class="hlt">flux</span> distributions also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24973505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24973505"><span><span class="hlt">Mass</span> discharge assessment at a brominated DNAPL site: Effects of known DNAPL source <span class="hlt">mass</span> removal.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Johnston, C D; Davis, G B; Bastow, T P; Woodbury, R J; Rao, P S C; Annable, M D; Rhodes, S</p> <p>2014-08-01</p> <p>Management and closure of contaminated sites is increasingly being proposed on the basis of <span class="hlt">mass</span> <span class="hlt">flux</span> of dissolved contaminants in groundwater. Better understanding of the links between source <span class="hlt">mass</span> removal and contaminant <span class="hlt">mass</span> <span class="hlt">fluxes</span> in groundwater would allow greater acceptance of this metric in dealing with contaminated sites. Our objectives here were to show how measurements of the distribution of contaminant <span class="hlt">mass</span> <span class="hlt">flux</span> and the overall <span class="hlt">mass</span> discharge emanating from the source under undisturbed groundwater conditions could be related to the processes and extent of source <span class="hlt">mass</span> depletion. In addition, these estimates of <span class="hlt">mass</span> discharge were sought in the application of agreed remediation targets set in terms of pumped groundwater quality from offsite wells. Results are reported from field studies conducted over a 5-year period at a brominated DNAPL (tetrabromoethane, TBA; and tribromoethene, TriBE) site located in suburban Perth, Western Australia. Groundwater <span class="hlt">fluxes</span> (qw; L(3)/L(2)/T) and <span class="hlt">mass</span> <span class="hlt">fluxes</span> (Jc; M/L(2)/T) of dissolved brominated compounds were simultaneously estimated by deploying Passive <span class="hlt">Flux</span> Meters (PFMs) in wells in a heterogeneous layered aquifer. PFMs were deployed in control plane (CP) wells immediately down-gradient of the source zone, before (2006) and after (2011) 69-85% of the source <span class="hlt">mass</span> was removed, mainly by groundwater pumping from the source zone. The high-resolution (26-cm depth interval) measures of qw and Jc along the source CP allowed investigation of the DNAPL source-zone architecture and impacts of source <span class="hlt">mass</span> removal. Comparable estimates of total <span class="hlt">mass</span> discharge (MD; M/T) across the source zone CP reduced from 104gday(-1) to 24-31gday(-1) (70-77% reductions). Importantly, this <span class="hlt">mass</span> discharge reduction was consistent with the estimated proportion of source <span class="hlt">mass</span> remaining at the site (15-31%). That is, a linear relationship between <span class="hlt">mass</span> discharge and source <span class="hlt">mass</span> is suggested. The spatial detail of groundwater and <span class="hlt">mass</span> <span class="hlt">flux</span> distributions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.6661K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.6661K"><span>Photochemical aging of aerosol particles in different <span class="hlt">air</span> <span class="hlt">masses</span> arriving at Baengnyeong Island, Korea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kang, Eunha; Lee, Meehye; Brune, William H.; Lee, Taehyoung; Park, Taehyun; Ahn, Joonyoung; Shang, Xiaona</p> <p>2018-05-01</p> <p>Atmospheric aerosol particles are a serious health risk, especially in regions like East Asia. We investigated the photochemical aging of ambient aerosols using a potential aerosol <span class="hlt">mass</span> (PAM) reactor at Baengnyeong Island in the Yellow Sea during 4-12 August 2011. The size distributions and chemical compositions of aerosol particles were measured alternately every 6 min from the ambient <span class="hlt">air</span> or through the highly oxidizing environment of a potential aerosol <span class="hlt">mass</span> (PAM) reactor. Particle size and chemical composition were measured by using the combination of a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol <span class="hlt">mass</span> spectrometer (HR-ToF-AMS). Inside the PAM reactor, O3 and OH levels were equivalent to 4.6 days of integrated OH exposure at typical atmospheric conditions. Two types of <span class="hlt">air</span> <span class="hlt">masses</span> were distinguished on the basis of the chemical composition and the degree of aging: <span class="hlt">air</span> transported from China, which was more aged with a higher sulfate concentration and O : C ratio, and the <span class="hlt">air</span> transported across the Korean Peninsula, which was less aged with more organics than sulfate and a lower O : C ratio. For both episodes, the particulate sulfate <span class="hlt">mass</span> concentration increased in the 200-400 nm size range when sampled through the PAM reactor. A decrease in organics was responsible for the loss of <span class="hlt">mass</span> concentration in 100-200 nm particles when sampled through the PAM reactor for the organics-dominated episode. This loss was especially evident for the m/z 43 component, which represents less oxidized organics. The m/z 44 component, which represents further oxidized organics, increased with a shift toward larger sizes for both episodes. It is not possible to quantify the maximum possible organic <span class="hlt">mass</span> concentration for either episode because only one OH exposure of 4.6 days was used, but it is clear that SO2 was a primary precursor of secondary aerosol in northeast Asia, especially during long-range transport from China. In addition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22086446-quenching-star-formation-intermediate-redshifts-downsizing-mass-flux-density-green-valley','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22086446-quenching-star-formation-intermediate-redshifts-downsizing-mass-flux-density-green-valley"><span>QUENCHING STAR FORMATION AT INTERMEDIATE REDSHIFTS: DOWNSIZING OF THE <span class="hlt">MASS</span> <span class="hlt">FLUX</span> DENSITY IN THE GREEN VALLEY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Goncalves, Thiago S.; Menendez-Delmestre, Karin; Martin, D. Christopher</p> <p>2012-11-01</p> <p>The bimodality in galaxy properties has been observed at low and high redshifts, with a clear distinction between star-forming galaxies in the blue cloud and passively evolving objects in the red sequence; the absence of galaxies with intermediate properties indicates that the quenching of star formation and subsequent transition between populations must happen rapidly. In this paper, we present a study of over 100 transiting galaxies in the so-called green valley at intermediate redshifts (z {approx} 0.8). By using very deep spectroscopy with the DEIMOS instrument at the Keck telescope we are able to infer the star formation histories ofmore » these objects and measure the stellar <span class="hlt">mass</span> <span class="hlt">flux</span> density transiting from the blue cloud to the red sequence when the universe was half its current age. Our results indicate that the process happened more rapidly and for more massive galaxies in the past, suggesting a top-down scenario in which the massive end of the red sequence is forming first. This represents another aspect of downsizing, with the <span class="hlt">mass</span> <span class="hlt">flux</span> density moving toward smaller galaxies in recent times.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860049509&hterms=thermal+noise&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthermal%2Bnoise','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860049509&hterms=thermal+noise&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthermal%2Bnoise"><span>Plasma diagnosis from thermal noise and limits on dust <span class="hlt">flux</span> or <span class="hlt">mass</span> in comet Giacobini-Zinner</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Meyer-Vernet, N.; Couturier, P.; Hoang, S.; Perche, C.; Steinberg, J. L.; Fainberg, J.</p> <p>1986-01-01</p> <p>Thermal noise spectroscopy was used to measure the density and temperature of the main (cold) electron plasma population during two hours around the point of closest approach of the International Cometary Explorer (ICE) to comet Giacobini-Zinner. The time resolution was 18 seconds in the plasma tail and 54 seconds elsewhere. Near the tail axis, the maximum plasma density was 670/cu cm and the temperature slightly above one volt. Away from the axis, the plasma density dropped to 100/cu cm over 2000 km, then decreased to 10/cu cm over 15,000 km; at the plasma tail, the density fluctuated between 10 and 30/cu cm, and the temperature, between 100,000 and 400,000 K. No evidence was found of grain impact on the spacecraft or antennas in the plasma tail. This yields an upper limit for the dust <span class="hlt">flux</span> or particle <span class="hlt">mass</span>, indicating either <span class="hlt">fluxes</span> or <span class="hlt">masses</span> in the tail smaller than those implied by models or an anomalous grain structure. Outside the tail, and particularly near 100,000 km from its axis, impulsive noises indicating plasma turbulence were observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008APS..DFD.GA002C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008APS..DFD.GA002C"><span><span class="hlt">Air</span> Layer Drag Reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ceccio, Steven; Elbing, Brian; Winkel, Eric; Dowling, David; Perlin, Marc</p> <p>2008-11-01</p> <p>A set of experiments have been conducted at the US Navy's Large Cavitation Channel to investigate skin-friction drag reduction with the injection of <span class="hlt">air</span> into a high Reynolds number turbulent boundary layer. Testing was performed on a 12.9 m long flat-plate test model with the surface hydraulically smooth and fully rough at downstream-distance-based Reynolds numbers to 220 million and at speeds to 20 m/s. Local skin-friction, near-wall bulk void fraction, and near-wall bubble imaging were monitored along the length of the model. The instrument suite was used to access the requirements necessary to achieve <span class="hlt">air</span> layer drag reduction (ALDR). Injection of <span class="hlt">air</span> over a wide range of <span class="hlt">air</span> <span class="hlt">fluxes</span> showed that three drag reduction regimes exist when injecting <span class="hlt">air</span>; (1) bubble drag reduction that has poor downstream persistence, (2) a transitional regime with a steep rise in drag reduction, and (3) ALDR regime where the drag reduction plateaus at 90% ± 10% over the entire model length with large void fractions in the near-wall region. These investigations revealed several requirements for ALDR including; sufficient volumetric <span class="hlt">air</span> <span class="hlt">fluxes</span> that increase approximately with the square of the free-stream speed, slightly higher <span class="hlt">air</span> <span class="hlt">fluxes</span> are needed when the surface tension is reduced, higher <span class="hlt">air</span> <span class="hlt">fluxes</span> are required for rough surfaces, and the formation of ALDR is sensitive to the inlet condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS31B1280P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS31B1280P"><span>Micrometeorological Measurement of Fetch- and Atmospheric Stability-Dependent <span class="hlt">Air</span>- Water Exchange of Legacy Semivolatile Organic Contaminants in Lake Superior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perlinger, J. A.; Tobias, D. E.; Rowe, M. D.</p> <p>2008-12-01</p> <p> one of the four trajectories and stable for the other three trajectories. Two of three transects carried out under stable conditions are complicated because, as revealed by back-trajectory analysis, different <span class="hlt">air</span> <span class="hlt">masses</span> were sampled at each station, and, for one of these transects, the <span class="hlt">air</span> <span class="hlt">masses</span> spent significant portions of time over land. Analyses of legacy pesticide concentrations carried out to date suggest that under stable and unstable conditions, <span class="hlt">fluxes</span> were out of the lake. We present and compare micrometeorological measurements and two-film estimates of <span class="hlt">fluxes</span> of legacy pesticides and PCBs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...805...56D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...805...56D"><span>The <span class="hlt">Mass</span>-Luminosity Relation in the L/T Transition: Individual Dynamical <span class="hlt">Masses</span> for the New J-band <span class="hlt">Flux</span> Reversal Binary SDSSJ105213.51+442255.7AB</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dupuy, Trent J.; Liu, Michael C.; Leggett, S. K.; Ireland, Michael J.; Chiu, Kuenley; Golimowski, David A.</p> <p>2015-05-01</p> <p>We have discovered that SDSS J105213.51+442255.7 (T0.5 ± 1.0) is a binary in Keck laser guide star adaptive optics imaging, displaying a large J- to K-band <span class="hlt">flux</span> reversal ({Δ }J=-0.45+/- 0.09 mag, {Δ }K=0.52+/- 0.05 mag). We determine a total dynamical <span class="hlt">mass</span> from Keck orbital monitoring (88 ± 5 {{M}Jup}) and a <span class="hlt">mass</span> ratio by measuring the photocenter orbit from CFHT/WIRCam absolute astrometry ({{M}B}/{{M}A}=0.78+/- 0.07). Combining these provides the first individual dynamical <span class="hlt">masses</span> for any field L or T dwarfs, 49 ± 3 {{M}Jup} for the L6.5±1.5 primary and 39 ± 3 {{M}Jup} for the T1.5±1.0 secondary. Such a low <span class="hlt">mass</span> ratio for a nearly equal luminosity binary implies a shallow <span class="hlt">mass</span>-luminosity relation over the L/T transition ({Δ }log {{L}bol}/{Δ }log M=0.6-0.8+0.6). This provides the first observational support that cloud dispersal plays a significant role in the luminosity evolution of substellar objects. Fully cloudy models fail our coevality test for this binary, giving ages for the two components that disagree by 0.2 dex (2.0σ). In contrast, our observed <span class="hlt">masses</span> and luminosities can be reproduced at a single age by “hybrid” evolutionary tracks where a smooth change from a cloudy to cloudless photosphere around 1300 K causes slowing of luminosity evolution. Remarkably, such models also match our observed JHK <span class="hlt">flux</span> ratios and colors well. Overall, it seems that the distinguishing features SDSS J1052+4422AB, like a J-band <span class="hlt">flux</span> reversal and high-amplitude variability, are normal for a field L/T binary caught during the process of cloud dispersal, given that the age (1.11-0.20+0.17 Gyr) and surface gravity (log g = 5.0-5.2) of SDSS J1052+4422AB are typical for field ultracool dwarfs. Based on data obtained with WIRCam, a joint project of CFHT, Taiwan, Korea, Canada, France, at the Canada-France-Hawaii Telescope, which is operated by the National Research Council of Canada, the Institute National des Sciences de l’Univers of the Centre National de la</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A13J3309T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A13J3309T"><span>An Eddy-Diffusivity <span class="hlt">Mass-flux</span> (EDMF) closure for the unified representation of cloud and convective processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Z.; Schneider, T.; Teixeira, J.; Lam, R.; Pressel, K. G.</p> <p>2014-12-01</p> <p>Sub-grid scale (SGS) closures in current climate models are usually decomposed into several largely independent parameterization schemes for different cloud and convective processes, such as boundary layer turbulence, shallow convection, and deep convection. These separate parameterizations usually do not converge as the resolution is increased or as physical limits are taken. This makes it difficult to represent the interactions and smooth transition among different cloud and convective regimes. Here we present an eddy-diffusivity <span class="hlt">mass-flux</span> (EDMF) closure that represents all sub-grid scale turbulent, convective, and cloud processes in a unified parameterization scheme. The buoyant updrafts and precipitative downdrafts are parameterized with a prognostic multiple-plume <span class="hlt">mass-flux</span> (MF) scheme. The prognostic term for the <span class="hlt">mass</span> <span class="hlt">flux</span> is kept so that the life cycles of convective plumes are better represented. The interaction between updrafts and downdrafts are parameterized with the buoyancy-sorting model. The turbulent mixing outside plumes is represented by eddy diffusion, in which eddy diffusivity (ED) is determined from a turbulent kinetic energy (TKE) calculated from a TKE balance that couples the environment with updrafts and downdrafts. Similarly, tracer variances are decomposed consistently between updrafts, downdrafts and the environment. The closure is internally coupled with a probabilistic cloud scheme and a simple precipitation scheme. We have also developed a relatively simple two-stream radiative scheme that includes the longwave (LW) and shortwave (SW) effects of clouds, and the LW effect of water vapor. We have tested this closure in a single-column model for various regimes spanning stratocumulus, shallow cumulus, and deep convection. The model is also run towards statistical equilibrium with climatologically relevant large-scale forcings. These model tests are validated against large-eddy simulation (LES) with the same forcings. The comparison of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080015925','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080015925"><span>Establishing Lagrangian Connections between Observations within <span class="hlt">Air</span> <span class="hlt">Masses</span> Crossing the Atlantic during the ICARTT Experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D.; Reeves, C.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20080015925'); toggleEditAbsImage('author_20080015925_show'); toggleEditAbsImage('author_20080015925_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20080015925_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20080015925_hide"></p> <p>2006-01-01</p> <p>The International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)-Lagrangian experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of <span class="hlt">air</span> <span class="hlt">masses</span> in the free troposphere away from emissions. To this end attempts were made to intercept and sample <span class="hlt">air</span> <span class="hlt">masses</span> several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts using two Lagrangian models that were used to direct the aircraft into target <span class="hlt">air</span> <span class="hlt">masses</span>. A novel technique is then used to identify Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole <span class="hlt">air</span> samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these coincident matches is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown and the downwind minus upwind differences in tracers are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5947730','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5947730"><span>Forward Modeling of Coronal <span class="hlt">Mass</span> Ejection <span class="hlt">Flux</span> Ropes in the Inner Heliosphere with 3DCORE</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Amerstorfer, T.; Palmerio, E.; Isavnin, A.; Farrugia, C. J.; Lowder, C.; Winslow, R. M.; Donnerer, J. M.; Kilpua, E. K. J.; Boakes, P. D.</p> <p>2018-01-01</p> <p>Abstract Forecasting the geomagnetic effects of solar storms, known as coronal <span class="hlt">mass</span> ejections (CMEs), is currently severely limited by our inability to predict the magnetic field configuration in the CME magnetic core and by observational effects of a single spacecraft trajectory through its 3‐D structure. CME magnetic <span class="hlt">flux</span> ropes can lead to continuous forcing of the energy input to the Earth's magnetosphere by strong and steady southward‐pointing magnetic fields. Here we demonstrate in a proof‐of‐concept way a new approach to predict the southward field B z in a CME <span class="hlt">flux</span> rope. It combines a novel semiempirical model of CME <span class="hlt">flux</span> rope magnetic fields (Three‐Dimensional Coronal ROpe Ejection) with solar observations and in situ magnetic field data from along the Sun‐Earth line. These are provided here by the MESSENGER spacecraft for a CME event on 9–13 July 2013. Three‐Dimensional Coronal ROpe Ejection is the first such model that contains the interplanetary propagation and evolution of a 3‐D <span class="hlt">flux</span> rope magnetic field, the observation by a synthetic spacecraft, and the prediction of an index of geomagnetic activity. A counterclockwise rotation of the left‐handed erupting CME <span class="hlt">flux</span> rope in the corona of 30° and a deflection angle of 20° is evident from comparison of solar and coronal observations. The calculated Dst matches reasonably the observed Dst minimum and its time evolution, but the results are highly sensitive to the CME axis orientation. We discuss assumptions and limitations of the method prototype and its potential for real time space weather forecasting and heliospheric data interpretation. PMID:29780287</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvD..92i3011C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvD..92i3011C"><span>Neutrino <span class="hlt">mass</span> hierarchy and precision physics with medium-baseline reactors: Impact of energy-scale and <span class="hlt">flux</span>-shape uncertainties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Capozzi, F.; Lisi, E.; Marrone, A.</p> <p>2015-11-01</p> <p>Nuclear reactors provide intense sources of electron antineutrinos, characterized by few-MeV energy E and unoscillated spectral shape Φ (E ). High-statistics observations of reactor neutrino oscillations over medium-baseline distances L ˜O (50 ) km would provide unprecedented opportunities to probe both the long-wavelength <span class="hlt">mass</span>-mixing parameters (δ m2 and θ12) and the short-wavelength ones (Δ mee 2 and θ13), together with the subtle interference effects associated with the neutrino <span class="hlt">mass</span> hierarchy (either normal or inverted). In a given experimental setting—here taken as in the JUNO project for definiteness—the achievable hierarchy sensitivity and parameter accuracy depend not only on the accumulated statistics but also on systematic uncertainties, which include (but are not limited to) the <span class="hlt">mass</span>-mixing priors and the normalizations of signals and backgrounds. We examine, in addition, the effect of introducing smooth deformations of the detector energy scale, E →E'(E ), and of the reactor <span class="hlt">flux</span> shape, Φ (E )→Φ'(E ), within reasonable error bands inspired by state-of-the-art estimates. It turns out that energy-scale and <span class="hlt">flux</span>-shape systematics can noticeably affect the performance of a JUNO-like experiment, both on the hierarchy discrimination and on precision oscillation physics. It is shown that a significant reduction of the assumed energy-scale and <span class="hlt">flux</span>-shape uncertainties (by, say, a factor of 2) would be highly beneficial to the physics program of medium-baseline reactor projects. Our results also shed some light on the role of the inverse-beta decay threshold, of geoneutrino backgrounds, and of matter effects in the analysis of future reactor oscillation data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840052007&hterms=Kilauea+volcano&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DKilauea%2Bvolcano','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840052007&hterms=Kilauea+volcano&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DKilauea%2Bvolcano"><span>First estimate of annual mercury <span class="hlt">flux</span> at the Kilauea main vent</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siegel, S. M.; Siegel, B. Z.</p> <p>1984-01-01</p> <p>Mercury and sulphur dioxide analyses were conducted from 1971 to 1980 on <span class="hlt">air</span> samples collected immediately downwind of Halemaumau, the Kilauea main vent, in Hawaii. On the basis of these measurements, an Hg/SO2 ratio of 0.00051 has been derived which, when applied to the recently determined SO2 <span class="hlt">mass</span> output of Halemaumau, yields a calculated Hg <span class="hlt">flux</span> of 2.6 x 10 to the 8th g annually. This rate is consistent with Varekamp and Busek's (1981) evidence suggesting that volcanogenic Hg significantly contributes to the atmospheric total.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730013508','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730013508"><span>The turbulent mean-flow, Reynolds-stress, and heat <span class="hlt">flux</span> equations in <span class="hlt">mass</span>-averaged dependent variables</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rubesin, M. W.; Rose, W. C.</p> <p>1973-01-01</p> <p>The time-dependent, turbulent mean-flow, Reynolds stress, and heat <span class="hlt">flux</span> equations in <span class="hlt">mass</span>-averaged dependent variables are presented. These equations are given in conservative form for both generalized orthogonal and axisymmetric coordinates. For the case of small viscosity and thermal conductivity fluctuations, these equations are considerably simpler than the general Reynolds system of dependent variables for a compressible fluid and permit a more direct extension of low speed turbulence modeling to computer codes describing high speed turbulence fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134734','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134734"><span>PAH and OPAH <span class="hlt">Flux</span> during the Deepwater Horizon Incident</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tidwell, Lane G.; Allan, Sarah E.; O'Connell, Steven G.; Hobbie, Kevin A.; Smith, Brian W.; Anderson, Kim A.</p> <p>2016-01-01</p> <p>Passive sampling devices were used to measure <span class="hlt">air</span> vapor and water dissolved phase concentrations of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) at four Gulf of Mexico coastal sites prior to, during and after shoreline oiling from the Deepwater Horizon oil spill (DWH). Measurements were taken at each site over a 13 month period, and <span class="hlt">flux</span> across the water-<span class="hlt">air</span> boundary was determined. This is the first report of vapor phase and diffusive <span class="hlt">flux</span> of both PAHs and OPAHs during the DWH. Vapor phase sum PAH and OPAH concentrations ranged between 6.6 and 210 ng/m3 and 0.02 and 34 ng/m3 respectively. PAH and OPAH concentrations in <span class="hlt">air</span> exhibited different spatial and temporal trends than in water, and <span class="hlt">air</span>-water <span class="hlt">flux</span> of 13 individual PAHs was shown to be at least partially influenced by the DWH incident. The largest PAH volatilizations occurred at the sites in Alabama and Mississippi at nominal rates of 56,000 and 42,000 ng/m2/day in the summer. Naphthalene was the PAH with the highest observed volatilization rate of 52,000 ng/m2/day in June 2010. This work represents additional evidence of the DWH incident contributing to <span class="hlt">air</span> contamination, and provides one of the first quantitative <span class="hlt">air</span>-water chemical <span class="hlt">flux</span> determinations with passive sampling technology. PMID:27391856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790012464','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790012464"><span>Thunderstorm vertical velocities and <span class="hlt">mass</span> <span class="hlt">flux</span> estimated from satellite data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adler, R. F.; Fenn, D. D.</p> <p>1979-01-01</p> <p>Infrared geosynchronous satellite data with an interval of five minutes between images are used to estimate thunderstorm top ascent rates on two case study days. A mean vertical velocity of 3.5/ms for 19 clouds is calculated at a height of 8.7 km. This upward motion is representative of an area of approximately 10km on a side. Thunderstorm <span class="hlt">mass</span> <span class="hlt">flux</span> of approximately 2x10 to the 11th power/gs is calculated, which compares favorably with previous estimates. There is a significant difference in the mean calculated vertical velocity between elements associated with severe weather reports (w bar=4.6/ms) and those with no such reports (2.5/ms). Calculations were made using a velocity profile for an axially symmetric jet to estimate the peak updraft velocity. For the largest observed w value of 7.8/ms the calculation indicates a peak updraft of approximately 50/ms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030025770','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030025770"><span>Version 2 Goddard Satellite-Based Surface Turbulent <span class="hlt">Fluxes</span> (GSSTF2)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Nelkin, Eric; Ardizzone, Joe; Atlas, Robert M.; Shie, Chung-Lin; Starr, David O'C. (Technical Monitor)</p> <p>2002-01-01</p> <p>Information on the turbulent <span class="hlt">fluxes</span> of momentum, moisture, and heat at the <span class="hlt">air</span>-sea interface is essential in improving model simulations of climate variations and in climate studies. We have derived a 13.5-year (July 1987-December 2000) dataset of daily surface turbulent <span class="hlt">fluxes</span> over global oceans from the Special Sensor Mcrowave/Imager (SSM/I) radiance measurements. This dataset, version 2 Goddard Satellite-based Surface Turbulent <span class="hlt">Fluxes</span> (GSSTF2), has a spatial resolution of 1 degree x 1 degree latitude-longitude and a temporal resolution of 1 day. Turbulent <span class="hlt">fluxes</span> are derived from the SSM/I surface winds and surface <span class="hlt">air</span> humidity, as well as the 2-m <span class="hlt">air</span> and sea surface temperatures (SST) of the NCEP/NCAR reanalysis, using a bulk aerodynamic algorithm based on the surface layer similarity theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890059524&hterms=Fuel+Jet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFuel%2BJet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890059524&hterms=Fuel+Jet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFuel%2BJet"><span>Opposed jet diffusion flames of nitrogen-diluted hydrogen vs <span class="hlt">air</span> - Axial LDA and CARS surveys; fuel/<span class="hlt">air</span> rates at extinction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pellett, G. L.; Northam, G. B.; Wilson, L. G.; Jarrett, Olin, Jr.; Antcliff, R. R.</p> <p>1989-01-01</p> <p>An experimental study of H-<span class="hlt">air</span> counterflow diffusion flames (CFDFs) is reported. Coaxial tubular opposed jet burners were used to form dish-shaped CFDFs centered by opposing laminar jets of H2/N2 and <span class="hlt">air</span> in an argon bath at 1 atm. Jet velocities for extinction and flame restoration limits are shown versus input H2 concentration. LDA velocity data and CARS temperature and absolute N2, O2 density data give detailed flame structure on the <span class="hlt">air</span> side of the stagnation point. The results show that <span class="hlt">air</span> jet velocity is a more fundamental and appropriate measure of H2-<span class="hlt">air</span> CFDF extinction than input H2 <span class="hlt">mass</span> <span class="hlt">flux</span> or fuel jet velocity. It is proposed that the observed constancy of <span class="hlt">air</span> jet velocity for fuel mixtures containing 80 to 100 percent H2 measure a maximum, kinetically controlled rate at which the CFDF can consume oxygen in <span class="hlt">air</span>. Fuel velocity mainly measures the input jet momentum required to center an H2/N2 versus <span class="hlt">air</span> CFDF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914777N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914777N"><span>Micrometeorological <span class="hlt">flux</span> measurements of aerosol and gases above Beijing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nemitz, Eiko; Langford, Ben; Mullinger, Neil; Cowan, Nicholas; Coyle, Mhairi; Acton, William Joe; Lee, James; Fu, Pingqing</p> <p>2017-04-01</p> <p><span class="hlt">Air</span> pollution is estimated to cause 1.6 million premature deaths in China every year and in the winter 2016/17 Beijing had to issue health alerts and put in place ad hoc limitations on industrial and vehicular activity. Much of this pollution is attributed to emissions from industrial processes and in particular coal combustion. By contrast, the diffuse pollutant sources within the city are less well understood. This includes, e.g., emissions from the Beijing traffic fleet, the sewage system, food preparation, solid fuel combustion in the streets and small industrial processes. Within the framework of a major UK-Chinese collaboration to study <span class="hlt">air</span> pollution and its impact on human health in Beijing, we therefore measured <span class="hlt">fluxes</span> of a large range of pollutants from a height of 102 m on the 325 m meteorological tower at the Institute of Atmospheric Physics. Several instruments were mounted at 102 m: <span class="hlt">fluxes</span> of CO2 and H2O were measured with an infrared gas analyser (LiCOR 7500) and <span class="hlt">fluxes</span> of ozone with a combination of a relative fast-response ozone analyser (ROFI) and a 2B absolute O3 instrument. Total particle number <span class="hlt">fluxes</span> were measured with a condensation particle counter (TSI CPC 3785), and size-segregated <span class="hlt">fluxes</span> over the size range 0.06 to 20 μm with a combination of an optical Ultrafine High Sensitivity Aerosol Spectrometer (UHSAS) and an Aerodynamic Particle Sizer Spectrometer (TSI APS3321). Ammonia (NH3) <span class="hlt">fluxes</span> were measured for the first time above the urban environment using an Aerodyne compact quantum cascade laser (QCL). In addition, composition resolved aerosol <span class="hlt">fluxes</span> were measured with an Aerodyne Aerosol <span class="hlt">Mass</span> Spectrometer (HR-ToF-AMS), operated in a measurement container at the bottom of the tower, which subsampled from a 120 m long copper tube (15 mm OD). The analysis so far suggests that, due to often low wind speeds, <span class="hlt">fluxes</span> were at times de-coupled from the surface. <span class="hlt">Fluxes</span> normalised by CO2, a tracer for the amount of fossil fuel consumed, should be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6265D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6265D"><span>The DFMS sensor of ROSINA onboard Rosetta: A computer-assisted approach to resolve <span class="hlt">mass</span> calibration, <span class="hlt">flux</span> calibration, and fragmentation issues</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhooghe, Frederik; De Keyser, Johan; Altwegg, Kathrin; Calmonte, Ursina; Fuselier, Stephen; Hässig, Myrtha; Berthelier, Jean-Jacques; Mall, Urs; Gombosi, Tamas; Fiethe, Björn</p> <p>2014-05-01</p> <p>Rosetta will rendezvous with comet 67P/Churyumov-Gerasimenko in May 2014. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument comprises three sensors: the pressure sensor (COPS) and two <span class="hlt">mass</span> spectrometers (RTOF and DFMS). The double focusing <span class="hlt">mass</span> spectrometer DFMS is optimized for <span class="hlt">mass</span> resolution and consists of an ion source, a <span class="hlt">mass</span> analyser and a detector package operated in analogue mode. The magnetic sector of the analyser provides the <span class="hlt">mass</span> dispersion needed for use with the position-sensitive microchannel plate (MCP) detector. Ions that hit the MCP release electrons that are recorded digitally using a linear electron detector array with 512 pixels. Raw data for a given commanded <span class="hlt">mass</span> are obtained as ADC counts as a function of pixel number. We have developed a computer-assisted approach to address the problem of calibrating such raw data. <span class="hlt">Mass</span> calibration: Ion identification is based on their <span class="hlt">mass</span>-over-charge (m/Z) ratio and requires an accurate correlation of pixel number and m/Z. The m/Z scale depends on the commanded <span class="hlt">mass</span> and the magnetic field and can be described by an offset of the pixel associated with the commanded <span class="hlt">mass</span> from the centre of the detector array and a scaling factor. <span class="hlt">Mass</span> calibration is aided by the built-in gas calibration unit (GCU), which allows one to inject a known gas mixture into the instrument. In a first, fully automatic step of the <span class="hlt">mass</span> calibration procedure, the calibration uses all GCU spectra and extracts information about the <span class="hlt">mass</span> peak closest to the centre pixel, since those peaks can be identified unambiguously. This preliminary <span class="hlt">mass</span>-calibration relation can then be applied to all spectra. Human-assisted identification of additional <span class="hlt">mass</span> peaks further improves the <span class="hlt">mass</span> calibration. Ion <span class="hlt">flux</span> calibration: ADC counts per pixel are converted to ion counts per second using the overall gain, the individual pixel gain, and the total data accumulation time. DFMS can perform an internal scan to determine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15732932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15732932"><span><span class="hlt">Mass</span> spectrometer characterization of halogen gases in <span class="hlt">air</span> at atmospheric pressure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ivey, Michelle M; Foster, Krishna L</p> <p>2005-03-01</p> <p>We have developed a new interface for a commercial ion trap <span class="hlt">mass</span> spectrometer equipped with APCI capable of real-time measurements of gaseous compounds with limits of detection on the order of pptv. The new interface has been tested using the detection of Br2 and Cl2 over synthetic seawater ice at atmospheric pressure as a model system. A mechanical pump is used to draw gaseous mixtures through a glass manifold into the corona discharge area, where the molecules are ionized. Analysis of bromine and chlorine in dry <span class="hlt">air</span> show that ion intensity is affected by the pumping rate and the position of the glass manifold. The <span class="hlt">mass</span> spectrometer signals for Br2 are linear in the 0.1-10.6 ppbv range, and the estimated 3sigma detection limit is 20 pptv. The MS signals for Cl2 are linear in the 0.2-25 ppbv range, and the estimated 3sigma detection limit is 1 ppbv. This new interface advances the field of analytical chemistry by introducing a practical modification to a commercially available ion trap <span class="hlt">mass</span> spectrometer that expands the available methods for performing highly specific and sensitive measurements of gases in <span class="hlt">air</span> at atmospheric pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950031278&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbiomass%2Bproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950031278&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbiomass%2Bproduction"><span>Enhancement of acidic gases in biomass burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> over Canada</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lefer, B. L.; Talbot, R. W.; Harriss, R. C.; Bradshaw, J. D.; Sandholm, S. T.; Olson, J. O.; Sachse, G. W.; Collins, J.; Shipham, M. A.; Blake, D. R.</p> <p>1994-01-01</p> <p>Biomass-burning impacted <span class="hlt">air</span> <span class="hlt">masses</span> sampled over central and eastern Canada during the summer of 1990 as part of ABLE 3B contained enhanced mixing ratios of gaseous HNO3, HCOOH, CH3COOH, and what appears to be (COOH)2. These aircraft-based samples were collected from a variety of fresh burning plumes and more aged haze layers from different source regions. Values of the enhancement factor, delta X/delta CO, where X represents an acidic gas, for combustion-impacted <span class="hlt">air</span> <span class="hlt">masses</span> sampled both near and farther away from the fires, were relatively uniform. However, comparison of carboxylic acid emission ratios measured in laboratory fires to field plume enhancement factors indicates significant in-plume production of HCOOH. Biomass-burning appears to be an important source of HNO3, HCOOH, and CH3COOH to the troposphere over subarctic Canada.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C13C0978D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C13C0978D"><span>The Breathing Snowpack: Pressure-induced Vapor <span class="hlt">Flux</span> of Temperate Snow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drake, S. A.; Selker, J. S.; Higgins, C. W.</p> <p>2017-12-01</p> <p>As surface <span class="hlt">air</span> pressure increases, hydrostatic compression of the <span class="hlt">air</span> column forces atmospheric <span class="hlt">air</span> into snowpack pore space. Likewise, as surface <span class="hlt">air</span> pressure decreases, the atmospheric <span class="hlt">air</span> column decompresses and saturated <span class="hlt">air</span> exits the snow. Alternating influx and efflux of <span class="hlt">air</span> can be thought of as a "breathing" process that produces an upward vapor <span class="hlt">flux</span> when <span class="hlt">air</span> above the snow is not saturated. The impact of pressure-induced vapor exchange is assumed to be small and is thus ignored in model parameterizations of surface processes over snow. Rationale for disregarding this process is that large amplitude pressure changes as caused by synoptic weather patterns are too infrequent to credibly impact vapor <span class="hlt">flux</span>. The amplitude of high frequency pressure changes is assumed to be too small to affect vapor <span class="hlt">flux</span>, however, the basis for this hypothesis relies on pressure measurements collected over an agricultural field (rather than snow). Resolution of the impact of pressure changes on vapor <span class="hlt">flux</span> over seasonal cycles depends on an accurate representation of the magnitude of pressure changes caused by changes in wind as a function of the frequency of pressure changes. High precision in situ pressure measurements in a temperature snowpack allowed us to compute the spectra of pressure changes vs. wind forcing. Using a simplified model for vapor exchange we then computed the frequency of pressure changes that maximize vapor exchange. We examine and evaluate the seasonal impact of pressure-induced vapor exchange relative to other snow ablation processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.B13B1199Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.B13B1199Z"><span>Grasland Stable Isotope <span class="hlt">Flux</span> Measurements: Three Isotopomers of Carbon Dioxide Measured by QCL Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeeman, M. J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Buchmann, N.; Emmenegger, L.</p> <p>2007-12-01</p> <p>To improve our understanding of greenhouse gas dynamics of managed ecosystems such as grasslands, we not only need to investigate the effects of management (e.g., grass cuts) and weather events (e.g., rainy days) on carbon dioxide <span class="hlt">fluxes</span>, but also need to increase the time resolution of our measurements. Thus, for the first time, we assessed respiration and assimilation <span class="hlt">fluxes</span> with high time resolution (5Hz) stable isotope measurements at an intensively managed farmland in Switzerland (Chamau, 400m ASL). Two different methods were used to quantify <span class="hlt">fluxes</span> of carbon dioxide and associated <span class="hlt">fluxes</span> of stable carbon isotopes: (1) the <span class="hlt">flux</span> gradient method, and (2) the eddy covariance method. During a week long intensive measurement campaign, we (1) measured mixing ratios of carbon dioxide isotopomers (12C16O2, 12C16O18O, 13C16O2) with a Quantum Cascade Laser (QCL, Aerodyne Inc.) spectroscope and (2) collected <span class="hlt">air</span> samples for isotope analyses (13C/12C) and (18O/16O) of carbon dioxide by Isotope Ratio <span class="hlt">Mass</span> Spectrometry (IRMS, Finnigan) every two hours, concurrently along a height profile (z = 0.05; 0.10; 0.31; 2.15m). In the following week, the QCL setup was used for closed-path eddy covariance <span class="hlt">flux</span> measurement of the carbon dioxide isotopomers, with the <span class="hlt">air</span> inlet located next to an open-path Infra Red Gas Analyzers (IRGA, LiCor 7500) used simultaneously for carbon dioxide measurements. During this second week, an area of grass inside the footprint was cut and harvested after several days. The first results of in-field continuous QCL measurements of carbon dioxide mixing ratios and their stable isotopic ratios show good agreement with IRGA measurements and isotope analysis of flask samples by IRMS. Thus, QCL spectroscopy is a very promising tool for stable isotope <span class="hlt">flux</span> investigations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V51F3086M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V51F3086M"><span>What's All the Talc About? <span class="hlt">Air</span> Entrainment in Dilute Pyroclastic Density Currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marshall, B. J.; Andrews, B. J.; Fauria, K.</p> <p>2015-12-01</p> <p>A quantitative understanding of <span class="hlt">air</span> entrainment is critical to predicting the behaviors of dilute Pyroclastic Density Currents (PDCs), including runout distance, liftoff, and <span class="hlt">mass</span> fractionation into co-PDC plumes. We performed experiments in an 8.5x6x2.6 meter tank using 20 micron talc powder over a range of conditions to describe <span class="hlt">air</span> entrainment as a function of temperature, duration and <span class="hlt">mass</span> <span class="hlt">flux</span>. The experiments are reproducible and are scaled with respect to the densimetric and thermal Richardson numbers (Ri and RiT), Froude number, thermal to kinetic energy density ratio (TEb/KE), Stokes number, and Settling number, such that they are dynamically similar to natural dilute PDCs. Experiments are illuminated with a swept laser sheet and imaged at 1000 Hz to create 3D reconstructions of the currents, with ~1-2 cm resolution, at up to 1.5 Hz. An array of 30 high-frequency thermocouples record the precise temperature in the currents at 3 Hz. Bulk entrainment rates are calculated based on measured current volumes, surface areas, temperatures and velocities. Entrainment rates vary from ~0-0.9 and do not show simple variation with TEb/KE, Ri, or RiT. Entrainment does, however, increase with decreasing eruption duration and increasing <span class="hlt">mass</span> <span class="hlt">flux</span>. Our results suggest that current heads entrain <span class="hlt">air</span> more efficiently than current bodies (>0.5 compared to ~0.1). Because shorter duration currents have proportionally larger heads, their bulk entrainment rates are controlled by those heads, whereas longer duration currents are dominated by their bodies. Our experiments demonstrate that <span class="hlt">air</span> entrainment, which exerts a fundamental control on PDC runout and liftoff, varies spatially and temporally within PDCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C41B1200Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C41B1200Q"><span>Quantifying the <span class="hlt">Mass</span> <span class="hlt">Flux</span>, Erosion Rates and Geomorphological Impact of Surging Karakoram Glaciers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quincey, D. J.; Glasser, N. F.; King, O.</p> <p>2017-12-01</p> <p>Surge-type glaciers switch between phases of rapid and slow flow on timescales of a few years to decades. Here, we describe glacier-surface debris changes, surface-elevation changes and velocity changes through surges lasting five to ten years on ten different Karakoram glaciers (Khurdopin, Gasherbrum, Kunyang, Braldu, Chong Khumdan, Qiogeli, Saxintulu, Shakesiga, Skamri and Unnamed). We use these data to characterise their geomorphological imprint on the landscape, calculate a minimum <span class="hlt">mass</span> <span class="hlt">flux</span> for each of the surges and provide first-order estimates of bed erosion rates. Surface debris transport through the surges includes widespread rearrangement of surface debris features, folding and the concentration of debris near glacier termini, confluences and margins. Ice and debris-<span class="hlt">flux</span> is partly dependent on the style of the surge, and in particular whether a surge-front propagates down-glacier during the active phase. Erosion rates also depend on the style and longevity of the surge, but are largely comparable between each of the studied datasets. We conclude by estimating the geomorphic work undertaken during surge events in comparison to work carried out by non-surging glaciers in the same region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1235747-role-surface-heat-fluxes-underneath-cold-pools','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1235747-role-surface-heat-fluxes-underneath-cold-pools"><span>Role of surface heat <span class="hlt">fluxes</span> underneath cold pools</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gentine, Pierre; Garelli, Alix; Park, Seung -Bu; ...</p> <p>2016-01-05</p> <p>In this paper, the role of surface heat <span class="hlt">fluxes</span> underneath cold pools is investigated using cloud–resolving simulations with either interactive or horizontally homogenous surface heat <span class="hlt">fluxes</span> over an ocean and a simplified land surface. Over the ocean, there are limited changes in the distribution of the cold pool temperature, humidity, and gust front velocity, yet interactive heat <span class="hlt">fluxes</span> induce more cold pools, which are smaller, and convection is then less organized. Correspondingly, the updraft <span class="hlt">mass</span> <span class="hlt">flux</span> and lateral entrainment are modified. Over the land surface, the heat <span class="hlt">fluxes</span> underneath cold pools drastically impact the cold pool characteristics with more numerousmore » and smaller pools, which are warmer and more humid and accompanied by smaller gust front velocities. The interactive <span class="hlt">fluxes</span> also modify the updraft <span class="hlt">mass</span> <span class="hlt">flux</span> and reduce convective organization. These results emphasize the importance of interactive surface <span class="hlt">fluxes</span> instead of prescribed <span class="hlt">flux</span> boundary conditions, as well as the formulation of surface heat <span class="hlt">fluxes</span>, when studying convection.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4819715','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4819715"><span>Role of surface heat <span class="hlt">fluxes</span> underneath cold pools</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Garelli, Alix; Park, Seung‐Bu; Nie, Ji; Torri, Giuseppe; Kuang, Zhiming</p> <p>2016-01-01</p> <p>Abstract The role of surface heat <span class="hlt">fluxes</span> underneath cold pools is investigated using cloud‐resolving simulations with either interactive or horizontally homogenous surface heat <span class="hlt">fluxes</span> over an ocean and a simplified land surface. Over the ocean, there are limited changes in the distribution of the cold pool temperature, humidity, and gust front velocity, yet interactive heat <span class="hlt">fluxes</span> induce more cold pools, which are smaller, and convection is then less organized. Correspondingly, the updraft <span class="hlt">mass</span> <span class="hlt">flux</span> and lateral entrainment are modified. Over the land surface, the heat <span class="hlt">fluxes</span> underneath cold pools drastically impact the cold pool characteristics with more numerous and smaller pools, which are warmer and more humid and accompanied by smaller gust front velocities. The interactive <span class="hlt">fluxes</span> also modify the updraft <span class="hlt">mass</span> <span class="hlt">flux</span> and reduce convective organization. These results emphasize the importance of interactive surface <span class="hlt">fluxes</span> instead of prescribed <span class="hlt">flux</span> boundary conditions, as well as the formulation of surface heat <span class="hlt">fluxes</span>, when studying convection. PMID:27134320</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V22C..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V22C..04C"><span>Continental Subduction: <span class="hlt">Mass</span> <span class="hlt">Fluxes</span> and Interactions with the Wider Earth System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuthbert, S. J.</p> <p>2011-12-01</p> <p>Substantial parts of ultra-high pressure (UHP) terrains probably represent subducted passive continental margins (PCM). This contribution reviews and synthesises research on processes operating in such systems and their implication for the wider Earth system. PCM sediments are large repositories of volatiles including hydrates, nitrogen species, carbonates and hydrocarbons. Sediments and upper/ mid-crustal basement are rich in incompatible elements and are fertile for melting. Lower crust may be more mafic and refractory. Juvenile rift-related mafic rocks also have the potential to generate substantial volumes of granitoid melts, especially if they have been hydrated. Exposed UHP terrains demonstrate the return of continental crust from mantle depths, show evidence for substantial <span class="hlt">fluxes</span> of aqueous fluid, anatexis and, in entrained orogenic peridotites, metasomatism of mantle rocks by crust- derived C-O-H fluids. However, substantial bodies of continental material may never return to the surface as coherent <span class="hlt">masses</span> of rock, but remain sequestered in the mantle where they melt or become entrained in the deeper mantle circulation. Hence during subduction, PCM's become partitioned by a range of mechanisms. Mechanical partitioning strips away weaker sediment and middle/upper crust, which circulate back up the subduction channel, while denser, stronger transitional pro-crust and lower crust may "stall" near the base of the lithosphere or be irreversibly subducted to join the global mantle circulation. Under certain conditions sediment and upper crustal basement may reach depths for UHPM. Further partitioning takes place by anatexis, which either aids stripping and exhumation of the more melt-prone rock-<span class="hlt">masses</span> through mechanical softening, or separates melt from residuum so that melt escapes and is accreted to the upper plate leading to "undercrusting", late-orogenic magmatism and further refinement of the crust. Melt that traverses sections of mantle will interact with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110013484&hterms=Mass+standards&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMass%2Bstandards','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110013484&hterms=Mass+standards&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMass%2Bstandards"><span>Global <span class="hlt">Mass</span> <span class="hlt">Flux</span> Solutions from GRACE: A Comparison of Parameter Estimation Strategies - <span class="hlt">Mass</span> Concentrations Versus Stokes Coefficients</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rowlands, D. D.; Luthcke, S. B.; McCarthy J. J.; Klosko, S. M.; Chinn, D. S.; Lemoine, F. G.; Boy, J.-P.; Sabaka, T. J.</p> <p>2010-01-01</p> <p>The differences between <span class="hlt">mass</span> concentration (mas con) parameters and standard Stokes coefficient parameters in the recovery of gravity infonnation from gravity recovery and climate experiment (GRACE) intersatellite K-band range rate data are investigated. First, mascons are decomposed into their Stokes coefficient representations to gauge the range of solutions available using each of the two types of parameters. Next, a direct comparison is made between two time series of unconstrained gravity solutions, one based on a set of global equal area mascon parameters (equivalent to 4deg x 4deg at the equator), and the other based on standard Stokes coefficients with each time series using the same fundamental processing of the GRACE tracking data. It is shown that in unconstrained solutions, the type of gravity parameter being estimated does not qualitatively affect the estimated gravity field. It is also shown that many of the differences in <span class="hlt">mass</span> <span class="hlt">flux</span> derivations from GRACE gravity solutions arise from the type of smoothing being used and that the type of smoothing that can be embedded in mas con solutions has distinct advantages over postsolution smoothing. Finally, a 1 year time series based on global 2deg equal area mascons estimated every 10 days is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..12213525C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..12213525C"><span>Investigating Local and Remote Terrestrial Influence on <span class="hlt">Air</span> <span class="hlt">Masses</span> at Contrasting Antarctic Sites Using Radon-222 and Back Trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambers, S. D.; Choi, T.; Park, S.-J.; Williams, A. G.; Hong, S.-B.; Tositti, L.; Griffiths, A. D.; Crawford, J.; Pereira, E.</p> <p>2017-12-01</p> <p>We report on the first summer of high-sensitivity radon measurements from a two-filter detector at Jang Bogo Station (Terra Nova Bay) and contrast them with simultaneous observations at King Sejong Station (King George Island). King Sejong radon concentrations were characteristic of a marine baseline station (0.02-0.3 Bq m-3), whereas Jang Bogo values were highly variable (0.06-5.2 Bq m-3), mainly due to emissions from exposed coastal ground (estimated mean <span class="hlt">flux</span> 0.09-0.11 atoms cm-2 s-1) and shallow atmospheric mixing depths. For wind speeds of ≤3.5 m s-1 the influence of local radon emissions became increasingly more prominent at both sites. A cluster analysis of back trajectories from King Sejong (62°S) revealed a fairly even distribution between <span class="hlt">air</span> <span class="hlt">masses</span> that had passed recently over South America, the Southern Ocean, and Antarctica, whereas at Jang Bogo (75°S) 80% of events had recently passed over the Ross Ice Shelf and West Antarctica, 12% were synoptically forced over Cape Adare, and 8% were associated with subsidence over the Antarctic interior and katabatic flow to the station. When cross-checked against radon concentrations, only half of the back trajectories ending at Jang Bogo that had indicated distant contact with nonpolar southern hemisphere continents within the past 10 days showed actual signs of terrestrial influence. A simple-to-implement technique based on high-pass filtered absolute humidity is developed to distinguish between predominantly katabatic, oceanic, and near-coastal <span class="hlt">air</span> <span class="hlt">masses</span> for characterization of trace gas and aerosol measurements at coastal East Antarctic sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984JMMM...41..427H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984JMMM...41..427H"><span>Influence of cutting strains and magnetic anisotropy of electrical steel on the <span class="hlt">air</span> gap <span class="hlt">flux</span> distribution of an induction motor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hribernik, Božo</p> <p>1984-02-01</p> <p>This paper describes an iterative algorithm for the simulation of various real magnetic materials in a small induction motor and their influence on the <span class="hlt">flux</span> distribution in the <span class="hlt">air</span> gap. Two standard materials, fully-, and semi-processed steel strips were used. The nonlinearity of the magnetization curve, the influence of cutting strains and magnetic anisotropy are also considered. All these influences bring out the facts that the uniformly rotated and sine form exitation causes a nonuniformly rotated and deformed magnetic field in the <span class="hlt">air</span> gap of the machine and that the magnetization current is winding place dependent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.2699S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.2699S"><span>Coccolithophore surface distributions in the North Atlantic and their modulation of the <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2 from 10 years of satellite Earth observation data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shutler, J. D.; Land, P. E.; Brown, C. W.; Findlay, H. S.; Donlon, C. J.; Medland, M.; Snooke, R.; Blackford, J. C.</p> <p>2013-04-01</p> <p>Coccolithophores are the primary oceanic phytoplankton responsible for the production of calcium carbonate (CaCO3). These climatically important plankton play a key role in the oceanic carbon cycle as a major contributor of carbon to the open ocean carbonate pump (~50%) and their calcification can affect the atmosphere-to-ocean (<span class="hlt">air</span>-sea) uptake of carbon dioxide (CO2) through increasing the seawater partial pressure of CO2 (pCO2). Here we document variations in the areal extent of surface blooms of the globally important coccolithophore, Emiliania huxleyi, in the North Atlantic over a 10-year period (1998-2007), using Earth observation data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). We calculate the annual mean sea surface areal coverage of E. huxleyi in the North Atlantic to be 474 000 ± 104 000 km2, which results in a net CaCO3 carbon (CaCO3-C) production of 0.14-1.71 Tg CaCO3-C per year. However, this surface coverage (and, thus, net production) can fluctuate inter-annually by -54/+8% about the mean value and is strongly correlated with the El Niño/Southern Oscillation (ENSO) climate oscillation index (r=0.75, p<0.02). Our analysis evaluates the spatial extent over which the E. huxleyi blooms in the North Atlantic can increase the pCO2 and, thus, decrease the localised <span class="hlt">air</span>-sea <span class="hlt">flux</span> of atmospheric CO2. In regions where the blooms are prevalent, the average reduction in the monthly <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> can reach 55%. The maximum reduction of the monthly <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> in the time series is 155%. This work suggests that the high variability, frequency and distribution of these calcifying plankton and their impact on pCO2 should be considered if we are to fully understand the variability of the North Atlantic <span class="hlt">air</span>-to-sea <span class="hlt">flux</span> of CO2. We estimate that these blooms can reduce the annual N. Atlantic net sink atmospheric CO2 by between 3-28%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024135','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024135"><span>Stable isotope composition of waters in the Great Basin, United States 1. <span class="hlt">Air-mass</span> trajectories</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Friedman, I.; Harris, J.M.; Smith, G.I.; Johnson, C.A.</p> <p>2002-01-01</p> <p>Isentropic trajectories, calculated using the NOAA/Climate Monitoring and Diagnostics Laboratory's isentropic transport model, were used to determine <span class="hlt">air</span>-parcel origins and the influence of <span class="hlt">air</span> <span class="hlt">mass</span> trajectories on the isotopic composition of precipitation events that occurred between October 1991 and September 1993 at Cedar City, Utah, and Winnemucca, Nevada. Examination of trajectories that trace the position of <span class="hlt">air</span> parcels backward in time for 10 days indicated five distinct regions of water vapor origin: (1) Gulf of Alaska and North Pacific, (2) central Pacific, (3) tropical Pacific, (4) Gulf of Mexico, and (5) continental land <span class="hlt">mass</span>. Deuterium (??D) and oxygen-18 (??18O) analyses were made of precipitation representing 99% of all Cedar City events. Similar analyses were made on precipitation representing 66% of the precipitation falling at Winnemucca during the same period. The average isotopic composition of precipitation derived from each water vapor source was determined. More than half of the precipitation that fell at both sites during the study period originated in the tropical Pacific and traveled northeast to the Great Basin; only a small proportion traversed the Sierra Nevada. The isotopic composition of precipitation is determined by <span class="hlt">air-mass</span> origin and its track to the collection station, mechanism of droplet formation, reequilibration within clouds, and evaporation during its passage from cloud to ground. The Rayleigh distillation model can explain the changes in isotopic composition of precipitation as an <span class="hlt">air</span> <span class="hlt">mass</span> is cooled pseudo-adiabatically during uplift. However, the complicated processes that take place in the rapidly convecting environment of cumulonimbus and other clouds that are common in the Great Basin, especially in summer, require modification of this model because raindrops that form in the lower portion of those clouds undergo isotopic change as they are elevated to upper levels of the clouds from where they eventually drop to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JMS...140...26M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMS...140...26M"><span>Spatio-temporal dynamics of biogeochemical processes and <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span> in the Western English Channel based on two years of FerryBox deployment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marrec, P.; Cariou, T.; Latimier, M.; Macé, E.; Morin, P.; Vernet, M.; Bozec, Y.</p> <p>2014-12-01</p> <p>From January 2011 to January 2013, a FerryBox system was installed on a Voluntary Observing Ship (VOS), which crossed the Western English Channel (WEC) between Roscoff (France) and Plymouth (UK) up to 3 times a day. The FerryBox continuously measured sea surface temperature (SST), sea surface salinity (SSS), dissolved oxygen (DO), fluorescence and partial pressure of CO2 (from April 2012) along the ferry track. Sensors were calibrated based on 714 bimonthly surface samplings with precisions of 0.016 for SSS, 3.3 μM for DO, 0.40 μg L- 1 for Chlorophyll-a (Chl-a) (based on fluorescence measurements) and 5.2 μatm for pCO2. Over the 2 years of deployment (900 crossings), we reported 9% of data lost due to technical issues and quality checked data was obtained to allow investigation of the dynamics of biogeochemical processes related to <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span> in the WEC. Based on this unprecedented high-frequency dataset, the physical structure of the WEC was assessed using SST anomalies and the presence of a thermal front was observed around the latitude 49.5°N, which divided the WEC in two main provinces: the seasonally stratified northern WEC (nWEC) and the all-year well-mixed southern WEC (sWEC). These hydrographical properties strongly influenced the spatial and inter-annual distributions of phytoplankton blooms, which were mainly limited by nutrients and light availability in the nWEC and the sWEC, respectively. <span class="hlt">Air</span>-sea CO2 <span class="hlt">fluxes</span> were also highly related to hydrographical properties of the WEC between late April and early September 2012, with the sWEC a weak source of CO2 to the atmosphere of 0.9 mmol m- 2 d- 1, whereas the nWEC acted as a sink for atmospheric CO2 of 6.9 mmol m- 2 d- 1. The study of short time-scale dynamics of <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span> revealed that an intense and short (less than 10 days) summer bloom in the nWEC contributed to 29% of the CO2 sink during the productive period, highlighting the necessity for high frequency observations in coastal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=319938','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=319938"><span>Threshold wind velocity dynamics as a driver of aeolian sediment mas <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Horizontal (saltation) <span class="hlt">mass</span> <span class="hlt">flux</span> is a key driver of aeolian dust emission. Estimates of the horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> underpin assessments of the global dust budget and influence our understanding of the dust cycle and its interactions. Current equations for predicting horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> are based on l...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/197554-pah-pcb-baltic-budget-approach-including-fluxes-occurrence-concentration-variability-air-suspended-settling-particulates-water-surface-sediments-river-water','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/197554-pah-pcb-baltic-budget-approach-including-fluxes-occurrence-concentration-variability-air-suspended-settling-particulates-water-surface-sediments-river-water"><span>PAH and PCB in the Baltic -- A budget approach including <span class="hlt">fluxes</span>, occurrence and concentration variability in <span class="hlt">air</span>, suspended and settling particulates in water, surface sediments and river water</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Broman, D.; Axelman, J.; Bandh, C.</p> <p></p> <p>In order to study the fate and occurrence of two groups of hydrophobic compounds in the Baltic aquatic environment a large number of samples were collected from the southern Baltic proper to the northern Bothnian Bay for the analyses of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). The following sample matrices were collected; bottom surface sediments (0--1 cm, collected with gravity corer), settling particulate matter (collected with sediment traps), open water samples and over water samples (suspended particulates and dissolved fraction sampled by filtration) and <span class="hlt">air</span> samples (aerosols and vapor phase sampled by filtration). All samples (except over watermore » and <span class="hlt">air</span>) were collected at open sea in the Baltic. The analyses results have been used to make a model approach on the whole Baltic and to elucidate different aspects of the behavior of PAHs and PCBs in the Baltic, such as the occurrence of the compounds in water and sediment, the total content as well as the concentration variabilities over such a large geographical area, Further, the data on settling particulate matter as well as the <span class="hlt">air</span> concentration data were used to estimate the total <span class="hlt">fluxes</span> of PAHs and PCBs to the bottoms of the Baltic and t o the total water area of the Baltic, respectively. Further, data on the PAH and PCB content in river water from four major rivers provides rough estimates of the riverine input to the Baltic. The dynamics of PAHs and PCBs within the water <span class="hlt">mass</span> have also been studied in terms of settling velocities and residence times in the water <span class="hlt">mass</span> for these type of compounds in the open Baltic.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJP..132..245M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJP..132..245M"><span>Aerosol concentration measurements and correlations with <span class="hlt">air</span> <span class="hlt">mass</span> trajectories at the Pierre Auger Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Micheletti, M. I.; Louedec, K.; Freire, M.; Vitale, P.; Piacentini, R. D.</p> <p>2017-06-01</p> <p>Aerosols play an important role in radiative transfer processes involved in different fields of study. In particular, their influence is crucial in the attenuation of light at astronomical and astrophysical observatories, and has to be taken into account in light transfer models employed to reconstruct the signals. The Andean Argentinean region is increasingly being considered as a good candidate to host such facilities, as well as the ones for solar-energy resources, and an adequate knowledge of aerosols characteristics there is needed, but it is not always possible due to the vast area involved and the scarce atmospheric data at ground. The aim of this work is to find correlations between aerosol data and particle trajectories that can give an insight into the origin and behaviour of aerosols in this zone and can be employed in situations in which one does not have local aerosol measurements. For this purpose, an aerosol spectrometer and dust monitor (Grimm 1.109) was installed at the Pierre Auger Observatory of ultra-high-energy cosmic rays, to record aerosol concentrations in different size intervals, at surface level. These measurements are analysed and correlated with <span class="hlt">air</span> <span class="hlt">mass</span> trajectories obtained from HYSPLIT (NOAA) model calculations. High aerosol concentrations are registered predominantly when <span class="hlt">air</span> <span class="hlt">masses</span> have travelled mostly over continental areas, mainly from the NE direction, while low aerosol concentrations are found in correspondence with <span class="hlt">air</span> <span class="hlt">masses</span> coming from the Pacific Ocean, from the NW direction. Different size distribution patterns were found for the aerosols depending on their origin: marine or continental. This work shows for the first time the size distribution of aerosols registered at the Pierre Auger Observatory. The correlations found between <span class="hlt">mass</span> and particle concentrations (total and for different size ranges) and HYSPLIT <span class="hlt">air</span> <span class="hlt">mass</span> trajectories, confirm that the latter can be employed as a useful tool to infer the sources, evolution</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4244...74M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4244...74M"><span>Sequential cryogen spraying for heat <span class="hlt">flux</span> control at the skin surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majaron, Boris; Aguilar, Guillermo; Basinger, Brooke; Randeberg, Lise L.; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart</p> <p>2001-05-01</p> <p>Heat transfer rate at the skin-<span class="hlt">air</span> interface is of critical importance for the benefits of cryogen spray cooling in combination with laser therapy of shallow subsurface skin lesions, such as port-wine stain birthmarks. With some cryogen spray devices, a layer of liquid cryogen builds up on the skin surface during the spurt, which may impair heat transfer across the skin surface due to relatively low thermal conductivity and potentially higher temperature of the liquid cryogen layer as compared to the spray droplets. While the <span class="hlt">mass</span> <span class="hlt">flux</span> of cryogen delivery can be adjusted by varying the atomizing nozzle geometry, this may strongly affect other spray properties, such as lateral spread (cone), droplet size, velocity, and temperature distribution. We present here first experiments with sequential cryogen spraying, which may enable accurate <span class="hlt">mass</span> <span class="hlt">flux</span> control through variation of spray duty cycle, while minimally affecting other spray characteristics. The observed increase of cooling rate and efficiency at moderate duty cycle levels supports the above described hypothesis of isolating liquid layer, and demonstrates a novel approach to optimization of cryogen spray devices for individual laser dermatological applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24216412','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24216412"><span>Particulate emissions from a beef cattle feedlot using the <span class="hlt">flux</span>-gradient technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bonifacio, Henry F; Maghirang, Ronaldo G; Trabue, Steven L; McConnell, Laura L; Prueger, John H; Razote, Edna B</p> <p>2013-09-01</p> <p>Data on <span class="hlt">air</span> emissions from open-lot beef cattle () feedlots are limited. This research was conducted to determine <span class="hlt">fluxes</span> of particulate matter with an aerodynamic diameter ≤10 μm (PM) from a commercial beef cattle feedlot in Kansas using the <span class="hlt">flux</span>-gradient technique, a widely used micrometeorological method for <span class="hlt">air</span> emissions from open sources. Vertical PM concentration profiles and micrometeorological parameters were measured at the feedlot using tapered element oscillating microbalance PM samplers and eddy covariance instrumentations (i.e., sonic anemometer and infrared hygrometer), respectively, from May 2010 through September 2011, representing feedlot conditions with <span class="hlt">air</span> temperatures ranging from -24 to 39°C. Calculated hourly PM <span class="hlt">fluxes</span> varied diurnally and seasonally, ranging up to 272 mg m h, with an overall median of 36 mg m h. For warm conditions (<span class="hlt">air</span> temperature of 21 ± 10°C), the highest hourly PM <span class="hlt">fluxes</span> (range 116-146 mg m h) were observed during the early evening period, from 2000 to 2100 h. For cold conditions (<span class="hlt">air</span> temperature of -2 ± 8°C), the highest PM <span class="hlt">fluxes</span> (range 14-27 mg m h) were observed in the afternoon, from 1100 to 1500 h. Changes in the hourly trend of PM <span class="hlt">fluxes</span> coincided with changes in friction velocity, <span class="hlt">air</span> temperature, sensible heat <span class="hlt">flux</span>, and surface roughness. The PM emission was also affected by the pen surface water content, where a water content of at least 20% (wet basis) would be sufficient to effectively reduce PM emissions from pens by as much as 60%. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080047996','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080047996"><span><span class="hlt">Mass</span> Spectrometer Containing Multiple Fixed Collectors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moskala, Robert; Celo, Alan; Voss, Guenter; Shaffer, Tom</p> <p>2008-01-01</p> <p>A miniature <span class="hlt">mass</span> spectrometer that incorporates features not typically found in prior <span class="hlt">mass</span> spectrometers is undergoing development. This <span class="hlt">mass</span> spectrometer is designed to simultaneously measure the relative concentrations of five gases (H2, He, N2, O2, and Ar) in <span class="hlt">air</span>, over the relative-concentration range from 10(exp -6) to 1, during a sampling time as short as 1 second. It is intended to serve as a prototype of a product line of easy-to-use, portable, lightweight, highspeed, relatively inexpensive instruments for measuring concentrations of multiple chemical species in such diverse applications as detecting explosive or toxic chemicals in <span class="hlt">air</span>, monitoring and controlling industrial processes, measuring concentrations of deliberately introduced isotopes in medical and biological investigations, and general environmental monitoring. The heart of this <span class="hlt">mass</span> spectrometer is an integral combination of a circular cycloidal <span class="hlt">mass</span> analyzer, multiple fixed ion collectors, and two <span class="hlt">mass</span>-selective ion sources. By circular cycloidal <span class="hlt">mass</span> analyzer is meant an analyzer that includes (1) two concentric circular cylindrical electrodes for applying a radial electric field and (2) a magnet arranged to impose a magnetic <span class="hlt">flux</span> aligned predominantly along the cylindrical axis, so that ions, once accelerated into the annulus between the electrodes, move along circular cycloidal trajectories. As in other <span class="hlt">mass</span> analyzers, trajectory of each ion is determined by its <span class="hlt">mass</span>-to-charge ratio, and so ions of different species can be collected simultaneously by collectors (Faraday cups) at different locations intersected by the corresponding trajectories (see figure). Unlike in other <span class="hlt">mass</span> analyzers, the installation of additional collectors to detect additional species does not necessitate increasing the overall size of the analyzer assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9230H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9230H"><span>Spatial variability of hailfalls in France: an analysis of <span class="hlt">air</span> <span class="hlt">mass</span> retro-trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hermida, Lucía; Merino, Andrés; Sánchez, José Luis; Berthet, Claude; Dessens, Jean; López, Laura; Fernández-González, Sergio; Gascón, Estíbaliz; García-Ortega, Eduardo</p> <p>2014-05-01</p> <p>Hail is the main meteorological risk in south-west France, with the strongest hailfalls being concentrated in just a few days. Specifically, this phenomenon occurs most often and with the greatest severity in the Midi-Pyrénées area. Previous studies have revealed the high spatial variability of hailfall in this part of France, even leading to different characteristics being recorded on hailpads that were relatively close together. For this reason, an analysis of the <span class="hlt">air</span> <span class="hlt">mass</span> trajectories was carried out at ground level and at altitude, which subsequently led to the formation of the hail recorded by these hailpads. It is already known that in the study zone, the trajectories of the storms usually stretch for long distances and are oriented towards the east, leading to hailstones with diameters in excess of 3 cm, and without any change in direction above 3 km. We analysed different days with hail precipitation where there was at least one stone with a diameter of 3 cm or larger. Using the simulations from these days, an analysis of the backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> was carried out. We used the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) to determine the origin of the <span class="hlt">air</span> <span class="hlt">masses</span>, and tracked them toward each of the hailpads that were hit during the day studied. The height of the final points was the height of the impacted hailpads. Similarly, the backward trajectories for different heights were also established. Finally, the results show how storms that affect neighbouring hailpads come from very different <span class="hlt">air</span> <span class="hlt">masses</span>; and provide a deeper understanding of the high variability that affects the characteristics of hailfalls. Acknowledgements The authors would like to thank the Regional Government of Castile-León for its financial support through the project LE220A11-2. This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1040267','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1040267"><span>Contaminant <span class="hlt">Flux</span> Reduction Barriers for Managing Difficult-to-Treat Source Zones in Unconsolidated Media</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-06-20</p> <p>OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON Charles J . Newell a. REPORT b. ABSTRACT c . THIS PAGE 163 19b. TELEPHONE NUMBER...2016. McHugh, T.E., J.A. Connor, F. Ahmad, and C . J . Newell, 2003. A Groundwater <span class="hlt">Mass</span> <span class="hlt">Flux</span> Model For Groundwater-To-Indoor-<span class="hlt">Air</span> Vapor Intrusion. in...Newell, C . J ., L. P. Hopkins, and P. B. Bedient, 1990. “A Hydrogeologic Database for Groundwater Modeling”, Ground Water, Vol. 28, No. 5. Newell, C</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLB..762..288A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLB..762..288A"><span>Evidence for a mixed <span class="hlt">mass</span> composition at the 'ankle' in the cosmic-ray spectrum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; Dallier, R.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; del Peral, L.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorofeev, A.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Glass, H.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Latronico, L.; Lauscher, M.; Lautridou, P.; Lebrun, P.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Molina-Bueno, L.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, G.; Muller, M. A.; Müller, S.; Naranjo, I.; Navas, S.; Nellen, L.; Neuser, J.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pȩkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollant, R.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Reinert, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Rogozin, D.; Rosado, J.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sanabria Gomez, J. D.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sarmiento-Cano, C.; Sato, R.; Scarso, C.; Schauer, M.; Scherini, V.; Schieler, H.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Taborda, O. A.; Tapia, A.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Torri, M.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valbuena-Delgado, A.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yang, L.; Yelos, D.; Younk, P.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.; Pierre Auger Collaboration</p> <p>2016-11-01</p> <p>We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of <span class="hlt">air</span>-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid <span class="hlt">air</span>-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary <span class="hlt">masses</span> in the cosmic-ray <span class="hlt">flux</span>. Up till now, constraints on the spread of primary <span class="hlt">masses</span> have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of <span class="hlt">air</span> showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the 'ankle' at lg ⁡ (E /eV) = 18.5- 19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with <span class="hlt">mass</span> A > 4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray <span class="hlt">flux</span> at Earth.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011GeCoA..75.3385G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeCoA..75.3385G"><span>Bromine species <span class="hlt">fluxes</span> from Lake Constance’s catchment, and a preliminary lake <span class="hlt">mass</span> balance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilfedder, B. S.; Petri, M.; Wessels, M.; Biester, H.</p> <p>2011-06-01</p> <p> the catchment, which is supported by Ti, Zr and Br/C org data. In the lake bromine was irreversibly lost to the sediments, with best <span class="hlt">flux</span> estimates based on <span class="hlt">mass</span>-balance and sediment trap data of +50-90 μg Br m -2 d -1. Overall, it appears that bromine is not simply a cyclic salt in the case of Lake Constance, with a clear geological component and dynamic lacustrine biogeochemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A11N..06N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A11N..06N"><span>ED(MF)n: Humidity-Convection Feedbacks in a <span class="hlt">Mass</span> <span class="hlt">Flux</span> Scheme Based on Resolved Size Densities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neggers, R.</p> <p>2014-12-01</p> <p>Cumulus cloud populations remain at least partially unresolved in present-day numerical simulations of global weather and climate, and accordingly their impact on the larger-scale flow has to be represented through parameterization. Various methods have been developed over the years, ranging in complexity from the early bulk models relying on a single plume to more recent approaches that attempt to reconstruct the underlying probability density functions, such as statistical schemes and multiple plume approaches. Most of these "classic" methods capture key aspects of cumulus cloud populations, and have been successfully implemented in operational weather and climate models. However, the ever finer discretizations of operational circulation models, driven by advances in the computational efficiency of supercomputers, is creating new problems for existing sub-grid schemes. Ideally, a sub-grid scheme should automatically adapt its impact on the resolved scales to the dimension of the grid-box within which it is supposed to act. It can be argued that this is only possible when i) the scheme is aware of the range of scales of the processes it represents, and ii) it can distinguish between contributions as a function of size. How to conceptually represent this knowledge of scale in existing parameterization schemes remains an open question that is actively researched. This study considers a relatively new class of models for sub-grid transport in which ideas from the field of population dynamics are merged with the concept of multi plume modelling. More precisely, a multiple <span class="hlt">mass</span> <span class="hlt">flux</span> framework for moist convective transport is formulated in which the ensemble of plumes is created in "size-space". It is argued that thus resolving the underlying size-densities creates opportunities for introducing scale-awareness and scale-adaptivity in the scheme. The behavior of an implementation of this framework in the Eddy Diffusivity <span class="hlt">Mass</span> <span class="hlt">Flux</span> (EDMF) model, named ED(MF)n, is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhFl...18i3601L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhFl...18i3601L"><span>Measurements and computations of <span class="hlt">mass</span> flow and momentum <span class="hlt">flux</span> through short tubes in rarefied gases</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lilly, T. C.; Gimelshein, S. F.; Ketsdever, A. D.; Markelov, G. N.</p> <p>2006-09-01</p> <p>Gas flows through orifices and short tubes have been extensively studied from the 1960s through the 1980s for both fundamental and practical reasons. These flows are a basic and often important element of various modern gas driven instruments. Recent advances in micro- and nanoscale technologies have paved the way for a generation of miniaturized devices in various application areas, from clinical analyses to biochemical detection to aerospace propulsion. The latter is the main area of interest of this study, where rarefied gas flow into a vacuum through short tubes with thickness-to-diameter ratios varying from 0.015 to 1.2 is investigated both experimentally and numerically with kinetic and continuum approaches. Helium and nitrogen gases are used in the range of Reynolds numbers from 0.02 to 770 (based on the tube diameter), corresponding to Knudsen numbers from 40 down to about 0.001. Propulsion properties of relatively thin and thick tubes are examined. Good agreement between experimental and numerical results is observed for <span class="hlt">mass</span> flow rate and momentum <span class="hlt">flux</span>, the latter being corrected for the experimental facility background pressure. For thick-to-thin tube ratios of <span class="hlt">mass</span> flow and momentum <span class="hlt">flux</span> versus pressure, a minimum is observed at a Knudsen number of about 0.5. A short tube propulsion efficiency is shown to be much higher than that of a thin orifice. The effect of surface specularity on a thicker tube specific impulse was found to be relatively small.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........41W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........41W"><span>The Response of the Ocean Thermal Skin Layer to <span class="hlt">Air</span>-Sea Surface Heat <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wong, Elizabeth Wing-See</p> <p></p> <p>There is much evidence that the ocean is heating as a result of an increase in concentrations of greenhouse gases (GHGs) in the atmosphere from human activities. GHGs absorb infrared radiation and re-emit infrared radiation back to the ocean's surface which is subsequently absorbed. However, the incoming infrared radiation is absorbed within the top micrometers of the ocean's surface which is where the thermal skin layer exists. Thus the incident infrared radiation does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of infrared radiation and its effect on heat transfer at the <span class="hlt">air</span>-sea boundary. The hypothesis is that since heat lost through the <span class="hlt">air</span>-sea interface is controlled by the thermal skin layer, which is directly influenced by the absorption and emission of infrared radiation, the heat flow through the thermal skin layer adjusts to maintain the surface heat loss, assuming the surface heat loss does not vary, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in incoming longwave radiation and analyzing retrieved thermal skin layer vertical temperature profiles from a shipboard infrared spectrometer from two research cruises. The data are limited to night-time, no precipitation and low winds of less than 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of thermal skin layer disruption. The results show independence of the turbulent <span class="hlt">fluxes</span> and emitted radiation on the incident radiative <span class="hlt">fluxes</span> which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation and increase infrared emission. Furthermore, independence was confirmed between the incoming and outgoing radiative <span class="hlt">flux</span> which implies the heat sink for upward flowing heat at the <span class="hlt">air</span>-sea interface is more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002122','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002122"><span>Natural <span class="hlt">Air</span>-Sea <span class="hlt">Flux</span> of CO2 in Simulations of the NASA-GISS Climate Model: Sensitivity to the Physical Ocean Model Formulation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Romanou, A.; Gregg, Watson W.; Romanski, J.; Kelley, M.; Bleck, R.; Healy, R.; Nazarenko, L.; Russell, G.; Schmidt, G. A.; Sun, S.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20150002122'); toggleEditAbsImage('author_20150002122_show'); toggleEditAbsImage('author_20150002122_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20150002122_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20150002122_hide"></p> <p>2013-01-01</p> <p>Results from twin control simulations of the preindustrial CO2 gas exchange (natural <span class="hlt">flux</span> of CO2) between the ocean and the atmosphere are presented here using the NASA-GISS climate model, in which the same atmospheric component (modelE2) is coupled to two different ocean models, the Russell ocean model and HYCOM. Both incarnations of the GISS climate model are also coupled to the same ocean biogeochemistry module (NOBM) which estimates prognostic distributions for biotic and abiotic fields that influence the <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2. Model intercomparison is carried out at equilibrium conditions and model differences are contrasted with biases from present day climatologies. Although the models agree on the spatial patterns of the <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2, they disagree on the strength of the North Atlantic and Southern Ocean sinks mainly because of kinematic (winds) and chemistry (pCO2) differences rather than thermodynamic (SST) ones. Biology/chemistry dissimilarities in the models stem from the different parameterizations of advective and diffusive processes, such as overturning, mixing and horizontal tracer advection and to a lesser degree from parameterizations of biogeochemical processes such as gravitational settling and sinking. The global meridional overturning circulation illustrates much of the different behavior of the biological pump in the two models, together with differences in mixed layer depth which are responsible for different SST, DIC and nutrient distributions in the two models and consequently different atmospheric feedbacks (in the wind, net heat and freshwater <span class="hlt">fluxes</span> into the ocean).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=pollution+AND+light&pg=5&id=EJ090046','ERIC'); return false;" href="https://eric.ed.gov/?q=pollution+AND+light&pg=5&id=EJ090046"><span>The Analysis of PPM Levels of Gases in <span class="hlt">Air</span> by Photoionization <span class="hlt">Mass</span> Spectrometry</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Driscoll, John N.; Warneck, Peter</p> <p>1973-01-01</p> <p>Discusses analysis of trace gases in <span class="hlt">air</span> by photoionization <span class="hlt">mass</span> spectrometer. It is shown that the necessary sensitivity can be obtained by eliminating the UV monochromator and using direct ionization with a hydrogen light source. (JP)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25827140','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25827140"><span><span class="hlt">Air</span>-Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Tian; Guo, Zhigang; Li, Yuanyuan; Nizzetto, Luca; Ma, Chuanliang; Chen, Yingjun</p> <p>2015-05-05</p> <p>Gaseous exchange <span class="hlt">fluxes</span> of organochlorine pesticides (OCPs) across the <span class="hlt">air</span>-water interface of the coastal East China Sea were determined in order to assess whether the contaminated plume of the Yangtze River could be an important regional source of OCPs to the atmosphere. Hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), and dichlorodiphenyltrichloroethanes (DDTs) were the most frequently detected OCPs in <span class="hlt">air</span> and water. <span class="hlt">Air</span>-water exchange was mainly characterized by net volatilization for all measured OCPs. The net gaseous exchange <span class="hlt">flux</span> ranged 10-240 ng/(m2·day) for γ-HCH, 60-370 ng/(m2·day) for trans-CHL, 97-410 ng/(m2·day) for cis-CHL, and ∼0 (e.g., equilibrium) to 490 ng/(m2·day) for p,p'-DDE. We found that the plume of the large contaminated river can serve as a significant regional secondary atmospheric source of legacy contaminants released in the catchment. In particular, the sediment plume represented the relevant source of DDT compounds (especially p,p'-DDE) sustaining net degassing when clean <span class="hlt">air</span> <span class="hlt">masses</span> from the open ocean reached the plume area. In contrast, a <span class="hlt">mass</span> balance showed that, for HCHs, contaminated river discharge (water and sediment) plumes were capable of sustaining volatilization throughout the year. These results demonstrate the inconsistencies in the fate of HCHs and DDTs in this large estuarine system with declining primary sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27077862','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27077862"><span>An Optimized <span class="hlt">Air</span>-Core Coil Sensor with a Magnetic <span class="hlt">Flux</span> Compensation Structure Suitable to the Helicopter TEM System.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Chen; Liu, Fei; Lin, Jun; Zhu, Kaiguang; Wang, Yanzhang</p> <p>2016-04-12</p> <p>The <span class="hlt">air</span>-core coil sensor (ACS) is widely used as a transducer to measure the variation in magnetic fields of a helicopter transient electromagnetic (TEM) system. A high periodic emitting current induces the magnetic field signal of the underground medium. However, such current also generates a high primary field signal that can affect the received signal of the ACS and even damage the receiver. To increase the dynamic range of the received signal and to protect the receiver when emitting current rises/falls, the combination of ACS with magnetic <span class="hlt">flux</span> compensation structure (bucking coil) is necessary. Moreover, the optimized ACS, which is composed of an <span class="hlt">air</span>-core coil and a differential pre-amplifier circuit, must be investigated to meet the requirements of the helicopter TEM system suited to rapid surveying for shallow buried metal mine in rough topography. Accordingly, two ACSs are fabricated in this study, and their performance is verified and compared inside a magnetic shielding room. Using the designed ACSs, field experiments are conducted in Baoqing County. The field experimental data show that the primary field response can be compensated when the bucking coil is placed at an appropriate point in the range of allowed shift distance beyond the center of the transmitting coil and that the damage to the receiver induced by the over-statured signal can be solved. In conclusion, a more suitable ACS is adopted and is shown to have better performance, with a <span class="hlt">mass</span> of 2.5 kg, resultant effective area of 11.6 m² (i.e., diameter of 0.496 m), 3 dB bandwidth of 66 kHz, signal-to-noise ratio of 4 (i.e., varying magnetic field strength of 0.2 nT/s), and normalized equivalent input noise of 3.62 nV/m².</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25460953','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25460953"><span>Physical and chemical processes of <span class="hlt">air</span> <span class="hlt">masses</span> in the Aegean Sea during Etesians: Aegean-GAME airborne campaign.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tombrou, M; Bossioli, E; Kalogiros, J; Allan, J D; Bacak, A; Biskos, G; Coe, H; Dandou, A; Kouvarakis, G; Mihalopoulos, N; Percival, C J; Protonotariou, A P; Szabó-Takács, B</p> <p>2015-02-15</p> <p>High-resolution measurements of gas and aerosols' chemical composition along with meteorological and turbulence parameters were performed over the Aegean Sea (AS) during an Etesian outbreak in the framework of the Aegean-GAME airborne campaign. This study focuses on two distinct Etesian patterns, with similarities inside the Marine Atmospheric Boundary Layer (MABL) and differences at higher levels. Under long-range transport and subsidence the pollution load is enhanced (by 17% for CO, 11% for O3, 28% for sulfate, 62% for organic <span class="hlt">mass</span>, 47% for elemental carbon), compared to the pattern with a weaker synoptic system. Sea surface temperature (SST) was a critical parameter for the MABL structure, turbulent <span class="hlt">fluxes</span> and pollutants' distribution at lower levels. The MABL height was below 500 m asl over the eastern AS (favoring higher accumulation), and deeper over the western AS. The most abundant components of total PM1 were sulfate (40-50%) and organics (30-45%). Higher average concentrations measured over the eastern AS (131 ± 76 ppbv for CO, 62.5 ± 4.1 ppbv for O3, 5.0 ± 1.1 μg m(-3) for sulfate, 4.7 ± 0.9 μg m(-3) for organic <span class="hlt">mass</span> and 0.5 ± 0.2 μg m(-3) for elemental carbon). Under the weaker synoptic system, cleaner but more acidic <span class="hlt">air</span> <span class="hlt">masses</span> prevailed over the eastern part, while distinct aerosol layers of different signature were observed over the western part. The Aitken and accumulation modes contributed equally during the long-range transport, while the Aitken modes dominated during local or medium range transport. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080113','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080113"><span>Heat <span class="hlt">Flux</span> Sensor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>A heat <span class="hlt">flux</span> microsensor developed under a NASP Small Business Innovation Research (SBIR) has a wide range of potential commercial applications. Vatell Corporation originally designed microsensors for use in very high temperatures. The company then used the technology to develop heat <span class="hlt">flux</span> sensors to measure the rate of heat energy flowing in and out of a surface as well as readings on the surface temperature. Additional major advantages include response to heat <span class="hlt">flux</span> in less than 10 microseconds and the ability to withstand temperatures up to 1,200 degrees centigrade. Commercial applications are used in high speed aerodynamics, supersonic combustion, blade cooling, and <span class="hlt">mass</span> flow measurements, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMGC51A1049C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMGC51A1049C"><span>Surface <span class="hlt">Flux</span> Measurements at King Sejong Station in West Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, T.; Lee, B.; Lee, H.; Shim, J.</p> <p>2004-12-01</p> <p>The Antarctic Peninsula is important in terms of global warming research due to pronounced increase of <span class="hlt">air</span> temperature over the last century. The first eddy covariance system was established and turbulent <span class="hlt">fluxes</span> of heat, water vapor, CO2 and momentum have been measured at King Sejong Station (62 \\deg 13øØS, 58 \\deg 47øØW) located in the northern edge of the Antarctic Peninsula since December in 2002. Our objectives are to better understand the interactions between the Antarctic land surface and the atmosphere and to test the feasibility of the long-term operation of eddy covariance system under extreme weather conditions. Various lichens cover the study area and the dominant species is Usnea fasciata-Himantormia. Based on the analyses on turbulent statistics such as integral turbulence characteristics of vertical velocity (w) and heat (T), stationarity test and investigation of correlation coefficient, they follow the Monin-Obukhov similarity and eddy covariance <span class="hlt">flux</span> data were reliable. About 50 % of total retrieved sensible heat <span class="hlt">flux</span> data could be used for further analysis. We will report on seasonal variations of energy and <span class="hlt">mass</span> <span class="hlt">fluxes</span> and environmental variables. In addition, factors controlling these <span class="hlt">fluxes</span> will be presented. Acknowledgement: This study was supported by ¡rEnvironmental Monitoring on Human Impacts at the King Sejong Station, Antarctica¡_ (Project PP04102 of Korea Polar Research Institute) and ¡rEco-technopia 21 project¡_ (Ministry of Environment of Korea).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990GMS....58.....R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990GMS....58.....R"><span>Physics of magnetic <span class="hlt">flux</span> ropes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C. T.; Priest, E. R.; Lee, L. C.</p> <p></p> <p>The present work encompasses papers on the structure, waves, and instabilities of magnetic <span class="hlt">flux</span> ropes (MFRs), photospheric <span class="hlt">flux</span> tubes (PFTs), the structure and heating of coronal loops, solar prominences, coronal <span class="hlt">mass</span> ejections and magnetic clouds, <span class="hlt">flux</span> ropes in planetary ionospheres, the magnetopause, magnetospheric field-aligned currents and <span class="hlt">flux</span> tubes, and the magnetotail. Attention is given to the equilibrium of MFRs, resistive instability, magnetic reconnection and turbulence in current sheets, dynamical effects and energy transport in intense <span class="hlt">flux</span> tubes, waves in solar PFTs, twisted <span class="hlt">flux</span> ropes in the solar corona, an electrodynamical model of solar flares, filament cooling and condensation in a sheared magnetic field, the magnetopause, the generation of twisted MFRs during magnetic reconnection, ionospheric <span class="hlt">flux</span> ropes above the South Pole, substorms and MFR structures, evidence for <span class="hlt">flux</span> ropes in the earth magnetotail, and MFRs in 3D MHD simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMED41A0493S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMED41A0493S"><span>Determining the Central Atlantic Magmatic Province (CAMPS)'s Role in the Increased <span class="hlt">Flux</span> of CO2 in the end-Triassic <span class="hlt">Mass</span> Extinction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srinivasan, P. S.; Bachan, A.; Stanford School of Earth Sciences Department of Paleobiology</p> <p>2011-12-01</p> <p>The Central Atlantic Magmatic Province (CAMP) is one of the largest flood basalt provinces known. Its empacement coincided with a period of major plant and animal extinctions-the end-Triassic <span class="hlt">mass</span> extinction. It is postulated that the release of large amounts of carbon dioxide into the atmosphere from the volcanics was one of the causes of this <span class="hlt">mass</span> extinction. However,the magnitude of impact on ocean chemistry, and timescales involved remain unclear. To determine CAMP's role in this increased <span class="hlt">flux</span> of CO2, we studied the geochemistry of samples of rock from the Triassic-Jurassic boundary, in northern Italy. Specifically, by observing the ratios of carbon isotopes 12 and 13 in the organic carbon found in these limestone sedimentary rocks, we could determine the ratio of carbonate to organic burial <span class="hlt">fluxes</span> globally. We drilled limestone rocks from two different sections in the Southern Alps-- Pozzo Glaciale and Val Adrara. Once they were drilled to a fine powder-like form, we acidified the CaCO3 with HCl to isolate the organic carbon. Then, the organic matter was cleaned to rid the acid, and eventually was placed into tin foil to be placed into the Elemental Analyzer, which determined the percent Carbon in each sample. We tested about 200 samples, and placed them into the <span class="hlt">Mass</span> Spectrometer machine to determine the isotopic ratios of C12 and C13. According to the data, there was a positive excursion for both sample sets, which means that there was an increase in the amount of C13 in the organic matter. The duration of this excursion was at least a few hundred thousand years. This suggests a protracted increase in the burial <span class="hlt">flux</span> of organic carbon globally, which is consistent with the hypothesized volcanically driven increase in CO2. This further bolsters the contention that CAMP was responsible, in part, for this <span class="hlt">mass</span> extinction. By studying the earth's recovery from increased carbon <span class="hlt">fluxes</span> in the past, we can predict the recovery path that our anthropogenically</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/203613-gaseous-exchange-polycyclic-aromatic-hydrocarbons-across-air-water-interface-lower-chesapeake-bay','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/203613-gaseous-exchange-polycyclic-aromatic-hydrocarbons-across-air-water-interface-lower-chesapeake-bay"><span>Gaseous exchange of polycyclic aromatic hydrocarbons across the <span class="hlt">air</span>-water interface of lower Chesapeake Bay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gustafson, K.E.; Dickhut, R.M.</p> <p>1995-12-31</p> <p>The gaseous exchange <span class="hlt">fluxes</span> of polycyclic aromatic hydrocarbons (PAHs) across the <span class="hlt">air</span>-water interface of lower Chesapeake Bay were determined using a modified two-film exchange model. Sampling covered the period January 1994 to June 1995 for five sites on lower Chesapeake Bay ranging from rural to urban and highly industrialized. Simultaneous <span class="hlt">air</span> and water samples were collected and the atmospheric gas phase and water column dissolved phase analyzed via GC/MS for 17 PAHs. The direction and magnitude of <span class="hlt">flux</span> for each PAH was calculated using Henry`s law constants, hydrological and meteorological parameters, Temperature was observed to be an important environmental factormore » in determining both the direction and magnitude of PAH gas exchange. Nonetheless, wind speed significantly impacts <span class="hlt">mass</span> transfer coefficients, and therefore was found to control the magnitude of <span class="hlt">flux</span>. Spatial and temporal variation of PAH gaseous exchange <span class="hlt">fluxes</span> were examined. <span class="hlt">Fluxes</span> were determined to be both into and out of Chesapeake Bay. The range of gas exchange <span class="hlt">fluxes</span> ({minus}560 to 600{micro}g/M{sup 2}*Mo) is of the same order to 10X greater than atmospheric wet and dry depositional <span class="hlt">fluxes</span> to lower Chesapeake Bay. The results of this study support the hypothesis that gas exchange is a major transport process affecting the net loadings of PAHs in lower Chesapeake Bay.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1327487-evidence-mixed-mass-composition-ankle-cosmic-ray-spectrum','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1327487-evidence-mixed-mass-composition-ankle-cosmic-ray-spectrum"><span>Evidence for a mixed <span class="hlt">mass</span> composition at the ‘ankle’ in the cosmic-ray spectrum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Aab, Alexander</p> <p>2016-09-28</p> <p>Here, we report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of <span class="hlt">air</span>-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid <span class="hlt">air</span>-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary <span class="hlt">masses</span> in the cosmic-ray <span class="hlt">flux</span>. Up till now, constraints on the spread of primary <span class="hlt">masses</span> have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of <span class="hlt">air</span> showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the `ankle' atmore » $$\\lg(E/{\\rm eV})=18.5-19.0$$ differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with <span class="hlt">mass</span> $A > 4$. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray <span class="hlt">flux</span> at Earth.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CSR...162...27C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CSR...162...27C"><span>Diurnal variability of CO2 <span class="hlt">flux</span> at coastal zone of Taiwan based on eddy covariance observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chien, Hwa; Zhong, Yao-Zhao; Yang, Kang-Hung; Cheng, Hao-Yuan</p> <p>2018-06-01</p> <p>In this study, we employed shore-based eddy covariance systems for a continuous measurement of the coastal CO2 <span class="hlt">flux</span> near the northwestern coast of Taiwan from 2011 to 2015. To ensure the validity of the analysis, the data was selected and filtered with a footprint model and an empirical mode decomposition method. The results indicate that the nearshore <span class="hlt">air</span>-sea and <span class="hlt">air</span>-land CO2 <span class="hlt">fluxes</span> exhibited a significant diurnal variability and a substantial day-night difference. The net <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> was -1.75 ± 0.98 μmol-C m-2 s-1, whereas the net <span class="hlt">air</span>-land CO2 <span class="hlt">flux</span> was 0.54 ± 7.35 μmol-C m-2 s-1, which indicated that in northwestern Taiwan, the coastal water acts as a sink of atmospheric CO2 but the coastal land acts as a source. The Random Forest Method was applied to hierarchize the influence of Chl-a, SST, DO, pH and U10 on <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span>. The result suggests that the strength of the diurnal <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> is strongly influenced by the local wind speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.8925R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.8925R"><span>On the Control of Solute <span class="hlt">Mass</span> <span class="hlt">Fluxes</span> and Concentrations Below Fields Irrigated With Low-Quality Water: A Numerical Study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russo, David</p> <p>2017-11-01</p> <p>The main goal of this study was to test the capability of irrigation water-based and soil-based approaches to control nitrate and chloride <span class="hlt">mass</span> <span class="hlt">fluxes</span> and concentrations below the root zone of agricultural fields irrigated with treated waste water (TWW). Using numerical simulations of flow and transport in relatively a fine-textured, unsaturated, spatially heterogeneous, flow domain, scenarios examined include: (i) irrigating with TWW only (REF); (ii) irrigation water is substituted between TWW and desalinized water (ADW); (iii) soil includes a capillary barrier (CB) and irrigating with TWW only (CB + TWW); and (iv) combination of (ii) and a CB (CB + ADW). Considering groundwater quality protection, plausible goals are: (i) to minimize solute discharges leaving the root zone, and, (ii) to maximize the probability that solute concentrations leaving the root zone will not exceed a prescribed, critical value. Results of the analyses suggest that in the case of a seasonal crop (a corn field) subject to irrigations only, with respect to the first goal, the CB + TWW and CB + ADW scenarios provide similar, excellent results, better than the ADW scenario; with respect to the second goal, however, the CB + ADW scenario gave substantially better results than the CB + TWW scenario. In the case a multiyear, perennial crop (a citrus orchard), subject to a sequence of irrigation and rainfall periods, for both solutes, and, particularly, nitrate, with respect to the two goals, both the ADW and CB + ADW scenarios perform better than the CB + TWW scenario. As compared with the REF and CB + TWW scenarios, the ADW and CB + ADW scenarios substantially reduce nitrogen <span class="hlt">mass</span> <span class="hlt">fluxes</span> to the groundwater and to the atmosphere, and, essentially, did not reduce nitrogen <span class="hlt">mass</span> <span class="hlt">fluxes</span> to the trees. Similar results, even better, were demonstrated for a relatively coarse-textured, spatially heterogeneous soil.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ACP....12.3761D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ACP....12.3761D"><span>Variability of aerosol, gaseous pollutants and meteorological characteristics associated with changes in <span class="hlt">air</span> <span class="hlt">mass</span> origin at the SW Atlantic coast of Iberia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.-M.; Drewnick, F.; Zorn, S. R.; von der Weiden-Reinmüller, S.-L.; Martinez, M.; Borrmann, S.</p> <p>2012-04-01</p> <p>Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean, a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of <span class="hlt">air</span> <span class="hlt">masses</span>. Backwards trajectories were examined and compared with local meteorology to classify characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types for several source regions. Aerosol number and <span class="hlt">mass</span> as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol (NR-PM1) was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle <span class="hlt">mass</span> and number concentrations were found in <span class="hlt">air</span> <span class="hlt">masses</span> arriving from the Atlantic Ocean with values around 2 μg m-3 and 1000 cm-3. These <span class="hlt">mass</span> concentrations were about two to four times lower than the values recorded in <span class="hlt">air</span> <span class="hlt">masses</span> of continental and urban origins. For some species PM1-fractions in marine <span class="hlt">air</span> were significantly larger than in <span class="hlt">air</span> <span class="hlt">masses</span> originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine <span class="hlt">air</span> <span class="hlt">masses</span> and was to a high degree not neutralized. In addition, small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions, could be identified in the particle phase</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=141711&keyword=planes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=141711&keyword=planes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>THE MEASUREMENT AND USE OF CONTAMINANT <span class="hlt">FLUX</span> FOR PERFORMANCE ASSESSMENT OF DNAPL REMEDIATION</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A review is presented of both <span class="hlt">mass</span> <span class="hlt">flux</span> as a DNAPL remedial performance metric and reduction in <span class="hlt">mass</span> <span class="hlt">flux</span> as a remedial performance objective at one or more control planes down gradient of DNAPL source areas. The use of <span class="hlt">mass</span> <span class="hlt">flux</span> to assess remedial performance has been proposed ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940019596','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940019596"><span>Miniature Convection Cooled Plug-type Heat <span class="hlt">Flux</span> Gauges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, Curt H.</p> <p>1994-01-01</p> <p>Tests and analysis of a new miniature plug-type heat <span class="hlt">flux</span> gauge configuration are described. This gauge can simultaneously measure heat <span class="hlt">flux</span> on two opposed active surfaces when heat <span class="hlt">flux</span> levels are equal to or greater than about 0.2 MW/m(sup 2). The performance of this dual active surface gauge was investigated over a wide transient and steady heat <span class="hlt">flux</span> and temperature range. The tests were performed by radiatively heating the front surface with an argon arc lamp while the back surface was convection cooled with <span class="hlt">air</span>. Accuracy is about +20 percent. The gauge is responsive to fast heat <span class="hlt">flux</span> transients and is designed to withstand the high temperature (1300 K), high pressure (15 MPa), erosive and corrosive environments in modern engines. This gauge can be used to measure heat <span class="hlt">flux</span> on the surfaces of internally cooled apparatus such as turbine blades and combustors used in jet propulsion systems and on the surfaces of hypersonic vehicles. Heat <span class="hlt">flux</span> measurement accuracy is not compromised when design considerations call for various size gauges to be fabricated into alloys of various shapes and properties. Significant gauge temperature reductions (120 K), which can lead to potential gauge durability improvement, were obtained when the gauges were <span class="hlt">air</span>-cooled by forced convection.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018CQGra..35b4001I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018CQGra..35b4001I"><span>Post-Newtonian templates for binary black-hole inspirals: the effect of the horizon <span class="hlt">fluxes</span> and the secular change in the black-hole <span class="hlt">masses</span> and spins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Isoyama, Soichiro; Nakano, Hiroyuki</p> <p>2018-01-01</p> <p>Black holes (BHs) in an inspiraling compact binary system absorb the gravitational-wave (GW) energy and angular-momentum <span class="hlt">fluxes</span> across their event horizons and this leads to the secular change in their <span class="hlt">masses</span> and spins during the inspiral phase. The goal of this paper is to present ready-to-use, 3.5 post-Newtonian (PN) template families for spinning, non-precessing, binary BH inspirals in quasicircular orbits, including the 2.5 PN and 3.5 PN horizon-<span class="hlt">flux</span> contributions as well as the correction due to the secular change in the BH <span class="hlt">masses</span> and spins through 3.5 PN order, respectively, in phase. We show that, for binary BHs observable by Advanced LIGO with high <span class="hlt">mass</span> ratios (larger than  ∼10) and large aligned-spins (larger than  ∼ 0.7 ), the mismatch between the frequency-domain template with and without the horizon-<span class="hlt">flux</span> contribution is typically above the 3% mark. For (supermassive) binary BHs observed by LISA, even a moderate <span class="hlt">mass</span>-ratios and spins can produce a similar level of the mismatch. Meanwhile, the mismatch due to the secular time variations of the BH <span class="hlt">masses</span> and spins is well below the 1% mark in both cases, hence this is truly negligible. We also point out that neglecting the cubic-in-spin, point-particle phase term at 3.5 PN order would deteriorate the effect of BH absorption in the template.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140008761','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140008761"><span>A Comparison of the Red Green Blue (RGB) <span class="hlt">Air</span> <span class="hlt">Mass</span> Imagery and Hyperspectral Infrared Retrieved Profiles and NOAA G-IV Dropsondes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berndt, Emily; Folmer, Michael; Dunion, Jason</p> <p>2014-01-01</p> <p>RGB <span class="hlt">air</span> <span class="hlt">mass</span> imagery is derived from multiple channels or paired channel differences. The combination of channels and channel differences means the resulting imagery does not represent a quantity or physical parameter such as brightness temperature in conventional single channel imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles and NOAA G-IV dropsondes provide insight about the vertical structure of the <span class="hlt">air</span> <span class="hlt">mass</span> represented on the RGB <span class="hlt">air</span> <span class="hlt">mass</span> imagery and are a first step to validating the imagery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ThApC.110..423C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ThApC.110..423C"><span>On the origin and destination of atmospheric moisture and <span class="hlt">air</span> <span class="hlt">mass</span> over the Tibetan Plateau</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Bin; Xu, Xiang-De; Yang, Shuai; Zhang, Wei</p> <p>2012-12-01</p> <p>The Tibet Plateau (TP) is a key region that imposes profound impacts on the atmospheric water cycle and energy budget of Asia, even the global climate. In this work, we develop a climatology of origin (destination) of <span class="hlt">air</span> <span class="hlt">mass</span> and moisture transported to (from) the TP using a Lagrangian moisture diagnosis combined with the forward and backward atmospheric tracking schemes. The climatology is derived from 6-h particle positions based on 5-year (2005-2009) seasonal summer trajectory dataset from the Lagrangian particle dispersion model FLEXPART using NCEP/GFS data as input, where the regional model atmosphere was globally filled with particles. The results show that (1) the dominant origin of the moisture supplied to the TP is a narrow tropical-subtropical band in the extended Arabian Sea covering a long distance from the Indian subcontinent to the Southern Hemisphere. Two additional moisture sources are located in the northwestern part of TP and the Bay of Bengal and play a secondary role. This result indicates that the moisture transporting to the TP more depends on the Indian summer monsoon controlled by large-scale circulation. (2) The moisture departing from the TP can be transported rapidly to East Asia, including East China, Korea, Japan, and even East Pacific. The qualitative similarity between the regions of diagnosed moisture loss and the pattern of the observed precipitation highlights the robustness of the role of the TP on precipitation over East Asia. (3) In contrast to the moisture origin confined in the low level, the origin and fate of whole column <span class="hlt">air</span> <span class="hlt">mass</span> over the TP is largely controlled by a strong high-level Asian anticyclone. The results show that the TP is a crossroad of <span class="hlt">air</span> <span class="hlt">mass</span> where <span class="hlt">air</span> enters mainly from the northwest and northeast and continues in two separate streams: one goes southwestwards over the Indian Ocean and the other southeastwards through western North Pacific. Both of them partly enter the trade wind zone, which manifests the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28372725','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28372725"><span>Analysis of volatile compounds by open-<span class="hlt">air</span> ionization <span class="hlt">mass</span> spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meher, Anil Kumar; Chen, Yu-Chie</p> <p>2017-05-08</p> <p>This study demonstrates a simple method for rapid and in situ identification of volatile and endogenous compounds in culinary spice samples through <span class="hlt">mass</span> spectrometry (MS). This method only requires a holder for solid spice sample (2-3 mm) that is placed close to a <span class="hlt">mass</span> spectrometer inlet, which is applied with a high voltage. Volatile species responsible for the aroma of the spice samples can be readily detected by the <span class="hlt">mass</span> spectrometer. Sample pretreatment is not required prior to MS analysis, and no solvent was used during MS analysis. The high voltage applied to the inlet of the <span class="hlt">mass</span> spectrometer induces the ionization of volatile compounds released from the solid spice samples. Furthermore, moisture in the <span class="hlt">air</span> also contributes to the ionization of volatile compounds. Dried spices including cinnamon and cloves are used as the model sample to demonstrate this straightforward MS analysis, which can be completed within few seconds. Furthermore, we also demonstrate the suitability of the current method for rapid screening of cinnamon quality through detection of the presence of a hepatotoxic agent, i.e. coumarin. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ExFl...50..233D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ExFl...50..233D"><span>Study of <span class="hlt">mass</span> and momentum transfer in diesel sprays based on X-ray <span class="hlt">mass</span> distribution measurements and on a theoretical derivation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Desantes, J. M.; Salvador, F. J.; López, J. J.; de La Morena, J.</p> <p>2011-02-01</p> <p>In this paper, a research aimed at quantifying <span class="hlt">mass</span> and momentum transfer in the near-nozzle field of diesel sprays injected into stagnant ambient <span class="hlt">air</span> is reported. The study combines X-ray measurements for two different nozzles and axial positions, which provide <span class="hlt">mass</span> distributions in the spray, with a theoretical model based on momentum <span class="hlt">flux</span> conservation, which was previously validated. This investigation has allowed the validation of Gaussian profiles for local fuel concentration and velocity near the nozzle exit, as well as the determination of Schmidt number at realistic diesel spray conditions. This information could be very useful for those who are interested in spray modeling, especially at high-pressure injection conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA617647','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA617647"><span>Processing Doppler Lidar and Cloud Radar Observations for Analysis of Convective <span class="hlt">Mass</span> <span class="hlt">Flux</span> Parameterizations Using DYNAMO Direct Observations</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-09-30</p> <p>for Analysis of Convective <span class="hlt">Mass</span> <span class="hlt">Flux</span> Parameterizations Using DYNAMO Direct Observations R. Michael Hardesty CIRES/University of Colorado/NOAA 325...the RV-Revell during legs 2 & 3 of the DYNAMO experiement to help characterize vertical transport through the boundary layer and to build statistics...obtained during DYNAMO , and to investigate whether cold pools that emanate from convection organize the interplay between humidity and convection and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H11F1256R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H11F1256R"><span>Assessment of attenuation processes in a chlorinated ethene plume by use of stream bed Passive <span class="hlt">Flux</span> Meters, streambed Point Velocity Probes and contaminant <span class="hlt">mass</span> balances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rønde, V.; McKnight, U. S.; Annable, M. D.; Devlin, J. F.; Cremeans, M.; Sonne, A. T.; Bjerg, P. L.</p> <p>2017-12-01</p> <p>Chlorinated ethenes (CE) are abundant groundwater contaminants and pose risk to both groundwater and surface water bodies, as plumes can migrate through aquifers to streams. After release to the environment, CE may undergo attenuation. The hyporheic zone is believed to enhance CE attenuation, however studies contradicting this have also been reported. Since dilution commonly reduces contaminant concentrations in streams to below quantification limits, use of <span class="hlt">mass</span> balances along the pathway from groundwater to stream is unusual. Our study is conducted at the low-land Grindsted stream, Denmark, which is impacted by a contaminant plume. CE have been observed in the stream water; hence our study site provides an unusual opportunity to study attenuation processes in a CE plume as it migrates through the groundwater at the stream bank, through the stream bed and further to the point of fully mixed conditions in the stream. The study undertook the determination of redox conditions and CE distribution from bank to stream; streambed contaminant <span class="hlt">flux</span> estimation using streambed Passive <span class="hlt">Flux</span> Meters (sPFM); and quantification of streambed water <span class="hlt">fluxes</span> using temperature profiling and streambed Point Velocity Probes (SBPVP). The advantage of the sPFM is that it directly measures the contaminant <span class="hlt">flux</span> without the need for water samples, while the advantage of the SBPVP is its ability to measure the vertical seepage velocity without the need for additional geological parameters. Finally, a <span class="hlt">mass</span> balance assessment along the plume pathway was conducted to account for any losses or accumulations. The results show consistencies in spatial patterns between redox conditions and extent of dechlorination; between contaminant <span class="hlt">fluxes</span> from sPFM and concentrations from water samples; and between seepage velocities from SBPVP and temperature-based water <span class="hlt">fluxes</span>. <span class="hlt">Mass</span> balances and parent-metabolite compound ratios indicate limited degradation between the bank and the point of fully mixed stream</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhyC..412..683T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhyC..412..683T"><span>Surface <span class="hlt">flux</span> density distribution characteristics of bulk high- Tc superconductor in external magnetic field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torii, S.; Yuasa, K.</p> <p>2004-10-01</p> <p>Various magnetic levitation systems using oxide superconductors are developed as strong pinning forces are obtained in melt-processed bulk. However, the trapped <span class="hlt">flux</span> of superconductor is moved by <span class="hlt">flux</span> creep and fluctuating magnetic field. Therefore, to examine the internal condition of superconductor, the authors measure the dynamic surface <span class="hlt">flux</span> density distribution of YBCO bulk. <span class="hlt">Flux</span> density measurement system has a structure with the <span class="hlt">air</span>-core coil and the Hall sensors. Ten Hall sensors are arranged in series. The YBCO bulk, which has 25 mm diameter and 13 mm thickness, is field cooled by liquid nitrogen. After that, magnetic field is changed by the <span class="hlt">air</span>-core coil. This paper describes about the measured results of <span class="hlt">flux</span> density distribution of YBCO bulk in the various frequencies of <span class="hlt">air</span>-core coils currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930057675&hterms=self+regulatory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dself%2Bregulatory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930057675&hterms=self+regulatory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dself%2Bregulatory"><span><span class="hlt">Flux</span>-tube divergence, coronal heating, and the solar wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Y.-M.</p> <p>1993-01-01</p> <p>Using model calculations based on a self-consistent treatment of the coronal energy balance, we show how the magnetic <span class="hlt">flux</span>-tube divergence rate controls the coronal temperature and the properties of the solar wind. For a fixed input of mechanical and Alfven-wave energy at the coronal base, we find that as the divergence rate increases, the maximum coronal temperature decreases but the <span class="hlt">mass</span> <span class="hlt">flux</span> leaving the sun gradually increases. As a result, the asymptotic wind speed decreases with increasing expansion factor near the sun, in agreement with empirical studies. As noted earlier by Withbroe, the calculated <span class="hlt">mass</span> <span class="hlt">flux</span> at the sun is remarkably insensitive to parameter variations; when combined with magnetohydrodynamic considerations, this self-regulatory property of the model explains the observed constancy of the <span class="hlt">mass</span> <span class="hlt">flux</span> at earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACPD...1131585D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACPD...1131585D"><span>Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine <span class="hlt">air</span> <span class="hlt">masses</span> at the SW Atlantic coast of Iberia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.-M.; Drewnick, F.; Zorn, S. R.; von der Weiden-Reinmüller, S.-L.; Martinez, M.; Borrmann, S.</p> <p>2011-12-01</p> <p>Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of <span class="hlt">air</span> <span class="hlt">masses</span>. Backwards trajectories were examined and compared with local meteorology to classify characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types for several source regions. Aerosol number and <span class="hlt">mass</span> as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle <span class="hlt">mass</span> and number concentrations were found in <span class="hlt">air</span> <span class="hlt">masses</span> arriving from the Atlantic Ocean with values around 2 μg m-3 and 1000 cm-3. These <span class="hlt">mass</span> concentrations were about two to four times lower than the values recorded in <span class="hlt">air</span> <span class="hlt">masses</span> of continental and urban origins. For some species PM1-fractions in marine <span class="hlt">air</span> were significantly larger than in <span class="hlt">air</span> <span class="hlt">masses</span> originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine <span class="hlt">air</span> <span class="hlt">masses</span> and was to a high degree not neutralized. In addition small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions could be identified in the particle phase. In all</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21233734-measurement-gas-species-temperatures-coal-burnout-wall-heat-fluxes-mwe-lignite-fired-boiler-different-overfire-air-damper-openings','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21233734-measurement-gas-species-temperatures-coal-burnout-wall-heat-fluxes-mwe-lignite-fired-boiler-different-overfire-air-damper-openings"><span>Measurement of gas species, temperatures, coal burnout, and wall heat <span class="hlt">fluxes</span> in a 200 MWe lignite-fired boiler with different overfire <span class="hlt">air</span> damper openings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jianping Jing; Zhengqi Li; Guangkui Liu</p> <p></p> <p>Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire <span class="hlt">air</span> (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat <span class="hlt">flux</span> and boiler efficiency were measured. Cold <span class="hlt">air</span> experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary <span class="hlt">air</span> region in the burner. As the secondary <span class="hlt">air</span> flow increases, the axial velocity of <span class="hlt">air</span> flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase,more » and the swirl intensity of <span class="hlt">air</span> flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary <span class="hlt">air</span> region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat <span class="hlt">flux</span> in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915393F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915393F"><span>Southeast Atlantic Cloud Properties in a Multivariate Statistical Model - How Relevant is <span class="hlt">Air</span> <span class="hlt">Mass</span> History for Local Cloud Properties?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, Julia; Cermak, Jan; Andersen, Hendrik</p> <p>2017-04-01</p> <p>This study aims at untangling the impacts of external dynamics and local conditions on cloud properties in the Southeast Atlantic (SEA) by combining satellite and reanalysis data using multivariate statistics. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget, and thus prominent in climate-system research. In this study, SEA stratocumulus cloud properties are observed not only as the result of local environmental conditions but also as affected by external dynamics and spatial origins of <span class="hlt">air</span> <span class="hlt">masses</span> entering the study area. In order to assess to what extent cloud properties are impacted by aerosol concentration, <span class="hlt">air</span> <span class="hlt">mass</span> history, and meteorology, a multivariate approach is conducted using satellite observations of aerosol and cloud properties (MODIS, SEVIRI), information on aerosol species composition (MACC) and meteorological context (ERA-Interim reanalysis). To account for the often-neglected but important role of <span class="hlt">air</span> <span class="hlt">mass</span> origin, information on <span class="hlt">air</span> <span class="hlt">mass</span> history based on HYSPLIT modeling is included in the statistical model. This multivariate approach is intended to lead to a better understanding of the physical processes behind observed stratocumulus cloud properties in the SEA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A43C2464G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A43C2464G"><span>The use of fair-weather cases from the ACT-America Summer 2016 field campaign to better constrain regional biogenic CO2 surface <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaudet, B. J.; Davis, K. J.; DiGangi, J. P.; Feng, S.; Hoffman, K.; Jacobson, A. R.; Lauvaux, T.; McGill, M. J.; Miles, N.; Pal, S.; Pauly, R.; Richardson, S.</p> <p>2017-12-01</p> <p>The Atmospheric Carbon and Transport - America (ACT-America) study is a multi-year NASA-funded project designed to increase our understanding of regional-scale greenhouse gas (GHG) <span class="hlt">fluxes</span> over North America through aircraft, satellite, and tower-based observations. This is being accomplished through a series of field campaigns that cover three focus regions (Mid-Atlantic, Gulf Coast, and Midwest), and all four seasons (summer, winter, fall, and spring), as well as a variety of meteorological conditions. While constraints on GHG <span class="hlt">fluxes</span> can be derived on the global scale (through remote-site concentration measurements and global <span class="hlt">flux</span> inversion models) and the local scale (through eddy-covariance <span class="hlt">flux</span> tower measurements), observational constraints on the intermediate scales are not as readily available. Biogenic CO2 <span class="hlt">fluxes</span> are particularly challenging because of their strong seasonal and diurnal cycles and large spatial variability. During the summer 2016 ACT field campaign, fair weather days were targeted for special flight patterns designed to estimate surface <span class="hlt">fluxes</span> at scales on the order of 105 km2 using a modified <span class="hlt">mass</span>-balance approach. For some onshore flow cases in the Gulf Coast, atmospheric boundary layer (ABL) flight transects were performed both inland and offshore when it could be reasonably inferred that the homogeneous Gulf <span class="hlt">air</span> provided the background GHG field for the inland transect. On other days, two-day flight sequences were performed, where the second-day location of the flight patterns was designed to encompass the <span class="hlt">air</span> <span class="hlt">mass</span> that was sampled on the first day. With these flight patterns, the average regional <span class="hlt">flux</span> can be estimated from the ABL CO2 concentration change. Direct measurements of ABL depth from both aircraft profiles and high-resolution airborne lidar will be used, while winds and free-tropospheric CO2 can be determined from model output and in situ aircraft observations. Here we will present examples of this <span class="hlt">flux</span> estimation for both Gulf</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.A41B0028A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.A41B0028A"><span>Ozone Modulation/Membrane Introduction <span class="hlt">Mass</span> Spectrometry for Analysis of Hydrocarbon Pollutants in <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atkinson, D. B.</p> <p>2001-12-01</p> <p>Modulation of volatile hydrocarbons in two-component mixtures is demonstrated using an ozonolysis pretreatment with membrane introduction <span class="hlt">mass</span> spectrometry (MIMS). The MIMS technique allows selective introduction of volatile and semivolatile analytes into a <span class="hlt">mass</span> spectrometer via processes known collectively as pervaporation [Kotiaho and Cooks, 1992]. A semipermeable polymer membrane acts as an interface between the sample (vapor or solution) and the vacuum of the <span class="hlt">mass</span> spectrometer. This technique has been demonstrated to allow for sensitive analysis of hydrocarbons and other non-polar volatile organic compounds (VOC`s) in <span class="hlt">air</span> samples[Cisper et al., 1995] . The methodology has the advantages of no sample pretreatment and short analysis time, which are promising for online monitoring applications but the chief disadvantage of lack of a separation step for the different analytes in a mixture. Several approaches have been investigated to overcome this problem including use of selective chemical ionization [Bier and Cooks, 1987] and multivariate calibration techniques[Ketola et al., 1999] . A new approach is reported for the quantitative measurement of VOCs in complex matrices. The method seeks to reduce the complexity of <span class="hlt">mass</span> spectra observed in hydrocarbon mixture analysis by selective pretreatment of the analyte mixture. In the current investigation, the rapid reaction of ozone with alkenes is used, producing oxygenated compounds which are suppressed by the MIMS system. This has the effect of removing signals due to unsaturated analytes from the compound <span class="hlt">mass</span> spectra, and comparison of the spectra before and after the ozone treatment reveals the nature of the parent compounds. In preliminary investigations, ozone reacted completely with cyclohexene from a mixture of cylohexene and cyclohexane, and with β -pinene from a mixture of toluene and β -pinene, suppressing the ion signals from the olefins. A slight attenuation of the cyclohexane and toluene in those</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC13C0652T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC13C0652T"><span>Southern Ocean <span class="hlt">air</span>-sea heat <span class="hlt">flux</span>, SST spatial anomalies, and implications for multi-decadal upper ocean heat content trends.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamsitt, V. M.; Talley, L. D.; Mazloff, M. R.</p> <p>2014-12-01</p> <p>The Southern Ocean displays a zonal dipole (wavenumber one) pattern in sea surface temperature (SST), with a cool zonal anomaly in the Atlantic and Indian sectors and a warm zonal anomaly in the Pacific sector, associated with the large northward excursion of the Malvinas and southeastward flow of the Antarctic Circumpolar Current (ACC). To the north of the cool Indian sector is the warm, narrow Agulhas Return Current (ARC). <span class="hlt">Air</span>-sea heat <span class="hlt">flux</span> is largely the inverse of this SST pattern, with ocean heat gain in the Atlantic/Indian, cooling in the southeastward-flowing ARC, and cooling in the Pacific, based on adjusted <span class="hlt">fluxes</span> from the Southern Ocean State Estimate (SOSE), a ⅙° eddy permitting model constrained to all available in situ data. This heat <span class="hlt">flux</span> pattern is dominated by turbulent heat loss from the ocean (latent and sensible), proportional to perturbations in the difference between SST and surface <span class="hlt">air</span> temperature, which are maintained by ocean advection. Locally in the Indian sector, intense heat loss along the ARC is contrasted by ocean heat gain of 0.11 PW south of the ARC. The IPCC AR5 50 year depth-averaged 0-700 m temperature trend shows surprising similarities in its spatial pattern, with upper ocean warming in the ARC contrasted by cooling to the south. Using diagnosed heat budget terms from the most recent (June 2014) 6-year run of the SOSE we find that surface cooling in the ARC is balanced by heating from south-eastward advection by the current whereas heat gain in the ACC is balanced by cooling due to northward Ekman transport driven by strong westerly winds. These results suggest that spatial patterns in multi-decadal upper ocean temperature trends depend on regional variations in upper ocean dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24037377','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24037377"><span>Calving <span class="hlt">fluxes</span> and basal melt rates of Antarctic ice shelves.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Depoorter, M A; Bamber, J L; Griggs, J A; Lenaerts, J T M; Ligtenberg, S R M; van den Broeke, M R; Moholdt, G</p> <p>2013-10-03</p> <p>Iceberg calving has been assumed to be the dominant cause of <span class="hlt">mass</span> loss for the Antarctic ice sheet, with previous estimates of the calving <span class="hlt">flux</span> exceeding 2,000 gigatonnes per year. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near the calving front. So far, however, no study has reliably quantified the calving <span class="hlt">flux</span> and the basal <span class="hlt">mass</span> balance (the balance between accretion and ablation at the ice-shelf base) for the whole of Antarctica. The distribution of fresh water in the Southern Ocean and its partitioning between the liquid and solid phases is therefore poorly constrained. Here we estimate the <span class="hlt">mass</span> balance components for all ice shelves in Antarctica, using satellite measurements of calving <span class="hlt">flux</span> and grounding-line <span class="hlt">flux</span>, modelled ice-shelf snow accumulation rates and a regional scaling that accounts for unsurveyed areas. We obtain a total calving <span class="hlt">flux</span> of 1,321 ± 144 gigatonnes per year and a total basal <span class="hlt">mass</span> balance of -1,454 ± 174 gigatonnes per year. This means that about half of the ice-sheet surface <span class="hlt">mass</span> gain is lost through oceanic erosion before reaching the ice front, and the calving <span class="hlt">flux</span> is about 34 per cent less than previous estimates derived from iceberg tracking. In addition, the fraction of <span class="hlt">mass</span> loss due to basal processes varies from about 10 to 90 per cent between ice shelves. We find a significant positive correlation between basal <span class="hlt">mass</span> loss and surface elevation change for ice shelves experiencing surface lowering and enhanced discharge. We suggest that basal <span class="hlt">mass</span> loss is a valuable metric for predicting future ice-shelf vulnerability to oceanic forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1344543','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1344543"><span>A connection to deep groundwater alters ecosystem carbon <span class="hlt">fluxes</span> and budgets: Example from a Costa Rican rainforest</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Genereux, David P.; Nagy, Laura A.; Osburn, Christopher L.</p> <p></p> <p>Field studies of watershed carbon <span class="hlt">fluxes</span> and budgets are critical for understanding the carbon cycle, but the role of deep regional groundwater is poorly known and field examples are lacking. Here we show that discharge of regional groundwater into a lowland Costa Rican rainforest has a major influence on ecosystem carbon <span class="hlt">fluxes</span>. Furthermore, this influence is observable through chemical, isotopic, and <span class="hlt">flux</span> signals in groundwater, surface water, and <span class="hlt">air</span>. Not addressing the influence of regional groundwater in the field measurement program and data analysis would give a misleading impression of the overall carbon source or sink status of the rainforest.more » In quantifying a carbon budget with the traditional "small watershed" <span class="hlt">mass</span>-balance approach, it would be critical at this site and likely many others to consider watershed inputs or losses associated with exchange between the ecosystem and the deeper hydrogeological system on which it sits.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1344543-connection-deep-groundwater-alters-ecosystem-carbon-fluxes-budgets-example-from-costa-rican-rainforest','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1344543-connection-deep-groundwater-alters-ecosystem-carbon-fluxes-budgets-example-from-costa-rican-rainforest"><span>A connection to deep groundwater alters ecosystem carbon <span class="hlt">fluxes</span> and budgets: Example from a Costa Rican rainforest</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Genereux, David P.; Nagy, Laura A.; Osburn, Christopher L.; ...</p> <p>2013-05-28</p> <p>Field studies of watershed carbon <span class="hlt">fluxes</span> and budgets are critical for understanding the carbon cycle, but the role of deep regional groundwater is poorly known and field examples are lacking. Here we show that discharge of regional groundwater into a lowland Costa Rican rainforest has a major influence on ecosystem carbon <span class="hlt">fluxes</span>. Furthermore, this influence is observable through chemical, isotopic, and <span class="hlt">flux</span> signals in groundwater, surface water, and <span class="hlt">air</span>. Not addressing the influence of regional groundwater in the field measurement program and data analysis would give a misleading impression of the overall carbon source or sink status of the rainforest.more » In quantifying a carbon budget with the traditional "small watershed" <span class="hlt">mass</span>-balance approach, it would be critical at this site and likely many others to consider watershed inputs or losses associated with exchange between the ecosystem and the deeper hydrogeological system on which it sits.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C21A0719B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C21A0719B"><span>Freshwater <span class="hlt">fluxes</span> into the subpolar North Atlantic from secular trends in Arctic land ice <span class="hlt">mass</span> balance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bamber, J. L.; Enderlin, E. M.; Howat, I. M.; Wouters, B.; van den Broeke, M.</p> <p>2015-12-01</p> <p>Freshwater <span class="hlt">fluxes</span> (FWF) from river runoff and precipitation minus evaporation for the pan Arctic seas are relatively well documented and prescribed in ocean GCMs. <span class="hlt">Fluxes</span> from Greenland and Arctic glaciers and ice caps on the other hand are generally ignored, despite their potential impacts on ocean circulation and marine biology and growing evidence for changes to the hydrography of parts of the subpolar North Atlantic. In a previous study we determined the FWF from Greenland for the period 1958-2010 using a combination of observations and regional climate modeling. Here, we update the analysis with data from new satellite observations to extend the record both in space and time. The new FWF estimates cover the period 1958-2014 and include the Canadian, Russian and Norwegian Arctic (Svalbard) in addition to the contributions from Greenland. We combine satellite altimetry (including CryoSat 2) with grounding line <span class="hlt">flux</span> data, regional climate modeling of surface <span class="hlt">mass</span> balance and gravimetry to produce consistent estimates of solid ice and liquid FWF into the Arctic and North Atlantic Oceans. The total cumulative FWF anomaly from land ice <span class="hlt">mass</span> loss started to increase significantly in the mid 1990s and now exceeds 5000 km^3, a value that is about half of the Great Salinity Anomaly of the 1970s. The majority of the anomaly is entering two key areas of deep water overturning in the Labrador and Irminger Seas, at a rate that has been increasing steadily over the last ~20 years. Since the mid 2000s, however, the Canadian Arctic archipelago has been making a significant contribution to the FW anomaly entering Baffin Bay. Tracer experiments with eddy-permitting ocean GCMs suggest that the FW input from southern Greenland and the Canadian Arctic should accumulate in Baffin Bay with the potential to affect geostrophic circulation, stratification in the region and possibly the strength of the Atlantic Meridional Overturning Circulation. We also examine the trajectory of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JTePh..60.1549K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JTePh..60.1549K"><span>Small-size <span class="hlt">mass</span> spectrometer for determining gases and volatile compounds in <span class="hlt">air</span> during breathing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.</p> <p>2015-10-01</p> <p>We describe an automated <span class="hlt">mass</span> spectrometer for diagnostics of deceases from the composition of exhaled <span class="hlt">air</span>. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled <span class="hlt">air</span>. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static <span class="hlt">mass</span> analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the <span class="hlt">mass</span> analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the <span class="hlt">mass</span> resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH11B2388N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH11B2388N"><span>Modeling Magnetic <span class="hlt">Flux</span>-Ropes Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nieves-Chinchilla, T.; Linton, M.; Hidalgo, M. A. U.; Vourlidas, A.; Savani, N.; Szabo, A.; Farrugia, C. J.; Yu, W.</p> <p>2015-12-01</p> <p><span class="hlt">Flux</span>-ropes are usually associated with magnetic structures embedded in the interplanetary Coronal <span class="hlt">Mass</span> Ejections (ICMEs) with a depressed proton temperature (called Magnetic Clouds, MCs). However, small-scale <span class="hlt">flux</span>-ropes in the solar wind are also identified with different formation, evolution, and dynamic involved. We present an analytical model to describe magnetic <span class="hlt">flux</span>-rope topologies. The model is generalized to different grades of complexity. It extends the circular-cylindrical concept of Hidalgo et al. (2002) by introducing a general form for the radial dependence of the current density. This generalization provides information on the force distribution inside the <span class="hlt">flux</span> rope in addition to the usual parameters of <span class="hlt">flux</span>-rope geometrical information and orientation. The generalized model provides flexibility for implementation in 3-D MHD simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001DSRII..48.1471C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001DSRII..48.1471C"><span>Seasonal and interannual variability in deep ocean particle <span class="hlt">fluxes</span> at the Oceanic <span class="hlt">Flux</span> Program (OFP)/Bermuda Atlantic Time Series (BATS) site in the western Sargasso Sea near Bermuda</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conte, Maureen H.; Ralph, Nate; Ross, Edith H.</p> <p></p> <p>Since 1978, the Oceanic <span class="hlt">Flux</span> Program (OFP) time-series sediment traps have measured particle <span class="hlt">fluxes</span> in the deep Sargasso Sea near Bermuda. There is currently a 20+yr <span class="hlt">flux</span> record at 3200-m depth, a 12+yr <span class="hlt">flux</span> at 1500-m depth, and a 9+yr record at 500-m depth. Strong seasonality is observed in <span class="hlt">mass</span> <span class="hlt">flux</span> at all depths, with a <span class="hlt">flux</span> maximum in February-March and a smaller maximum in December-January. There is also significant interannual variability in the <span class="hlt">flux</span>, especially with respect to the presence/absence of the December-January <span class="hlt">flux</span> maximum and in the duration of the high <span class="hlt">flux</span> period in the spring. The <span class="hlt">flux</span> records at the three depths are surprisingly coherent, with no statistically significant temporal lag between 500 and 3200-m <span class="hlt">fluxes</span> at our biweekly sample resolution. Bulk compositional data indicate an extremely rapid decrease in the <span class="hlt">flux</span> of organic constituents with depth between 500 and 1500-m, and a smaller decrease with depth between 1500 and 3200-m depth. In contrast, carbonate <span class="hlt">flux</span> is uniform or increases slightly between 500 and 1500-m, possibly reflecting deep secondary calcification by foraminifera. The lithogenic <span class="hlt">flux</span> increases by over 50% between 500 and 3200-m depth, indicating strong deep water scavenging/repackaging of suspended lithogenic material. Concurrent with the rapid changes in <span class="hlt">flux</span> composition, there is a marked reduction in the heterogeneity of the sinking particle pool with depth, especially within the mesopelagic zone. By 3200-m depth, the bulk composition of the sinking particle pool is strikingly uniform, both seasonally and over variations in <span class="hlt">mass</span> <span class="hlt">flux</span> of more than an order of magnitude. These OFP results provide strong indirect evidence for the intensity of reprocessing of the particle pool by resident zooplankton within mesopelagic and bathypelagic waters. The rapid loss of organic components, the marked reduction in the heterogeneity of the bulk composition of the <span class="hlt">flux</span>, and the increase in terrigenous <span class="hlt">fluxes</span> with depth are most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmEn..55..347L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmEn..55..347L"><span>Role of aerosols in enhancing SVOC <span class="hlt">flux</span> between <span class="hlt">air</span> and indoor surfaces and its influence on exposure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Cong; Morrison, Glenn C.; Zhang, Yinping</p> <p>2012-08-01</p> <p>Indoor surfaces play an important role in the transport of, and exposure to, semi-volatile organic compounds (SVOCs) in buildings. In this study, we develop a model that accounts for SVOC transport mediated by particles and find that, due to large gas-particle partition coefficients along with large differences in Brownian and gas diffusivities, SVOC transport across concentration boundary layers is significantly enhanced in the presence of particles. Two important dimensionless parameters, Bim,g and Bim,g/Bim,p, were identified: Bim,g is the ratio of 1) the characteristic time for the SVOC to transport across the concentration boundary layer to 2) the characteristic time for boundary layer to either be "swept" of SVOCs by particles or "saturated" by release of SVOCs from particles. This parameter can be regarded as a dimensionless <span class="hlt">mass</span> transfer coefficient. Bim,g/Bim,p characterizes the SVOC <span class="hlt">mass</span> associated with particles, relative to SVOCs in the gas-phase. Analysis on monodisperse particles shows that <span class="hlt">flux</span> can be enhanced by as much as a factor of 5 over transport in the absence of particles, for a large particle/gas partition coefficient (log Kpart = 13), small particles (dp ˜ 0.1 μm) and a small free stream velocity (U∞ = 0.01 m s-1). As particle diameter decreases, <span class="hlt">flux</span> enhancement tends to increase. However, as particles become very small (e.g., dp < 0.05 μm), <span class="hlt">flux</span> enhancement for SVOCs with log Kpart = 13 decreases slightly. Particles larger than 2 μm do not significantly influence the <span class="hlt">flux</span>. An exponential correlation is found to fit the results for polydisperse particles associated with typical indoor environments, cooking and smoking. Two illustrative examples are used to show that, 1) the timescale for di(2-ethylhexyl) phthalate (DEHP) to approach equilibrium between the gas and a surface is shortened from 3.0 years to 0.45 years; and 2) in the presence of particles, the gas-phase DEHP concentration and emission rate are predicted to be as much as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JGR....90.2409Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JGR....90.2409Z"><span><span class="hlt">Air</span>-to-sea <span class="hlt">fluxes</span> of lipids at Enewetak Atoll</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zafiriou, Oliver C.; Gagosian, Robert B.; Peltzer, Edward T.; Alford, Jane B.; Loder, T.</p> <p>1985-02-01</p> <p>We report data for the Enewetak site of the SEAREX program from the rainy season in 1979. The concentrations of n-alkanes, n-alkanols, sterols, n-alkanoic acids and their salts, and total organic compounds in rain are reported, as well as the apparent gaseous hydrocarbon concentrations. These data and information on the particulate forms are analyzed in conjunction with ancillary chemical and meteorological data to draw inferences about sources, <span class="hlt">fluxes</span>, and chemical speciations. While the higher molecular weight lipid biomarker components are exclusively terrestrial, the organic carbon in rain may be derived from atmospheric transformations of terrestrial carbon. Distinctively marine components are nearly absent. Comparison of the scavenging ratios of the organic components in rain vs. those for clays reveals that the alkanoic acids and the higher molecular weight alkanols behave as essentially particulate materials, whereas lower alkanols and most hydrocarbons show much higher scavenging ratios, probably due to the involvement of a gaseous phase or sampling artifact. Vaporization in the atmosphere and scavenging of a gas phase would lead to higher scavenging ratios; vaporization during sampling would give low aerosol concentrations and high gas-phase concentrations, leading to high scavenging ratios. The major <span class="hlt">fluxes</span> at Enewetak result from rain rather than dry deposition, and extrapolating the measured values to meaningful annual averages requires adjustment for seasonally varying source intensity and rain dynamics. Aerosol data for other seasons and other substances are used to correct for source-strength intensity variations, and a 210Pb/organic compound correlation is established and extrapolated to adjust for rainfall volume effects. These corrections, assumed independent and applied together, yield inferred <span class="hlt">fluxes</span> 2.5-9 times larger than the <span class="hlt">fluxes</span> calculated for mean concentrations. The inferred <span class="hlt">fluxes</span> to the ocean, while small compared to primary</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1423947-prompt-atmospheric-neutrino-fluxes-perturbative-qcd-models-nuclear-effects','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1423947-prompt-atmospheric-neutrino-fluxes-perturbative-qcd-models-nuclear-effects"><span>Prompt atmospheric neutrino <span class="hlt">fluxes</span>: perturbative QCD models and nuclear effects</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Bhattacharya, Atri; Enberg, Rikard; Jeong, Yu Seon; ...</p> <p>2016-11-28</p> <p>We evaluate the prompt atmospheric neutrino <span class="hlt">flux</span> at high energies using three different frameworks for calculating the heavy quark production cross section in QCD: NLO perturbative QCD, k T factorization including low-x resummation, and the dipole model including parton saturation. We use QCD parameters, the value for the charm quark <span class="hlt">mass</span> and the range for the factorization and renormalization scales that provide the best description of the total charm cross section measured at fixed target experiments, at RHIC and at LHC. Using these parameters we calculate differential cross sections for charm and bottom production and compare with the latest datamore » on forward charm meson production from LHCb at 7 TeV and at 13 TeV, finding good agreement with the data. In addition, we investigate the role of nuclear shadowing by including nuclear parton distribution functions (PDF) for the target <span class="hlt">air</span> nucleus using two different nuclear PDF schemes. Depending on the scheme used, we find the reduction of the <span class="hlt">flux</span> due to nuclear effects varies from 10% to 50% at the highest energies. Finally, we compare our results with the IceCube limit on the prompt neutrino <span class="hlt">flux</span>, which is already providing valuable information about some of the QCD models.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12732918','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12732918"><span>Uncertainty evaluation of <span class="hlt">mass</span> values determined by electronic balances in analytical chemistry: a new method to correct for <span class="hlt">air</span> buoyancy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wunderli, S; Fortunato, G; Reichmuth, A; Richard, Ph</p> <p>2003-06-01</p> <p>A new method to correct for the largest systematic influence in <span class="hlt">mass</span> determination-<span class="hlt">air</span> buoyancy-is outlined. A full description of the most relevant influence parameters is given and the combined measurement uncertainty is evaluated according to the ISO-GUM approach [1]. A new correction method for <span class="hlt">air</span> buoyancy using an artefact is presented. This method has the advantage that only a <span class="hlt">mass</span> artefact is used to correct for <span class="hlt">air</span> buoyancy. The classical approach demands the determination of the <span class="hlt">air</span> density and therefore suitable equipment to measure at least the <span class="hlt">air</span> temperature, the <span class="hlt">air</span> pressure and the relative <span class="hlt">air</span> humidity within the demanded uncertainties (i.e. three independent measurement tasks have to be performed simultaneously). The calculated uncertainty is lower for the classical method. However a field laboratory may not always be in possession of fully traceable measurement systems for these room climatic parameters.A comparison of three approaches applied to the calculation of the combined uncertainty of <span class="hlt">mass</span> values is presented. Namely the classical determination of <span class="hlt">air</span> buoyancy, the artefact method, and the neglecting of this systematic effect as proposed in the new EURACHEM/CITAC guide [2]. The artefact method is suitable for high-precision measurement in analytical chemistry and especially for the production of certified reference materials, reference values and analytical chemical reference materials. The method could also be used either for volume determination of solids or for <span class="hlt">air</span> density measurement by an independent method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A14G..06A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A14G..06A"><span>Studying emissions of CO2 in the Baltimore/Washington area using airborne measurements: source attribution, <span class="hlt">flux</span> quantification, and model comparison</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, D.; Hansford, J. R.; Salawitch, R. J.; Ren, X.; Cohen, M.; Karion, A.; Whetstone, J. R.; Salmon, O. E.; Shepson, P. B.; Gurney, K. R.; Osterman, G. B.; Dickerson, R. R.</p> <p>2017-12-01</p> <p>We study emissions of CO2 in the Baltimore-Washington area using airborne in-situ measurements, obtained during the February 2015 <span class="hlt">Fluxes</span> of Greenhouse Gases in Maryland (FLAGG-MD) campaign. In this study, we attributed enhanced signals of CO2 to several power plants and two urban areas (Baltimore City and Washington, DC), using the NOAA HYSPLIT <span class="hlt">air</span> parcel trajectory model as well as the analysis of chemical ratios to quantify the source/receptor relationship. Then, the <span class="hlt">fluxes</span> of attributed CO2 are estimated using a <span class="hlt">mass</span> balance approach. The uncertainty in the aircraft-based <span class="hlt">mass</span> balance approach is estimated by conducting a detailed sensitivity analysis of CO2 <span class="hlt">fluxes</span>, considering factors such as the background mixing ratio of CO2, wind direction and speed, PBL heights, the horizontal boundary, and vertical interpolation methods. Estimated <span class="hlt">fluxes</span> of CO2 with estimated uncertainty ranges are then compared to output from various emissions data and models, such as CEMS, CarbonTracker, FFDAS, and ODIAC. Finally, column CO2 data over the Baltimore-Washington region observed by the OCO-2 satellite instrument are statistically compared to aircraft in-situ observations, to assess how well OCO-2 is able to quantify geographic and synoptic-scale variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=176545&keyword=Detection+AND+ammonium&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=176545&keyword=Detection+AND+ammonium&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>AUTOMATED DECONVOLUTION OF COMPOSITE <span class="hlt">MASS</span> SPECTRA OBTAINED WITH AN OPEN-<span class="hlt">AIR</span> IONIZATIONS SOURCE BASED ON EXACT <span class="hlt">MASSES</span> AND RELATIVE ISOTIPIC ABUNDANCES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Chemicals dispersed by accidental, deliberate, or weather-related events must be rapidly identified to assess health risks. <span class="hlt">Mass</span> spectra from high levels of analytes obtained using rapid, open-<span class="hlt">air</span> ionization by a Direct Analysis in Real Time (DART®) ion source often contain<br><b...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1020274','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1020274"><span>Eddy Correlation <span class="hlt">Flux</span> Measurement System (ECOR) Handbook</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cook, DR</p> <p>2011-01-31</p> <p>The eddy correlation (ECOR) <span class="hlt">flux</span> measurement system provides in situ, half-hour measurements of the surface turbulent <span class="hlt">fluxes</span> of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The <span class="hlt">fluxes</span> are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the <span class="hlt">air</span> temperature, the water vapor density, and the CO2 concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT........80P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT........80P"><span>Moist synoptic transport of carbon dioxide along midlatitude storm tracks, transport uncertainty, and implications for carbon dioxide <span class="hlt">flux</span> estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parazoo, Nicholas C.</p> <p></p> <p><span class="hlt">Mass</span> transport along moist isentropic surfaces on baroclinic waves represents an important component of the atmospheric heat engine that operates between the equator and poles. This is also an important vehicle for tracer transport, and is correlated with ecosystem metabolism because large-scale baroclinicity and photosynthesis are both driven seasonally by variations in solar radiation. In this research, I pursue a dynamical framework for explaining atmospheric transport of CO2 by synoptic weather systems at middle and high latitudes. A global model of atmospheric tracer transport, driven by meteorological analysis in combination with a detailed description of surface <span class="hlt">fluxes</span>, is used to create time varying CO2 distributions in the atmosphere. Simulated <span class="hlt">mass</span> <span class="hlt">fluxes</span> of CO2 are then decomposed into a zonal monthly mean component and deviations from the monthly mean in space and time. <span class="hlt">Mass</span> <span class="hlt">fluxes</span> of CO2 are described on moist isentropic surfaces to represent frontal transport along storm tracks. Forward simulations suggest that synoptic weather systems transport large amounts of CO2 north and south in northern mid-latitudes, up to 1 PgC month-1 during winter when baroclinic wave activity peaks. During boreal winter when northern plants respire, warm moist <span class="hlt">air</span>, high in CO2, is swept upward and poleward along the east side of baroclinic waves and injected into the polar vortex, while cold dry <span class="hlt">air</span>, low in CO 2, that had been transported into the polar vortex earlier in the year is advected equatorward. These synoptic eddies act to strongly reduce seasonality of CO2 in the biologically active mid-latitudes by 50% of that implied by local net ecosystem exchange while correspondingly amplifying seasonality in the Arctic. Transport along stormtracks is correlated with rising, moist, cloudy <span class="hlt">air</span>, which systematically hides this CO2 transport from satellite observing systems. Meridional <span class="hlt">fluxes</span> of CO2 are of comparable magnitude as surface exchange of CO2 in mid-latitudes, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70164484','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70164484"><span>Gas exchange rates across the sediment-water and <span class="hlt">air</span>-water interfaces in south San Francisco Bay</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hartman, Blayne; Hammond, Douglas E.</p> <p>1984-01-01</p> <p>Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and <span class="hlt">air</span>-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic <span class="hlt">fluxes</span> from shoal areas is nearly a factor of 2 greater than <span class="hlt">fluxes</span> from the channel areas. <span class="hlt">Fluxes</span> from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the <span class="hlt">air</span>-water interface were determined by constructing a radon <span class="hlt">mass</span> balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the <span class="hlt">mass</span> balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon <span class="hlt">mass</span> balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...778L...8C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...778L...8C"><span>Simulation of Homologous and Cannibalistic Coronal <span class="hlt">Mass</span> Ejections produced by the Emergence of a Twisted <span class="hlt">Flux</span> Rope into the Solar Corona</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chatterjee, Piyali; Fan, Yuhong</p> <p>2013-11-01</p> <p>We report the first results of a magnetohydrodynamic simulation of the development of a homologous sequence of three coronal <span class="hlt">mass</span> ejections (CMEs) and demonstrate their so-called cannibalistic behavior. These CMEs originate from the repeated formations and partial eruptions of kink unstable <span class="hlt">flux</span> ropes as a result of continued emergence of a twisted <span class="hlt">flux</span> rope across the lower boundary into a pre-existing coronal potential arcade field. The simulation shows that a CME erupting into the open magnetic field created by a preceding CME has a higher speed. The second of the three successive CMEs is cannibalistic, catching up and merging with the first into a single fast CME before exiting the domain. All the CMEs including the leading merged CME, attained speeds of about 1000 km s-1 as they exit the domain. The reformation of a twisted <span class="hlt">flux</span> rope after each CME eruption during the sustained <span class="hlt">flux</span> emergence can naturally explain the X-ray observations of repeated reformations of sigmoids and "sigmoid-under-cusp" configurations at a low-coronal source of homologous CMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AtmEn.172..102H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AtmEn.172..102H"><span>Characteristics of GHG <span class="hlt">flux</span> from water-<span class="hlt">air</span> interface along a reclaimed water intake area of the Chaobai River in Shunyi, Beijing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Baonan; He, Jiangtao; Wang, Jian; Li, Jie; Wang, Fei</p> <p>2018-01-01</p> <p>To understand greenhouse gas (GHG) <span class="hlt">flux</span> in reclaimed water intake area impact on urban climate, 'static chamber' method was used to investigate the spatio-diurnal variations and the influence factors of GHG <span class="hlt">fluxes</span> at water-<span class="hlt">air</span> interface from Jian River to Chaobai River. Results showed that the average <span class="hlt">fluxes</span> of CO2 from the Jian River and the Chaobai River were 73.46 mg(m2·h)-1 and -64.75 mg(m2·h)-1, respectively. CO2 was emitted the most in the Jian River, but it was absorbed from the atmosphere in the Chaobai River. Unary linear regression analyses demonstrated that Chlorophyll a (Chl a) and pH variation controlled the carbon source and sink from the Jian River to the Chaobai River. The diurnal variation of CO2 <span class="hlt">fluxes</span> was higher at night than in the daytime in the Jian River, and it was the inverse in the Chaobai River, which highly correlated with dissociative CO2 and HCO3- transformation to CO32-. The average <span class="hlt">fluxes</span> of CH4 from the Jian River and Chaobai River were 0.973 mg(m2·h)-1 and 5.556 mg(m2·h)-1, respectively, which increased along the water flow direction. Unary and multiple linear regression analyses demonstrated that Chl a and total organic carbon (TOC) controlled the increase of CH4 along the flow direction. The diurnal variation of CH4 <span class="hlt">fluxes</span> was slightly higher in the daytime than at night due to the effect of water temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPJ10054S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPJ10054S"><span>Temperature Dependence of Lithium Reactions with <span class="hlt">Air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherrod, Roman; Skinner, C. H.; Koel, Bruce</p> <p>2016-10-01</p> <p>Liquid lithium plasma facing components (PFCs) are being developed to handle long pulse, high heat loads in tokamaks. Wetting by lithium of its container is essential for this application, but can be hindered by lithium oxidation by residual gases or during tokamak maintenance. Lithium PFCs will experience elevated temperatures due to plasma heat <span class="hlt">flux</span>. This work presents measurements of lithium reactions at elevated temperatures (298-373 K) when exposed to natural <span class="hlt">air</span>. Cylindrical TZM wells 300 microns deep with 1 cm2 surface area were filled with metallic lithium in a glovebox containing argon with less than 1.6 ppm H20, O2, and N2. The wells were transferred to a hot plate in <span class="hlt">air</span>, and then removed periodically for <span class="hlt">mass</span> gain measurements. Changes in the surface topography were recorded with a microscope. The <span class="hlt">mass</span> gain of the samples at elevated temperatures followed a markedly different behavior to that at room temperature. One sample at 373 K began turning red indicative of lithium nitride, while a second turned white indicative of lithium carbonate formation. Data on the <span class="hlt">mass</span> gain vs. temperature and associated topographic changes of the surface will be presented. Science Undergraduate Laboratory Internship funded by Department of Energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810005654','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810005654"><span>New methods to detect particle velocity and <span class="hlt">mass</span> <span class="hlt">flux</span> in arc-heated ablation/erosion facilities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brayton, D. B.; Bomar, B. W.; Seibel, B. L.; Elrod, P. D.</p> <p>1980-01-01</p> <p>Arc-heated flow facilities with injected particles are used to simulate the erosive and ablative/erosive environments encountered by spacecraft re-entry through fog, clouds, thermo-nuclear explosions, etc. Two newly developed particle diagnostic techniques used to calibrate these facilities are discussed. One technique measures particle velocity and is based on the detection of thermal radiation and/or chemiluminescence from the hot seed particles in a model ablation/erosion facility. The second technique measures a local particle rate, which is proportional to local particle <span class="hlt">mass</span> <span class="hlt">flux</span>, in a dust erosion facility by photodetecting and counting the interruptions of a focused laser beam by individual particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17120570','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17120570"><span>Magnitude and directional measures of water and Cr(VI) <span class="hlt">fluxes</span> by passive <span class="hlt">flux</span> meter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campbell, Timothy J; Hatfield, Kirk; Klammler, Harald; Annable, Michael D; Rao, P S C</p> <p>2006-10-15</p> <p>A new configuration of the passive fluxmeter (PFM) is presented that provides for simultaneous measurements of both the magnitude and the direction of ambient groundwater specific discharge qo and Cr(VI) <span class="hlt">mass</span> <span class="hlt">flux</span> J(Cr). The PFM is configured as a cylindrical unit with an interior divided into a center section and three outer sectors, each packed with a granular anion exchange resin having high sorption capacity for the Cr(VI) oxyanions CrO4(2-) and HCrO4-. The sorbent in the center section is preloaded with benzoate as the "resident" tracer. Laboratory experiments were conducted in which PFMs were placed in porous packed bed columns, through which was passed a measured volume of synthetic groundwater containing Cr(VI). During the deployment period, some of the resident tracer is depleted while the Cr(VI) is sorbed. The resin was then removed from the four sectors separately and extracted to determine the "captured" <span class="hlt">mass</span> of Cr(VI) and the residual <span class="hlt">mass</span> of the resident tracer in each. Cumulative specific discharge, q0t, values were assessed using the residual <span class="hlt">mass</span> of benzoate retained in the center section. The direction of this discharge theta was ascertained from the <span class="hlt">mass</span> distribution of benzoate intercepted and retained in the outer three sections of the PFM. Cumulative chromium <span class="hlt">fluxes</span>, J(Cr)t, were quantified using the total Cr(VI) <span class="hlt">mass</span> intercepted and retained on the PFM. Experiments produced an average measurement error for direction theta of 3 degrees +/- 14 degrees, while the average measurement errors for q0 and J(Cr) were, respectively, -8% +/- 15% and -12% +/- 23%. Results demonstrate the potential utility of the new PFM configuration for characterizing groundwater and contaminant <span class="hlt">fluxes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmEn..46..669C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmEn..46..669C"><span>Wind tunnel measurements of pollutant turbulent <span class="hlt">fluxes</span> in urban intersections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carpentieri, Matteo; Hayden, Paul; Robins, Alan G.</p> <p>2012-01-01</p> <p>Wind tunnel experiments have been carried out at the EnFlo laboratory to measure mean and turbulent tracer <span class="hlt">fluxes</span> in geometries of real street canyon intersections. The work was part of the major DAPPLE project, focussing on the area surrounding the intersection between Marylebone Road and Gloucester Place in Central London, UK. Understanding flow and dispersion in urban streets is a very important issue for <span class="hlt">air</span> quality management and planning, and turbulent <span class="hlt">mass</span> exchange processes are important phenomena that are very often neglected in urban modelling studies. The adopted methodology involved the combined use of laser Doppler anemometry and tracer concentration measurements. This methodology was applied to quantify the mean and turbulent flow and dispersion fields within several street canyon intersections. Vertical profiles of turbulent tracer <span class="hlt">flux</span> were also measured. The technique, despite a number of limitations, proved reliable and allowed tracer balance calculations to be undertaken in the selected street canyon intersections. The experience gained in this work will enable much more precise studies in the future as issues affecting the accuracy of the experimental technique have been identified and resolved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22205764','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22205764"><span><span class="hlt">Air</span> quality implications of the Deepwater Horizon oil spill.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Middlebrook, Ann M; Murphy, Daniel M; Ahmadov, Ravan; Atlas, Elliot L; Bahreini, Roya; Blake, Donald R; Brioude, Jerome; de Gouw, Joost A; Fehsenfeld, Fred C; Frost, Gregory J; Holloway, John S; Lack, Daniel A; Langridge, Justin M; Lueb, Rich A; McKeen, Stuart A; Meagher, James F; Meinardi, Simone; Neuman, J Andrew; Nowak, John B; Parrish, David D; Peischl, Jeff; Perring, Anne E; Pollack, Ilana B; Roberts, James M; Ryerson, Thomas B; Schwarz, Joshua P; Spackman, J Ryan; Warneke, Carsten; Ravishankara, A R</p> <p>2012-12-11</p> <p>During the Deepwater Horizon (DWH) oil spill, a wide range of gas and aerosol species were measured from an aircraft around, downwind, and away from the DWH site. Additional hydrocarbon measurements were made from ships in the vicinity. Aerosol particles of respirable sizes were on occasions a significant <span class="hlt">air</span> quality issue for populated areas along the Gulf Coast. Yields of organic aerosol particles and emission factors for other atmospheric pollutants were derived for the sources from the spill, recovery, and cleanup efforts. Evaporation and subsequent secondary chemistry produced organic particulate matter with a <span class="hlt">mass</span> yield of 8 ± 4% of the oil mixture reaching the water surface. Approximately 4% by <span class="hlt">mass</span> of oil burned on the surface was emitted as soot particles. These yields can be used to estimate the effects on <span class="hlt">air</span> quality for similar events as well as for this spill at other times without these data. Whereas emission of soot from burning surface oil was large during the episodic burns, the <span class="hlt">mass</span> <span class="hlt">flux</span> of secondary organic aerosol to the atmosphere was substantially larger overall. We use a regional <span class="hlt">air</span> quality model to show that some observed enhancements in organic aerosol concentration along the Gulf Coast were likely due to the DWH spill. In the presence of evaporating hydrocarbons from the oil, NO(x) emissions from the recovery and cleanup operations produced ozone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3528553','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3528553"><span><span class="hlt">Air</span> quality implications of the Deepwater Horizon oil spill</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Middlebrook, Ann M.; Murphy, Daniel M.; Ahmadov, Ravan; Atlas, Elliot L.; Bahreini, Roya; Blake, Donald R.; Brioude, Jerome; de Gouw, Joost A.; Fehsenfeld, Fred C.; Frost, Gregory J.; Holloway, John S.; Lack, Daniel A.; Langridge, Justin M.; Lueb, Rich A.; McKeen, Stuart A.; Meagher, James F.; Meinardi, Simone; Neuman, J. Andrew; Nowak, John B.; Parrish, David D.; Peischl, Jeff; Perring, Anne E.; Pollack, Ilana B.; Roberts, James M.; Ryerson, Thomas B.; Schwarz, Joshua P.; Spackman, J. Ryan; Warneke, Carsten; Ravishankara, A. R.</p> <p>2012-01-01</p> <p>During the Deepwater Horizon (DWH) oil spill, a wide range of gas and aerosol species were measured from an aircraft around, downwind, and away from the DWH site. Additional hydrocarbon measurements were made from ships in the vicinity. Aerosol particles of respirable sizes were on occasions a significant <span class="hlt">air</span> quality issue for populated areas along the Gulf Coast. Yields of organic aerosol particles and emission factors for other atmospheric pollutants were derived for the sources from the spill, recovery, and cleanup efforts. Evaporation and subsequent secondary chemistry produced organic particulate matter with a <span class="hlt">mass</span> yield of 8 ± 4% of the oil mixture reaching the water surface. Approximately 4% by <span class="hlt">mass</span> of oil burned on the surface was emitted as soot particles. These yields can be used to estimate the effects on <span class="hlt">air</span> quality for similar events as well as for this spill at other times without these data. Whereas emission of soot from burning surface oil was large during the episodic burns, the <span class="hlt">mass</span> <span class="hlt">flux</span> of secondary organic aerosol to the atmosphere was substantially larger overall. We use a regional <span class="hlt">air</span> quality model to show that some observed enhancements in organic aerosol concentration along the Gulf Coast were likely due to the DWH spill. In the presence of evaporating hydrocarbons from the oil, NOx emissions from the recovery and cleanup operations produced ozone. PMID:22205764</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AtmEn..60...88C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AtmEn..60...88C"><span>Atmospheric pollutants in Chiang Mai (Thailand) over a five-year period (2005-2009), their possible sources and relation to <span class="hlt">air</span> <span class="hlt">mass</span> movement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chantara, Somporn; Sillapapiromsuk, Sopittaporn; Wiriya, Wan</p> <p>2012-12-01</p> <p>Monitoring and analysis of the chemical composition of <span class="hlt">air</span> pollutants were conducted over a five-year period (2005-2009) in the sub-urban area of Chiang Mai, Thailand. This study aims to determine the seasonal variation of atmospheric ion species and gases, examine their correlations, identify possible sources and assess major <span class="hlt">air</span>-flow patterns to the receptor. The dominant gas and particulate pollutants were NH3 (43-58%) and SO42- (39-48%), respectively. The annual mean concentrations of NH3 (μg m-3) in descending order were 4.08 (2009) > 3.32 (2007) > 2.68 (2008) > 2.47 (2006) and 1.87 (2005), while those of SO42- (μg m-3) were 2.60 (2007) > 2.20 (2006) > 1.95 (2009) > 1.75 (2008) and 1.26 (2005). Concentrations of particulate ions were analyzed by principle component analysis to find out the possible sources of <span class="hlt">air</span> pollutants in this area. The first component of each year had a high loading of SO42- and NH4+, which probably came from fuel combustion and agricultural activity, respectively. K+, a tracer of biomass burning, also contributed to the first or the second components of each year. Concentrations of NH4+ and SO42- were well correlated (r > 0.777, p < 0.01), which lead to the conclusion that (NH4)2SO4 was a major compound present in this area. The 3-day backward trajectories of <span class="hlt">air</span> <span class="hlt">mass</span> arriving at Chiang Mai from 2005 to 2009 were analyzed using the hybrid single particle langrangian integrated trajectory (HYSPLIT) model and grouped by cluster analysis. The <span class="hlt">air</span> <span class="hlt">mass</span> data was analyzed for the dry season (n = 18; 100%). The trajectory of <span class="hlt">air</span> <span class="hlt">mass</span> in 2005 mainly originated locally (67%). In 2006, the recorded data showed that 56% of <span class="hlt">air</span> <span class="hlt">mass</span> was emitted from the western continental region of Thailand. In 2007, the percent ratios from the western and eastern continental areas were equal (39%). In 2008, 67% originated from the western continental area. In 2009, the recorded <span class="hlt">air</span> <span class="hlt">mass</span> mainly came from the western continental area (72%). In conclusion, the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..149a2048J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..149a2048J"><span>The influence of surface roughness and turbulence on heat <span class="hlt">fluxes</span> from an oil palm plantation in Jambi, Indonesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>June, Tania; Meijide, Ana; Stiegler, Christian; Purba Kusuma, Alan; Knohl, Alexander</p> <p>2018-05-01</p> <p>Oil palm plantations are expanding vastly in Jambi, resulted in altered surface roughness and turbulence characteristics, which may influence exchange of heat and <span class="hlt">mass</span>. Micrometeorological measurements above oil palm canopy were conducted for the period 2013–2015. The oil palms were 12.5 years old, canopy height 13 meters and 1.5 years old canopy height 2.5 m. We analyzed the influence of surface roughness and turbulence strenght on heat (sensible and latent) <span class="hlt">fluxes</span> by investigating the profiles and gradient of wind speed, and temperature, surface roughness (roughness length, zo, and zero plane displacement, d), and friction velocity u*. <span class="hlt">Fluxes</span> of heat were calculated using profile similarity methods taking into account atmospheric stability calculated using Richardson number Ri and the generalized stability factor ζ. We found that roughness parameters (zo, d, and u*) directly affect turbulence in oil palm canopy and hence heat <span class="hlt">fluxes</span>; they are affected by canopy height, wind speed and atmospheric stability. There is a negative trend of d towards <span class="hlt">air</span> temperature above the oil palm canopy, indicating the effect of plant volume and height in lowering <span class="hlt">air</span> temperature. We propose studying the relation between zero plane displacement d with a remote sensing vegetation index for scaling up this point based analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009DSRII..56..554T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009DSRII..56..554T"><span>Climatological mean and decadal change in surface ocean pCO 2, and net sea-<span class="hlt">air</span> CO 2 <span class="hlt">flux</span> over the global oceans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takahashi, Taro; Sutherland, Stewart C.; Wanninkhof, Rik; Sweeney, Colm; Feely, Richard A.; Chipman, David W.; Hales, Burke; Friederich, Gernot; Chavez, Francisco; Sabine, Christopher; Watson, Andrew; Bakker, Dorothee C. E.; Schuster, Ute; Metzl, Nicolas; Yoshikawa-Inoue, Hisayuki; Ishii, Masao; Midorikawa, Takashi; Nojiri, Yukihiro; Körtzinger, Arne; Steinhoff, Tobias; Hoppema, Mario; Olafsson, Jon; Arnarson, Thorarinn S.; Tilbrook, Bronte; Johannessen, Truls; Olsen, Are; Bellerby, Richard; Wong, C. S.; Delille, Bruno; Bates, N. R.; de Baar, Hein J. W.</p> <p>2009-04-01</p> <p>A climatological mean distribution for the surface water pCO 2 over the global oceans in non-El Niño conditions has been constructed with spatial resolution of 4° (latitude) ×5° (longitude) for a reference year 2000 based upon about 3 million measurements of surface water pCO 2 obtained from 1970 to 2007. The database used for this study is about 3 times larger than the 0.94 million used for our earlier paper [Takahashi et al., 2002. Global sea-<span class="hlt">air</span> CO 2 <span class="hlt">flux</span> based on climatological surface ocean pCO 2, and seasonal biological and temperature effects. Deep-Sea Res. II, 49, 1601-1622]. A time-trend analysis using deseasonalized surface water pCO 2 data in portions of the North Atlantic, North and South Pacific and Southern Oceans (which cover about 27% of the global ocean areas) indicates that the surface water pCO 2 over these oceanic areas has increased on average at a mean rate of 1.5 μatm y -1 with basin-specific rates varying between 1.2±0.5 and 2.1±0.4 μatm y -1. A global ocean database for a single reference year 2000 is assembled using this mean rate for correcting observations made in different years to the reference year. The observations made during El Niño periods in the equatorial Pacific and those made in coastal zones are excluded from the database. Seasonal changes in the surface water pCO 2 and the sea-<span class="hlt">air</span> pCO 2 difference over four climatic zones in the Atlantic, Pacific, Indian and Southern Oceans are presented. Over the Southern Ocean seasonal ice zone, the seasonality is complex. Although it cannot be thoroughly documented due to the limited extent of observations, seasonal changes in pCO 2 are approximated by using the data for under-ice waters during austral winter and those for the marginal ice and ice-free zones. The net <span class="hlt">air</span>-sea CO 2 <span class="hlt">flux</span> is estimated using the sea-<span class="hlt">air</span> pCO 2 difference and the <span class="hlt">air</span>-sea gas transfer rate that is parameterized as a function of (wind speed) 2 with a scaling factor of 0.26. This is estimated by inverting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10548806','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10548806"><span>Airborne <span class="hlt">mass</span> spectrometers: four decades of atmospheric and space research at the <span class="hlt">Air</span> Force research laboratory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Viggiano, A A; Hunton, D E</p> <p>1999-11-01</p> <p><span class="hlt">Mass</span> spectrometry is a versatile research tool that has proved to be extremely useful for exploring the fundamental nature of the earth's atmosphere and ionosphere and in helping to solve operational problems facing the <span class="hlt">Air</span> Force and the Department of Defense. In the past 40 years, our research group at the <span class="hlt">Air</span> Force Research Laboratory has flown quadrupole <span class="hlt">mass</span> spectrometers of many designs on nearly 100 sounding rockets, nine satellites, three Space Shuttles and many missions of high-altitude research aircraft and balloons. We have also used our instruments in ground-based investigations of rocket and jet engine exhaust, combustion chemistry and microwave breakdown chemistry. This paper is a review of the instrumentation and techniques needed for space research, a summary of the results from many of the experiments, and an introduction to the broad field of atmospheric and space <span class="hlt">mass</span> spectrometry in general. Copyright 1999 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28638396','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28638396"><span>Defoliating Insect <span class="hlt">Mass</span> Outbreak Affects Soil N <span class="hlt">Fluxes</span> and Tree N Nutrition in Scots Pine Forests.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grüning, Maren M; Simon, Judy; Rennenberg, Heinz; L-M-Arnold, Anne</p> <p>2017-01-01</p> <p>Biotic stress by <span class="hlt">mass</span> outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N <span class="hlt">fluxes</span> and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output <span class="hlt">fluxes</span> via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of <span class="hlt">mass</span> insect herbivory on tree N acquisition (i.e., organic and inorganic 15 N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine ( Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth ( Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860037918&hterms=water+cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dwater%2Bcycle','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860037918&hterms=water+cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dwater%2Bcycle"><span>The Martian hydrologic cycle - Effects of CO2 <span class="hlt">mass</span> <span class="hlt">flux</span> on global water distribution</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, P. B.</p> <p>1985-01-01</p> <p>The Martian CO2 cycle, which includes the seasonal condensation and subsequent sublimation of up to 30 percent of the planet's atmosphere, produces meridional winds due to the consequent <span class="hlt">mass</span> <span class="hlt">flux</span> of CO2. These winds currently display strong seasonal and hemispheric asymmetries due to the large asymmetries in the distribution of insolation on Mars. It is proposed that asymmetric meridional advection of water vapor on the planet due to these CO2 condensation winds is capable of explaining the observed dessication of Mars' south polar region at the current time. A simple model for water vapor transport is used to verify this hypothesis and to speculate on the effects of changes in orbital parameters on the seasonal water cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370419-evolution-magnetic-helicity-flux-during-formation-eruption-flux-ropes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370419-evolution-magnetic-helicity-flux-during-formation-eruption-flux-ropes"><span>Evolution of the magnetic helicity <span class="hlt">flux</span> during the formation and eruption of <span class="hlt">flux</span> ropes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Romano, P.; Zuccarello, F. P.; Guglielmino, S. L.</p> <p></p> <p>We describe the evolution and the magnetic helicity <span class="hlt">flux</span> for two active regions (ARs) since their appearance on the solar disk: NOAA 11318 and NOAA 11675. Both ARs hosted the formation and destabilization of magnetic <span class="hlt">flux</span> ropes. In the former AR, the formation of the <span class="hlt">flux</span> rope culminated in a flare of C2.3 GOES class and a coronal <span class="hlt">mass</span> ejection (CME) observed by Large Angle and Spectrometric Coronagraph Experiment. In the latter AR, the region hosting the <span class="hlt">flux</span> rope was involved in several flares, but only a partial eruption with signatures of a minor plasma outflow was observed. We foundmore » a different behavior in the accumulation of the magnetic helicity <span class="hlt">flux</span> in the corona, depending on the magnetic configuration and on the location of the <span class="hlt">flux</span> ropes in the ARs. Our results suggest that the complexity and strength of the photospheric magnetic field is only a partial indicator of the real likelihood of an AR producing the eruption of a <span class="hlt">flux</span> rope and a subsequent CME.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027775','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027775"><span>An upper limit of muon <span class="hlt">flux</span> of energies above 100 TeV determined from horizontal <span class="hlt">air</span> showers observed at Akeno</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nagano, M.; Yoshii, H.; Hara, T.; Kamata, K.; Kawaguchi, S.; Kifune, T.</p> <p>1985-01-01</p> <p>Muon energy spectrum above 100 TeV was determined by observing the extensive <span class="hlt">air</span> showers (EAS) from the horizontal direction (HAS). No definite muon originated shower of sizes above 100,000 and zenith angles above 60 deg was observed. The upper limits of HAS intensity is 5x10/12 m/2 s/1 sn/1 above 100,000. It is indicated that the upper limit of muon <span class="hlt">flux</span> above 100 TeV is about 1.3x10/8 m/2 s/1 sr/1 and is in agreement with that expected from the primary spectrum with a knee assuming scaling in the fragmentation region and 40% protons in the primary beam. The critical energy at which muon <span class="hlt">flux</span> from prompt processes take over that from the conventional process is higher than 100 Tev at horizontal direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.2219S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.2219S"><span>Accounting for observation uncertainties in an evaluation metric of low latitude turbulent <span class="hlt">air</span>-sea <span class="hlt">fluxes</span>: application to the comparison of a suite of IPSL model versions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Servonnat, Jérôme; Găinuşă-Bogdan, Alina; Braconnot, Pascale</p> <p>2017-09-01</p> <p>Turbulent momentum and heat (sensible heat and latent heat) <span class="hlt">fluxes</span> at the <span class="hlt">air</span>-sea interface are key components of the whole energetic of the Earth's climate. The evaluation of these <span class="hlt">fluxes</span> in the climate models is still difficult because of the large uncertainties associated with the reference products. In this paper we present an objective metric accounting for reference uncertainties to evaluate the annual cycle of the low latitude turbulent <span class="hlt">fluxes</span> of a suite of IPSL climate models. This metric consists in a Hotelling T 2 test between the simulated and observed field in a reduce space characterized by the dominant modes of variability that are common to both the model and the reference, taking into account the observational uncertainty. The test is thus more severe when uncertainties are small as it is the case for sea surface temperature (SST). The results of the test show that for almost all variables and all model versions the model-reference differences are not zero. It is not possible to distinguish between model versions for sensible heat and meridional wind stress, certainly due to the large observational uncertainties. All model versions share similar biases for the different variables. There is no improvement between the reference versions of the IPSL model used for CMIP3 and CMIP5. The test also reveals that the higher horizontal resolution fails to improve the representation of the turbulent surface <span class="hlt">fluxes</span> compared to the other versions. The representation of the <span class="hlt">fluxes</span> is further degraded in a version with improved atmospheric physics with an amplification of some of the biases in the Indian Ocean and in the intertropical convergence zone. The ranking of the model versions for the turbulent <span class="hlt">fluxes</span> is not correlated with the ranking found for SST. This highlights that despite the fact that SST gradients are important for the large-scale atmospheric circulation patterns, other factors such as wind speed, and <span class="hlt">air</span>-sea temperature contrast play an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26975003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26975003"><span><span class="hlt">Air</span>-sea exchange of gaseous mercury in the East China Sea.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan</p> <p>2016-05-01</p> <p>Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in <span class="hlt">air</span> and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) <span class="hlt">flux</span>. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the <span class="hlt">air</span> <span class="hlt">masses</span> with high GEM levels during fall largely originated from the land, while the <span class="hlt">air</span> <span class="hlt">masses</span> with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) <span class="hlt">flux</span> (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) <span class="hlt">flux</span>: 3.6 ± 2.8 ng m(-2) h(-1)). The emission <span class="hlt">flux</span> of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AMT.....9.2581R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AMT.....9.2581R"><span>Application of an online ion-chromatography-based instrument for gradient <span class="hlt">flux</span> measurements of speciated nitrogen and sulfur</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rumsey, Ian C.; Walker, John T.</p> <p>2016-06-01</p> <p>The dry component of total nitrogen and sulfur atmospheric deposition remains uncertain. The lack of measurements of sufficient chemical speciation and temporal extent make it difficult to develop accurate <span class="hlt">mass</span> budgets and sufficient process level detail is not available to improve current <span class="hlt">air</span>-surface exchange models. Over the past decade, significant advances have been made in the development of continuous <span class="hlt">air</span> sampling measurement techniques, resulting with instruments of sufficient sensitivity and temporal resolution to directly quantify <span class="hlt">air</span>-surface exchange of nitrogen and sulfur compounds. However, their applicability is generally restricted to only one or a few of the compounds within the deposition budget. Here, the performance of the Monitor for AeRosols and GAses in ambient <span class="hlt">air</span> (MARGA 2S), a commercially available online ion-chromatography-based analyzer is characterized for the first time as applied for <span class="hlt">air</span>-surface exchange measurements of HNO3, NH3, NH4+, NO3-, SO2 and SO42-. Analytical accuracy and precision are assessed under field conditions. Chemical concentrations gradient precision are determined at the same sampling site. <span class="hlt">Flux</span> uncertainty measured by the aerodynamic gradient method is determined for a representative 3-week period in fall 2012 over a grass field. Analytical precision and chemical concentration gradient precision were found to compare favorably in comparison to previous studies. During the 3-week period, percentages of hourly chemical concentration gradients greater than the corresponding chemical concentration gradient detection limit were 86, 42, 82, 73, 74 and 69 % for NH3, NH4+, HNO3, NO3-, SO2 and SO42-, respectively. As expected, percentages were lowest for aerosol species, owing to their relatively low deposition velocities and correspondingly smaller gradients relative to gas phase species. Relative hourly median <span class="hlt">flux</span> uncertainties were 31, 121, 42, 43, 67 and 56 % for NH3, NH4+, HNO3, NO3-, SO2 and SO42-, respectively. <span class="hlt">Flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........17O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........17O"><span>Observations and Modeling of Turbulent <span class="hlt">Air</span>-Sea Coupling in Coastal and Strongly Forced Condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortiz-Suslow, David G.</p> <p></p> <p>The turbulent <span class="hlt">fluxes</span> of momentum, <span class="hlt">mass</span>, and energy across the ocean-atmosphere boundary are fundamental to our understanding of a myriad of geophysical processes, such as wind-wave generation, oceanic circulation, and <span class="hlt">air</span>-sea gas transfer. In order to better understand these <span class="hlt">fluxes</span>, empirical relationships were developed to quantify the interfacial exchange rates in terms of easily observed parameters (e.g., wind speed). However, mounting evidence suggests that these empirical formulae are only valid over the relatively narrow parametric space, i.e. open ocean conditions in light to moderate winds. Several near-surface processes have been observed to cause significant variance in the <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> not predicted by the conventional functions, such as a heterogeneous surfaces, swell waves, and wave breaking. Further study is needed to fully characterize how these types of processes can modulate the interfacial exchange; in order to achieve this, a broad investigation into <span class="hlt">air</span>-sea coupling was undertaken. The primary focus of this work was to use a combination of field and laboratory observations and numerical modeling, in regimes where conventional theories would be expected to breakdown, namely: the nearshore and in very high winds. These seemingly disparate environments represent the marine atmospheric boundary layer at its physical limit. In the nearshore, the convergence of land, <span class="hlt">air</span>, and sea in a depth-limited domain marks the transition from a marine to a terrestrial boundary layer. Under extreme winds, the physical nature of the boundary layer remains unknown as an intermediate substrate layer, sea spray, develops between the atmosphere and ocean surface. At these ends of the MABL physical spectrum, direct measurements of the near-surface processes were made and directly related to local sources of variance. Our results suggest that the conventional treatment of <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> in terms of empirical relationships developed from a relatively narrow set of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16575583','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16575583"><span>An objective classification system of <span class="hlt">air</span> <span class="hlt">mass</span> types for Szeged, Hungary, with special attention to plant pollen levels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Makra, László; Juhász, Miklós; Mika, János; Bartzokas, Aristides; Béczi, Rita; Sümeghy, Zoltán</p> <p>2006-07-01</p> <p>This paper discusses the characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types over the Carpathian Basin in relation to plant pollen levels over annual pollination periods. Based on the European Centre for Medium-Range Weather Forecasts dataset, daily sea-level pressure fields analysed at 00 UTC were prepared for each <span class="hlt">air</span> <span class="hlt">mass</span> type (cluster) in order to relate sea-level pressure patterns to pollen levels in Szeged, Hungary. The database comprises daily values of 12 meteorological parameters and daily pollen concentrations of 24 species for their pollination periods from 1997 to 2001. Characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types were objectively defined via factor analysis and cluster analysis. According to the results, nine <span class="hlt">air</span> <span class="hlt">mass</span> types (clusters) were detected for pollination periods of the year corresponding to pollen levels that appear with higher concentration when irradiance is moderate while wind speed is moderate or high. This is the case when an anticyclone prevails in the region west of the Carpathian Basin and when Hungary is under the influence of zonal currents (wind speed is high). The sea level pressure systems associated with low pollen concentrations are mostly similar to those connected to higher pollen concentrations, and arise when wind speed is low or moderate. Low pollen levels occur when an anticyclone prevails in the region west of the Carpathian Basin, as well as when an anticyclone covers the region with Hungary at its centre. Hence, anticyclonic or anticyclonic ridge weather situations seem to be relevant in classifying pollen levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22367641','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22367641"><span>Characterization of simultaneous heat and <span class="hlt">mass</span> transfer phenomena for water vapour condensation on a solid surface in an abiotic environment--application to bioprocesses.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tiwari, Akhilesh; Kondjoyan, Alain; Fontaine, Jean-Pierre</p> <p>2012-07-01</p> <p>The phenomenon of heat and <span class="hlt">mass</span> transfer by condensation of water vapour from humid <span class="hlt">air</span> involves several key concepts in aerobic bioreactors. The high performance of bioreactors results from optimised interactions between biological processes and multiphase heat and <span class="hlt">mass</span> transfer. Indeed in various processes such as submerged fermenters and solid-state fermenters, gas/liquid transfer need to be well controlled, as it is involved at the microorganism interface and for the control of the global process. For the theoretical prediction of such phenomena, mathematical models require heat and <span class="hlt">mass</span> transfer coefficients. To date, very few data have been validated concerning <span class="hlt">mass</span> transfer coefficients from humid <span class="hlt">air</span> inflows relevant to those bioprocesses. Our study focussed on the condensation process of water vapour and developed an experimental set-up and protocol to study the velocity profiles and the <span class="hlt">mass</span> <span class="hlt">flux</span> on a small size horizontal flat plate in controlled environmental conditions. A closed circuit wind tunnel facility was used to control the temperature, hygrometry and hydrodynamics of the flow. The temperature of the active surface was controlled and kept isothermal below the dew point to induce condensation, by the use of thermoelectricity. The experiments were performed at ambient temperature for a relative humidity between 35-65% and for a velocity of 1.0 ms⁻¹. The obtained data are analysed and compared to available theoretical calculations on condensation <span class="hlt">mass</span> <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhD...45z5202C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhD...45z5202C"><span>Properties of <span class="hlt">air</span>-aluminum thermal plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cressault, Y.; Gleizes, A.; Riquel, G.</p> <p>2012-07-01</p> <p>We present the calculation and the main results of the properties of <span class="hlt">air</span>-aluminum thermal plasmas, useful for complete modelling of arc systems involving aluminum contacts. The properties are calculated assuming thermal equilibrium and correspond to the equilibrium composition, thermodynamic functions, transport coefficients including diffusion coefficients and net emission coefficient representing the divergence of the radiative <span class="hlt">flux</span> in the hottest plasma regions. The calculation is developed in the temperature range between 2000 and 30 000 K, for a pressure range from 0.1 to 1 bar and for several metal <span class="hlt">mass</span> proportions. As in the case of other metals, the presence of aluminum vapours has a strong influence on three properties at intermediate temperatures: the electron number density, the electrical conductivity and the net emission coefficient. Some comparisons with other metal vapour (Cu, Fe and Ag) properties are made and show the original behaviour for Al-containing mixtures: <span class="hlt">mass</span> density at high temperatures is low due to the low Al atomic <span class="hlt">mass</span>; high electrical conductivity at T < 10 000 K due to low ionization potential (around 2 V less for Al than for the other metals); very strong self-absorption of ionized aluminum lines, leading to a net emission coefficient lower than that of pure <span class="hlt">air</span> when T > 10 000 K, in contrast to copper or iron radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HMT....52.1081G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HMT....52.1081G"><span><span class="hlt">Mass</span> transfer characteristics of bisporus mushroom ( Agaricus bisporus) slices during convective hot <span class="hlt">air</span> drying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghanbarian, Davoud; Baraani Dastjerdi, Mojtaba; Torki-Harchegani, Mehdi</p> <p>2016-05-01</p> <p>An accurate understanding of moisture transfer parameters, including moisture diffusivity and moisture transfer coefficient, is essential for efficient <span class="hlt">mass</span> transfer analysis and to design new dryers or improve existing drying equipments. The main objective of the present study was to carry out an experimental and theoretical investigation of mushroom slices drying and determine the <span class="hlt">mass</span> transfer characteristics of the samples dried under different conditions. The mushroom slices with two thicknesses of 3 and 5 mm were dried at <span class="hlt">air</span> temperatures of 40, 50 and 60 °C and <span class="hlt">air</span> flow rates of 1 and 1.5 m s-1. The Dincer and Dost model was used to determine the moisture transfer parameters and predict the drying curves. It was observed that the entire drying process took place in the falling drying rate period. The obtained lag factor and Biot number indicated that the moisture transfer in the samples was controlled by both internal and external resistance. The effective moisture diffusivity and the moisture transfer coefficient increased with increasing <span class="hlt">air</span> temperature, <span class="hlt">air</span> flow rate and samples thickness and varied in the ranges of 6.5175 × 10-10 to 1.6726 × 10-9 m2 s-1 and 2.7715 × 10-7 to 3.5512 × 10-7 m s-1, respectively. The validation of the Dincer and Dost model indicated a good capability of the model to describe the drying curves of the mushroom slices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PolSc..10..323Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PolSc..10..323Y"><span>Mapping of the <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> in the Arctic Ocean and its adjacent seas: Basin-wide distribution and seasonal to interannual variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yasunaka, Sayaka; Murata, Akihiko; Watanabe, Eiji; Chierici, Melissa; Fransson, Agneta; van Heuven, Steven; Hoppema, Mario; Ishii, Masao; Johannessen, Truls; Kosugi, Naohiro; Lauvset, Siv K.; Mathis, Jeremy T.; Nishino, Shigeto; Omar, Abdirahman M.; Olsen, Are; Sasano, Daisuke; Takahashi, Taro; Wanninkhof, Rik</p> <p>2016-09-01</p> <p>We produced 204 monthly maps of the <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> in the Arctic north of 60°N, including the Arctic Ocean and its adjacent seas, from January 1997 to December 2013 by using a self-organizing map technique. The partial pressure of CO2 (pCO2) in surface water data were obtained by shipboard underway measurements or calculated from alkalinity and total inorganic carbon of surface water samples. Subsequently, we investigated the basin-wide distribution and seasonal to interannual variability of the CO2 <span class="hlt">fluxes</span>. The 17-year annual mean CO2 <span class="hlt">flux</span> shows that all areas of the Arctic Ocean and its adjacent seas were net CO2 sinks. The estimated annual CO2 uptake by the Arctic Ocean was 180 TgC yr-1. The CO2 influx was strongest in winter in the Greenland/Norwegian Seas (>15 mmol m-2 day-1) and the Barents Sea (>12 mmol m-2 day-1) because of strong winds, and strongest in summer in the Chukchi Sea (∼10 mmol m-2 day-1) because of the sea-ice retreat. In recent years, the CO2 uptake has increased in the Greenland/Norwegian Sea and decreased in the southern Barents Sea, owing to increased and decreased <span class="hlt">air</span>-sea pCO2 differences, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017cxo..prop.5112D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017cxo..prop.5112D"><span>The Extreme Ultraviolet <span class="hlt">Flux</span> of Very Low <span class="hlt">Mass</span> Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drake, Jeremy</p> <p>2017-09-01</p> <p>The X-ray and EUV emission of stars is vital for understanding the atmospheres and evolution of their planets. The coronae of dwarf stars later than M6 behave differently to those of earlier spectral types and are more X-ray dim and radio bright. Too faint to have been observed by EUVE, their EUV behavior is currently highly uncertain. We propose to observe a small sample of late M dwarfs using the off-axis HRC-S thin Al" filter that is sensitive to EUV emission in the 50-200 A range. The measured <span class="hlt">fluxes</span> will be used to understand the amount of cooler coronal plasma present, and extend X-ray-EUV <span class="hlt">flux</span> relations to the latest stellar types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ACP....10.8413D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ACP....10.8413D"><span>Aerosol properties associated with <span class="hlt">air</span> <span class="hlt">masses</span> arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dall'Osto, M.; Ceburnis, D.; Martucci, G.; Bialek, J.; Dupuy, R.; Jennings, S. G.; Berresheim, H.; Wenger, J.; Healy, R.; Facchini, M. C.; Rinaldi, M.; Giulianelli, L.; Finessi, E.; Worsnop, D.; Ehn, M.; Mikkilä, J.; Kulmala, M.; O'Dowd, C. D.</p> <p>2010-09-01</p> <p>As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June, 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the N. E. Atlantic and centered on the west Irish coastline. During the campaign, continental <span class="hlt">air</span> <span class="hlt">masses</span> comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical <span class="hlt">air</span> <span class="hlt">masses</span>. Polluted-continental aerosol concentrations were of the order of 3000 cm-3, while background marine <span class="hlt">air</span> aerosol concentrations were between 400-600 cm-3. The highest marine <span class="hlt">air</span> concentrations occurred in polar <span class="hlt">air</span> <span class="hlt">masses</span> in which a 15 nm nucleation mode, with concentration of 1100 cm-3, was observed and attributed to open ocean particle formation. Continental <span class="hlt">air</span> submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate <span class="hlt">mass</span>. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine <span class="hlt">air</span>, sulphate <span class="hlt">mass</span> dominated the sub-micron component, followed by water soluble organic carbon, which, in turn, was dominated by methanesulphonic acid (MSA). Sulphate concentrations were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24732885','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24732885"><span>Decomposing the profile of PM in two low polluted German cities--mapping of <span class="hlt">air</span> <span class="hlt">mass</span> residence time, focusing on potential long range transport impacts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dimitriou, Konstantinos; Kassomenos, Pavlos</p> <p>2014-07-01</p> <p>This paper aims to decompose the profile of particulates in Karlsruhe and Potsdam (Germany), focusing on the localization of PM potential transboundary sources. An <span class="hlt">air</span> <span class="hlt">mass</span> cluster analysis was implemented, followed by a study of <span class="hlt">air</span> <span class="hlt">mass</span> residence time on a grid of a 0.5° × 0.5° resolution. Particulate/gaseous daily <span class="hlt">air</span> pollution and meteorological data were used to indicate PM local sources. Four Principal Component Analysis (PCA) components were produced: traffic, photochemical, industrial/domestic and particulate. PM2.5/PM10 ratio seasonal trends, indicated production of PMCOARSE (PM10-PM2.5) from secondary sources in Potsdam during warm period (WP). The residing areas of incoming slow moving <span class="hlt">air</span> <span class="hlt">masses</span> are potential transboundary PM sources. For Karlsruhe those areas were mainly around the city. An <span class="hlt">air</span> <span class="hlt">mass</span> residence time secondary peak was observed over Stuttgart. For Potsdam, areas with increased dwelling time of the arriving <span class="hlt">air</span> parcels were detected particularly above E/SE Germany. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018TDM.....5b5012Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018TDM.....5b5012Z"><span>Liquid phase <span class="hlt">mass</span> production of <span class="hlt">air</span>-stable black phosphorus/phospholipids nanocomposite with ultralow tunneling barrier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Qiankun; Liu, Yinan; Lai, Jiawei; Qi, Shaomian; An, Chunhua; Lu, Yao; Duan, Xuexin; Pang, Wei; Zhang, Daihua; Sun, Dong; Chen, Jian-Hao; Liu, Jing</p> <p>2018-04-01</p> <p>Few-layer black phosphorus (FLBP), a recently discovered two-dimensional semiconductor, has attracted substantial attention in the scientific and technical communities due to its great potential in electronic and optoelectronic applications. However, reactivity of FLBP flakes with ambient species limits its direct applications. Among various methods to passivate FLBP in ambient environment, nanocomposites mixing FLBP flakes with stable matrix may be one of the most promising approaches for industry applications. Here, we report a simple one-step procedure to <span class="hlt">mass</span> produce <span class="hlt">air</span>-stable FLBP/phospholipids nanocomposite in liquid phase. The resultant nanocomposite is found to have ultralow tunneling barrier for charge carriers which can be described by an Efros-Shklovskii variable range hopping mechanism. Devices made from such <span class="hlt">mass</span>-produced FLBP/phospholipids nanocomposite show highly stable electrical conductivity and opto-electrical response in ambient conditions, indicating its promising applications in both electronic and optoelectronic applications. This method could also be generalized to the <span class="hlt">mass</span> production of nanocomposites consisting of other <span class="hlt">air</span>-sensitive 2D materials, such as FeSe, NbSe2, WTe2, etc.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GBioC..30..983L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GBioC..30..983L"><span>Quantifying the drivers of ocean-atmosphere CO2 <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauderdale, Jonathan M.; Dutkiewicz, Stephanie; Williams, Richard G.; Follows, Michael J.</p> <p>2016-07-01</p> <p>A mechanistic framework for quantitatively mapping the regional drivers of <span class="hlt">air</span>-sea CO2 <span class="hlt">fluxes</span> at a global scale is developed. The framework evaluates the interplay between (1) surface heat and freshwater <span class="hlt">fluxes</span> that influence the potential saturated carbon concentration, which depends on changes in sea surface temperature, salinity and alkalinity, (2) a residual, disequilibrium <span class="hlt">flux</span> influenced by upwelling and entrainment of remineralized carbon- and nutrient-rich waters from the ocean interior, as well as rapid subduction of surface waters, (3) carbon uptake and export by biological activity as both soft tissue and carbonate, and (4) the effect on surface carbon concentrations due to freshwater precipitation or evaporation. In a steady state simulation of a coarse-resolution ocean circulation and biogeochemistry model, the sum of the individually determined components is close to the known total <span class="hlt">flux</span> of the simulation. The leading order balance, identified in different dynamical regimes, is between the CO2 <span class="hlt">fluxes</span> driven by surface heat <span class="hlt">fluxes</span> and a combination of biologically driven carbon uptake and disequilibrium-driven carbon outgassing. The framework is still able to reconstruct simulated <span class="hlt">fluxes</span> when evaluated using monthly averaged data and takes a form that can be applied consistently in models of different complexity and observations of the ocean. In this way, the framework may reveal differences in the balance of drivers acting across an ensemble of climate model simulations or be applied to an analysis and interpretation of the observed, real-world <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031097','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031097"><span><span class="hlt">Mass</span> balance assessment for mercury in Lake Champlain</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gao, N.; Armatas, N.G.; Shanley, J.B.; Kamman, N.C.; Miller, E.K.; Keeler, G.J.; Scherbatskoy, T.; Holsen, T.M.; Young, T.; McIlroy, L.; Drake, S.; Olsen, Bill; Cady, C.</p> <p>2006-01-01</p> <p>A <span class="hlt">mass</span> balance model for mercury in Lake Champlain was developed in an effort to understand the sources, inventories, concentrations, and effects of mercury (Hg) contamination in the lake ecosystem. To construct the <span class="hlt">mass</span> balance model, <span class="hlt">air</span>, water, and sediment were sampled as a part of this project and other research/monitoring projects in the Lake Champlain Basin. This project produced a STELLA-based computer model and quantitative apportionments of the principal input and output pathways of Hg for each of 13 segments in the lake. The model Hg concentrations in the lake were consistent with measured concentrations. Specifically, the modeling identified surface water inflows as the largest direct contributor of Hg into the lake. Direct wet deposition to the lake was the second largest source of Hg followed by direct dry deposition. Volatilization and sedimentation losses were identified as the two major removal mechanisms. This study significantly improves previous estimates of the relative importance of Hg input pathways and of wet and dry deposition <span class="hlt">fluxes</span> of Hg into Lake Champlain. It also provides new estimates of volatilization <span class="hlt">fluxes</span> across different lake segments and sedimentation loss in the lake. ?? 2006 American Chemical Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26642083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26642083"><span>Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive Sampling: Spatial Trends and <span class="hlt">Air</span>-Water Exchange.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer</p> <p>2016-05-17</p> <p>Polyethylene passive sampling was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the <span class="hlt">air</span> and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and <span class="hlt">air</span>-water exchange across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. <span class="hlt">Air</span>-water exchange <span class="hlt">fluxes</span> of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in <span class="hlt">air</span>-water exchange <span class="hlt">fluxes</span> was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and <span class="hlt">mass</span> <span class="hlt">fluxes</span> in <span class="hlt">air</span>-water exchange of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where <span class="hlt">air</span>-water exchange <span class="hlt">fluxes</span> dominated atmospheric concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ACPD....926265D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ACPD....926265D"><span>Aerosol properties associated with <span class="hlt">air</span> <span class="hlt">masses</span> arriving into the North East Atlantic during the 2008 Mace Head EUCAARI intensive observing period: an overview</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dall'Osto, M.; Ceburnis, D.; Martucci, G.; Bialek, J.; Dupuy, R.; Jennings, S. G.; Berresheim, H.; Wenger, J. C.; Sodeau, J. R.; Healy, R. M.; Facchini, M. C.; Rinaldi, M.; Giulianelli, L.; Finessi, E.; Worsnop, D.; O'Dowd, C. D.</p> <p>2009-12-01</p> <p>As part of the EUCAARI Intensive Observing Period, a 4-week campaign to measure aerosol physical, chemical and optical properties, atmospheric structure, and cloud microphysics was conducted from mid-May to mid-June 2008 at the Mace Head Atmospheric Research Station, located at the interface of Western Europe and the NE Atlantic and centered on the west Irish coastline. During the campaign, continental <span class="hlt">air</span> <span class="hlt">masses</span> comprising both young and aged continental plumes were encountered, along with polar, Arctic and tropical <span class="hlt">air</span> <span class="hlt">masses</span>. Polluted-continental aerosol concentrations were of the order of 3000 cm-3, while background marine <span class="hlt">air</span> aerosol concentrations were between 400-600 cm-3. The highest marine <span class="hlt">air</span> concentrations occurred in polar <span class="hlt">air</span> <span class="hlt">masses</span> in which a 15 nm nucleation mode, with concentration of 1100 cm-3, was observed and attributed to open ocean particle formation. Black carbon concentrations in polluted <span class="hlt">air</span> were between 300-400 ng m-3, and in clean marine <span class="hlt">air</span> were less than 50 ng m-3. Continental <span class="hlt">air</span> submicron chemical composition (excluding refractory sea salt) was dominated by organic matter, closely followed by sulphate <span class="hlt">mass</span>. Although the concentrations and size distribution spectral shape were almost identical for the young and aged continental cases, hygroscopic growth factors (GF) and cloud condensation nuclei (CCN) to total condensation nuclei (CN) concentration ratios were significantly less in the younger pollution plume, indicating a more oxidized organic component to the aged continental plume. The difference in chemical composition and hygroscopic growth factor appear to result in a 40-50% impact on aerosol scattering coefficients and Aerosol Optical Depth, despite almost identical aerosol microphysical properties in both cases, with the higher values been recorded for the more aged case. For the CCN/CN ratio, the highest ratios were seen in the more age plume. In marine <span class="hlt">air</span>, sulphate <span class="hlt">mass</span> dominated the sub-micron component, followed by water</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020001355&hterms=dataset&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddataset','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020001355&hterms=dataset&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddataset"><span>A Multiyear Dataset of SSM/I-Derived Global Ocean Surface Turbulent <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Shie, Chung-Lin; Atlas, Robert M.; Ardizzone, Joe; Nelkin, Eric; Einaudi, Franco (Technical Monitor)</p> <p>2001-01-01</p> <p>The surface turbulent <span class="hlt">fluxes</span> of momentum, latent heat, and sensible heat over global oceans are essential to weather, climate and ocean problems. Evaporation is a key component of the hydrological cycle and the surface heat budget, while the wind stress is the major forcing for driving the oceanic circulation. The global <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> of momentum, latent and sensible heat, radiation, and freshwater (precipitation-evaporation) are the forcing for driving oceanic circulation and, hence, are essential for understanding the general circulation of global oceans. The global <span class="hlt">air</span>-sea <span class="hlt">fluxes</span> are required for driving ocean models and validating coupled ocean-atmosphere global models. We have produced a 7.5-year (July 1987-December 1994) dataset of daily surface turbulent <span class="hlt">fluxes</span> over the global oceans from the Special Sensor microwave/Imager (SSM/I) data. Daily turbulent <span class="hlt">fluxes</span> were derived from daily data of SSM/I surface winds and specific humidity, National Centers for Environmental Prediction (NCEP) sea surface temperatures, and European Centre for Medium-Range Weather Forecasts (ECMWF) <span class="hlt">air</span>-sea temperature differences, using a stability-dependent bulk scheme. The retrieved instantaneous surface <span class="hlt">air</span> humidity (with a 25-km resolution) validated well with that of the collocated radiosonde observations over the global oceans. Furthermore, the retrieved daily wind stresses and latent heat <span class="hlt">fluxes</span> were found to agree well with that of the in situ measurements (IMET buoy, RV Moana Wave, and RV Wecoma) in the western Pacific warm pool during the TOGA COARE intensive observing period (November 1992-February 1993). The global distributions of 1988-94 seasonal-mean turbulent <span class="hlt">fluxes</span> will be presented. In addition, the global distributions of 1990-93 annual-means turbulent <span class="hlt">fluxes</span> and input variables will be compared with those of UWM/COADS covering the same period. The latter is based on the COADS (comprehensive ocean-atmosphere data set) and is recognized to be one of the best</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUSM.A31C..03V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUSM.A31C..03V"><span><span class="hlt">Flux</span> Measurements of Trace Gases, Aerosols and Energy from the Urban Core of Mexico City</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velasco, E.; Molina, L.; Lamb, B.; Pressley, S.; Grivicke, R.; Westberg, H.; Jobson, T.; Allwine, E.; Coons, T.; Jimenez, J.; Nemitz, E.; Alexander, L. M.; Worsnop, D.; Ramos, R.</p> <p>2007-05-01</p> <p>As part of the MILAGRO field campaign in March 2006 we deployed a <span class="hlt">flux</span> system in a busy district of Mexico City surrounded by congested avenues. The <span class="hlt">flux</span> system consisted of a tall tower instrumented with fast-response sensors coupled with eddy covariance (EC) techniques to measure <span class="hlt">fluxes</span> of volatile organic compounds (VOCs), CO2, CO, aerosols and energy. The measured <span class="hlt">fluxes</span> represent direct measurements of emissions that include all major and minor emission sources from a typical residential and commercial district. In a previous study we demonstrated that the EC techniques are valuable tools to evaluate emissions inventories in urban areas, and understand better the atmospheric chemistry and the role that megacities play in global change. We measured <span class="hlt">fluxes</span> of olefins using a Fast Olefin Sensor (FOS) and the EC technique, <span class="hlt">fluxes</span> of aromatic and oxygenated VOCs by Proton Transfer Reaction-<span class="hlt">Mass</span> Spectroscopy (PTR-MS) and the disjunct eddy covariance (DEC) technique, <span class="hlt">fluxes</span> of CO2 and H2O with an open path Infrared Gas Analyzer (IRGA) and the EC technique, <span class="hlt">fluxes</span> of CO using a modified gradient method and a commercial CO instrument, and <span class="hlt">fluxes</span> of aerosols (organics, nitrates and sulfates) using an Aerodyne Aerosol <span class="hlt">Mass</span> Spectrometer (AMS) and the EC technique. In addition we used a disjunct eddy accumulation (DEA) system to extend the number of VOCs. This system collected whole <span class="hlt">air</span> samples as function of the direction of the vertical wind component, and the samples were analyzed on site using gas chromatography / flame ionization detection (GC-FID). We also measured <span class="hlt">fluxes</span> of sensible and latent heat by EC and the radiation components with a net radiometer. Overall, these <span class="hlt">flux</span> measurements confirm the results of our previous <span class="hlt">flux</span> measurements in Mexico City in terms of the magnitude, composition, and distribution. We found that the urban surface is a net source of CO2 and VOCs. The diurnal patterns show clear anthropogenic signatures, with important contributions from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSM33C2684N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSM33C2684N"><span>Plasma Transport and Magnetic <span class="hlt">Flux</span> Circulation in Saturn's Magnetosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neupane, B. R.; Delamere, P. A.; Ma, X.; Wilson, R. J.</p> <p>2017-12-01</p> <p>Radial transport of plasma in the rapidly rotating magnetospheres is an important dynamical process. Radial transport is due to the centrifugally driven interchange instability and magnetodisc reconnection, allowing net <span class="hlt">mass</span> to be transported outward while conserving magnetic <span class="hlt">flux</span>. Using Cassini Plasma Spectrometer instrument (CAPS) data products (e.g., Thomsen et al., [2010]; Wilson et al., [2017]) we estimate plasma <span class="hlt">mass</span> and magnetic <span class="hlt">flux</span> transport rates as functions of radial distance and local time. The physical requirement for zero net magnetic <span class="hlt">flux</span> transport provides a key benchmark for assessing the validity of our <span class="hlt">mass</span> transport estimate. We also evaluate magnetodisc stability using a two-dimensional axisymmetric equilibrium model [Caudal, 1986]. Observed local properties (e.g., specific entropy and estimates of <span class="hlt">flux</span> tube <span class="hlt">mass</span> and entropy content) are compared with modeled equilibrium conditions such that departures from equilibrium can be correlated with radial flows and local magnetic field structure. Finally, observations of specific entropy indicate that plasma is non-adiabatic heated during transport. However, the values of specific entropy are well organized in inner magnetosphere (i.e. L<10), and become widely scattered in the middle magnetosphere, suggesting that the transport dynamics of the inner and middle magnetosphere are different.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15385099','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15385099"><span>Design and laboratory testing of a chamber device to measure total <span class="hlt">flux</span> of volatile organic compounds from the unsaturated zone under natural conditions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tillman, Fred D; Smith, James A</p> <p>2004-11-01</p> <p>To determine if an aquifer contaminated with volatile organic compounds (VOCs) has potential for natural remediation, all natural processes affecting the fate and transport of VOCs in the subsurface must be identified and quantified. This research addresses the quantification of <span class="hlt">air</span>-phase volatile organic compounds (VOCs) leaving the unsaturated zone soil gas and entering the atmosphere-including the additional <span class="hlt">flux</span> provided by advective soil-gas movement induced by barometric pumping. A simple and easy-to-use device for measuring VOC <span class="hlt">flux</span> under natural conditions is presented. The vertical <span class="hlt">flux</span> chamber (VFC) was designed using numerical simulations and evaluated in the laboratory. <span class="hlt">Mass</span>-balance numerical simulations based on continuously stirred tank reactor equations (CSTR) provided information on <span class="hlt">flux</span> measurement performance of several sampling configurations with the final chamber configuration measuring greater than 96% of model-simulated <span class="hlt">fluxes</span>. A laboratory device was constructed to evaluate the <span class="hlt">flux</span> chamber under both diffusion-only and advection-plus-diffusion transport conditions. The <span class="hlt">flux</span> chamber measured an average of 82% of 15 diffusion-only <span class="hlt">fluxes</span> and an average of 95% of 15 additional advection-plus-diffusion <span class="hlt">flux</span> experiments. The vertical <span class="hlt">flux</span> chamber has the capability of providing reliable measurement of VOC <span class="hlt">flux</span> from the unsaturated zone under both diffusion and advection transport conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhPro...3..153O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhPro...3..153O"><span>Influence of power ultrasound application on <span class="hlt">mass</span> transport and microstructure of orange peel during hot <span class="hlt">air</span> drying</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortuño, Carmen; Pérez-Munuera, Isabel; Puig, Ana; Riera, Enrique; Garcia-Perez, J. V.</p> <p>2010-01-01</p> <p>Power ultrasound application on convective drying of foodstuffs may be considered an emergent technology. This work deals with the influence of power ultrasound on drying of natural materials addressing the kinetic as well as the product's microstructure. Convective drying kinetics of orange peel slabs (thickness 5.95±0.41 mm) were carried out at 40 ∘C and 1 m/s with (US) and without (<span class="hlt">AIR</span>) power ultrasound application. A diffusion model considering external resistance to <span class="hlt">mass</span> transfer was considered to describe drying kinetics. Fresh, US and <span class="hlt">AIR</span> dried samples were analyzed using Cryo-SEM. Results showed that drying kinetics of orange peel were significantly improved by the application of power ultrasound. From modeling, it was observed a significant (p¡0.05) increase in both <span class="hlt">mass</span> transfer coefficient and effective moisture diffusivity. The effects on <span class="hlt">mass</span> transfer properties were confirmed from microestructural observations. In the cuticle surface, the pores were obstructed by wax components scattering, which evidence the ultrasonic effects on the interfaces. The cells of the flavedo were compressed and large intercellular <span class="hlt">air</span> spaces were generated in the albedo facilitating water transfer through it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A31G..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A31G..06D"><span>Characterization of key aerosol, trace gas and meteorological properties and particle formation and growth processes dependent on <span class="hlt">air</span> <span class="hlt">mass</span> origins in coastal Southern Spain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diesch, J.; Drewnick, F.; Sinha, V.; Williams, J.; Borrmann, S.</p> <p>2011-12-01</p> <p>The chemical composition and concentration of aerosols at a certain site can vary depending on season, the <span class="hlt">air</span> <span class="hlt">mass</span> source region and distance from sources. Regardless of the environment, new particle formation (NPF) events are one of the major sources for ultrafine particles which are potentially hazardous to human health. Grown particles are optically active and efficient CCN resulting in important implications for visibility and climate (Zhang et al., 2004). The study presented here is intended to provide information about various aspects of continental, urban and marine <span class="hlt">air</span> <span class="hlt">masses</span> reflected by wind patterns of the <span class="hlt">air</span> arriving at the measurement site. Additionally we will be focusing on NPF events associated with different types of <span class="hlt">air</span> <span class="hlt">masses</span> affecting their emergence and temporal evolution. Measurements of the ambient aerosol, various trace gases and meteorological parameters were performed within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from mid-November to mid-December 2008 at the atmospheric research station "El Arenosillo" located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean. Number and <span class="hlt">mass</span> as well as PAH and black carbon concentrations were measured in PM1 and size distribution instruments covered the size range 6 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol <span class="hlt">Mass</span> Spectrometer (AMS). In order to evaluate the characteristics of different <span class="hlt">air</span> <span class="hlt">masses</span> linking local and regional sources as well as NPF processes, characteristic <span class="hlt">air</span> <span class="hlt">mass</span> types were classified dependent on backwards trajectory pathways and local meteorology. Large nuclei mode concentrations in the number size distribution were found within continental and urban influenced <span class="hlt">air</span> <span class="hlt">mass</span> types due to frequently occurring NPF events. Exploring individual production and sink variables, sulfuric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20727628','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20727628"><span>Inverse modeling of Asian (222)Rn <span class="hlt">flux</span> using surface <span class="hlt">air</span> (222)Rn concentration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hirao, Shigekazu; Yamazawa, Hiromi; Moriizumi, Jun</p> <p>2010-11-01</p> <p>When used with an atmospheric transport model, the (222)Rn <span class="hlt">flux</span> distribution estimated in our previous study using soil transport theory caused underestimation of atmospheric (222)Rn concentrations as compared with measurements in East Asia. In this study, we applied a Bayesian synthesis inverse method to produce revised estimates of the annual (222)Rn <span class="hlt">flux</span> density in Asia by using atmospheric (222)Rn concentrations measured at seven sites in East Asia. The Bayesian synthesis inverse method requires a prior estimate of the <span class="hlt">flux</span> distribution and its uncertainties. The atmospheric transport model MM5/HIRAT and our previous estimate of the (222)Rn <span class="hlt">flux</span> distribution as the prior value were used to generate new <span class="hlt">flux</span> estimates for the eastern half of the Eurasian continent dividing into 10 regions. The (222)Rn <span class="hlt">flux</span> densities estimated using the Bayesian inversion technique were generally higher than the prior <span class="hlt">flux</span> densities. The area-weighted average (222)Rn <span class="hlt">flux</span> density for Asia was estimated to be 33.0 mBq m(-2) s(-1), which is substantially higher than the prior value (16.7 mBq m(-2) s(-1)). The estimated (222)Rn <span class="hlt">flux</span> densities decrease with increasing latitude as follows: Southeast Asia (36.7 mBq m(-2) s(-1)); East Asia (28.6 mBq m(-2) s(-1)) including China, Korean Peninsula and Japan; and Siberia (14.1 mBq m(-2) s(-1)). Increase of the newly estimated <span class="hlt">fluxes</span> in Southeast Asia, China, Japan, and the southern part of Eastern Siberia from the prior ones contributed most significantly to improved agreement of the model-calculated concentrations with the atmospheric measurements. The sensitivity analysis of prior <span class="hlt">flux</span> errors and effects of locally exhaled (222)Rn showed that the estimated <span class="hlt">fluxes</span> in Northern and Central China, Korea, Japan, and the southern part of Eastern Siberia were robust, but that in Central Asia had a large uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25901845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25901845"><span>The effect of long-range <span class="hlt">air</span> <span class="hlt">mass</span> transport pathways on PM10 and NO2 concentrations at urban and rural background sites in Ireland: Quantification using clustering techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Donnelly, Aoife A; Broderick, Brian M; Misstear, Bruce D</p> <p>2015-01-01</p> <p>The specific aims of this paper are to: (i) quantify the effects of various long range transport pathways nitrogen dioxide (NO2) and particulate matter with diameter less than 10μm (PM10) concentrations in Ireland and identify <span class="hlt">air</span> <span class="hlt">mass</span> movement corridors which may lead to incidences poor <span class="hlt">air</span> quality for application in forecasting; (ii) compare the effects of such pathways at various sites; (iii) assess pathways associated with a period of decreased <span class="hlt">air</span> quality in Ireland. The origin of and the regions traversed by an <span class="hlt">air</span> <span class="hlt">mass</span> 96h prior to reaching a receptor is modelled and k-means clustering is applied to create <span class="hlt">air-mass</span> groups. Significant differences in <span class="hlt">air</span> pollution levels were found between <span class="hlt">air</span> <span class="hlt">mass</span> cluster types at urban and rural sites. It was found that easterly or recirculated <span class="hlt">air</span> <span class="hlt">masses</span> lead to higher NO2 and PM10 levels with average NO2 levels varying between 124% and 239% of the seasonal mean and average PM10 levels varying between 103% and 199% of the seasonal mean at urban and rural sites. Easterly <span class="hlt">air</span> <span class="hlt">masses</span> are more frequent during winter months leading to higher overall concentrations. The span in relative concentrations between <span class="hlt">air</span> <span class="hlt">mass</span> clusters is highest at the rural site indicating that regional factors are controlling concentration levels. The methods used in this paper could be applied to assist in modelling and forecasting <span class="hlt">air</span> quality based on long range transport pathways and forecast meteorology without the requirement for detailed emissions data over a large regional domain or the use of computationally demanding modelling techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993DSRI...40..653J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993DSRI...40..653J"><span>Annual cycles of <span class="hlt">mass</span> <span class="hlt">flux</span> and isotopic composition of pteropod shells settling into the deep Sargasso sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jasper, John P.; Deuser, Werner G.</p> <p>1993-04-01</p> <p><span class="hlt">Mass</span> <span class="hlt">fluxes</span> and stable isotopic compositions ( δ18O and δ13C) pteropod shells collected during a 6-year series of 2-month sediment-trap deployments in the deep (3.2 km) Sargasso Sea provide information on annual population changes, habitat depths and life spans of thecosome pteropods (Euthecosomata). The <span class="hlt">flux</span> of pteropod shells responds to the annual cycle of primary production in the upper ocean. <span class="hlt">Flux</span> maxima of the shells (> 1 mm) of eight species occur from late winter through autumn. Seasonal changes in the hydrography of the upper water column are quite accurately recorded in the δ18O variations of six perennial species, which generally confirm the distinction between non-migratory ( Creseis acicula, Creseis virgula conica, and Diacria quadridentata) and diurnally migratory taxa ( Styliola subula, Cuvierina columnella, and Clio pyramidata). Isotopic records of C. acicula and C. virgula conica are consistent with shell formation above 50 m. The records of the migratory species reflect what appear to be average calcification depths of 50-75 m. Average annual δ13C variations reveal the annual cycles of primary production and stratification of near-surface waters. Adult life spans of the species studied appear to be no more than a few months. The results of this study should be useful in paleoceanographic reconstructions based on isotopic measurements of sedimentary pteropod shells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.H33D1406C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.H33D1406C"><span>Analysis of Evaporative <span class="hlt">Flux</span> Over Irrigated and Unirrigated Pasture in the Wood River Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cuenca, R. H.; Mahrt, L.; Hagimoto, Y.; Peterson, S.</p> <p>2005-12-01</p> <p> the <span class="hlt">air</span> <span class="hlt">mass</span> within the valley. The persistence of the evaporative <span class="hlt">flux</span> rate at the unirrigated site was probably due to contributions from the water table, as exhibited in the diurnal piezometer data. The difference in soil heat <span class="hlt">flux</span> rates between the two sites after dry-down of the unirrigated site was relatively high and affected the difference in available energy (net radiation - soil heat <span class="hlt">flux</span>). Initial application of LANDSAT data to integrate regional effects of unirrigated project lands over the basin is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018IJMPD..2750072D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IJMPD..2750072D"><span>Superenergy <span class="hlt">flux</span> of Einstein-Rosen waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Domínguez, P. J.; Gallegos, A.; Macías-Díaz, J. E.; Vargas-Rodríguez, H.</p> <p></p> <p>In this work, we consider the propagation speed of the superenergy <span class="hlt">flux</span> associated to the Einstein-Rosen cylindrical waves propagating in vacuum and over the background of the gravitational field of an infinitely long <span class="hlt">mass</span> line distribution. The velocity of the <span class="hlt">flux</span> is determined considering the reference frame in which the super-Poynting vector vanishes. This reference frame is then considered as comoving with the <span class="hlt">flux</span>. The explicit expressions for the velocities are given with respect to a reference frame at rest with the symmetry axis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010022990','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010022990"><span>BOREAS TF-4 CO2 and CH4 Chamber <span class="hlt">Flux</span> Data from the SSA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, Dean; Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Conrad, Sara (Editor)</p> <p>2000-01-01</p> <p>The BOREAS TF-4 team measured <span class="hlt">fluxes</span> of CO2 and CH4 across the soil-<span class="hlt">air</span> interface in four ages of jack pine forest at the BOREAS SSA during August 1993 to March 1995. Gross and net <span class="hlt">flux</span> of CO2 and <span class="hlt">flux</span> of CH4 between soil and <span class="hlt">air</span> are presented for 24 chamber sites in mature jack pine forest, 20-year-old, 4-year-old, and clear cut areas. The data are stored in tabular ASCII files.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013BGeo...10.3109C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013BGeo...10.3109C"><span>Implications of elevated CO2 on pelagic carbon <span class="hlt">fluxes</span> in an Arctic mesocosm study - an elemental <span class="hlt">mass</span> balance approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czerny, J.; Schulz, K. G.; Boxhammer, T.; Bellerby, R. G. J.; Büdenbender, J.; Engel, A.; Krug, S. A.; Ludwig, A.; Nachtigall, K.; Nondal, G.; Niehoff, B.; Silyakova, A.; Riebesell, U.</p> <p>2013-05-01</p> <p>Recent studies on the impacts of ocean acidification on pelagic communities have identified changes in carbon to nutrient dynamics with related shifts in elemental stoichiometry. In principle, mesocosm experiments provide the opportunity of determining temporal dynamics of all relevant carbon and nutrient pools and, thus, calculating elemental budgets. In practice, attempts to budget mesocosm enclosures are often hampered by uncertainties in some of the measured pools and <span class="hlt">fluxes</span>, in particular due to uncertainties in constraining <span class="hlt">air</span>-sea gas exchange, particle sinking, and wall growth. In an Arctic mesocosm study on ocean acidification applying KOSMOS (Kiel Off-Shore Mesocosms for future Ocean Simulation), all relevant element pools and <span class="hlt">fluxes</span> of carbon, nitrogen and phosphorus were measured, using an improved experimental design intended to narrow down the mentioned uncertainties. Water-column concentrations of particulate and dissolved organic and inorganic matter were determined daily. New approaches for quantitative estimates of material sinking to the bottom of the mesocosms and gas exchange in 48 h temporal resolution as well as estimates of wall growth were developed to close the gaps in element budgets. However, losses elements from the budgets into a sum of insufficiently determined pools were detected, and are principally unavoidable in mesocosm investigation. The comparison of variability patterns of all single measured datasets revealed analytic precision to be the main issue in determination of budgets. Uncertainties in dissolved organic carbon (DOC), nitrogen (DON) and particulate organic phosphorus (POP) were much higher than the summed error in determination of the same elements in all other pools. With estimates provided for all other major elemental pools, <span class="hlt">mass</span> balance calculations could be used to infer the temporal development of DOC, DON and POP pools. Future elevated pCO2 was found to enhance net autotrophic community carbon uptake in two of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25950136','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25950136"><span>Measuring <span class="hlt">air</span>-water interfacial area for soils using the <span class="hlt">mass</span> balance surfactant-tracer method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Araujo, Juliana B; Mainhagu, Jon; Brusseau, Mark L</p> <p>2015-09-01</p> <p>There are several methods for conducting interfacial partitioning tracer tests to measure <span class="hlt">air</span>-water interfacial area in porous media. One such approach is the <span class="hlt">mass</span> balance surfactant tracer method. An advantage of the <span class="hlt">mass</span>-balance method compared to other tracer-based methods is that a single test can produce multiple interfacial area measurements over a wide range of water saturations. The <span class="hlt">mass</span>-balance method has been used to date only for glass beads or treated quartz sand. The purpose of this research is to investigate the effectiveness and implementability of the <span class="hlt">mass</span>-balance method for application to more complex porous media. The results indicate that interfacial areas measured with the <span class="hlt">mass</span>-balance method are consistent with values obtained with the miscible-displacement method. This includes results for a soil, for which solid-phase adsorption was a significant component of total tracer retention. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970017305','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970017305"><span>Cosmic Ray-<span class="hlt">Air</span> Shower Measurement from Space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Takahashi, Yoshiyuki</p> <p>1997-01-01</p> <p>A feasibility study has been initiated to observe from space the highest energy cosmic rays above 1021 eV. A satellite observatory concept, the Maximum-energy Auger (<span class="hlt">Air</span>)-Shower Satellite (<span class="hlt">MASS</span>), is recently renamed as the Orbital Wide-angle Collector (OWL) by taking its unique feature of using a very wide field-of-view (FOV) optics. A huge array of imaging devices (about 10(exp 6) pixels) is required to detect and record fluorescent light profiles of cosmic ray cascades in the atmosphere. The FOV of <span class="hlt">MASS</span> could extend to as large as about 60 in. diameter, which views (500 - 1000 km) of earth's surface and more than 300 - 1000 cosmic ray events per year could be observed above 1020 eV. From far above the atmosphere, the <span class="hlt">MASS</span>/OWL satellite should be capable of observing events at all angles including near horizontal tracks, and would have considerable aperture for high energy photon and neutrino observation. With a large aperture and the spatial and temporal resolution, <span class="hlt">MASS</span> could determine the energy spectrum, the <span class="hlt">mass</span> composition, and arrival anisotropy of cosmic rays from 1020 eV to 1022 eV; a region hitherto not explored by ground-based detectors such as the Fly's Eye and <span class="hlt">air</span>-shower arrays. <span class="hlt">MASS</span>/OWL's ability to identify cosmic neutrinos and gamma rays may help providing evidence for the theory which attributes the above cut-off cosmic ray <span class="hlt">flux</span> to the decay of topological defects. Very wide FOV optics system of <span class="hlt">MASS</span>/OWL with a large array of imaging devices is applicable to observe other atmospheric phenomena including upper atmospheric lightning. The wide FOV <span class="hlt">MASS</span> optics being developed can also improve ground-based gamma-ray observatories by allowing simultaneous observation of many gamma ray sources located at different constellations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A43C0283L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A43C0283L"><span><span class="hlt">Air</span>-sea Exchange of Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs), Organochlorine Pesticides (OCPs) and Polybrominated Diphenyl Ethers (PBDEs) in the Mediterranean Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lammel, G. P.; Heil, A.; Kukucka, P.; Meixner, F. X.; Mulder, M. D.; Prybilova, P.; Prokes, R.; Rusina, T. S.; Song, G. Z.; Vrana, B.</p> <p>2015-12-01</p> <p>The marine atmospheric environment is a receptor for persistent organic pollutants (POPs) which are advected from sources on land, primary, such as biomass burning by-products (PAHs, dioxins), and secondary, such as volatilization from contaminated soils (PCBs, pesticides). Primary sources do not exist in the marine environment, except for PAHs (ship engines) but following previous atmospheric deposition, the sea surface may turn to a secondary source by reversal of diffusive <span class="hlt">air</span>-sea <span class="hlt">mass</span> exchange. No monitoring is in place. We studied the vertical <span class="hlt">fluxes</span> of a wide range of primary and secondary emitted POPs based on measurements in <span class="hlt">air</span> and surface seawater at a remote coastal site in the eastern Mediterranean (2012). To this end, silicon rubbers were used as passive water samplers, vertical concentration gradients were determined in <span class="hlt">air</span> and <span class="hlt">fluxes</span> were quantified based on Eddy covariance. Diffusive <span class="hlt">air</span>-sea exchange <span class="hlt">fluxes</span> of hexachlorocyclohexanes (HCHs) and semivolatile PAHs were found close to phase equilibrium, except one PAH, retene, a wood burning tracer, was found seasonally net-volatilisational. Some PCBs, p,p'-DDE, penta- and hexachlorobenzene (PeCB, HCB) were mostly net-depositional, while PBDEs were net-volatilizational. <span class="hlt">Fluxes</span> determined at a a remote coastal site ranged -33 - +2.4 µg m-2 d-1 for PAHs and -4.0 - +0.3 µg m-2 d-1for halogenated compounds (< 0 means net-deposition, > 0 means net-volatilization). It is concluded that nowadays in open seas more pollutants are undergoing reversal of the direction of <span class="hlt">air</span>-sea exchange. Recgional fire activity records in combination with box model simulations suggest that deposition of retene during summer is followed by a reversal of <span class="hlt">air</span>-sea exchange. The seawater surface as secondary source of pollution should be assessed based on <span class="hlt">flux</span> measurements across seasons and over longer time periods.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17221854','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17221854"><span>Evaluation of tunable diode laser absorption spectroscopy for in-process water vapor <span class="hlt">mass</span> <span class="hlt">flux</span> measurements during freeze drying.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gieseler, Henning; Kessler, William J; Finson, Michael; Davis, Steven J; Mulhall, Phillip A; Bons, Vincent; Debo, David J; Pikal, Michael J</p> <p>2007-07-01</p> <p>The goal of this work was to demonstrate the use of Tunable Diode Laser Absorption Spectroscopy (TDLAS) as a noninvasive method to continuously measure the water vapor concentration and the vapor flow velocity in the spool connecting a freeze-dryer chamber and condenser. The instantaneous measurements were used to determine the water vapor <span class="hlt">mass</span> flow rate (g/s). The <span class="hlt">mass</span> flow determinations provided a continuous measurement of the total amount of water removed. Full load runs of pure water at different pressure and shelf temperature settings and a 5% (w/w) mannitol product run were performed in both laboratory and pilot scale freeze dryers. The ratio of "gravimetric/TDLAS" measurements of water removed was 1.02 +/- 0.06. A theoretical heat transfer model was used to predict the <span class="hlt">mass</span> flow rate and the model results were compared to both the gravimetric and TDLAS data. Good agreement was also observed in the "gravimetric/TDLAS" ratio for the 5% mannitol runs dried in both freeze dryers. The endpoints of primary and secondary drying for the product runs were clearly identified. Comparison of the velocity and <span class="hlt">mass</span> <span class="hlt">flux</span> profiles between the laboratory and pilot dryers indicated a higher restriction to <span class="hlt">mass</span> flow for the lab scale freeze dryer. Copyright 2007 Wiley-Liss, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5461291','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5461291"><span>Defoliating Insect <span class="hlt">Mass</span> Outbreak Affects Soil N <span class="hlt">Fluxes</span> and Tree N Nutrition in Scots Pine Forests</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Grüning, Maren M.; Simon, Judy; Rennenberg, Heinz; l-M-Arnold, Anne</p> <p>2017-01-01</p> <p>Biotic stress by <span class="hlt">mass</span> outbreaks of defoliating pest insects does not only affect tree performance by reducing its photosynthetic capacity, but also changes N cycling in the soil of forest ecosystems. However, how insect induced defoliation affects soil N <span class="hlt">fluxes</span> and, in turn, tree N nutrition is not well-studied. In the present study, we quantified N input and output <span class="hlt">fluxes</span> via dry matter input, throughfall, and soil leachates. Furthermore, we investigated the effects of <span class="hlt">mass</span> insect herbivory on tree N acquisition (i.e., organic and inorganic 15N net uptake capacity of fine roots) as well as N pools in fine roots and needles in a Scots pine (Pinus sylvestris L.) forest over an entire vegetation period. Plots were either infested by the nun moth (Lymantria monacha L.) or served as controls. Our results show an increased N input by insect feces, litter, and throughfall at the infested plots compared to controls, as well as increased leaching of nitrate. However, the additional N input into the soil did not increase, but reduce inorganic and organic net N uptake capacity of Scots pine roots. N pools in the fine roots and needles of infested trees showed an accumulation of total N, amino acid-N, protein-N, and structural N in the roots and the remaining needles as a compensatory response triggered by defoliation. Thus, although soil N availability was increased via surplus N input, trees did not respond with an increased N acquisition, but rather invested resources into defense by accumulation of amino acid-N and protein-N as a survival strategy. PMID:28638396</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22140015-injection-helicity-shearing-motion-fluxes-relation-flares-coronal-mass-ejections','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22140015-injection-helicity-shearing-motion-fluxes-relation-flares-coronal-mass-ejections"><span>ON THE INJECTION OF HELICITY BY THE SHEARING MOTION OF <span class="hlt">FLUXES</span> IN RELATION TO FLARES AND CORONAL <span class="hlt">MASS</span> EJECTIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Vemareddy, P.; Ambastha, A.; Maurya, R. A.</p> <p></p> <p>An investigation of helicity injection by photospheric shear motions is carried out for two active regions (ARs), NOAA 11158 and 11166, using line-of-sight magnetic field observations obtained from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. We derived the horizontal velocities in the ARs from the differential affine velocity estimator (DAVE) technique. Persistent strong shear motions at maximum velocities in the range of 0.6-0.9 km s{sup -1} along the magnetic polarity inversion line and outward flows from the peripheral regions of the sunspots were observed in the two ARs. The helicities injected in NOAA 11158 and 11166more » during their six-day evolution period were estimated as 14.16 Multiplication-Sign 10{sup 42} Mx{sup 2} and 9.5 Multiplication-Sign 10{sup 42} Mx{sup 2}, respectively. The estimated injection rates decreased up to 13% by increasing the time interval between the magnetograms from 12 minutes to 36 minutes, and increased up to 9% by decreasing the DAVE window size from 21 Multiplication-Sign 18 to 9 Multiplication-Sign 6 pixel{sup 2}, resulting in 10% variation in the accumulated helicity. In both ARs, the flare-prone regions (R2) had inhomogeneous helicity <span class="hlt">flux</span> distribution with mixed helicities of both signs and coronal <span class="hlt">mass</span> ejection (CME) prone regions had almost homogeneous distribution of helicity <span class="hlt">flux</span> dominated by a single sign. The temporal profiles of helicity injection showed impulsive variations during some flares/CMEs due to negative helicity injection into the dominant region of positive helicity <span class="hlt">flux</span>. A quantitative analysis reveals a marginally significant association of helicity <span class="hlt">flux</span> with CMEs but not flares in AR 11158, while for the AR 11166, we find a marginally significant association of helicity <span class="hlt">flux</span> with flares but not CMEs, providing evidence of the role of helicity injection at localized sites of the events. These short-term variations of helicity <span class="hlt">flux</span> are further discussed in view of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29290633','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29290633"><span>SAM-CAAM: A Concept for Acquiring Systematic Aircraft Measurements to Characterize Aerosol <span class="hlt">Air</span> <span class="hlt">Masses</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kahn, Ralph A; Berkoff, Tim A; Brock, Charles; Chen, Gao; Ferrare, Richard A; Ghan, Steven; Hansico, Thomas F; Hegg, Dean A; Martins, J Vanderlei; McNaughton, Cameron S; Murphy, Daniel M; Ogren, John A; Penner, Joyce E; Pilewskie, Peter; Seinfeld, John H; Worsnop, Douglas R</p> <p>2017-10-01</p> <p>A modest operational program of systematic aircraft measurements can resolve key satellite-aerosol-data-record limitations. Satellite observations provide frequent, global aerosol-amount maps, but offer only loose aerosol property constraints needed for climate and <span class="hlt">air</span> quality applications. We define and illustrate the feasibility of flying an aircraft payload to measure key aerosol optical, microphysical, and chemical properties in situ . The flight program could characterize major aerosol <span class="hlt">air-mass</span> types statistically, at a level-of-detail unobtainable from space. It would: (1) enhance satellite aerosol retrieval products with better climatology assumptions, and (2) improve translation between satellite-retrieved optical properties and species-specific aerosol <span class="hlt">mass</span> and size simulated in climate models to assess aerosol forcing, its anthropogenic components, and other environmental impacts. As such, Systematic Aircraft Measurements to Characterize Aerosol <span class="hlt">Air</span> <span class="hlt">Masses</span> (SAM-CAAM) could add value to data records representing several decades of aerosol observations from space, improve aerosol constraints on climate modeling , help interrelate remote-sensing, in situ, and modeling aerosol-type definitions , and contribute to future satellite aerosol missions. Fifteen Required Variables are identified, and four Payload Options of increasing ambition are defined, to constrain these quantities. "Option C" could meet all the SAM-CAAM objectives with about 20 instruments, most of which have flown before, but never routinely several times per week, and never as a group. Aircraft integration, and approaches to data handling, payload support, and logistical considerations for a long-term, operational mission are discussed. SAM-CAAM is feasible because, for most aerosol sources and specified seasons, particle properties tend to be repeatable , even if aerosol loading varies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRC..121.8787G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRC..121.8787G"><span>Assessing recent <span class="hlt">air</span>-sea freshwater <span class="hlt">flux</span> changes using a surface temperature-salinity space framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grist, Jeremy P.; Josey, Simon A.; Zika, Jan D.; Evans, Dafydd Gwyn; Skliris, Nikolaos</p> <p>2016-12-01</p> <p>A novel assessment of recent changes in <span class="hlt">air</span>-sea freshwater <span class="hlt">fluxes</span> has been conducted using a surface temperature-salinity framework applied to four atmospheric reanalyses. Viewed in the T-S space of the ocean surface, the complex pattern of the longitude-latitude space mean global Precipitation minus Evaporation (PME) reduces to three distinct regions. The analysis is conducted for the period 1979-2007 for which there is most evidence for a broadening of the (atmospheric) tropical belt. All four of the reanalyses display an increase in strength of the water cycle. The range of increase is between 2% and 30% over the period analyzed, with an average of 14%. Considering the average across the reanalyses, the water cycle changes are dominated by changes in tropical as opposed to mid-high latitude precipitation. The increases in the water cycle strength, are consistent in sign, but larger than in a 1% greenhouse gas run of the HadGEM3 climate model. In the model a shift of the precipitation/evaporation cells to higher temperatures is more evident, due to the much stronger global warming signal. The observed changes in freshwater <span class="hlt">fluxes</span> appear to be reflected in changes in the T-S distribution of the Global Ocean. Specifically, across the diverse range of atmospheric reanalyses considered here, there was an acceleration of the hydrological cycle during 1979-2007 which led to a broadening of the ocean's salinity distribution. Finally, although the reanalyses indicate that the warm temperature tropical precipitation dominated water cycle change, ocean observations suggest that ocean processes redistributed the freshening to lower ocean temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A11C0071B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A11C0071B"><span>Transport Regimes of <span class="hlt">Air</span> <span class="hlt">Masses</span> Affecting the Tropospheric Composition of the Canadian and European Arctic During RACEPAC 2014 and NETCARE 2014/2015</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bozem, H.; Hoor, P. M.; Koellner, F.; Kunkel, D.; Schneider, J.; Schulz, C.; Herber, A. B.; Borrmann, S.; Wendisch, M.; Ehrlich, A.; Leaitch, W. R.; Willis, M. D.; Burkart, J.; Thomas, J. L.; Abbatt, J.</p> <p>2015-12-01</p> <p>The Arctic is warming much faster than any other place in the world and undergoes a rapid change dominated by a changing climate in this region. The impact of polluted <span class="hlt">air</span> <span class="hlt">masses</span> traveling to the Arctic from various remote sources significantly contributes to the observed climate change, in contrast there are additional local emission sources contributing to the level of pollutants (trace gases and aerosol). Processes affecting the emission and transport of these pollutants are not well understood and need to be further investigated. We present aircraft based trace gas measurements in the Arctic during RACEPAC (2014) and NETCARE (2014 and 2015) with the Polar 6 aircraft of Alfred Wegener Institute (AWI) covering an area from 134°W to 17°W and 68°N to 83°N. We focus on cloud, aerosol and general transport processes of polluted <span class="hlt">air</span> <span class="hlt">masses</span> into the high Arctic. Based on CO and CO2 measurements and kinematic 10-day back trajectories we analyze the transport regimes prevalent during spring (RACEPAC 2014 and NETCARE 2015) and summer (NETCARE 2014) in the observed region. Whereas the eastern part of the Canadian Arctic is affected by <span class="hlt">air</span> <span class="hlt">masses</span> with their origin in Asia, in the central and western parts of the Canadian and European Arctic <span class="hlt">air</span> <span class="hlt">masses</span> from North America are predominant at the time of the measurement. In general the more northern parts of the Arctic were relatively unaffected by pollution from mid-latitudes since <span class="hlt">air</span> <span class="hlt">masses</span> mostly travel within the polar dome, being quite isolated. Associated mixing ratios of CO and CO2 fit into the seasonal cycle observed at NOAA ground stations throughout the Arctic, but show a more mid-latitudinal characteristic at higher altitudes. The transition is remarkably sharp and allows for a chemical definition of the polar dome. At low altitudes, synoptic disturbances transport polluted <span class="hlt">air</span> <span class="hlt">masses</span> from mid-latitudes into regions of the polar dome. These <span class="hlt">air</span> <span class="hlt">masses</span> contribute to the Arctic pollution background, but also</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012563','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012563"><span>Moisture <span class="hlt">Fluxes</span> Derived from EOS Aqua Satellite Data for the North Water Polynya Over 2003-2009</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Boisvert, Linette N.; Markus, Thorsten; Parkinson, Claire L.; Vihma, Timo</p> <p>2012-01-01</p> <p>Satellite data were applied to calculate the moisture <span class="hlt">flux</span> from the North Water polynya during a series of events spanning 2003-2009. The <span class="hlt">fluxes</span> were calculated using bulk aerodynamic formulas with the stability effects according to the Monin-Obukhov similarity theory. Input parameters were taken from three sources: <span class="hlt">air</span> relative humidity, <span class="hlt">air</span> temperature, and surface temperature from the Atmospheric Infrared Sounder (<span class="hlt">AIRS</span>) onboard NASA's Earth Observing System (EOS) Aqua satellite, sea ice concentration from the Advanced Microwave Scanning Radiometer (AMSR-E, also onboard Aqua), and wind speed from the ECMWF ERA-Interim reanalysis. Our results show the progression of the moisture <span class="hlt">fluxes</span> from the polynya during each event, as well as their atmospheric effects after the polynya has closed up. These results were compared to results from studies on other polynyas, and fall within one standard deviation of the moisture <span class="hlt">flux</span> estimates from these studies. Although the estimated moisture <span class="hlt">fluxes</span> over the entire study region from <span class="hlt">AIRS</span> are smaller in magnitude than ERA-Interim, they are more accurate due to improved temperature and relative humidity profiles and ice concentration estimates over the polynya. Error estimates were calculated to be 5.56 x10(exp -3) g/sq. m/ s, only 25% of the total moisture <span class="hlt">flux</span>, thus suggesting that <span class="hlt">AIRS</span> and AMSR-E can be used with confidence to study smaller scale features in the Arctic sea ice pack and can capture their atmospheric effects. These findings bode well for larger-scale studies of moisture <span class="hlt">fluxes</span> over the entire Arctic Ocean and the thinning ice pack.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17716909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17716909"><span>Remote <span class="hlt">mass</span> spectrometric sampling of electrospray- and desorption electrospray-generated ions using an <span class="hlt">air</span> ejector.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dixon, R Brent; Bereman, Michael S; Muddiman, David C; Hawkridge, Adam M</p> <p>2007-10-01</p> <p>A commercial <span class="hlt">air</span> ejector was coupled to an electrospray ionization linear ion trap <span class="hlt">mass</span> spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary <span class="hlt">mass</span> spectrometric data are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ResPh...9..851K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...9..851K"><span>Impact of heat source/sink on radiative heat transfer to Maxwell nanofluid subject to revised <span class="hlt">mass</span> <span class="hlt">flux</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, M.; Irfan, M.; Khan, W. A.</p> <p>2018-06-01</p> <p>Nanofluids retain noteworthy structure that have absorbed attentions of numerous investigators because of their exploration in nanotechnology and nanoscience. In this scrutiny a mathematical computation of 2D flows of Maxwell nanoliquid influenced by a stretched cylinder has been established. The heat transfer structure is conceded out in the manifestation of thermal radiation and heat source/sink. Moreover, the nanoparticles <span class="hlt">mass</span> <span class="hlt">flux</span> condition is engaged in this exploration. This newly endorsed tactic is more realistic where the conjecture is made that the nanoparticle <span class="hlt">flux</span> is zero and nanoparticle fraction regulates itself on the restrictions consequently. By utilizing apposite conversion the governing PDEs are transformed into ODEs and then tackled analytically via HAM. The attained outcomes are plotted and deliberated in aspect for somatic parameters. It is remarked that with an intensification in the Deborah number β diminish the liquid temperature while it boosts for radiation parameter Rd . Furthermore, the concentration of Maxwell liquid has conflicting impact for Brownian motion Nb and thermophoresis parameters Nt .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8300V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8300V"><span>Intraday evaporation and heat <span class="hlt">fluxes</span> variation at <span class="hlt">air</span>-water interface of extremely shallow lakes in Chilean Andean Plateau</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vergara, Jaime; de la Fuente, Alberto</p> <p>2016-04-01</p> <p>Salars are landscapes formed by evapo-concentration of salts that usually have extremely shallow terminal lagoons (de la Fuente & Niño, 2010). They are located in the altiplanic region of the Andes Mountains of Chile, Argentina, Bolivia and Peru, and they sustain highly vulnerable and isolated ecosystems in the Andean Desert. These ecosystems are sustained by benthic primary production, which is directly linked to <span class="hlt">mass</span>, heat and momentum transfer between the water column and the atmosphere (de la Fuente, 2014). Despite the importance of these transport processes across the <span class="hlt">air</span>-water interface, there are few studies describing their intraday variation and how they are influenced by the stability of the atmospheric boundary layer in the altiplano. The main objective of this work is to analyze the intraday vertical transport variation of water vapor, temperature and momentum between the atmosphere and a shallow water body on Salar del Huasco located in northern Chile (20°19'40"S, 68°51'25"W). To achieve this goal, we measured atmospheric and water variables in a campaign realized on late October 2015, using high frequency meteorological instruments (a sonic anemometer with an incorporated infrared gas analyzer, and a standard meteorological station) and water sensors. From these data, we characterize the intraday variation of water vapor, temperature and momentum <span class="hlt">fluxes</span>, we quantify the influence of the atmospheric boundary layer stability on them, and we estimate transfer coefficients associated to latent heat, sensible heat, hydrodynamic drag and vertical transport of water vapor. As first results, we found that latent and sensible heat <span class="hlt">fluxes</span> are highly influenced by wind speed rather buoyancy, and we can identify four intraday intervals with different thermo-hydrodynamic features: (1) cooling under stable condition with wind speed near 0 from midnight until sunrise; (2) free convection with nearly no wind speed under unstable condition from sunrise until midday</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1130204-interaction-between-marine-boundary-layer-cellular-cloudiness-surface-heat-fluxes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1130204-interaction-between-marine-boundary-layer-cellular-cloudiness-surface-heat-fluxes"><span>On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface Heat <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kazil, J.; Feingold, G.; Wang, Hailong</p> <p>2014-01-02</p> <p>The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent heat is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface <span class="hlt">fluxes</span> of sensible heat, latent heat, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface heat <span class="hlt">fluxes</span> in the closed- and open-cell state are investigated and explained. Itmore » is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric <span class="hlt">air</span>, the spatial distribution of surface <span class="hlt">air</span> temperature and water vapor, and, to a lesser degree, of the surface sensible and latent heat <span class="hlt">flux</span>. The synchronized dynamics of the the open-cell state drives oscillations in surface <span class="hlt">air</span> temperature, water vapor, and in the surface <span class="hlt">fluxes</span> of sensible and latent heat, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface <span class="hlt">air</span> temperature and sensible heat <span class="hlt">flux</span>, but not of surface water vapor and latent heat <span class="hlt">flux</span>. It is shown that by enhancing the surface sensible heat <span class="hlt">flux</span>, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt <span class="hlt">fluxes</span>, it also enhances the sea-salt <span class="hlt">flux</span> relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface <span class="hlt">fluxes</span> is found</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...763..112I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...763..112I"><span>A Method to Search for Correlations of Ultra-high Energy Cosmic-Ray <span class="hlt">Masses</span> with the Large-scale Structures in the Local Galaxy Density Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ivanov, A. A.</p> <p>2013-02-01</p> <p>One of the main goals of investigations using present and future giant extensive <span class="hlt">air</span> shower (EAS) arrays is the <span class="hlt">mass</span> composition of ultra-high energy cosmic rays (UHECRs). A new approach to the problem is presented, combining the analysis of arrival directions with the statistical test of the paired EAS samples. One of the ideas of the method is to search for possible correlations between UHECR <span class="hlt">masses</span> and their separate sources; for instance, if there are two sources in different areas of the celestial sphere injecting different nuclei, but the <span class="hlt">fluxes</span> are comparable so that arrival directions are isotropic, then the aim is to reveal a difference in the <span class="hlt">mass</span> composition of cosmic-ray <span class="hlt">fluxes</span>. The method is based on a non-parametric statistical test—the Wilcoxon signed-rank routine—which does not depend on the populations fitting any parameterized distributions. Two particular algorithms are proposed: first, using measurements of the depth of the EAS maximum position in the atmosphere; and second, relying on the age variance of <span class="hlt">air</span> showers initiated by different primary particles. The formulated method is applied to the Yakutsk array data, in order to demonstrate the possibility of searching for a difference in average <span class="hlt">mass</span> composition between the two UHECR sets, arriving particularly from the supergalactic plane and a complementary region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.4462H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.4462H"><span>Biotic, abiotic and management controls on methanol <span class="hlt">fluxes</span> above a temperate mountain grassland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hörtnagl, Lukas; Bamberger, Ines; Graus, Martin; Ruuskanen, Taina; Schnitzhofer, Ralf; Müller, Markus; Hansel, Armin; Wohlfahrt, Georg</p> <p>2010-05-01</p> <p>It was previously hypothesised that (i) stomatal conductance and plant growth play a key role in the emission of methanol (Hüve et al. 2007, Niinemets et al. 2004), (ii) methanol <span class="hlt">fluxes</span> increase with <span class="hlt">air</span> temperature (Niinemets and Reichstein 2003), and (iii) during cutting (leaf wounding) events and during drying high amounts of methanol are emitted into the atmosphere (Davison et al. 2008). Methanol <span class="hlt">fluxes</span> were measured above a managed, temperate mountain grassland in Stubai Valley (Tyrol, Austria) during two growing seasons (2008 and 2009). Half-hourly <span class="hlt">flux</span> values were calculated by means of the disjunct eddy covariance method using 3-dimensional wind-data of a sonic anemometer and mixing ratios of methanol measured with a proton-transfer-reaction-<span class="hlt">mass</span>-spectrometer (PTR-MS). The surface conductance to water vapour was derived from measured evapotranspiration by inverting the Penman-Monteith combination equation (Wohlfahrt et al., 2009) for dry canopy conditions and used as a proxy for canopyscale stomatal conductance. Methanol <span class="hlt">fluxes</span> exhibited a clear diurnal cycle with closetozero <span class="hlt">fluxes</span> during nighttime and emissions, up to 10 nmol m-2 s-1, which followed the diurnal course of radiation and <span class="hlt">air</span> temperature during daytime. Higher emissions of up to 30 nmol m-2 s-1were observed during cut events and spreading of organic manure. Methanol <span class="hlt">fluxes</span> showed positive correlations with <span class="hlt">air</span> temperature, stomatal conductance, and photosynthetically active radiation (PAR), confirming previous studies (e.g. Niinemets and Reichstein 2003). All three previously mentioned factors combined together were able to explain 40% of the observed <span class="hlt">flux</span> variability. The influence of rapid changes in stomatal conductance on methanol <span class="hlt">fluxes</span>, pointed out in earlier studies at the leaf-level (e.g. Niinemets and Reichstein 2003), could not be confirmed on ecosystem scale, possibly due to within-canopy gradients in stomatal conductance and the fact that <span class="hlt">fluxes</span> were determined as half</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=185344&keyword=planes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=185344&keyword=planes&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span><span class="hlt">FLUX</span>-BASED METHODS FOR DNAPL REMEDIATION DESIGN AND ASSESSMENT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>One tool that has been investigated for use in DNAPL site characterization and remediation is <span class="hlt">mass</span> <span class="hlt">flux</span> (<span class="hlt">mass</span> per unit area per unit time) and <span class="hlt">mass</span> discharge (<span class="hlt">mass</span> per unit time) measurements. These measurements, when collected across one or more control planes located down grad...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=194003&keyword=disadvantages&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=194003&keyword=disadvantages&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Integration of <span class="hlt">Flux</span>-Based Methods and Triad Principles for DNAPL Site Management, Part II: Review of <span class="hlt">Flux</span> Measurement Methods</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Managing dense nonaqueous phase liquid (DNAPL) contaminated sites continues to be among the most pressing environmental problems currently faced. One approach that has recently been investigated for use in DNAPL site characterization and remediation is <span class="hlt">mass</span> <span class="hlt">flux</span> (<span class="hlt">mass</span> per unit ar...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1402563-analytical-modeling-double-sided-flux-concentrating-core-transverse-flux-machine-pole-windings','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1402563-analytical-modeling-double-sided-flux-concentrating-core-transverse-flux-machine-pole-windings"><span>Analytical Modeling of a Double-Sided <span class="hlt">Flux</span> Concentrating E-Core Transverse <span class="hlt">Flux</span> Machine with Pole Windings</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Muljadi, Eduard; Hasan, Iftekhar; Husain, Tausif</p> <p></p> <p>In this paper, a nonlinear analytical model based on the Magnetic Equivalent Circuit (MEC) method is developed for a double-sided E-Core Transverse <span class="hlt">Flux</span> Machine (TFM). The proposed TFM has a cylindrical rotor, sandwiched between E-core stators on both sides. Ferrite magnets are used in the rotor with <span class="hlt">flux</span> concentrating design to attain high airgap <span class="hlt">flux</span> density, better magnet utilization, and higher torque density. The MEC model was developed using a series-parallel combination of <span class="hlt">flux</span> tubes to estimate the reluctance network for different parts of the machine including <span class="hlt">air</span> gaps, permanent magnets, and the stator and rotor ferromagnetic materials, in amore » two-dimensional (2-D) frame. An iterative Gauss-Siedel method is integrated with the MEC model to capture the effects of magnetic saturation. A single phase, 1 kW, 400 rpm E-Core TFM is analytically modeled and its results for <span class="hlt">flux</span> linkage, no-load EMF, and generated torque, are verified with Finite Element Analysis (FEA). The analytical model significantly reduces the computation time while estimating results with less than 10 percent error.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28334669','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28334669"><span>Distribution and sea-to-<span class="hlt">air</span> <span class="hlt">flux</span> of isoprene in the East China Sea and the South Yellow Sea during summer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Jian-Long; Zhang, Hong-Hai; Yang, Gui-Peng</p> <p>2017-07-01</p> <p>Spatial distribution and sea-to-<span class="hlt">air</span> <span class="hlt">flux</span> of isoprene in the East China Sea and the South Yellow Sea in July 2013 were investigated. This study is the first to report the concentrations of isoprene in the China marginal seas. Isoprene concentrations in the surface seawater during summer ranged from 32.46 to 173.5 pM, with an average of 83.62 ± 29.22 pM. Distribution of isoprene in the study area was influenced by the diluted water from the Yangtze River, which stimulated higher in-situ phytoplankton production of isoprene rather than direct freshwater input. Variations in isoprene concentrations were found to be diurnal, with high values observed during daytime. A significant correlation was observed between isoprene and chlorophyll a in the study area. Relatively higher isoprene concentrations were recorded at stations where the phytoplankton biomass was dominated by Chaetoceros, Skeletonema, Pennate-nitzschia, and Thalassiosira. Positive correlation was observed between isoprene and methyl iodide. In addition, sea-to-<span class="hlt">air</span> <span class="hlt">fluxes</span> of isoprene approximately ranged from 22.17 nmol m -2  d -1 -537.2 nmol m -2  d -1 , with an average of 161.5 ± 133.3 nmol m -2  d -1 . These results indicate that the coastal and shelf areas may be important sources of atmospheric isoprene. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H51F0675W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H51F0675W"><span>Comparison of evaporative <span class="hlt">fluxes</span> from porous surfaces resolved by remotely sensed and in-situ temperature and soil moisture data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wallen, B.; Trautz, A.; Smits, K. M.</p> <p>2014-12-01</p> <p>The estimation of evaporation has important implications in modeling climate at the regional and global scale, the hydrological cycle and estimating environmental stress on agricultural systems. In field and laboratory studies, remote sensing and in-situ techniques are used to collect thermal and soil moisture data of the soil surface and subsurface which is then used to estimate evaporative <span class="hlt">fluxes</span>, oftentimes using the sensible heat balance method. Nonetheless, few studies exist that compare the methods due to limited data availability and the complexity of many of the techniques, making it difficult to understand <span class="hlt">flux</span> estimates. This work compares different methods used to quantify evaporative <span class="hlt">flux</span> based on remotely sensed and in-situ temperature and soil moisture data. A series of four laboratory experiments were performed under ambient and elevated <span class="hlt">air</span> temperature conditions with homogeneous and heterogeneous soil configurations in a small two-dimensional soil tank interfaced with a small wind tunnel apparatus. The soil tank and wind tunnel were outfitted with a suite of sensors that measured soil temperature (surface and subsurface), <span class="hlt">air</span> temperature, soil moisture, and tank weight. <span class="hlt">Air</span> and soil temperature measurements were obtained using infrared thermography, heat pulse sensors and thermistors. Spatial and temporal thermal data were numerically inverted to obtain the evaporative <span class="hlt">flux</span>. These values were then compared with rates of <span class="hlt">mass</span> loss from direct weighing of the samples. Results demonstrate the applicability of different methods under different surface boundary conditions; no one method was deemed most applicable under every condition. Infrared thermography combined with the sensible heat balance method was best able to determine evaporative <span class="hlt">fluxes</span> under stage 1 conditions while distributed temperature sensing combined with the sensible heat balance method best determined stage 2 evaporation. The approaches that appear most promising for determining the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.107...35V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.107...35V"><span>Influence of <span class="hlt">air</span> <span class="hlt">mass</span> origin on aerosol properties at a remote Michigan forest site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; Pressley, S. N.; Erickson, M. H.; Jobson, B. T.; Lamb, B. K.</p> <p>2015-04-01</p> <p>The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere-Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the <span class="hlt">air</span> <span class="hlt">masses</span> reaching the site. For ∼60% of the study period, <span class="hlt">air</span> was transported from sparsely populated regions to the northwest. During these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm-3 and 1.91 μm3 cm-3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When <span class="hlt">air</span> was from more populated regions to the east and south (∼29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate <span class="hlt">mass</span>, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). These trends are have the potential to influence forest-atmosphere interactions and should be targeted for future study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1353457-influence-air-mass-origin-aerosol-properties-remote-michigan-forest-site','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1353457-influence-air-mass-origin-aerosol-properties-remote-michigan-forest-site"><span>Influence of <span class="hlt">air</span> <span class="hlt">mass</span> origin on aerosol properties at a remote Michigan forest site</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; ...</p> <p>2015-02-10</p> <p>The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere–Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the <span class="hlt">air</span> <span class="hlt">masses</span> reaching the site. For ~60% of the study period, <span class="hlt">air</span> was transported from sparsely populated regions to the northwest. Duringmore » these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm -3 and 1.91 μm 3 cm -3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When <span class="hlt">air</span> was from more populated regions to the east and south (~29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate <span class="hlt">mass</span>, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). Furthermore, these trends are have the potential to influence forest–atmosphere interactions and should be targeted for future study.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.A11A0834B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.A11A0834B"><span>Particle <span class="hlt">Fluxes</span> Over a Ponderosa Pine Plantation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, B.; Goldstein, A.</p> <p>2006-12-01</p> <p>Atmospheric aerosols can affect visibility, climate, and health. Particle <span class="hlt">fluxes</span> were measured continuously over a 15 year-old ponderosa pine plantation in the foothills of the Sierra Nevada from mid July to the end of September in the year 2005. <span class="hlt">Air</span> at this field site is affected by both biogenic emissions from the dense forests of the surrounding area and by urban pollution transported from the Sacramento valley. It is believed that <span class="hlt">fluxes</span> of very reactive hydrocarbons from plants to the atmosphere have an impact on the production and growth of atmospheric particles at this site. Two condensation particle counters (CPCs) were located near the top of a 12 m measurement tower, several meters above the top of the tree canopy. Particle count data was collected at 10 Hz and particle <span class="hlt">fluxes</span> were determined using the eddy covariance method. A set of diffusion screens was added to the inlet of one of the CPCs such that the lower particle size limit for detection was increased to a diameter of approximately 40 nm. The other CPC counted particles with minimum diameters of 3 nm. Particle concentrations showed a distinct diurnal pattern with minimum daily average concentrations of 2000 particles cm-3 occurring at dawn, and average daily maximum concentrations of 5700 particles cm-3 occurring at dusk. The evening increase of particle number corresponded to the arrival of polluted <span class="hlt">air</span> from the Sacramento region. During the day, deposition of particles to the forest canopy (daytime average of 5.8x106 particles m-2 s-1 was generally observed. Concentrations and <span class="hlt">fluxes</span> of particles under 40 nm could be examined by subtracting the data of one CPC from the other. On average, the fraction of particles under 40 nm increased from less than 20% at dawn to more than 50% at dusk; indicating that <span class="hlt">air</span> coming from the Sacramento region was enriched in smaller, newly formed aerosol. Daily average deposition <span class="hlt">fluxes</span> of particles under 40 nm were 1.0x107 particles m-2 s-1. Much of this <span class="hlt">flux</span> was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H44F..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H44F..07L"><span>GRACE <span class="hlt">Mass</span> <span class="hlt">Flux</span> Measurements of Inland and Marginal Seas from Mascons: Analysis and Validation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loomis, B.; Luthcke, S. B.; Sabaka, T. J.</p> <p>2015-12-01</p> <p>The latest GRACE time-variable gravity mascon solution from the NASA Goddard Space Flight Center (GSFC) applies an optimized set of models and constraints towards the direct measurement of 1-arc-degree global <span class="hlt">mass</span> <span class="hlt">flux</span> parameters each month. Separate mascon spatial constraint regions have been defined for the largest inland and marginal seas: Mediterranean Sea, Black Sea, Caspian Sea, Red Sea, and Hudson Bay. The mascon estimation approach, when applied with well-designed constraints, minimizes signal leakage across regional boundaries and eliminates the need for post-processing strategies. These post-processing techniques (e.g. smoothed averaging kernels) are necessary for computing regional <span class="hlt">mass</span> change from the unconstrained spherical harmonics provided by the GRACE project to reduce the effect of noisy high degree and order terms, but introduce signal leakage into and out of the considered region. These <span class="hlt">mass</span> signals are also difficult to obtain from altimetry measurements due to the comparatively sparse temperature and salinity data in these regions, which is needed to compute and remove the steric component of sea level variations. We provide new GSFC mascon measurements of these inland and marginal seas and compare to results obtained from kernel-averaged spherical harmonic solutions and steric-corrected altimetry measurements. The relative accuracy of the various solutions is determined by incorporating their output into the set of forward models applied in our processing of the GRACE Level-1B data and analyzing the effect on the inter-satellite range-rate residuals, where a reduction in residuals is a direct validation of improved solution quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17737437','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17737437"><span>Condensation of atmospheric moisture from tropical maritime <span class="hlt">air</span> <span class="hlt">masses</span> as a freshwater resource.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gerard, R D; Worzel, J L</p> <p>1967-09-15</p> <p>A method is proposed whereby potable water may be obtained by condensing moisture from the atmosphere in suitable seashore or island areas. Deep, cold, offshore seawater is used as a source of cold and is pumped to condensers set up on shore to intercept the flow of highly humid, tropical, maritime <span class="hlt">air</span> <span class="hlt">masses</span>. This <span class="hlt">air</span>, when cooled, condenses moisture, which is conducted away and stored for use as a water supply. Windmill-driven generators would supply low-cost power for the operation. Side benefits are derived by using the nutritious deep water to support aquiculture in nearby lagoons or to enhance the productivity of the outfall area. Additional benefits are derived from the condenser as an <span class="hlt">air</span>-conditioning device for nearby residents. The islands of the Caribbean are used as an example of a location in the trade-winds belt where nearly optimum conditions for the operation of this system can be found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2151844','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2151844"><span>Remote <span class="hlt">Mass</span> Spectrometric Sampling of Electrospray- and Desorption Electrospray-Generated Ions Using an <span class="hlt">Air</span> Ejector</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dixon, R. Brent; Bereman, Michael S.; Muddiman, David C.; Hawkridge, Adam M.</p> <p>2007-01-01</p> <p>A commercial <span class="hlt">air</span> ejector was coupled to an electrospray ionization linear ion trap <span class="hlt">mass</span> spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary <span class="hlt">mass</span> spectrometric data is presented. PMID:17716909</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=87693&Lab=NRMRL&keyword=fourier&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=87693&Lab=NRMRL&keyword=fourier&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DETERMINATION OF AMMONIA <span class="hlt">MASS</span> EMISSION <span class="hlt">FLUX</span> FROM HOG WASTE EFFLUENT SPRAYING OPERATION USING OPEN PATH TUNABLE DIODE LASER SPECTROSCOPY WITH VERTICAL RADIAL PLUME MAPPING ANALYSIS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Emission of ammonia from concentrated animal feeding operations represents an increasingly important environmental issue. Determination of total ammonia <span class="hlt">mass</span> emission <span class="hlt">flux</span> from extended area sources such as waste lagoons and waste effluent spraying operations can be evaluated usi...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS22B..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS22B..05M"><span>Atmospheric responses to sensible and latent heating <span class="hlt">fluxes</span> over the Gulf Stream</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minobe, S.; Ida, T.; Takatama, K.</p> <p>2016-12-01</p> <p><span class="hlt">Air</span>-sea interaction over mid-latitude oceanic fronts such as the Gulf Stream attracted large attention in the last decade. Observational analyses and modelling studies revealed that atmospheric responses over the Gulf Stream including surface wind convergence, enhanced precipitation and updraft penetrating to middle-to-upper troposphere roughly on the Gulf Stream current axis or on the warmer flank of sea-surface temperature (SST) front of the Gulf Stream . For these atmospheric responses, oceanic information should be transmitted to the atmosphere via turbulent heat <span class="hlt">fluxes</span>, and thus the mechanisms for atmospheric responses can be understood better by examining latent and sensible <span class="hlt">air</span>-sea heat <span class="hlt">fluxes</span> more closely. Thus, the roles of the sensible and latent heat <span class="hlt">fluxes</span> are examined by conducting a series of numerical experiments using the IPRC Regional Atmospheric Model over the Gulf Stream by applying SST smoothing for latent and sensible heating separately. The results indicate that the sensible and latent heat <span class="hlt">fluxes</span> affect the atmosphere differently. Sensible heat <span class="hlt">flux</span> intensifies surface wind convergence to produce sea-level pressure (SLP) anomaly. Latent heat <span class="hlt">flux</span> supplies moistures and maintains enhanced precipitation. The different heat <span class="hlt">flux</span> components cause upward wind velocity at different levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3373A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3373A"><span>Estimating sensible heat <span class="hlt">flux</span> in agricultural screenhouses by the <span class="hlt">flux</span>-variance and half-order time derivative methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Achiman, Ori; Mekhmandarov, Yonatan; Pirkner, Moran; Tanny, Josef</p> <p>2016-04-01</p> <p>Previous studies have established that the eddy covariance (EC) technique is reliable for whole canopy <span class="hlt">flux</span> measurements in agricultural crops covered by porous screens, i.e., screenhouses. Nevertheless, the eddy covariance technique remains difficult to apply in the farm due to costs, operational complexity, and post-processing of data - thereby inviting alternative techniques to be developed. The subject of this research was estimating the sensible heat <span class="hlt">flux</span> by two turbulent transport techniques, namely, <span class="hlt">Flux</span>-Variance (FV) and Half-order Time Derivative (HTD) whose instrumentation needs and operational demands are not as elaborate as the EC. The FV is based on the standard deviation of high frequency temperature measurements and a similarity constant CT. The HTD method requires mean <span class="hlt">air</span> temperature and <span class="hlt">air</span> velocity data. Measurements were carried out in two types of screenhouses: (i) a banana plantation in a light shading (8%) screenhouse; (ii) a pepper crop in a dense insect-proof (50-mesh) screenhouse. In each screenhouse an EC system was deployed for reference and high frequency <span class="hlt">air</span> temperature measurements were conducted using miniature thermocouples installed at several levels to identify the optimal measurement height. Quality control analysis showed that turbulence development and flow stationarity conditions in the two structures were suitable for <span class="hlt">flux</span> measurements by the EC technique. Energy balance closure slopes in the two screenhouses were larger than 0.71, in agreement with results for open fields. Regressions between sensible heat <span class="hlt">flux</span> measured by EC and estimated by FV resulted with CT values that were usually larger than 1, the typical value for open field. In both shading and insect-proof screenhouses the CT value generally increased with height. The optimal measurement height, defined as the height with maximum R2 of the regression between EC and FV sensible heat <span class="hlt">fluxes</span>, was just above the screen. CT value at optimal height was 2.64 and 1.52 for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10191398','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10191398"><span>Metabolite-balancing techniques vs. 13C tracer experiments to determine metabolic <span class="hlt">fluxes</span> in hybridoma cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bonarius, H P; Timmerarends, B; de Gooijer, C D; Tramper, J</p> <p></p> <p>The estimation of intracellular <span class="hlt">fluxes</span> of mammalian cells using only <span class="hlt">mass</span> balances of the relevant metabolites is not possible because the set of linear equations defined by these <span class="hlt">mass</span> balances is underdetermined. In order to quantify <span class="hlt">fluxes</span> in cyclic pathways the <span class="hlt">mass</span> balance equations can be complemented with several constraints: (1) the <span class="hlt">mass</span> balances of co-metabolites, such as ATP or NAD(P)H, (2) linear objective functions, (3) <span class="hlt">flux</span> data obtained by isotopic-tracer experiments. Here, these three methods are compared for the analysis of <span class="hlt">fluxes</span> in the primary metabolism of continuously cultured hybridoma cells. The significance of different theoretical constraints and different objective functions is discussed after comparing their resulting <span class="hlt">flux</span> distributions to the <span class="hlt">fluxes</span> determined using 13CO2 and 13C-lactate measurements of 1 - 13C-glucose-fed hybridoma cells. Metabolic <span class="hlt">fluxes</span> estimated using the objective functions "maximize ATP" and "maximize NADH" are relatively similar to the experimentally determined <span class="hlt">fluxes</span>. This is consistent with the observation that cancer cells, such as hybridomas, are metabolically hyperactive, and produce ATP and NADH regardless of the need for these cofactors. Copyright 1998 John Wiley & Sons, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C21B1120W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C21B1120W"><span>Autonomous Ice <span class="hlt">Mass</span> Balance Buoys for Seasonal Sea Ice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whitlock, J. D.; Planck, C.; Perovich, D. K.; Parno, J. T.; Elder, B. C.; Richter-Menge, J.; Polashenski, C. M.</p> <p>2017-12-01</p> <p>The ice <span class="hlt">mass</span>-balance represents the integration of all surface and ocean heat <span class="hlt">fluxes</span> and attributing the impact of these forcing <span class="hlt">fluxes</span> on the ice cover can be accomplished by increasing temporal and spatial measurements. <span class="hlt">Mass</span> balance information can be used to understand the ongoing changes in the Arctic sea ice cover and to improve predictions of future ice conditions. Thinner seasonal ice in the Arctic necessitates the deployment of Autonomous Ice <span class="hlt">Mass</span> Balance buoys (IMB's) capable of long-term, in situ data collection in both ice and open ocean. Seasonal IMB's (SIMB's) are free floating IMB's that allow data collection in thick ice, thin ice, during times of transition, and even open water. The newest generation of SIMB aims to increase the number of reliable IMB's in the Arctic by leveraging inexpensive commercial-grade instrumentation when combined with specially developed monitoring hardware. Monitoring tasks are handled by a custom, expandable data logger that provides low-cost flexibility for integrating a large range of instrumentation. The SIMB features ultrasonic sensors for direct measurement of both snow depth and ice thickness and a digital temperature chain (DTC) for temperature measurements every 2cm through both snow and ice. <span class="hlt">Air</span> temperature and pressure, along with GPS data complete the Arctic picture. Additionally, the new SIMB is more compact to maximize deployment opportunities from multiple types of platforms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=187443&keyword=aggressive&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=187443&keyword=aggressive&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Changes in Contaminant <span class="hlt">Mass</span> Discharge from DNAPL Source <span class="hlt">Mass</span> Depletion: Evaluation at Two Field Sites</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Changes in contaminant <span class="hlt">fluxes</span> resulting from aggressive remediation of dense nonaqueous phase liquid (DNAPL) source zone were investigated at two sites, one at Hill <span class="hlt">Air</span> Force Base (AFB), Utah, and the other at Ft. Lewis Military Reservation, WA. Passive <span class="hlt">Flux</span> Meters (PFM) and a va...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC33A1208P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC33A1208P"><span>Developing an Approach to Model UV <span class="hlt">Fluxes</span> in Smoke Laden Conditions over Central Asia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Y. H.; Sokolik, I. N.</p> <p>2016-12-01</p> <p>The UV characteristics of smoke aerosols are valuable inputs to the UV Index forecasts, <span class="hlt">air</span> quality studies, and assessments of the impact of regional environmental changes. The wavelength dependence of light absorption by aerosol particles is pronounced throughout the UV spectral region. Also in assumption that smoke consists of BC, OC, and Sulfate, the <span class="hlt">mass</span> fraction of smoke is different with fire types. The purpose of this study is to introduce an approach to calculate the UV <span class="hlt">fluxes</span> in the aerosol laden conditions, and investigate the irradiance compared to measured irradiance in the UV spectrum. To compute the spectral optical properties (e.g., the effective single scattering albedo, asymmetry parameter, and aerosol optical thickness) for the selected scenarios, the representative size distribution and the refractive index are selected and used in the Mie code. Smoke aerosol information (e.g. emission injection height, <span class="hlt">mass</span> concentration of smoke components) from WRF Chem is applied to run tropospheric ultraviolet and visible (TUV) model. Using the TUV model, we make the comparisons between model and measured irradiance in UV spectrum in smoke aerosol conditions. An advantage of this approach and the uncertainty of the evaluation are discussed. Overall, the results of this investigation show that this approach is valuable to estimate UV <span class="hlt">fluxes</span> in smoke laden conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6048380-atmospheric-electron-flux-airplane-altitude','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6048380-atmospheric-electron-flux-airplane-altitude"><span>Atmospheric electron <span class="hlt">flux</span> at airplane altitude</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Enomoto, R.; Chiba, J.; Ogawa, K.</p> <p>1991-12-01</p> <p>We have developed a new detector to systematically measure the cosmic-ray electron <span class="hlt">flux</span> at airplane altitudes. We loaded a lead-glass-based electron telescope onto a commercial cargo airplane. The first experiment was carried out using the <span class="hlt">air</span> route between Narita (Japan) and Sydney (Australia); during this flight we measured the electron <span class="hlt">flux</span> at various altitudes and latitudes. The thresholds of the electron energies were 1, 2, and 4 GeV. The results agree with a simple estimation using one-dimensional shower theory. A comparison with a Monte Carlo calculation was made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2014/1035/pdf/ofr2014-1035.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2014/1035/pdf/ofr2014-1035.pdf"><span>Weekly resolution particulate <span class="hlt">flux</span> from a sediment trap in the northern Gulf of Mexico, 2008-2012</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Richey, Julie N.; Reynolds, Caitlin E.; Tappa, Eric; Thunell, Robert</p> <p>2014-01-01</p> <p>The U.S. Geological Survey anchored a sediment trap in the northern Gulf of Mexico to collect time-series data on sediment <span class="hlt">flux</span> from 2008 to 2012. There are continuous measurements of total <span class="hlt">mass</span> <span class="hlt">flux</span> and organic carbon <span class="hlt">flux</span> (ogC) at 7–14 day resolution from 2008 to 2012. The <span class="hlt">flux</span> of calcium carbonate (CaCO3), particulate nitrogen (nitro), and biogenic silica (Opal) were also measured from January-December, 2008. The <span class="hlt">mass</span> <span class="hlt">flux</span> ranged from 0.01 g m-2day-1 (grams per square meter per day) to 2.50 g m-2day-1, with a mean <span class="hlt">mass</span> <span class="hlt">flux</span> of 0.20 g m -2day-1 over the 5-year study period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A33F2423H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A33F2423H"><span>Number concentration, size distribution and horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> of Asian dust particles collected over free troposphere of Chinese desert region in calm weather condition using balloon borne measurements.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Habib, A.; Chen, B.</p> <p>2017-12-01</p> <p>Balloon borne measurements were carried out during calm weather conditions in Taklamakan Desert, which is considered as one of the major source areas of Asian dust (KOSA) particles. Vertical distribution of aerosols number concentration, size distribution, <span class="hlt">mass</span> concentration and horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> due to westerly wind was investigated .Vertical distribution of aerosol number concentration and size distribution at Dunhuang (40 °00'N, 94°30'E) China were observed by optical particle counter (OPC) on August 17, 2001, October 17, 2011, January 11, 2002, April 30, 2002. Five channels (0.3, 0.5, 0.8, 1.2 and 3.6 µm) were used in OPC for particle sizing measurements. Aerosol number concentration in winter season (January 11, 2002) at 3-5 km was very high. Variation of free tropospheric aerosols in April 30, 2002 was noticeable. Many inversions of temperature and aerosol concentration change are found at these inversion points. Super micron range was noticeable in size distribution of all balloon borne measurements. High values of estimated <span class="hlt">mass</span> concentration of aerosols were observed at the ground atmosphere (1-2 km), and interestingly relatively high concentrations were frequently detected above about 2 km. Wind pattern observed by ERA-interim data sets at 500 and 850 hPa, shows that westerly winds were dominated in Taklamakan Desert during balloon borne observation period. Average horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> of background Asian dust due to westerly wind was about in the range of 1219-58.5 μg/m³ tons/km2/day. Most of the profiles showed active transport of aerosols in the westerly dominated region, while, <span class="hlt">fluxes</span> were found to be very low on January 11, 2002, compared with the other seasons. Vertical profiles of aerosols number concentration showed that significant transport of aerosols was dominated in westerly region (4-7 km). Low horizontal <span class="hlt">mass</span> <span class="hlt">flux</span> of aerosols was found in winter season</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HMT....51.1121T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HMT....51.1121T"><span>Estimation of whole lemon <span class="hlt">mass</span> transfer parameters during hot <span class="hlt">air</span> drying using different modelling methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torki-Harchegani, Mehdi; Ghanbarian, Davoud; Sadeghi, Morteza</p> <p>2015-08-01</p> <p>To design new dryers or improve existing drying equipments, accurate values of <span class="hlt">mass</span> transfer parameters is of great importance. In this study, an experimental and theoretical investigation of drying whole lemons was carried out. The whole lemons were dried in a convective hot <span class="hlt">air</span> dryer at different <span class="hlt">air</span> temperatures (50, 60 and 75 °C) and a constant <span class="hlt">air</span> velocity (1 m s-1). In theoretical consideration, three moisture transfer models including Dincer and Dost model, Bi- G correlation approach and conventional solution of Fick's second law of diffusion were used to determine moisture transfer parameters and predict dimensionless moisture content curves. The predicted results were then compared with the experimental data and the higher degree of prediction accuracy was achieved by the Dincer and Dost model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6940335-interspecific-variation-so-sub-flux-leaf-surface-versus-internal-flux-components-leaf-conductance-pisum-sativum-lycopersicon-esculentum-mill-flacca-geranium-carolinianum-diplacus-aurantiacus-curtis-jeps','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6940335-interspecific-variation-so-sub-flux-leaf-surface-versus-internal-flux-components-leaf-conductance-pisum-sativum-lycopersicon-esculentum-mill-flacca-geranium-carolinianum-diplacus-aurantiacus-curtis-jeps"><span>Interspecific variation in SO/sub 2/ <span class="hlt">flux</span>: leaf surface versus internal <span class="hlt">flux</span>, and components of leaf conductance. [Pisum sativum L. , Lycopersicon esculentum Mill. Flacca, Geranium carolinianum L. , Diplacus aurantiacus (Curtis) Jeps</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Olszyk, D.M.; Tingey, D.T.</p> <p></p> <p>The objective of this study was to clarify the relationships among stomatal, residual, and epidermal conductances in determining the <span class="hlt">flux</span> of SO/sub 2/ <span class="hlt">air</span> pollution to leaves. Variations in leaf SO/sub 2/ and H/sub 2/O vapor <span class="hlt">fluxes</span> were determined using four plant species: Pisum sativum L. (garden pea), Lycopersicon esculentum Mill. flacca (mutant of tomato), Geranium carolinianum L. (wild geranium), and Diplacus aurantiacus (Curtis) Jeps. (a native California shrub). <span class="hlt">Fluxes</span> were measured using the <span class="hlt">mass</span>-balance approach during exposure to 4.56 micromoles per cubic meter (0.11 microliters per liter) SO/sub 2/ for 2 hours in a controlled environmental chamber. <span class="hlt">Flux</span> throughmore » adaxial and abaxial leaf surfaces with closed stomata ranged from 1.9 to 9.4 nanomoles per square meter per second for SO/sub 2/, and 0.3 to 1.3 millimoles per square meter per second for H/sub 2/O vapor. <span class="hlt">Flux</span> of SO/sub 2/ into leaves through stomata ranged from approx.0 to 8.5 (dark) and 3.8 to 16.0 (light) millimoles per square meter per second. <span class="hlt">Flux</span> of H/sub 2/O vapor from leaves through stomata ranged from approx.0 to 0.6 (dark) to 0.4 to 0.9 (light) millimole per square meter per second. Lycopersicon had internal <span class="hlt">flux</span> rates for both SO/sub 2/ and H/sub 2/O vapor over twice as high as for the other species. Stomatal conductance based on H/sub 2/O vapor <span class="hlt">flux</span> averaged from 0.07 to 0.13 mole per square meter per second among the four species. Internal conductance of SO/sub 2/ as calculated from SO/sub 2/ <span class="hlt">flux</span> was from 0.04 mole per square meter per second lower to 0.06 mole per square meter per second higher than stomatal conductance. For Pisum, Geranium, and Diplacus stomatal conductance was the same or slightly higher than internal conductance, indicating that, in general, SO/sub 2/ <span class="hlt">flux</span> could be predicted from stomatal conductance for H/sub 2/O vapor.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14..742J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14..742J"><span>In situ evaluation of <span class="hlt">air</span>-sea CO2 gas transfer velocity in an inner estuary using eddy covariance - with a special focus on the importance of using reliable CO2-<span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jørgensen, E. T.; Sørensen, L. L.; Jensen, B.; Sejr, M. K.</p> <p>2012-04-01</p> <p>The <span class="hlt">air</span>-sea exchange of CO2 or CO2 <span class="hlt">flux</span> is driven by the difference in the partial pressure of CO2 in the water and the atmosphere (ΔpCO2), the solubility of CO2 (K0) and the gas transfer velocity (k) (Wanninkhof et al., 2009;Weiss, 1974) . ΔpCO2 and K0 are determined with relatively high precision and it is estimated that the biggest uncertainty when modelling the <span class="hlt">air</span>-sea <span class="hlt">flux</span> is the parameterization of k. As an example; the estimated global <span class="hlt">air</span>-sea <span class="hlt">flux</span> increases by 70 % when using the parameterization by Wanninkhof and McGillis (1999) instead of Wanninkhof (1992) (Rutgersson et al., 2008). In coastal areas the uncertainty is even higher and only few studies have focused on determining transfer velocity for the coastal waters and even fewer on estuaries (Borges et al., 2004;Rutgersson et al., 2008). The transfer velocity (k600) of CO2 in the inner estuary of Roskilde Fjord, Denmark was investigated using eddy covariance CO2 <span class="hlt">fluxes</span> (ECM) and directly measured ΔpCO2 during May and June 2010. The data was strictly sorted to heighten the certainty of the results and the outcome was; DS1; using only ECM, and DS2; including the inertial dissipation method (IDM). The inner part of Roskilde Fjord showed to be a very biological active CO2 sink and preliminary results showed that the average k600 was more than 10 times higher than transfer velocities from similar studies of other coastal areas. The much higher transfer velocities were estimated to be caused by the greater fetch and shallower water in Roskilde Fjord, which indicated that turbulence in both <span class="hlt">air</span> and water influence k600. The wind speed parameterization of k600 using DS1 showed some scatter but when including IDM the r2 of DS2 reached 0.93 with an exponential parameterization, where U10 was based on the Businger-Dyer relationships using friction velocity and atmospheric stability. This indicates that some of the uncertainties coupled with CO2 <span class="hlt">fluxes</span> calculated by the ECM are removed when including the IDM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146004&keyword=distribution+AND+determinants&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=146004&keyword=distribution+AND+determinants&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>IMPACTS OF DNAPL SOURCE TREATMENT ON CONTAMINANT <span class="hlt">MASS</span> <span class="hlt">FLUX</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Current remedial techniques are unable to completely eliminate all dense nonaqueous phase liquid (DNAPL) from source zone areas at most sites, and conflicting views on the benefits of partial DNAPL source zone remediation exist in the literature. A comparison of contaminant <span class="hlt">flux</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=327584','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=327584"><span>Toward a better understanding of the impact of <span class="hlt">mass</span> transit <span class="hlt">air</span> pollutants on human health</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Modern <span class="hlt">mass</span> transit systems, based on roads, rail, water, and <span class="hlt">air</span>, generate toxic airborne pollutants throughout the developed world. This has become one of the leading concerns about the use of modern transportation, particularly in densely-populated urban areas where their use is enormous and inc...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACP.....6.5649M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACP.....6.5649M"><span>Cluster Analysis of the Organic Peaks in Bulk <span class="hlt">Mass</span> Spectra Obtained During the 2002 New England <span class="hlt">Air</span> Quality Study with an Aerodyne Aerosol <span class="hlt">Mass</span> Spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M.; Bertman, S. B.; Middlebrook, A. M.</p> <p>2006-12-01</p> <p>We applied hierarchical cluster analysis to an Aerodyne aerosol <span class="hlt">mass</span> spectrometer (AMS) bulk <span class="hlt">mass</span> spectral dataset collected aboard the NOAA research vessel R. H. Brown during the 2002 New England <span class="hlt">Air</span> Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their <span class="hlt">mass</span> spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when <span class="hlt">air</span> <span class="hlt">masses</span> from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic <span class="hlt">mass</span> that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated <span class="hlt">mass</span> spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol <span class="hlt">mass</span> spectra from a field study.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25501714','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25501714"><span>Characterization of ion processes in a GC/DMS <span class="hlt">air</span> quality monitor by integration of the instrument to a <span class="hlt">mass</span> spectrometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Limero, T F; Nazarov, E G; Menlyadiev, M; Eiceman, G A</p> <p>2015-02-07</p> <p>The <span class="hlt">air</span> quality monitor (AQM), which included a portable gas chromatograph (GC) and a detector was interfaced to a <span class="hlt">mass</span> spectrometer (MS) by introducing flow from the GC detector to the atmospheric pressure ion source of the MS. This small GC system, with a gas recirculation loop for carrier and detector make-up gases, comprised an inlet to preconcentrate volatile organic compounds (VOCs) in <span class="hlt">air</span>, a thermal desorber before the GC column, a differential mobility spectrometer (DMS), and another DMS as an atmospheric pressure ionization source for the MS. Return flow to the internally recirculated <span class="hlt">air</span> system of the AQM's DMS was replenished using purified <span class="hlt">air</span>. Although ions and unreacted neutral vapors flowed from the detector through Viton® tubing into the source of the MS, ions were not detected in the MS without the auxillary ion source, (63)Ni as in the mobility detector. The GC-DMS-MS instrument provided a 3-D measurement platform (GC, DMS, and MS analysis) to explore the gas composition inside the GC-DMS recirculation loop and provide DMS-MS measurement of the components of a complex VOC mixture with performance significantly enhanced by <span class="hlt">mass</span>-analysis, either with <span class="hlt">mass</span> spectral scans or with an extracted ion chromatogram. This combination of a mobility spectrometer and a <span class="hlt">mass</span> spectrometer was possible as vapors and ions are carried together through the DMS analyzer, thereby preserving the chromatographic separation efficiency. The critical benefit of this instrument concept is that all flows in and through the thoroughly integrated GC-DMS analyzer are kept intact allowing a full measure of the ion and vapor composition in the complete system. Performance has been evaluated using a synthetic <span class="hlt">air</span> sample and a sample of airborne vapors in a laboratory. Capabilities and performance values are described using results from AQM-MS analysis of purified <span class="hlt">air</span>, ambient <span class="hlt">air</span> from a research laboratory in a chemistry building, and a sample of synthetic <span class="hlt">air</span> of known composition</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGRE..108.8115T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGRE..108.8115T"><span>Dust <span class="hlt">Flux</span> Monitor Instrument for the Stardust mission to comet Wild 2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tuzzolino, A. J.; Economou, T. E.; McKibben, R. B.; Simpson, J. A.; McDonnell, J. A. M.; Burchell, M. J.; Vaughan, B. A. M.; Tsou, P.; Hanner, M. S.; Clark, B. C.; Brownlee, D. E.</p> <p>2003-10-01</p> <p>The Dust <span class="hlt">Flux</span> Monitor Instrument (DFMI) is part of the Stardust instrument payload. The prime goal of the DFMI is to measure the particle <span class="hlt">flux</span>, intensity profile, and <span class="hlt">mass</span> distribution during passage through the coma of comet Wild 2 in January 2004. This information is valuable for assessment of spacecraft risk and health and also for interpretation of the laboratory analysis of dust captured by the Aerogel dust collectors and returned to Earth. At the encounter speed of 6.1 km/s, the DFMI measurements will extend over the particle <span class="hlt">mass</span> range of 8 decades, from 10-11 to >10-3 g. A secondary science goal is to measure the particle <span class="hlt">flux</span> and <span class="hlt">mass</span> distribution during the ~7 year interplanetary portions of the mission, where, in addition to measurements of the background interplanetary dust over the radial range 0.98 AU to 2.7 AU, multiple opportunities exist for possible detection by the DFMI of interplanetary meteor-stream particles and interstellar dust. The DFMI consists of two different dust detector systems: a polyvinylidene fluoride (PVDF) Dust Sensor Unit (SU), which measures particles with <span class="hlt">mass</span> <~10-4 g, and a Dual Acoustic Sensor System (DASS), which utilizes two quartz piezoelectric accelerometers mounted on the first two layers of the spacecraft Whipple dust shield to measure the <span class="hlt">flux</span> of particles with <span class="hlt">mass</span> >10-4 g. The large Whipple shield structures provide the large effective sensitive area required for detection of the expected low <span class="hlt">flux</span> of high-<span class="hlt">mass</span> particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900065220&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900065220&hterms=sing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsing"><span>Inviscid <span class="hlt">flux</span>-splitting algorithms for real gases with non-equilibrium chemistry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shuen, Jian-Shun; Liou, Meng-Sing; Van Leer, Bram</p> <p>1990-01-01</p> <p>Formulations of inviscid <span class="hlt">flux</span> splitting algorithms for chemical nonequilibrium gases are presented. A chemical system for <span class="hlt">air</span> dissociation and recombination is described. Numerical results for one-dimensional shock tube and nozzle flows of <span class="hlt">air</span> in chemical nonequilibrium are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820018907','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820018907"><span><span class="hlt">Air</span> Brayton Solar Receiver, phase 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deanda, L. E.</p> <p>1981-01-01</p> <p>An <span class="hlt">air</span> Brayton solar receiver (ABSR) is discussed. The ABSR consists of a cylindrical, insulated, offset plate fin heat exchanger which is mounted at the focal plane of a fully tracking parabolic solar collector. The receiver transfer heat from the concentrated solar radiation (which impinges on the inside walls of the heat exchanger) to the working fluid i.e., <span class="hlt">air</span>. The hot <span class="hlt">air</span> would then e used to drive a small Brayton cycle heat engine. The engine in turn drives a generator which produces electrical energy. Symmetrical and asymmetrical solar power input into the ABSR are analyzed. The symmetrical cases involve the baseline incident <span class="hlt">flux</span> and the axially shifted incident <span class="hlt">fluxes</span>. The asymmetrical cases correspond to the solar <span class="hlt">fluxes</span> that are obtained by reduced solar input from one half of the concentrator or by receiver offset of plus or minus 1 inch from the concentrator optical axis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ACPD....6.4601M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ACPD....6.4601M"><span>Cluster analysis of the organic peaks in bulk <span class="hlt">mass</span> spectra obtained during the 2002 New England <span class="hlt">Air</span> Quality Study with an Aerodyne aerosol <span class="hlt">mass</span> spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M. L.; Bertman, S. B.; Middlebrook, A. M.</p> <p>2006-06-01</p> <p>We applied hierarchical cluster analysis to an Aerodyne aerosol <span class="hlt">mass</span> spectrometer (AMS) bulk <span class="hlt">mass</span> spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England <span class="hlt">Air</span> Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their <span class="hlt">mass</span> spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when <span class="hlt">air</span> <span class="hlt">masses</span> from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol <span class="hlt">mass</span> - 17% of the total organic <span class="hlt">mass</span> - that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated <span class="hlt">mass</span> spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol <span class="hlt">mass</span> spectra from a field study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.7197S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.7197S"><span>SAMOS Surface <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, Shawn; Bourassa, Mark</p> <p>2014-05-01</p> <p>The development of a new surface <span class="hlt">flux</span> dataset based on underway meteorological observations from research vessels will be presented. The research vessel data center at the Florida State University routinely acquires, quality controls, and distributes underway surface meteorological and oceanographic observations from over 30 oceanographic vessels. These activities are coordinated by the Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative in partnership with the Rolling Deck to Repository (R2R) project. Recently, the SAMOS data center has used these underway observations to produce bulk <span class="hlt">flux</span> estimates for each vessel along individual cruise tracks. A description of this new <span class="hlt">flux</span> product, along with the underlying data quality control procedures applied to SAMOS observations, will be provided. Research vessels provide underway observations at high-temporal frequency (1 min. sampling interval) that include navigational (position, course, heading, and speed), meteorological (<span class="hlt">air</span> temperature, humidity, wind, surface pressure, radiation, rainfall), and oceanographic (surface sea temperature and salinity) samples. Vessels recruited to the SAMOS initiative collect a high concentration of data within the U.S. continental shelf and also frequently operate well outside routine shipping lanes, capturing observations in extreme ocean environments (Southern, Arctic, South Atlantic, and South Pacific oceans). These observations are atypical for their spatial and temporal sampling, making them very useful for many applications including validation of numerical models and satellite retrievals, as well as local assessments of natural variability. Individual SAMOS observations undergo routine automated quality control and select vessels receive detailed visual data quality inspection. The result is a quality-flagged data set that is ideal for calculating turbulent <span class="hlt">flux</span> estimates. We will describe the bulk <span class="hlt">flux</span> algorithms that have been applied to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A41B3033D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A41B3033D"><span>Estimating Turbulent Surface <span class="hlt">Fluxes</span> from Small Unmanned Aircraft: Evaluation of Current Abilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Boer, G.; Lawrence, D.; Elston, J.; Cassano, J. J.; Mack, J.; Wildmann, N.; Nigro, M. A.; Ivey, M.; Wolfe, D. E.; Muschinski, A.</p> <p>2014-12-01</p> <p>Heat transfer between the atmosphere and Earth's surface represents a key component to understanding Earth energy balance, making it important in understanding and simulating climate. Arguably, the oceanic <span class="hlt">air</span>-sea interface and Polar sea-ice-<span class="hlt">air</span> interface are amongst the most challenging in which to measure these <span class="hlt">fluxes</span>. This difficulty results partially from challenges associated with infrastructure deployment on these surfaces and partially from an inability to obtain spatially representative values over a potentially inhomogeneous surface. Traditionally sensible (temperature) and latent (moisture) <span class="hlt">fluxes</span> are estimated using one of several techniques. A preferred method involves eddy-correlation where cross-correlation between anomalies in vertical motion (w) and temperature (T) or moisture (q) is used to estimate heat transfer. High-frequency measurements of these quantities can be derived using tower-mounted instrumentation. Such systems have historically been deployed over land surfaces or on ships and buoys to calculate <span class="hlt">fluxes</span> at the <span class="hlt">air</span>-land or <span class="hlt">air</span>-sea interface, but such deployments are expensive and challenging to execute, resulting in a lack of spatially diverse measurements. A second ("bulk") technique involves the observation of horizontal windspeed, temperature and moisture at a given altitude over an extended time period in order to estimate the surface <span class="hlt">fluxes</span>. Small Unmanned Aircraft Systems (sUAS) represent a unique platform from which to derive these <span class="hlt">fluxes</span>. These sUAS can be small ( 1 m), lightweight ( 700 g), low cost ( $2000) and relatively easy to deploy to remote locations and over inhomogeneous surfaces. We will give an overview of the ability of sUAS to provide measurements necessary for estimating surface turbulent <span class="hlt">fluxes</span>. This discussion is based on flights in the vicinity of the 1000 ft. Boulder Atmospheric Observatory (BAO) tower, and over the US Department of Energy facility at Oliktok Point, Alaska. We will present initial comparisons</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.B21E..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.B21E..06W"><span>Spatial and Temporal Patterns in the Carbon Isotopic Signal of Leaf Wax Aerosols in Continental <span class="hlt">Air</span> <span class="hlt">Masses</span>: Linkages with Ecosystem Discrimination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, J.; Conte, M. H.</p> <p>2006-12-01</p> <p>Temporal and spatial variations in the concentration and isotopic composition of atmospheric carbon dioxide can be used to estimate the relative magnitudes of the terrestrial and oceanic carbon sinks. An important model parameter is the terrestrial photosynthetic carbon isotopic fractionation of CO2 (Δ), yet estimating Δ over the large spatial scales required by models remains problematic. Epiculticular leaf waxes appear to closely reflect the plant's carbon isotopic discrimination; therefore, the ablated wax aerosols present in well-mixed continental <span class="hlt">air</span> <span class="hlt">masses</span> may be used as a proxy to estimate the magnitude of Δ integrated over large (subcontinental) spatial scales. Over the last several years, we have been conducting time-series studies of wax aerosol molecular and isotopic composition at strategically located sites (Maine, northern Alaska, Florida, Bermuda, Barbados) which receive continental <span class="hlt">air</span> <span class="hlt">masses</span> passing over major terrestrial biomes (northern temperate/ecotonal boreal forests, tundra, southern US pine/hardwood forests, North American and north African). In this presentation, we describe and contrast patterns of wax aerosol-derived estimates of Δ at these sites. In North American <span class="hlt">air</span> <span class="hlt">masses</span>, estimates of Δ range from 14.5-20.5 using the concentration-weighted average δ13C of wax n-acids and from 13.5-19.5 for the wax n-alcohols. Seasonal trends observed in the Florida (southern US) and Bermuda samples (mixed North American <span class="hlt">air</span> <span class="hlt">masses</span>) indicate maximum discrimination in early spring and minimum discrimination during the summer dry season. In northern US and high latitude <span class="hlt">air</span> <span class="hlt">masses</span>, seasonal trends are less pronounced but in general temporally offset with highest discrimination occurring during late summer. At Barbados, which is dominated by north African <span class="hlt">air</span> <span class="hlt">masses</span> passing over regions largely comprised of arid C4 grasslands, estimated Δ for the wax n-acids is significantly lower (14.0-15.5 per mil), consistent with a higher predominance of C4</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCHyd.198...11P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCHyd.198...11P"><span>Chemical structure influence on NAPL mixture nonideality evolution, rate-limited dissolution, and contaminant <span class="hlt">mass</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Padgett, Mark C.; Tick, Geoffrey R.; Carroll, Kenneth C.; Burke, William R.</p> <p>2017-03-01</p> <p>The influence of chemical structure on NAPL mixture nonideality evolution, rate-limited dissolution, and contaminant <span class="hlt">mass</span> <span class="hlt">flux</span> was examined. The variability of measured and UNIFAC modeled NAPL activity coefficients as a function of mole fraction was compared for two NAPL mixtures containing structurally-different contaminants of concern including toluene (TOL) or trichloroethene (TCE) within a hexadecane (HEXDEC) matrix. The results showed that dissolution from the NAPL mixtures transitioned from ideality for mole fractions > 0.05 to nonideality as mole fractions decreased. In particular, the TCE generally exhibited more ideal dissolution behavior except at lower mole fractions, and may indicate greater structural/polarity similarity between the two compounds. Raoult's Law and UNIFAC generally under-predicted the batch experiment results for TOL:HEXDEC mixtures especially for mole fractions ≤ 0.05. The dissolution rate coefficients were similar for both TOL and TCE over all mole fractions tested. <span class="hlt">Mass</span> <span class="hlt">flux</span> reduction (MFR) analysis showed that more efficient removal behavior occurred for TOL and TCE with larger mole fractions compared to the lower initial mole fraction mixtures (i.e. < 0.2). However, compared to TOL, TCE generally exhibited more efficient removal behavior over all mole fractions tested and may have been the result of structural and molecular property differences between the compounds. Activity coefficient variability as a function of mole fraction was quantified through regression analysis and incorporated into dissolution modeling analyses for the dynamic flushing experiments. TOL elution concentrations were modeled (predicted) reasonable well using ideal and equilibrium assumptions, but the TCE elution concentrations could not be predicted using the ideal model. Rather, the dissolution modeling demonstrated that TCE elution was better described by the nonideal model whereby NAPL-phase activity coefficient varied as a function of COC mole</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B53I..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B53I..06S"><span>Forest canopy temperatures: dynamics, controls, and relationships with ecosystem <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Still, C. J.; Griffith, D.; Kim, Y.; Law, B. E.; Hanson, C. V.; Kwon, H.; Schulze, M.; Detto, M.; Pau, S.</p> <p>2017-12-01</p> <p>Temperature strongly affects enzymatic reactions, ecosystem biogeochemistry, and species distributions. Although most focus is on <span class="hlt">air</span> temperature, the radiative or skin temperature of plants is more relevant. Canopy skin temperature dynamics reflect biophysical, physiological, and anatomical characteristics and interactions with the environment, and can be used to examine forest responses to stresses like droughts and heat waves. Thermal infrared (TIR) imaging allows for extensive temporal and spatial sampling of canopy temperatures, particularly compared to spot measurements using thermocouples. We present results of TIR imaging of forest canopies at eddy covariance <span class="hlt">flux</span> tower sites in the US Pacific Northwest and in Panama. These forests range from an old-growth temperate rainforest to a second growth semi-arid pine forest to a semi-deciduous tropical forest. Canopy temperature regimes at these sites are highly variable. Canopy temperatures at all forest sites displayed frequent departures from <span class="hlt">air</span> temperature, particularly during clear sky conditions, with elevated canopy temperatures during the day and depressed canopy temperatures at night compared to <span class="hlt">air</span> temperature. Comparison of canopy temperatures to <span class="hlt">fluxes</span> of carbon dioxide, water vapor, and energy reveals stronger relationships than those found with <span class="hlt">air</span> temperature. Daytime growing season net ecosystem exchange at the pine forest site is better explained by canopy temperature (r2 = 0.61) than <span class="hlt">air</span> temperature (r2 = 0.52). At the semi-deciduous tropical forest, canopy photosynthesis is highly correlated with canopy temperature (r2 = 0.51), with a distinct optimum temperature for photosynthesis ( 31 °C) that agrees with leaf-level measurements. During the peak of one heat wave at an old-growth temperate rainforest, hourly averaged <span class="hlt">air</span> temperature exceeded 35 °C, 10 °C above average. Peak hourly canopy temperature approached 40 °C, and leaf-to-<span class="hlt">air</span> vapor pressure deficit exceeded 6 kPa. These extreme</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53K..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53K..05K"><span>Properties and <span class="hlt">Fluxes</span> of Primary Marine Aerosol Generated Via Detrainment of Turbulence-Modulated Bubble Plumes from Fresh North Atlantic Seawater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keene, W. C.; Long, M. S.; Duplessis, P.; Kieber, D. J.; Maben, J. R.; Frossard, A. A.; Kinsey, J. D.; Beaupre, S. R.; Lu, X.; Chang, R.; Zhu, Y.; Bisgrove, J.</p> <p>2017-12-01</p> <p>During a September-October 2016 cruise of the R/V Endeavor in the western North Atlantic Ocean, primary marine aerosol (PMA) was produced in a high capacity generator during day and night via detrainment of bubbles from biologically productive and oligotrophic seawater. The turbulent mixing of clean <span class="hlt">air</span> and seawater in a Venturi nozzle produced bubble plumes with tunable size distributions. Physicochemical characteristics of size-resolved PMA and seawater were measured. PMA number production efficiencies per unit <span class="hlt">air</span> detrained (PEnum) increased with increasing detainment rate. For given conditions, PEnum values summed over size distributions were roughly ten times greater than those for frits whereas normalized size distributions were similar. Results show that bubble size distributions significantly modulated number production <span class="hlt">fluxes</span> but not relative shapes of corresponding size distributions. In contrast, <span class="hlt">mass</span> production efficiencies (PEmass) decreased with increasing <span class="hlt">air</span> detrainment and were similar to those for frits, consistent with the hypothesis that bubble rafts on the seawater surface modulate emissions of larger jet droplets that dominate PMA <span class="hlt">mass</span> production. Production efficiencies of organic matter were about three times greater than those for frits whereas organic enrichment factors integrated over size distributions were similar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26741542','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26741542"><span>Ceramic membrane defouling (cleaning) by <span class="hlt">air</span> Nano Bubbles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghadimkhani, Aliasghar; Zhang, Wen; Marhaba, Taha</p> <p>2016-03-01</p> <p>Ceramic membranes are among the most promising technologies for membrane applications, owing to their excellent resistance to mechanical, chemical, and thermal stresses. However, membrane fouling is still an issue that hampers the applications at large scales. <span class="hlt">Air</span> Nano Bubbles (NBs), due to high <span class="hlt">mass</span> transfer efficiency, could potentially prevent fouling of ceramic membrane filtration processes. In this study, bench and pilot scale ceramic membrane filtration was performed with <span class="hlt">air</span> NBs to resist fouling. To simulate fouling, humic acid, as an organic foulant, was applied to the membrane flat sheet surface. Complete membrane clogging was achieved in less than 6 h. Membrane defouling (cleaning) was performed by directly feeding of <span class="hlt">air</span> NBs to the membrane cells. The surface of the ceramic membrane was superbly cleaned by <span class="hlt">air</span> NBs, as revealed by atomic force microscope (AFM) images before and after the treatment. The permeate <span class="hlt">flux</span> recovered to its initial level (e.g., 26.7 × 10(-9) m(3)/m(2)/s at applied pressure of 275.8 kPa), which indicated that NBs successfully unclogged the pores of the membrane. The integrated ceramic membrane and <span class="hlt">air</span> NBs system holds potential as an innovative sustainable technology. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.5566F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.5566F"><span>Effects of sea-ice and biogeochemical processes and storms on under-ice water fCO2 during the winter-spring transition in the high Arctic Ocean: Implications for sea-<span class="hlt">air</span> CO2 <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fransson, Agneta; Chierici, Melissa; Skjelvan, Ingunn; Olsen, Are; Assmy, Philipp; Peterson, Algot K.; Spreen, Gunnar; Ward, Brian</p> <p>2017-07-01</p> <p>We performed measurements of carbon dioxide fugacity (fCO2) in the surface water under Arctic sea ice from January to June 2015 during the Norwegian young sea ICE (N-ICE2015) expedition. Over this period, the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first winter-time under-ice water fCO2 observations in this region. The observed under-ice fCO2 ranged between 315 µatm in winter and 153 µatm in spring, hence was undersaturated relative to the atmospheric fCO2. Although the sea ice partly prevented direct CO2 exchange between ocean and atmosphere, frequently occurring leads and breakup of the ice sheet promoted sea-<span class="hlt">air</span> CO2 <span class="hlt">fluxes</span>. The CO2 sink varied between 0.3 and 86 mmol C m-2 d-1, depending strongly on the open-water fractions (OW) and storm events. The maximum sea-<span class="hlt">air</span> CO2 <span class="hlt">fluxes</span> occurred during storm events in February and June. In winter, the main drivers of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In June, in addition to these processes, primary production and sea-<span class="hlt">air</span> CO2 <span class="hlt">fluxes</span> were important. The cumulative loss due to CaCO3 dissolution of 0.7 mol C m-2 in the upper 10 m played a major role in sustaining the undersaturation of fCO2 during the entire study. The relative effects of the total fCO2 change due to CaCO3 dissolution was 38%, primary production 26%, vertical mixing 16%, sea-<span class="hlt">air</span> CO2 <span class="hlt">fluxes</span> 16%, and temperature and salinity insignificant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS33A1443Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS33A1443Y"><span>Diagnosing CO2 <span class="hlt">fluxes</span> and seasonality in the Arabian Sea as an Ocean-Dominated Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, W.; Dai, M.</p> <p>2017-12-01</p> <p>The Arabian Sea is a large marginal sea of the Indian Ocean characterized by highly predictable annual circulation cycle driven by Asian monsoon. The Arabian Sea is generally sources to atmospheric CO2. In this study, we applied the physical-biogeochemical coupled approach previously adopted for diagnosis of CO2 <span class="hlt">fluxes</span> in Ocean-dominated margin (OceMar) to assesses the CO2 <span class="hlt">fluxes</span> and their seasonality in Arabian Sea using data collected during five US JGOFS Arabian Sea Process Study cruises (ttn-043, ttn-045, ttn-049, ttn-053, ttn-054) conducted from September 1994 to December 1995. The pCO2 estimated during the 5 cruises was 396±5μatm, 359±7 μatm, 373±7 μatm, 379±9 μatm and 387±12 μatm, respectively, which agreed well with the pCO2 observed during the cruises of 389±8 μatm, 361±6 μatm, 366±6 μatm, 371±8 μatm and 367±11 μatm from underway measurements. This strongly suggests that our semi-analytical diagnostic approach in the OceMar framework can evaluate the pCO2 in Arabian Sea. Our coupled diagnostic approach assumes that water <span class="hlt">mass</span> mixing, biological response and <span class="hlt">air</span>-sea exchange under steady state over a similar time scale. This assumption should be justified at the region with intensified upwelling where decoupling between upwelling and biological response may occur, where only water <span class="hlt">mass</span> mixing and <span class="hlt">air</span>-sea CO2 exchange should be accounted for. This presentation will also examine the seasonality of the CO2 dynamics and its controls.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1245979','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1245979"><span>Eddy Correlation <span class="hlt">Flux</span> Measurement System Handbook</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cook, D. R.</p> <p>2016-01-01</p> <p>The eddy correlation (ECOR) <span class="hlt">flux</span> measurement system provides in situ, half-hour measurements of the surface turbulent <span class="hlt">fluxes</span> of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The <span class="hlt">fluxes</span> are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the <span class="hlt">air</span> temperature, the water vapor density, and the CO2 concentration. The instruments used are: • a fast-response, three-dimensional (3D) wind sensor (sonic anemometer) to obtain the orthogonal wind componentsmore » and the speed of sound (SOS) (used to derive the <span class="hlt">air</span> temperature) • an open-path infrared gas analyzer (IRGA) to obtain the water vapor density and the CO2 concentration, and • an open-path infrared gas analyzer (IRGA) to obtain methane density and methane <span class="hlt">flux</span> at one SGP EF and at the NSA CF. The ECOR systems are deployed at the locations where other methods for surface <span class="hlt">flux</span> measurements (e.g., energy balance Bowen ratio [EBBR] systems) are difficult to employ, primarily at the north edge of a field of crops. A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system in SGP, NSA, Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat <span class="hlt">fluxes</span> with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes. The SEBS at one SGP and one NSA site also support upwelling and downwelling PAR measurements to qualify those two locations as Ameriflux sites.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140005396','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140005396"><span>Surface Ocean pCO2 Seasonality and Sea-<span class="hlt">Air</span> CO2 <span class="hlt">Flux</span> Estimates for the North American East Coast</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Signorini, Sergio; Mannino, Antonio; Najjar, Raymond G., Jr.; Friedrichs, Marjorie A. M.; Cai, Wei-Jun; Salisbury, Joe; Wang, Zhaohui Aleck; Thomas, Helmuth; Shadwick, Elizabeth</p> <p>2013-01-01</p> <p>Underway and in situ observations of surface ocean pCO2, combined with satellite data, were used to develop pCO2 regional algorithms to analyze the seasonal and interannual variability of surface ocean pCO2 and sea-<span class="hlt">air</span> CO2 <span class="hlt">flux</span> for five physically and biologically distinct regions of the eastern North American continental shelf: the South Atlantic Bight (SAB), the Mid-Atlantic Bight (MAB), the Gulf of Maine (GoM), Nantucket Shoals and Georges Bank (NS+GB), and the Scotian Shelf (SS). Temperature and dissolved inorganic carbon variability are the most influential factors driving the seasonality of pCO2. Estimates of the sea-<span class="hlt">air</span> CO2 <span class="hlt">flux</span> were derived from the available pCO2 data, as well as from the pCO2 reconstructed by the algorithm. Two different gas exchange parameterizations were used. The SS, GB+NS, MAB, and SAB regions are net sinks of atmospheric CO2 while the GoM is a weak source. The estimates vary depending on the use of surface ocean pCO2 from the data or algorithm, as well as with the use of the two different gas exchange parameterizations. Most of the regional estimates are in general agreement with previous studies when the range of uncertainty and interannual variability are taken into account. According to the algorithm, the average annual uptake of atmospheric CO2 by eastern North American continental shelf waters is found to be between 3.4 and 5.4 Tg C/yr (areal average of 0.7 to 1.0 mol CO2 /sq m/yr) over the period 2003-2010.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.B13F0715B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.B13F0715B"><span>Evaluation of DeNitrification DeComposition Model to Estimate Ammonia <span class="hlt">Fluxes</span> from Chemical Fertilizer Application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balasubramanian, S.; Nelson, A. J.; Koloutsou-Vakakis, S.; Lin, J.; Myles, L.; Rood, M. J.</p> <p>2016-12-01</p> <p>Biogeochemical models such as DeNitrification DeComposition (DNDC) are used to model greenhouse and other trace gas <span class="hlt">fluxes</span> (e.g., ammonia (NH3)) from agricultural ecosystems. NH3 is of interest to <span class="hlt">air</span> quality because it is a precursor to ambient particulate matter. NH3 <span class="hlt">fluxes</span> from chemical fertilizer application are uncertain due to dependence on local weather and soil properties, and farm nitrogen management practices. DNDC can be advantageously implemented to model the underlying spatial and temporal trends to support <span class="hlt">air</span> quality modeling. However, such implementation, requires a detailed evaluation of model predictions, and model behavior. This is the first study to assess DNDC predictions of NH3 <span class="hlt">fluxes</span> to/from the atmosphere, from chemical fertilizer application, during an entire crop growing season, in the United States. Relaxed eddy accumulation (REA) measurements over corn in Central Illinois, in year 2014, were used to evaluate magnitude and trends in modeled NH3 <span class="hlt">fluxes</span>. DNDC was able to replicate both magnitude and trends in measured NH3 <span class="hlt">fluxes</span>, with greater accuracy during the initial 33 days after application, when NH3 was mostly emitted to the atmosphere. However, poorer performance was observed when depositional <span class="hlt">fluxes</span> were measured. Sensitivity analysis using Monte Carlo simulations indicated that modeled NH3 <span class="hlt">fluxes</span> were most sensitive to input <span class="hlt">air</span> temperature and precipitation, soil organic carbon, field capacity and pH and fertilizer loading rate, timing, and application depth and tilling date. By constraining these inputs for conditions in Central Illinois, uncertainty in annual NH3 <span class="hlt">fluxes</span> was estimated to vary from -87% to 61%. Results from this study provides insight to further improve DNDC predictions and inform efforts for upscaling site predictions to regional scale for the development of emission inventories for <span class="hlt">air</span> quality modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS33A1438C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS33A1438C"><span>Seasonal and spatial variations in surface pCO2 and <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> in the Chesapeake Bay</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, W. J.; Chen, B.</p> <p>2017-12-01</p> <p>Bay-wide observations of surface water partial pressure of carbon dioxide (pCO2) were conducted in May, June, August, and October 2016 to study the spatial and seasonal variations in surface pCO2 and to estimate <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span> in the Chesapeake Bay. Overall, high surface pCO2 in the upper-bay decreased downstream rapidly below the atmospheric value near the bay bridge in the mid-bay and then increased slightly to the lower-bay where pCO2 approached the atmospheric level. Over the course of a year, pCO2 was higher than 1000 µatm in the upper bay and the highest pCO2 (2500 µatm) was observed in August. Significant biologically-induced pCO2 undersaturation was observed at the upper part of the mid-bay in August with pCO2 as low as 50 µatm and oversaturated DO% of 200%. In addition to biological control, vertical mixing and upwelling controlled by wind direction and tidal stage played an important role in controlling surface pCO2 in the mid-bay as is evidenced by co-occurrence of high pCO2 with low temperature and low oxygen or high salinity from the subsurface. These physical processes occurred regularly and in short time scale of hours, suggesting they must be considered in the assessment of annual <span class="hlt">air</span>-sea CO2 <span class="hlt">flux</span>. Seasonally, the upper-bay acted as a source for atmospheric CO2 over the course of a year. The boundary of upper and mid bay transited from a CO2 source to a sink from May to August and was a source again in October due to strong biological production in summer. In contrast, the mid-bay represented as a CO2 source with large temporal variation due to dynamic hydrographic settings. The lower-bay transited from a weak sink in May to equilibrated with the atmosphere from June to August, while became a source again in October. Moreover, the CO2 <span class="hlt">flux</span> could be reversed very quickly under episodic severe weather events. Thus further research, including the influence of severe weather and subsequent bloom, is needed to get better understanding of the carbon</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2080D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2080D"><span>Wind stress and heat <span class="hlt">fluxes</span> over a Brazilian Coastal Upwelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dourado, Marcelo; Candella, Rogério</p> <p>2017-04-01</p> <p>Coastal upwelling zones have been intensively studied in the last decades especially due to their importance to the biological cycle. The coastal upwelling system of the Cabo Frio region (east coast of the Rio de Janeiro state, Brazil) keeps the surface water cold during most part of the year, what induces a stable atmospheric boundary layer associated to northeast winds. The main goal of this study is to investigate the wind stress and heat <span class="hlt">fluxes</span> exchanges between the ocean and the atmosphere in that area. For this purpose, a set of hourly data meteorological and oceanographic data collected by a Wavescan metocean buoy anchored at 23o59S; 42oW, were used, as well as solar radiation and relative humidity from a terrestrial meteorological station from the Instituto Nacional de Meteorologia (InMet). COARE 3.0 algorithm was used to calculate the latent and sensible heat <span class="hlt">fluxes</span>. In this discussion, positive values represent <span class="hlt">fluxes</span> towards the ocean. The average net heat <span class="hlt">flux</span> over our study period is 88 W m-2. The reduction of the net heat <span class="hlt">flux</span> is due to the increase of the ocean latent heat loss, although a reduction in incoming shortwave radiation and an increase in ocean long wave cooling also contributes. The latent heat is 20 times larger than the sensible heat <span class="hlt">flux</span>, but the mean value of the latent heat <span class="hlt">flux</span>, 62 W m-2, is half the typical value found in open ocean. The temporal variability of both sensible and latent heat <span class="hlt">fluxes</span> reflects their dependence on wind speed and <span class="hlt">air</span>-sea temperature differences. When upwelling events, here periods when diurnal SST is lower than 18oC, are compared with undisturbed (without upwelling) events, it can be noted the sensible heat <span class="hlt">fluxes</span> are positives and 10 times greater in magnitude. This is related to an increment, during these upwelling events, of the <span class="hlt">air</span>-sea temperature difference and an increasing of the wind speed. The cold waters of the upwelling increase the <span class="hlt">air</span>-sea temperature gradient and, also, the horizontal land</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160011064','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160011064"><span>Optical Meteor <span class="hlt">Fluxes</span> and Application to the 2015 Perseids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blaauw, R. C.; Campbell-Brown, M.; Kingery, A.</p> <p>2016-01-01</p> <p>This paper outlines new methods to measure optical meteor <span class="hlt">fluxes</span> for showers and sporadic sources. Many past approaches have found the collecting area of a detector at a fixed 100 km altitude, but this approach considers the full volume, finding the area in two km height intervals based on the position of the shower or sporadic source radiant and the population's velocity. Here, the stellar limiting magnitude is found every 10 minutes during clear periods and converted to a limiting meteor magnitude for the shower or sporadic source having <span class="hlt">fluxes</span> measured, which is then converted to a limiting <span class="hlt">mass</span>. The final output is a <span class="hlt">mass</span> limited <span class="hlt">flux</span> for meteor showers or sporadic sources. Presented are the results of these <span class="hlt">flux</span> methods as applied to the 2015 Perseid meteor shower as seen by the Meteoroid Environment Office's eight wide-field cameras. The peak Perseid <span class="hlt">flux</span> on the night of August 13, 2015, was measured to be 0.002989 meteoroids/km2/hr down to 0.00051 grams, corresponding to a ZHR of 100.7.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28178609','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28178609"><span>Toward a better understanding of the impact of <span class="hlt">mass</span> transit <span class="hlt">air</span> pollutants on human health.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Ki-Hyun; Kumar, Pawan; Szulejko, Jan E; Adelodun, Adedeji A; Junaid, Muhammad Faisal; Uchimiya, Minori; Chambers, Scott</p> <p>2017-05-01</p> <p>Globally, modern <span class="hlt">mass</span> transport systems whether by road, rail, water, or <span class="hlt">air</span> generate airborne pollutants in both developing and developed nations. <span class="hlt">Air</span> pollution is the primary human health concern originating from modern transportation, particularly in densely-populated urban areas. This review will specifically focus on the origin and the health impacts of carbonaceous traffic-related <span class="hlt">air</span> pollutants (TRAP), including particulate matter (PM), volatile organic compounds (VOCs), and elemental carbon (EC). We conclude that the greatest current challenge regarding urban TRAP is understanding and evaluating the human health impacts well enough to set appropriate pollution control measures. Furthermore, we provide a detailed discussion regarding the effects of TRAP on local environments and pedestrian health in low and high traffic-density environments. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040034110','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040034110"><span>A Comparison of Latent Heat <span class="hlt">Fluxes</span> over Global Oceans for Four <span class="hlt">Flux</span> Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Nelkin, Eric; Ardizzone, Joe; Atlas, Robert M.</p> <p>2003-01-01</p> <p>To improve our understanding of global energy and water cycle variability, and to improve model simulations of climate variations, it is vital to have accurate latent heat <span class="hlt">fluxes</span> (LHF) over global oceans. Monthly LHF, 10-m wind speed (U10m), 10-m specific humidity (Q10h), and sea-<span class="hlt">air</span> humidity difference (Qs-Q10m) of GSSTF2 (version 2 Goddard Satellite-based Surface Turbulent <span class="hlt">Fluxes</span>) over global Oceans during 1992-93 are compared with those of HOAPS (Hamburg Ocean Atmosphere Parameters and <span class="hlt">Fluxes</span> from Satellite Data), NCEP (NCEP/NCAR reanalysis). The mean differences, standard deviations of differences, and temporal correlation of these monthly variables over global Oceans during 1992-93 between GSSTF2 and each of the three datasets are analyzed. The large-scale patterns of the 2yr-mean fields for these variables are similar among these four datasets, but significant quantitative differences are found. The temporal correlation is higher in the northern extratropics than in the south for all variables, with the contrast being especially large for da Silva as a result of more missing ship data in the south. The da Silva has extremely low temporal correlation and large differences with GSSTF2 for all variables in the southern extratropics, indicating that da Silva hardly produces a realistic variability in these variables. The NCEP has extremely low temporal correlation (0.27) and large spatial variations of differences with GSSTF2 for Qs-Q10m in the tropics, which causes the low correlation for LHF. Over the tropics, the HOAPS LHF is significantly smaller than GSSTF2 by approx. 31% (37 W/sq m), whereas the other two datasets are comparable to GSSTF2. This is because the HOAPS has systematically smaller LHF than GSSTF2 in space, while the other two datasets have very large spatial variations of large positive and negative LHF differences with GSSTF2 to cancel and to produce smaller regional-mean differences. Our analyses suggest that the GSSTF2 latent heat <span class="hlt">flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008DSRI...55..661S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008DSRI...55..661S"><span>Aragonite pteropod <span class="hlt">flux</span> to the Somali Basin, NW Arabian Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, A. D.; Conan, S. M.-H.</p> <p>2008-05-01</p> <p>Aragonite export <span class="hlt">fluxes</span> of pteropods (>250, 150-250 and 125-150 μm) in the Somali Basin were estimated using a 9-month time-series sediment trap (MST9-E) from June 1992 to February 1993. The trap with 23 time-series sediment collectors placed at 1032 m water depth collected settling particles over a total of 249 days. Pteropods showed large seasonal variations in both the numerical and <span class="hlt">mass</span> <span class="hlt">fluxes</span> (>125 μm) with their maxima at the end of the SW Monsoon during September and early October. It was also observed that records of pteropod <span class="hlt">fluxes</span> varied in different size fractions. The average numerical <span class="hlt">flux</span> and <span class="hlt">mass</span> <span class="hlt">flux</span> of pteropods (>125 μm) from the 9-month record of the sediment trap was estimated to be about 1830 shells m -2 d -1 and 18 mg m -2 d -1, respectively. We estimate that about 22.5% of the total CaCO 3 in the Somali Basin was contributed by aragonitic pteropods (>125 μm).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25837315','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25837315"><span>Development of a particle-trap preconcentration-soft ionization <span class="hlt">mass</span> spectrometric technique for the quantification of mercury halides in <span class="hlt">air</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deeds, Daniel A; Ghoshdastidar, Avik; Raofie, Farhad; Guérette, Élise-Andrée; Tessier, Alain; Ariya, Parisa A</p> <p>2015-01-01</p> <p>Measurement of oxidized mercury, Hg(II), in the atmosphere poses a significant analytical challenge as Hg(II) is present at ultra-trace concentrations (picograms per cubic meter <span class="hlt">air</span>). Current technologies are sufficiently sensitive to measure the total Hg present as Hg(II) but cannot determine the chemical speciation of Hg(II). We detail here the development of a soft ionization <span class="hlt">mass</span> spectrometric technique coupled with preconcentration onto nano- or microparticle-based traps prior to analysis for the measurement of mercury halides in <span class="hlt">air</span>. The current methodology has comparable detection limits (4-11 pg m(-3)) to previously developed techniques for the measurement of total inorganic mercury in <span class="hlt">air</span> while allowing for the identification of HgX2 in collected samples. Both mercury chloride and mercury bromide have been sporadically detected in Montreal urban and indoor <span class="hlt">air</span> using atmospheric pressure chemical ionization-<span class="hlt">mass</span> spectrometry (APCI-MS). We discuss limitations and advantages of the current technique and discuss potential avenues for future research including quantitative trace measurements of a larger range of mercury compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23668111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23668111"><span>[Characteristics of mercury exchange <span class="hlt">flux</span> between soil and atmosphere under the snow retention and snow melting control].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Gang; Wang, Ning; Ai, Jian-Chao; Zhang, Lei; Yang, Jing; Liu, Zi-Qi</p> <p>2013-02-01</p> <p>Jiapigou gold mine, located in the upper Songhua River, was once the largest mine in China due to gold output, where gold extraction with algamation was widely applied to extract gold resulting in severe mercury pollution to ambient environmental medium. In order to study the characteristics of mercury exchange <span class="hlt">flux</span> between soil (snow) and atmosphere under the snow retention and snow melting control, sampling sites were selected in equal distances along the slope which is situated in the typical hill-valley terrain unit. Mercury exchange <span class="hlt">flux</span> between soil (snow) and atmosphere was determined with the method of dynamic <span class="hlt">flux</span> chamber and in all sampling sites the atmosphere concentration from 0 to 150 cm near to the earth in the vertical direction was measured. Furthermore, the impact factors including synchronous meteorology, the surface characteristics under the snow retention and snow melting control and the mercury concentration in vertical direction were also investigated. The results are as follows: During the period of snow retention and melting the <span class="hlt">air</span> mercury tends to gather towards valley bottom along the slope and an obvious deposit tendency process was found from <span class="hlt">air</span> to the earth's surface under the control of thermal inversion due to the underlying surface of cold source (snow surface). However, during the period of snow melting, mercury exchange <span class="hlt">flux</span> between the soil and atmosphere on the surface of the earth with the snow being melted demonstrates alternative deposit and release processes. As for the earth with snow covered, the deposit level of mercury exchange <span class="hlt">flux</span> between soil and atmosphere is lower than that during the period of snow retention. The relationship between mercury exchange <span class="hlt">flux</span> and impact factors shows that in snow retention there is a remarkable negative linear correlation between mercury exchange <span class="hlt">flux</span> and <span class="hlt">air</span> mercury concentration as well as between the former and the <span class="hlt">air</span> temperature. In addition, in snow melting mercury exchange</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032849','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032849"><span>Geochemical investigation of weathering processes in a forested headwater catchment: <span class="hlt">Mass</span>-balance weathering <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jones, B.F.; Herman, J.S.</p> <p>2008-01-01</p> <p>Geochemical research on natural weathering has often been directed towards explanations of the chemical composition of surface water and ground water resulting from subsurface water-rock interactions. These interactions are often defined as the incongruent dissolution of primary silicates, such as feldspar, producing secondary weathering products, such as clay minerals and oxyhydroxides, and solute <span class="hlt">fluxes</span> (Meunier and Velde, 1979). The chemical composition of the clay-mineral product is often ignored. However, in earlier investigations, the saprolitic weathering profile at the South Fork Brokenback Run (SFBR) watershed, Shenandoah National Park, Virginia, was characterized extensively in terms of its mineralogical and chemical composition (Piccoli, 1987; Pochatila et al., 2006; Jones et al., 2007) and its basic hydrology. O'Brien et al. (1997) attempted to determine the contribution of primary mineral weathering to observed stream chemistry at SFBR. <span class="hlt">Mass</span>-balance model results, however, could provide only a rough estimate of the weathering reactions because idealized mineral compositions were utilized in the calculations. Making use of detailed information on the mineral occurrence in the regolith, the objective of the present study was to evaluate the effects of compositional variation on mineral-solute <span class="hlt">mass</span>-balance modelling and to generate plausible quantitative weathering reactions that support both the chemical evolution of the surface water and ground water in the catchment, as well as the mineralogical evolution of the weathering profile. ?? 2008 The Mineralogical Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.7294V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.7294V"><span>Volatile organic compound <span class="hlt">fluxes</span> and concentrations in London (ClearfLo)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valach, Amy; Langford, Ben; Nemitz, Eiko; MacKenzie, Rob; Hewitt, Nick</p> <p>2014-05-01</p> <p>Volatile organic compounds (VOCs) from anthropogenic sources such as fuel combustion or evaporative emissions can directly and indirectly affect human health. Some VOCs, such as benzene and 1,3- butadiene are carcinogens. These and other VOCs contribute to the formation of ozone (O3) and aerosol particles, which have effects on human health and the radiative balance of the atmosphere. Although in the UK VOC emissions are subject to control under European Commission Directive 2008/50/EC and emission reducing technologies have been implemented, urban <span class="hlt">air</span> pollution remains a concern. Urban <span class="hlt">air</span> quality is likely to remain a priority since currently >50% of the global population live in urban areas with trends in urbanization and population migration predicted to increase. The ClearfLo project is a large multi-institutional consortium funded by the UK Natural Environment Research Council (NERC) and provides integrated measurements of meteorology, gas phase and particulate composition of the atmosphere over London. Both long term and IOP measurements were made at street and elevated locations at a range of sites across London and its surroundings during 2011 and 2012. Mixing ratios of a selection of nine VOCs were measured using a high sensitivity proton transfer reaction-<span class="hlt">mass</span> spectrometer (PTR-MS) at a ground level urban background (North Kensington) and kerbside (Marylebone Road) site during the winter IOP. VOC <span class="hlt">fluxes</span> were measured by virtually disjunct eddy covariance (vDEC) at an elevated urban site (King's College Strand) in Aug-Dec 2012. Our results for the first IOP showed that most of the selected compound concentrations depended on traffic emissions, although there was a marked difference between the urban background and kerbside sites. We identified some temperature effects on VOC concentrations. We also present the first analyses of VOC <span class="hlt">flux</span> measurements over London. Preliminary analyses indicate most compounds associated with vehicle emissions closely</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS31A1368B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS31A1368B"><span><span class="hlt">Mass</span> <span class="hlt">fluxes</span> in the Canary Basin (eastern boundary of the North Atlantic subtropical gyre)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burgoa, N.; Machin, F.; Marrero-Díaz, Á.; Rodríguez-Santana, Á.; Martínez-Marrero, A.</p> <p>2017-12-01</p> <p>The circulation patterns in the Canary Basin are examined with hydrographic data from two cruises carried out in 2002 and 2003 in the eastern boundary of the North Atlantic subtropical gyre (21-27.5ºN, 17.5-26ºW). These cruises were part of the COCA Project (Coastal-Ocean Carbon Exchange in the Canary Region). First we estimate the geostrophic flow within a closed box divided into 12 layers of neutral density surfaces using the thermal wind equation. The geostrophic velocities are initially referenced to a selected neutral surface previously analyzed in deep. Then, the divergence and the convergence of the flow are analyzed in the closed water volume considering the Ekman transport in the surface of this whole region. The accumulated <span class="hlt">mass</span> transport along the perimeter of the box is estimated with the aim to study transport imbalances in the different water <span class="hlt">masses</span>. In addition, variables like the anomalies in the transport of the salt and heat are also considered. In general, <span class="hlt">mass</span> transport results show that more than 50% of this transport takes place in central waters and around 25% in intermediate waters. In the first cruise carried out in late summer, the circulation of the shallowest layers goes into the box along the north and south transects with values which can arrive to 2 Sv and 1 Sv respectively and it flows westward with a maximum value of 2 Sv. At intermediate levels the <span class="hlt">mass</span> transport changes its direction going out to the north with 0.5 Sv. On the other hand, in the second cruise carried out in late spring, the transport in the shallowest layers also gets in the box through the north transect, but it goes out along the west and south transects with values which can arrive to 1 Sv and 2 Sv, respectively. At intermediate levels the transports are similar to those already described for the summer cruise. Finally, an inverse box model is applied to both datasets to obtain a solution consistent with both the thermal wind equation and with the <span class="hlt">mass</span> and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.A62A0125A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.A62A0125A"><span>The Advective <span class="hlt">Flux</span> and Temporal Evolution of Aerosols from the Western Pacific Rim as Observed during TRACE-P</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, B. E.; Jordan, C. E.; Grant, W. B.; Browell, E. V.; Hudgins, C. H.; Winstead, E. L.; Thornhill, K. L.</p> <p>2002-12-01</p> <p>The 2001, NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment was conducted during late winter and early spring, the time of year when eastward transport of dust and pollution from southern and central Asia reaches a maximum. From bases of operation in Hong Kong, Japan, and Hawaii, extensive measurements of trace species concentrations and characteristics were made from aboard a P-3B and DC-8 aircraft as they flew coordinated sampling missions within <span class="hlt">air</span> <span class="hlt">masses</span> at varying distances from the Asian coast and at altitudes ranging from near surface to over 12 km. Data recorded aboard the DC-8 included total condensation nuclei (CN) number densities and fractional volatility; aerosol size distributions, composition and optical properties; and multi-wavelength profiles of polarized, aerosol backscatter. Examining these data in light of simultaneous meteorological and chemical species measurements, we have calculated the advective <span class="hlt">flux</span> and mean values of aerosol <span class="hlt">mass</span> and physical properties at various locations within the Western Pacific Basin. At distances >100 km offshore, we find that the highest <span class="hlt">fluxes</span> of sub-micron particles occurred below 2 km in the region downwind of Shanghai. These <span class="hlt">air</span> <span class="hlt">masses</span> exhibited CN concentrations approaching 50,000 cm-3 and visible scattering coefficients in excess of 200 Mm-1. For near-shore sampling between 26° and 36°N within this height range, these parameters averaged ~8,000 cm-3 and 130 Mm-, respectively, . As a result of dilution, surface deposition, and precipitation scavenging, these values rapidly diminished during eastward transport so that parcels sampled at low altitudes >1500 km from land typically contained ~1000 cm-3 CN and exhibited scattering coefficients <30 Mm-1. Because of the decreased strength of loss processes and greater atmospheric stability, parcels sampled in the 2- to 7-km height range were more apt to maintain their initial aerosol signatures during long-range transport.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22648347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22648347"><span>Seasonal and <span class="hlt">air</span> <span class="hlt">mass</span> trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santos, Patrícia S M; Santos, Eduarda B H; Duarte, Armando C</p> <p>2013-01-01</p> <p>Rainwater contains a complex mixture of organic compounds which may influence climate, terrestrial and maritime ecosystems and thus human health. In this work, the characteristics of DOM of bulk deposition at a coastal town on the southwest of Europe were assessed by UV-visible and three-dimensional excitation-emission matrix fluorescence spectroscopies and by dissolved organic carbon (DOC) content. The seasonal and <span class="hlt">air</span> <span class="hlt">mass</span> trajectory effects on dissolved organic matter (DOM) of bulk deposition were evaluated. The absorbance at 250 nm (UV(250 nm)) and integrated fluorescence showed to be positively correlated with each other, and they were also positively correlated to the DOC in bulk deposition, which suggest that a constant fraction of DOM is likely to fluoresce. There was more chromophoric dissolved organic matter (CDOM) present in summer and autumn seasons than in winter and spring. Bulk deposition associated with terrestrial <span class="hlt">air</span> <span class="hlt">masses</span> contained a higher CDOM content than bulk deposition related to marine <span class="hlt">air</span> <span class="hlt">masses</span>, thus highlighting the contribution of terrestrial/anthropogenic sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2382T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2382T"><span>Impact of <span class="hlt">air</span>-sea drag coefficient for latent heat <span class="hlt">flux</span> on large scale climate in coupled and atmosphere stand-alone simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torres, Olivier; Braconnot, Pascale; Marti, Olivier; Gential, Luc</p> <p>2018-05-01</p> <p>The turbulent <span class="hlt">fluxes</span> across the ocean/atmosphere interface represent one of the principal driving forces of the global atmospheric and oceanic circulation. Despite decades of effort and improvements, representation of these <span class="hlt">fluxes</span> still presents a challenge due to the small-scale acting turbulent processes compared to the resolved scales of the models. Beyond this subgrid parameterization issue, a comprehensive understanding of the impact of <span class="hlt">air</span>-sea interactions on the climate system is still lacking. In this paper we investigates the large-scale impacts of the transfer coefficient used to compute turbulent heat <span class="hlt">fluxes</span> with the IPSL-CM4 climate model in which the surface bulk formula is modified. Analyzing both atmosphere and coupled ocean-atmosphere general circulation model (AGCM, OAGCM) simulations allows us to study the direct effect and the mechanisms of adjustment to this modification. We focus on the representation of latent heat <span class="hlt">flux</span> in the tropics. We show that the heat transfer coefficients are highly similar for a given parameterization between AGCM and OAGCM simulations. Although the same areas are impacted in both kind of simulations, the differences in surface heat <span class="hlt">fluxes</span> are substantial. A regional modification of heat transfer coefficient has more impact than uniform modification in AGCM simulations while in OAGCM simulations, the opposite is observed. By studying the global energetics and the atmospheric circulation response to the modification, we highlight the role of the ocean in dampening a large part of the disturbance. Modification of the heat exchange coefficient modifies the way the coupled system works due to the link between atmospheric circulation and SST, and the different feedbacks between ocean and atmosphere. The adjustment that takes place implies a balance of net incoming solar radiation that is the same in all simulations. As there is no change in model physics other than drag coefficient, we obtain similar latent heat <span class="hlt">flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AtmEn..91..175H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AtmEn..91..175H"><span>New Directions: Questions surrounding suspended particle <span class="hlt">mass</span> used as a surrogate for <span class="hlt">air</span> quality and for regulatory control of ambient urban <span class="hlt">air</span> pollution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoare, John L.</p> <p>2014-07-01</p> <p>The original choice of particulate matter <span class="hlt">mass</span> (PM) as a realistic surrogate for gross <span class="hlt">air</span> pollution has gradually evolved into routine use nowadays of epidemiologically-based estimates of the monetary and other benefits expected from regulating urban <span class="hlt">air</span> quality. Unfortunately, the statistical associations facilitating such calculations usually are based on single indices of <span class="hlt">air</span> pollution whereas the health effects themselves are more broadly based causally. For this and other reasons the economic benefits of control tend to be exaggerated. Primarily because of their assumed inherently inferior respirability, particles ≥10 μm are generally excluded from such considerations. Where the particles themselves are chemically heterogeneous, as in an urban context, this may be inappropriate. Clearly all <span class="hlt">air</span>-borne particles, whether coarse or fine, are susceptible to inhalation. Hence, the possibility exists for any adhering potentially harmful semi-volatile substances to be subsequently de-sorbed in vivo thereby facilitating their transport deeper into the lungs. Consequently, this alone may be a sufficient reason for including rather than rejecting during <span class="hlt">air</span> quality monitoring the relatively coarse 10-100 μm particle fraction, ideally in conjunction with routine estimation of the gaseous co-pollutants thereby facilitating a multi-pollutant approach apropos regulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110013480&hterms=time+series+modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtime%2Bseries%2Bmodeling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110013480&hterms=time+series+modeling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtime%2Bseries%2Bmodeling"><span>Improving Global <span class="hlt">Mass</span> <span class="hlt">Flux</span> Solutions from Gravity Recovery and Climate Experiment (GRACE) Through Forward Modeling and Continuous Time Correlation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sabaka, T. J.; Rowlands, D. D.; Luthcke, S. B.; Boy, J.-P.</p> <p>2010-01-01</p> <p>We describe Earth's <span class="hlt">mass</span> <span class="hlt">flux</span> from April 2003 through November 2008 by deriving a time series of mas cons on a global 2deg x 2deg equal-area grid at 10 day intervals. We estimate the <span class="hlt">mass</span> <span class="hlt">flux</span> directly from K band range rate (KBRR) data provided by the Gravity Recovery and Climate Experiment (GRACE) mission. Using regularized least squares, we take into account the underlying process dynamics through continuous space and time-correlated constraints. In addition, we place the mascon approach in the context of other filtering techniques, showing its equivalence to anisotropic, nonsymmetric filtering, least squares collocation, and Kalman smoothing. We produce mascon time series from KBRR data that have and have not been corrected (forward modeled) for hydrological processes and fmd that the former produce superior results in oceanic areas by minimizing signal leakage from strong sources on land. By exploiting the structure of the spatiotemporal constraints, we are able to use a much more efficient (in storage and computation) inversion algorithm based upon the conjugate gradient method. This allows us to apply continuous rather than piecewise continuous time-correlated constraints, which we show via global maps and comparisons with ocean-bottom pressure gauges, to produce time series with reduced random variance and full systematic signal. Finally, we present a preferred global model, a hybrid whose oceanic portions are derived using forward modeling of hydrology but whose land portions are not, and thus represent a pure GRACE-derived signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920014110','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920014110"><span>High-Order Polynomial Expansions (HOPE) for <span class="hlt">flux</span>-vector splitting</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liou, Meng-Sing; Steffen, Chris J., Jr.</p> <p>1991-01-01</p> <p>The Van Leer <span class="hlt">flux</span> splitting is known to produce excessive numerical dissipation for Navier-Stokes calculations. Researchers attempt to remedy this deficiency by introducing a higher order polynomial expansion (HOPE) for the <span class="hlt">mass</span> <span class="hlt">flux</span>. In addition to Van Leer's splitting, a term is introduced so that the <span class="hlt">mass</span> diffusion error vanishes at M = 0. Several splittings for pressure are proposed and examined. The effectiveness of the HOPE scheme is illustrated for 1-D hypersonic conical viscous flow and 2-D supersonic shock-wave boundary layer interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24430498','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24430498"><span>Sources and <span class="hlt">mass</span> <span class="hlt">fluxes</span> of the main contaminants in a heavily polluted and modified river of the North China Plain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Wenzan; Li, Xuyong; Su, Jingjun; Zhao, Hongtao</p> <p>2014-04-01</p> <p>Many rivers in China and other newly industrialized countries have suffered from severe degradation of water quality in the context of rapid economic growth. An accounting method was developed to investigate the source and <span class="hlt">mass</span> <span class="hlt">fluxes</span> of the main contaminants in the Ziya River, a severely polluted and heavily modified river in a semiarid area of the North China Plain, where chemical oxygen demand (COD) and ammonia nitrogen (NH4-N) were the most important indicators of pollution. The results showed that the urban sewage with high concentration of COD and NH4-N dominated the streams, contributing to 80.7 % of the streamflow, 92.2 % of COD, and 94.5 % of NH4-N. The concentrations of COD and NH4-N in streams varied from 24.0-195.0 to 5.8-43.8 mg/L, respectively. <span class="hlt">Mass</span> <span class="hlt">fluxes</span> of COD and NH4-N of all pathways were quantified. Much of the polluted water was diverted to irrigation, and some eventually flowed into the Bohai Sea. Installation of adequate wastewater treatment facilities and making strict discharge standards can help improve the water quality. Our findings imply that a simple accounting method provides an extremely well-documented example for load estimation and can be useful for intervention strategies in heavily polluted and modified rivers in newly industrialized countries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A41A0026S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A41A0026S"><span>Advances in the Surface Renewal <span class="hlt">Flux</span> Measurement Method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapland, T. M.; McElrone, A.; Paw U, K. T.; Snyder, R. L.</p> <p>2011-12-01</p> <p>The measurement of ecosystem-scale energy and <span class="hlt">mass</span> <span class="hlt">fluxes</span> between the planetary surface and the atmosphere is crucial for understanding geophysical processes. Surface renewal is a <span class="hlt">flux</span> measurement technique based on analyzing the turbulent coherent structures that interact with the surface. It is a less expensive technique because it does not require fast-response velocity measurements, but only a fast-response scalar measurement. It is therefore also a useful tool for the study of the global cycling of trace gases. Currently, surface renewal requires calibration against another <span class="hlt">flux</span> measurement technique, such as eddy covariance, to account for the linear bias of its measurements. We present two advances in the surface renewal theory and methodology that bring the technique closer to becoming a fully independent <span class="hlt">flux</span> measurement method. The first advance develops the theory of turbulent coherent structure transport associated with the different scales of coherent structures. A novel method was developed for identifying the scalar change rate within structures at different scales. Our results suggest that for canopies less than one meter in height, the second smallest coherent structure scale dominates the energy and <span class="hlt">mass</span> <span class="hlt">flux</span> process. Using the method for resolving the scalar exchange rate of the second smallest coherent structure scale, calibration is unnecessary for surface renewal measurements over short canopies. This study forms the foundation for analysis over more complex surfaces. The second advance is a sensor frequency response correction for measuring the sensible heat <span class="hlt">flux</span> via surface renewal. Inexpensive fine-wire thermocouples are frequently used to record high frequency temperature data in the surface renewal technique. The sensible heat <span class="hlt">flux</span> is used in conjunction with net radiation and ground heat <span class="hlt">flux</span> measurements to determine the latent heat <span class="hlt">flux</span> as the energy balance residual. The robust thermocouples commonly used in field experiments</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT........97Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........97Z"><span>Assessing Regional Scale <span class="hlt">Fluxes</span> of <span class="hlt">Mass</span>, Momentum, and Energy with Small Environmental Research Aircraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zulueta, Rommel Callejo</p> <p></p> <p>Natural ecosystems are rarely structurally or functionally homogeneous. This is true for the complex coastal regions of Magdalena Bay, Baja California Sur, Mexico, and the Barrow Peninsula on the Arctic Coastal Plain of Alaska. The coastal region of Magdalena Bay is comprised of the Pacific coastal ocean, eutrophic lagoon, mangroves, and desert ecosystems all adjacent and within a few kilometers, while the Barrow Peninsula is a mosaic of small ponds, thaw lakes, different aged vegetated thaw-lake basins ( VDTLBs ) and interstitial tundra which have been dynamically formed by both short- and long-term processes. We used a combination of tower- and small environmental research aircraft (SERA)-based eddy covariance measurements to characterize the spatial and temporal patterns of CO2, latent, and sensible heat <span class="hlt">fluxes</span> along with MODIS NDVI, and land surface information, to scale the SERA-based CO2 <span class="hlt">fluxes</span> up to the regional scale. In the first part of this research, the spatial variability in ecosystem <span class="hlt">fluxes</span> from the Pacific coastal ocean, eutrophic lagoon, mangroves, and desert areas of northern Magdalena Bay were studied. SERA-derived average midday CO2 <span class="hlt">fluxes</span> from the desert showed a slight uptake of -1.32 mumol CO2 m-2 s-1, the coastal ocean also showed uptake of -3.48 mumol CO2 m-2 s -1, and the lagoon mangroves showed the highest uptake of -8.11 mumol CO2 m-2 s-1. Additional simultaneous measurements of NDVI allowed simple linear modeling of CO2 <span class="hlt">flux</span> as a function of NDVI for the mangroves of the Magdalena Bay region. In the second part of this research, the spatial variability of ecosystem <span class="hlt">fluxes</span> across the 1802 km2 Barrow Peninsula region was studied. During typical 2006 summer conditions, the midday hourly CO2 <span class="hlt">flux</span> over the region was -2.04 x 105 kgCO2 hr-1. The CO2 <span class="hlt">fluxes</span> among the interstitial tundra, Ancient and Old VDTLBs, as well as between the Medium and Young VDTLBs were not significantly different. Combined, the interstitial tundra and Old and Ancient</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016QuRes..85...87C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016QuRes..85...87C"><span>Variability of 14C reservoir age and <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2 in the Peru-Chile upwelling region during the past 12,000 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carré, Matthieu; Jackson, Donald; Maldonado, Antonio; Chase, Brian M.; Sachs, Julian P.</p> <p>2016-01-01</p> <p>The variability of radiocarbon marine reservoir age through time and space limits the accuracy of chronologies in marine paleo-environmental archives. We report here new radiocarbon reservoir ages (ΔR) from the central coast of Chile ( 32°S) for the Holocene period and compare these values to existing reservoir age reconstructions from southern Peru and northern Chile. Late Holocene ΔR values show little variability from central Chile to Peru. Prior to 6000 cal yr BP, however, ΔR values were markedly increased in southern Peru and northern Chile, while similar or slightly lower-than-modern ΔR values were observed in central Chile. This extended dataset suggests that the early Holocene was characterized by a substantial increase in the latitudinal gradient of marine reservoir age between central and northern Chile. This change in the marine reservoir ages indicates that the early Holocene <span class="hlt">air</span>-sea <span class="hlt">flux</span> of CO2 could have been up to five times more intense than in the late Holocene in the Peruvian upwelling, while slightly reduced in central Chile. Our results show that oceanic circulation changes in the Humboldt system during the Holocene have substantially modified the <span class="hlt">air</span>-sea carbon <span class="hlt">flux</span> in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007Icar..191..141D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007Icar..191..141D"><span>Measurement of the meteoroid <span class="hlt">flux</span> at Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Domokos, A.; Bell, J. F.; Brown, P.; Lemmon, M. T.; Suggs, R.; Vaubaillon, J.; Cooke, W.</p> <p>2007-11-01</p> <p>In the fall of 2005, a dedicated meteor observing campaign was carried out by the Panoramic Camera (Pancam) onboard the Mars Exploration Rover (MER) Spirit to determine the viability of using MER cameras as meteor detectors and to obtain the first experimental estimate of the meteoroid <span class="hlt">flux</span> at Mars. Our observing targets included both the sporadic meteoroid background and two predicted martian meteor showers: one associated with 1P/Halley and a potential stream associated with 2001/R1 LONEOS. A total of 353 images covering 2.7 h of net exposure time were analyzed with no conclusive meteor detections. From these data, an upper limit to the background meteoroid <span class="hlt">flux</span> at Mars is estimated to be <4.4×10 meteoroidskmh for meteoroids with <span class="hlt">mass</span> larger than 4 g. For comparison, the estimated <span class="hlt">flux</span> to this <span class="hlt">mass</span> limit at the Earth is 10 meteoroidskmh [Grün, E., Zook, H.A., Fechtig, H., Giese, R.H., 1985. Icarus 62, 244-272]. This result is qualitatively consistent, within error bounds, with theoretical models predicting martian <span class="hlt">fluxes</span> of ˜50% that at Earth for meteoroids of <span class="hlt">mass</span> 10-10 g [Adolfsson, L.G., Gustafson, B.A.S., Murray, C.D., 1996. Icarus 119, 144-152]. The MER cameras, even using the most sensitive mode of operation, should expect to see on average only one coincident meteor on of order 40-150 h of total exposure time based on these same theoretical martian <span class="hlt">flux</span> estimates. To more meaningfully constrain these <span class="hlt">flux</span> models, a longer total integrated exposure time or more sensitive camera is needed. Our analysis also suggests that the event reported as the first martian meteor [Selsis, F., Lemmon, M.T., Vaubaillon, J., Bell, J.F., 2005. Nature 435, 581] is more likely a grazing cosmic ray impact, which we show to be a major source of confusion with potential meteors in all Pancam images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACP....14.1205J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACP....14.1205J"><span>On the relationship between Arctic ice clouds and polluted <span class="hlt">air</span> <span class="hlt">masses</span> over the North Slope of Alaska in April 2008</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jouan, C.; Pelon, J.; Girard, E.; Ancellet, G.; Blanchet, J. P.; Delanoë, J.</p> <p>2014-02-01</p> <p>Recently, two types of ice clouds (TICs) properties have been characterized using the Indirect and Semi-Direct Aerosol Campaign (ISDAC) airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (< 10 L-1) and larger (> 110 μm) ice crystals, and a larger ice supersaturation (> 15%) compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of ice nuclei (IN) through acidification, resulting in a smaller concentration of larger ice crystals and leading to precipitation (e.g., cloud regime TIC-2B). Here, the origin of <span class="hlt">air</span> <span class="hlt">masses</span> forming the ISDAC TIC-1/2A (1 April 2008) and TIC-2B (15 April 2008) is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor <span class="hlt">air</span> <span class="hlt">masses</span> transport from three potential SO2 emission sources into Alaska: eastern China and Siberia where anthropogenic and biomass burning emissions, respectively, are produced, and the volcanic region of the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China and Siberia over Alaska, most probably with the contribution of acidic volcanic aerosol during the TIC-2B period. Observation Monitoring Instrument (OMI) satellite observations reveal that SO2 concentrations in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-2B were larger than in <span class="hlt">air</span> <span class="hlt">masses</span> forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results support the hypothesis that acidic coating on IN could be at the origin of the formation of TIC-2B.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22666016-modeling-initiation-december-coronal-mass-ejection-ar-structure-dynamics-erupting-flux-rope','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22666016-modeling-initiation-december-coronal-mass-ejection-ar-structure-dynamics-erupting-flux-rope"><span>MODELING THE INITIATION OF THE 2006 DECEMBER 13 CORONAL <span class="hlt">MASS</span> EJECTION IN AR 10930: THE STRUCTURE AND DYNAMICS OF THE ERUPTING <span class="hlt">FLUX</span> ROPE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Fan, Yuhong, E-mail: yfan@ucar.edu</p> <p>2016-06-20</p> <p>We carry out a 3D magnetohydrodynamic simulation to model the initiation of the coronal <span class="hlt">mass</span> ejection (CME) on 2006 December 13 in the emerging δ -sunspot active region NOAA 10930. The setup of the simulation is similar to a previous simulation by Fan, but with a significantly widened simulation domain to accommodate the wide CME. The simulation shows that the CME can result from the emergence of a east–west oriented twisted <span class="hlt">flux</span> rope whose positive, following emerging pole corresponds to the observed positive rotating sunspot emerging against the southern edge of the dominant pre-existing negative sunspot. The erupting <span class="hlt">flux</span> ropemore » in the simulation accelerates to a terminal speed that exceeds 1500 km s{sup −1} and undergoes a counter-clockwise rotation of nearly 180° such that its front and flanks all exhibit southward directed magnetic fields, explaining the observed southward magnetic field in the magnetic cloud impacting the Earth. With continued driving of <span class="hlt">flux</span> emergence, the source region coronal magnetic field also shows the reformation of a coronal <span class="hlt">flux</span> rope underlying the flare current sheet of the erupting <span class="hlt">flux</span> rope, ready for a second eruption. This may explain the build up for another X-class eruptive flare that occurred the following day from the same region.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050206364','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050206364"><span>High-Altitude <span class="hlt">Air</span> <span class="hlt">Mass</span> Zero Calibration of Solar Cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woodyard, James R.; Snyder, David B.</p> <p>2005-01-01</p> <p><span class="hlt">Air</span> <span class="hlt">mass</span> zero calibration of solar cells has been carried out for several years by NASA Glenn Research Center using a Lear-25 aircraft and Langley plots. The calibration flights are carried out during early fall and late winter when the tropopause is at the lowest altitude. Measurements are made starting at about 50,000 feet and continue down to the tropopause. A joint NASA/Wayne State University program called Suntracker is underway to explore the use of weather balloon and communication technologies to characterize solar cells at elevations up to about 100 kft. The balloon flights are low-cost and can be carried out any time of the year. AMO solar cell characterization employing the mountaintop, aircraft and balloon methods are reviewed. Results of cell characterization with the Suntracker are reported and compared with the NASA Glenn Research Center aircraft method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23932146','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23932146"><span>The sea-<span class="hlt">air</span> exchange of mercury (Hg) in the marine boundary layer of the Augusta basin (southern Italy): concentrations and evasion <span class="hlt">flux</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bagnato, E; Sproveri, M; Barra, M; Bitetto, M; Bonsignore, M; Calabrese, S; Di Stefano, V; Oliveri, E; Parello, F; Mazzola, S</p> <p>2013-11-01</p> <p>The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hgatm concentrations of about 1.5±0.4 (range 0.9-3.1) and 2.1±0.98 (range 1.1-3.1) ng m(-3) for the two seasons, respectively. These data are somewhat higher than the background Hg atm value measured over the land (range 1.1±0.3 ng m(-3)) at downtown Augusta, while are similar to those detected in other polluted regions elsewhere. Hg evasion <span class="hlt">fluxes</span> estimated at the sea/<span class="hlt">air</span> interface over the Bay range from 3.6±0.3 (unpolluted site) to 72±0.1 (polluted site of the basin) ng m(-2) h(-1). By extending these measurements to the entire area of the Augusta basin (~23.5 km(2)), we calculated a total sea-<span class="hlt">air</span> Hg evasion <span class="hlt">flux</span> of about 9.7±0.1 g d(-1) (~0.004 tyr(-1)), accounting for ~0.0002% of the global Hg oceanic evasion (2000 tyr(-1)). The new proposed data set offers a unique and original study on the potential outflow of Hg from the sea-<span class="hlt">air</span> interface at the basin, and it represents an important step for a better comprehension of the processes occurring in the marine biogeochemical cycle of this element. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH31B2406L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH31B2406L"><span>Origin of the High-speed Jets Fom Magnetic <span class="hlt">Flux</span> Emergence in the Solar Transition Region as well as Their <span class="hlt">Mass</span> and Energy Contribuctions to the Solar Wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liping, Y.; He, J.; Peter, H.; Tu, C. Y.; Feng, X. S.</p> <p>2015-12-01</p> <p>In the solar atmosphere, the jets are ubiquitous and found to be at various spatia-temporal scales. They are significant to understand energy and <span class="hlt">mass</span> transport in the solar atmosphere. Recently, the high-speed transition region jets are reported from the observation. Here we conduct a numerical simulation to investigate the mechanism in their formation, as well as their <span class="hlt">mass</span> and energy contributions to the solar wind. Driven by the supergranular convection motion, the magnetic reconnection between the magnetic loop and the background open <span class="hlt">flux</span> occurring in the transition region is simulated with a two-dimensional MHD model. The simulation results show that not only a fast hot jet, much resemble the found transition region jets, but also a adjacent slow cool jet, mostly like classical spicules, is launched. The force analysis shows that the fast hot jet is continually driven by the Lorentz force around the reconnection region, while the slow cool jet is induced by an initial kick through the Lorentz force associated with the emerging magnetic <span class="hlt">flux</span>. Also, the features of the driven jets change with the amount of the emerging magnetic <span class="hlt">flux</span>, giving the varieties of both jets.With the developed one-dimensional hydrodynamic solar wind model, the time-dependent pulses are imposed at the bottom to simulate the jet behaviors. The simulation results show that without other energy source, the injected plasmas are accelerated effectively to be a transonic wind with a substantial <span class="hlt">mass</span> <span class="hlt">flux</span>. The rapid acceleration occurs close to the Sun, and the resulting asymptotic speeds, number density at 0.3 AU, as well as <span class="hlt">mass</span> <span class="hlt">flux</span> normalized to 1 AU are compatible with in site observations. As a result of the high speed, the imposed pulses lead to a train of shocks traveling upward. By tracing the motions of the injected plasma, it is found that these shocks heat and accelerate the injected plasma to make part of them propagate upward and eventually escape. The parametric study shows</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AJ....147..127B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AJ....147..127B"><span>Hubble Space Telescope CALSPEC <span class="hlt">Flux</span> Standards: Sirius (and Vega)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bohlin, R. C.</p> <p>2014-06-01</p> <p>The Space Telescope Imaging Spectrograph (STIS) has measured the <span class="hlt">flux</span> for Sirius from 0.17 to 1.01 μm on the Hubble Space Telescope (HST) White Dwarf scale. Because of the cool debris disk around Vega, Sirius is commonly recommended as the primary IR <span class="hlt">flux</span> standard. The measured STIS <span class="hlt">flux</span> agrees well with predictions of a special Kurucz model atmosphere, adding confidence to the modeled IR <span class="hlt">flux</span> predictions. The IR <span class="hlt">flux</span> agrees to 2%-3% with respect to the standard template of Cohen and to 2% with the Midcourse Space Experiment absolute <span class="hlt">flux</span> measurements in the mid-IR. A weighted average of the independent visible and mid-IR absolute <span class="hlt">flux</span> measures implies that the monochromatic <span class="hlt">flux</span> at 5557.5 Å (5556 Å in <span class="hlt">air</span>) for Sirius and Vega, respectively, is 1.35 × 10-8 and 3.44 × 10-9 erg cm-2 s-1 Å-1 with formal uncertainties of 0.5%. Contrary to previously published conclusions, the Hipparcos photometry offers no support for the variability of Vega. Pulse pileup severely affects the Hp photometry for the brightest stars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615273S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615273S"><span>Micrometeorological <span class="hlt">flux</span> measurements at a coastal site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Guozheng; Meixner, Franz X.; Bruse, Michael; Mamtimin, Buhalqem</p> <p>2014-05-01</p> <p>The eddy covariance (EC) technique is the only direct measurement of the momentum, heat, and trace gas (e.g. water vapor, CO2 and ozone) <span class="hlt">fluxes</span>. The measurements are expected to be most accurate over flat terrain where there is an extended homogenous surface upwind from the tower, and when the environmental conditions are steady. Additionally, the one dimensional approach assumes that vertical turbulent exchange is the dominant <span class="hlt">flux</span>, whereas advective influences should be negligible. The application of EC method under non-ideal conditions, for example in complex terrain, has yet to be fully explored. To explore the possibilities and limitations of EC technique under non-ideal conditions, an EC system was set up at Selles beach, Crete, Greece (35.33°N, 25.71°E) in the beginning of July 2012. The dominant wind direction was west, parallel to the coast. The EC system consisted of a sonic anemometer (CSAT3 Campbell Scientific), an infrared open-path CO2/H2O gas analyzer (LI-7500, Li-COR Biosciences) and a fast chemiluminescence ozone analyzer (enviscope GmbH). All the signals of these fast response instruments were sampled at 10 Hz and the measurement height was 3 m. Besides, another gradient system was setup. <span class="hlt">Air</span> temperature, relative humidity (HYGROMER MP 103 A), and wind speed (WMT700 Vaisala) were measured every 10 seconds at 3 heights (0.7, 1.45, 3 m). <span class="hlt">Air</span> intakes were set up at 0.7m and 3m. A pump drew the <span class="hlt">air</span> through a flow system and a telflon valve alternately switched between the two heights every 30 seconds. H2O, CO2 (LI-840A, Li-COR Biosciences) and ozone mixing ratio s (model 205, 2BTechnologies) were measured every 10 seconds. Momentum, heat, CO2 and ozone <span class="hlt">fluxes</span> were evaluated by both EC and gradient technique. For the calculation of turbulent <span class="hlt">fluxes</span>, TK3 algorithm (Department of Micrometeorology, University Bayreuth, Germany) was applied. We will present the measured <span class="hlt">fluxes</span> of the two systems and assess the data quality under such non-ideal condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27274702','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27274702"><span>Cluster <span class="hlt">mass</span> profile reconstruction with size and <span class="hlt">flux</span> magnification on the HST STAGES survey.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duncan, Christopher A J; Heymans, Catherine; Heavens, Alan F; Joachimi, Benjamin</p> <p>2016-03-21</p> <p>We present the first measurement of individual cluster <span class="hlt">mass</span> estimates using weak lensing size and <span class="hlt">flux</span> magnification. Using data from the HST STAGES (Space Telescope A901/902 Galaxy Evolution Survey) survey of the A901/902 supercluster we detect the four known groups in the supercluster at high significance using magnification alone. We discuss the application of a fully Bayesian inference analysis, and investigate a broad range of potential systematics in the application of the method. We compare our results to a previous weak lensing shear analysis of the same field finding the recovered signal-to-noise of our magnification-only analysis to range from 45 to 110 per cent of the signal-to-noise in the shear-only analysis. On a case-by-case basis we find consistent magnification and shear constraints on cluster virial radius, and finding that for the full sample, magnification constraints to be a factor 0.77 ± 0.18 lower than the shear measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917443W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917443W"><span>Nitrous oxide <span class="hlt">fluxes</span> from tree stems of temperate forests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wen, Yuan; Corre, Marife D.; Rachow, Christine; Veldkamp, Edzo</p> <p>2017-04-01</p> <p>Although trees are recognized as conduits of soil-generated N2O, little is known about N2O <span class="hlt">fluxes</span> from mature trees under field conditions and thier contributions to total forest N2O <span class="hlt">fluxes</span>. Here, we quantified in situ stem N2O <span class="hlt">fluxes</span> from mature alder trees on poorly-drained soil and mature beech and spruce trees on well-drained soils in Solling, Germany from March to October 2015. Soil N2O <span class="hlt">fluxes</span>, soil N2O concentrations at 40-cm depth, and soil and climatic variables known to influence N2O <span class="hlt">fluxes</span> were also measured concurrently with the stem N2O <span class="hlt">fluxes</span>. Alder, beech and spruce consistently emitted N2O via stems and all displayed higher emission rates in summer than in spring and in autumn. Stem N2O <span class="hlt">fluxes</span> from alder stand were higher than those from beech and spruce stands (P < 0.01), which was attributed to the presence of aerenchyma and lenticels as well as higher soil water content and soil C and N availability in the alder stand (P < 0.01-0.05). The correlations of stem N2O <span class="hlt">fluxes</span> from alder with soil N2O <span class="hlt">fluxes</span>, soil N2O concentrations, soil and <span class="hlt">air</span> temperature and vapor pressure deficit (R = 0.60 - 0.90, P < 0.01-0.05) suggest that N2O transport in alder was facilitated by a combination of passive gas diffusion through aerenchyma and active transport of dissolved N2O through sap flow. In the beech and spruce stands, correlations of stem N2O <span class="hlt">fluxes</span> with soil and <span class="hlt">air</span> temperature and vapor pressure deficit (R = 0.57 - 0.78, P < 0.01-0.07) suggest that active transport of dissolved N2O via xylem sap was the major mechanism for stem N2O emissions in upland trees. Stem N2O <span class="hlt">fluxes</span> represented 8-11% of the total (soil + stem) N2O <span class="hlt">fluxes</span> in the spruce and beech stands whereas in the alder stand, with its large soil N2O emission, stem emission contributed only 1% of the total <span class="hlt">flux</span>. Our results suggest that the relative contribution of tree-mediated N2O <span class="hlt">fluxes</span> is more important in upland trees than in wetland trees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930004479','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930004479"><span>Fabrication of Thin Film Heat <span class="hlt">Flux</span> Sensors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Will, Herbert A.</p> <p>1992-01-01</p> <p>Prototype thin film heat <span class="hlt">flux</span> sensors have been constructed and tested. The sensors can be applied to propulsion system materials and components. The sensors can provide steady state and fast transient heat <span class="hlt">flux</span> information. Fabrication of the sensor does not require any matching of the mounting surface. Heat <span class="hlt">flux</span> is proportional to the temperature difference across the upper and lower surfaces of an insulation material. The sensor consists of an array of thermocouples on the upper and lower surfaces of a thin insulating layer. The thermocouples for the sensor are connected in a thermopile arrangement. A 100 thermocouple pair heat <span class="hlt">flux</span> sensor has been fabricated on silicon wafers. The sensor produced an output voltage of 200-400 microvolts when exposed to a hot <span class="hlt">air</span> heat gun. A 20 element thermocouple pair heat <span class="hlt">flux</span> sensor has been fabricated on aluminum oxide sheet. Thermocouples are Pt-Pt/Rh with silicon dioxide as the insulating material. This sensor produced an output of 28 microvolts when exposed to the radiation of a furnace operating at 1000 C. Work is also underway to put this type of heat <span class="hlt">flux</span> sensor on metal surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19476883','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19476883"><span><span class="hlt">Mass</span> casualty tracking with <span class="hlt">air</span> traffic control methodologies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoskins, Jason D; Graham, Ross F; Robinson, Duane R; Lutz, Clifford C; Folio, Les R</p> <p>2009-06-01</p> <p>An intrahospital casualty throughput system modeled after <span class="hlt">air</span> traffic control (ATC) tracking procedures was tested in <span class="hlt">mass</span> casualty exercises. ATC uses a simple tactile process involving informational progress strips representing each aircraft, which are held in bays representing each stage of flight to prioritize and manage aircraft. These strips can be reordered within the bays to indicate a change in priority of aircraft sequence. In this study, a similar system was designed for patient tracking. We compared the ATC model and traditional casualty tracking methods of paper and clipboard in 18 four-hour casualty scenarios, each with 5 to 30 mock casualties. The experimental and control groups were alternated to maximize exposure and minimize training effects. Results were analyzed with Mann-Whitney statistical analysis with p value < 0.05 (two-sided). The ATC method had significantly (p = 0.017) fewer errors in critical patient data (eg, name, social security number, diagnosis). Specifically, the ATC method better tracked the mechanism of injury, working diagnosis, and disposition of patients. The ATC method also performed considerably better with patient accountability during <span class="hlt">mass</span> casualty scenarios. Data strips were comparable with the control method in terms of ease of use. In addition, participants preferred the ATC method to the control (p = 0.003) and preferred using the ATC method (p = 0.003) to traditional methods in the future. The ATC model more effectively tracked patient data with fewer errors when compared with the clipboard method. Application of these principles can enhance trauma management and can have application in civilian and military trauma centers and emergency rooms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16271812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16271812"><span>Atmospheric concentrations and <span class="hlt">air</span>-sea exchanges of nonylphenol, tertiary octylphenol and nonylphenol monoethoxylate in the North Sea.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xie, Zhiyong; Lakaschus, Soenke; Ebinghaus, Ralf; Caba, Armando; Ruck, Wolfgang</p> <p>2006-07-01</p> <p>Concentrations of nonylphenol isomers (NP), tertiary octylphenol (t-OP) and nonylphenol monoethoxylate isomers (NP1EO) have been simultaneously determined in the sea water and atmosphere of the North Sea. A decreasing concentration profile appeared following the distance increasing from the coast to the central part of the North Sea. <span class="hlt">Air</span>-sea exchanges of t-OP and NP were estimated using the two-film resistance model based upon relative <span class="hlt">air</span>-water concentrations and experimentally derived Henry's law constant. The average of <span class="hlt">air</span>-sea exchange <span class="hlt">fluxes</span> was -12+/-6 ng m(-2)day(-1) for t-OP and -39+/-19 ng m(-2)day(-1) for NP, which indicates a net deposition is occurring. These results suggest that the <span class="hlt">air</span>-sea vapour exchange is an important process that intervenes in the <span class="hlt">mass</span> balance of alkylphenols in the North Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915460V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915460V"><span>Integrated passive <span class="hlt">flux</span> measurement in groundwater: design and performance of i<span class="hlt">FLUX</span> samplers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verreydt, Goedele; Razaei, Meisam; Meire, Patrick; Van Keer, Ilse; Bronders, Jan; Seuntjens, Piet</p> <p>2017-04-01</p> <p>The monitoring and management of soil and groundwater is a challenge. Current methods for the determination of movement or <span class="hlt">flux</span> of pollution in groundwater use no direct measurements but only simulations based on concentration measurements and Darcy velocity estimations. This entails large uncertainties which cause remediation failures and higher costs for contaminated site owners. On top of that, the lack of useful data makes it difficult to get approval for a risk-based management approach which completely avoids costly remedial actions. The i<span class="hlt">FLUX</span> technology is a key development of Dr. Goedele Verreydt at the University of Antwerp and VITO. It is supported by the passive <span class="hlt">flux</span> measurement technology as invented by Prof. Mike Annable and his team at the University of Florida. The i<span class="hlt">FLUX</span> technology includes an in situ measurement device for capturing dynamic groundwater quality and quantity, the i<span class="hlt">FLUX</span> sampler, and an associated interpretation and visualization method. The i<span class="hlt">FLUX</span> sampler is a modular passive sampler that provides simultaneous in situ point determinations of a time-averaged target compound <span class="hlt">mass</span> <span class="hlt">flux</span> and water <span class="hlt">flux</span>. The sampler is typically installed in a monitoring well where it intercepts the groundwater flow and captures the compounds of interest. The sampler consists of permeable cartridges which are each packed with a specific sorbent matrix. The sorbent matrix of the water <span class="hlt">flux</span> cartridge is impregnated with known amounts of water soluble resident tracers. These tracers are leached from the matrix at rates proportional to the groundwater <span class="hlt">flux</span>. The measurements of the contaminants and the remaining resident tracer are used to determine groundwater and target compound <span class="hlt">fluxes</span>. Exposure times range from 1 week to 6 months, depending on the expected concentration and groundwater flow velocity. The i<span class="hlt">FLUX</span> sampler technology has been validated and tested at several field projects. Currently, 4 cartridges are tested and available: 1 waterflux cartridge to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4992071','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4992071"><span>Features of <span class="hlt">air</span> <span class="hlt">masses</span> associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Monteil, Caroline L; Bardin, Marc; Morris, Cindy E</p> <p>2014-01-01</p> <p>Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005–2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the <span class="hlt">air</span> <span class="hlt">mass</span> associated with the precipitation and certain physical conditions of the <span class="hlt">air</span> <span class="hlt">mass</span> (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination. PMID:24722630</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24722630','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24722630"><span>Features of <span class="hlt">air</span> <span class="hlt">masses</span> associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monteil, Caroline L; Bardin, Marc; Morris, Cindy E</p> <p>2014-11-01</p> <p>Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005-2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the <span class="hlt">air</span> <span class="hlt">masses</span> associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the <span class="hlt">air</span> <span class="hlt">mass</span> associated with the precipitation and certain physical conditions of the <span class="hlt">air</span> <span class="hlt">mass</span> (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3348023','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3348023"><span>An anthropometric model to estimate neonatal fat <span class="hlt">mass</span> using <span class="hlt">air</span> displacement plethysmography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Current validated neonatal body composition methods are limited/impractical for use outside of a clinical setting because they are labor intensive, time consuming, and require expensive equipment. The purpose of this study was to develop an anthropometric model to estimate neonatal fat <span class="hlt">mass</span> (kg) using an <span class="hlt">air</span> displacement plethysmography (PEA POD® Infant Body Composition System) as the criterion. Methods A total of 128 healthy term infants, 60 females and 68 males, from a multiethnic cohort were included in the analyses. Gender, race/ethnicity, gestational age, age (in days), anthropometric measurements of weight, length, abdominal circumference, skin-fold thicknesses (triceps, biceps, sub scapular, and thigh), and body composition by PEA POD® were collected within 1-3 days of birth. Backward stepwise linear regression was used to determine the model that best predicted neonatal fat <span class="hlt">mass</span>. Results The statistical model that best predicted neonatal fat <span class="hlt">mass</span> (kg) was: -0.012 -0.064*gender + 0.024*day of measurement post-delivery -0.150*weight (kg) + 0.055*weight (kg)2 + 0.046*ethnicity + 0.020*sum of three skin-fold thicknesses (triceps, sub scapular, and thigh); R2 = 0.81, MSE = 0.08 kg. Conclusions Our anthropometric model explained 81% of the variance in neonatal fat <span class="hlt">mass</span>. Future studies with a greater variety of neonatal anthropometric measurements may provide equations that explain more of the variance. PMID:22436534</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83f3503B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83f3503B"><span>Surface analysis using a new plasma assisted desorption/ionisation source for <span class="hlt">mass</span> spectrometry in ambient <span class="hlt">air</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bowfield, A.; Barrett, D. A.; Alexander, M. R.; Ortori, C. A.; Rutten, F. M.; Salter, T. L.; Gilmore, I. S.; Bradley, J. W.</p> <p>2012-06-01</p> <p>The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient <span class="hlt">air</span> rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient <span class="hlt">mass</span> spectrometry to analyse species released from the surfaces of polytetrafluoroethylene, and generic ibuprofen and paracetamol tablets through remote activation of the surface by the plasma. The <span class="hlt">mass</span> spectra from these surfaces compare favourably to those produced by a PADI device constructed using an earlier design and confirm that the new ion source is an effective device which can be used to achieve ambient <span class="hlt">mass</span> spectrometry with improved spatial resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23192280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23192280"><span>Measurement of the <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> for x-rays in the range from 3 to 60 keV.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buhr, H; Büermann, L; Gerlach, M; Krumrey, M; Rabus, H</p> <p>2012-12-21</p> <p>For the first time the absolute photon <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radiant power and the fraction of power deposited in dry <span class="hlt">air</span> were measured using a cryogenic electrical substitution radiometer and a free <span class="hlt">air</span> ionization chamber, respectively. The measured absorption coefficients were compared with state-of-the art calculations and showed an average deviation of 2% from calculations by Seltzer. However, they agree within 1% with data calculated earlier by Hubbell. In the course of this work, an improvement of the data analysis of a previous experimental determination of the <span class="hlt">mass</span> energy-absorption coefficient of <span class="hlt">air</span> in the range of 3 to 10 keV was found to be possible and corrected values of this preceding study are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817725V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817725V"><span>Spatial-temporal variability in GHG <span class="hlt">fluxes</span> and their functional interpretation in Rus<span class="hlt">Flux</span>Net</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasenev, Ivan; Meshalkina, Julia; Sarzhanov, Dmitriy; Mazirov, Ilia; Yaroslavtsev, Alex; Komarova, Tatiana; Tikhonova, Maria</p> <p>2016-04-01</p> <p> different meso- or micro-relief forms, natural or man-made succession studies, topsoil texture or organic matter state, subsoil or perched groundwater features. Zonal, seasonal and functional subdividing the monitoring data allows essentially increase the regression links between GHG <span class="hlt">fluxes</span> and <span class="hlt">air</span> or soil temperature and moisture (to 0.75-0.87) that is very important for their modeling and prediction. In taiga and mix-forest zones usually there is stronger effect on GHG <span class="hlt">fluxes</span> by <span class="hlt">air</span> temperature than soil one due to comparatively thin (from 3 till 10 cm) layer of principal soil organic and/or humus-accumulative horizons with maximum biological activity that usually determines the total rate of GHG soil <span class="hlt">fluxes</span>. Unfavorable seasonal conditions (dry season or low temperature) determine essential (in 1.5-2 times) decreasing not only in soil GHG <span class="hlt">fluxes</span> but in level of their spatial variability, intraseasonal and daily dynamics too. These trends are most obvious in case of more open and sensitive to the external factors ecosystems, for example in case of industrial area lawns or at the first stages of the windthrow or fallow-forest successions. Understanding the principal regional and land-use-determined regularities of spatial and temporal changes in ecosystem and soil GHG <span class="hlt">fluxes</span> help better modeling them in the process of spatial intra- and extrapolations, seasonal and interseasonal predictions, taking into attention basic and current principal ecological factors limiting GHG <span class="hlt">fluxes</span> and balances. Their introduction in the ecological or agroecological models and land-use decision support systems allows improve the quality of environmental/agroecological monitoring and control not only for GHG emission but also for soil organic matter conservation, manure and nitrogen fertilizer application that is often crucially important for sustainable rural development and profitable farming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JCHyd..75..155H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JCHyd..75..155H"><span>A direct passive method for measuring water and contaminant <span class="hlt">fluxes</span> in porous media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hatfield, Kirk; Annable, Michael; Cho, Jaehyun; Rao, P. S. C.; Klammler, Harald</p> <p>2004-12-01</p> <p>This paper introduces a new direct method for measuring water and contaminant <span class="hlt">fluxes</span> in porous media. The method uses a passive <span class="hlt">flux</span> meter (PFM), which is essentially a self-contained permeable unit properly sized to fit tightly in a screened well or boring. The meter is designed to accommodate a mixed medium of hydrophobic and/or hydrophilic permeable sorbents, which retain dissolved organic/inorganic contaminants present in the groundwater flowing passively through the meter. The contaminant <span class="hlt">mass</span> intercepted and retained on the sorbent is used to quantify cumulative contaminant <span class="hlt">mass</span> <span class="hlt">flux</span>. The sorptive matrix is also impregnated with known amounts of one or more water soluble 'resident tracers'. These tracers are displaced from the sorbent at rates proportional to the groundwater <span class="hlt">flux</span>; hence, in the current meter design, the resident tracers are used to quantify cumulative groundwater <span class="hlt">flux</span>. Theory is presented and quantitative tools are developed to interpret the water <span class="hlt">flux</span> from tracers possessing linear and nonlinear elution profiles. The same theory is extended to derive functional relationships useful for quantifying cumulative contaminant <span class="hlt">mass</span> <span class="hlt">flux</span>. To validate theory and demonstrate the passive <span class="hlt">flux</span> meter, results of multiple box-aquifer experiments are presented and discussed. From these experiments, it is seen that accurate water <span class="hlt">flux</span> measurements are obtained when the tracer used in calculations resides in the meter at levels representing 20 to 70 percent of the initial condition. 2,4-Dimethyl-3-pentanol (DMP) is used as a surrogate groundwater contaminant in the box aquifer experiments. Cumulative DMP <span class="hlt">fluxes</span> are measured within 5% of known <span class="hlt">fluxes</span>. The accuracy of these estimates generally increases with the total volume of water intercepted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27056141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27056141"><span>STUDY OF RADON <span class="hlt">FLUX</span> FROM SOIL IN BUDHAKEDAR REGION USING SRM.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bourai, A A; Aswal, Sunita; Kandari, Tushar; Kumar, Shiv; Joshi, Veena; Sahoo, B K; Ramola, R C</p> <p>2016-10-01</p> <p>In the present study, the radon <span class="hlt">flux</span> rate of the soil is measured using portable radon monitor (scintillation radon monitor) in the Budhakedar region of District Tehri, India. The study area falls along a fault zone named Main Central Thrust, which is relatively rich in radium-bearing minerals. Radon <span class="hlt">flux</span> rate from the soil is one of the most important factors for the evaluation of environmental radon levels. The earlier studies in the Budhakedar region shows a high level of radon (>4000 Bq m -3 ). Hence, it is important to measure the radon <span class="hlt">flux</span> rate. The aim of the present study is to calculate the average estimate of the surface radon <span class="hlt">flux</span> rate as well as the effective <span class="hlt">mass</span> exhalation rate. A positive correlation of 0.54 was found between radon <span class="hlt">flux</span> rate and radon <span class="hlt">mass</span> exhalation rate. © The Author 2016. Published by Oxford University Press. All rights reserved. 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