Vertical profiles of BC direct radiative effect over Italy: high vertical resolution data and atmospheric feedbacks

NASA Astrophysics Data System (ADS)

Močnik, Griša; Ferrero, Luca; Castelli, Mariapina; Ferrini, Barbara S.; Moscatelli, Marco; Grazia Perrone, Maria; Sangiorgi, Giorgia; Rovelli, Grazia; D'Angelo, Luca; Moroni, Beatrice; Scardazza, Francesco; Bolzacchini, Ezio; Petitta, Marcello; Cappelletti, David

2016-04-01

Black carbon (BC), and its vertical distribution, affects the climate. Global measurements of BC vertical profiles are lacking to support climate change research. To fill this gap, a campaign was conducted over three Italian basin valleys, Terni Valley (Appennines), Po Valley and Passiria Valley (Alps), to characterize the impact of BC on the radiative budget under similar orographic conditions. 120 vertical profiles were measured in winter 2010. The BC vertical profiles, together with aerosol size distribution, aerosol chemistry and meteorological parameters, have been determined using a tethered balloon-based platform equipped with: a micro-Aethalometer AE51 (Magee Scientific), a 1.107 Grimm OPC (0.25-32 μm, 31 size classes), a cascade impactor (Siuotas SKC), and a meteorological station (LSI-Lastem). The aerosol chemical composition was determined from collected PM2.5 samples. The aerosol absorption along the vertical profiles was measured and optical properties calculated using the Mie theory applied to the aerosol size distribution. The aerosol optical properties were validated with AERONET data and then used as inputs to the radiative transfer model libRadtran. Vertical profiles of the aerosol direct radiative effect, the related atmospheric absorption and the heating rate were calculated. Vertical profile measurements revealed some common behaviors over the studied basin valleys. From below the mixing height to above it, a marked concentration drop was found for both BC (from -48.4±5.3% up to -69.1±5.5%) and aerosol number concentration (from -23.9±4.3% up to -46.5±7.3%). These features reflected on the optical properties of the aerosol. Absorption and scattering coefficients decreased from below the MH to above it (babs from -47.6±2.5% up to -71.3±3.0% and bsca from -23.5±0.8% up to -61.2±3.1%, respectively). Consequently, the Single Scattering Albedo increased above the MH (from +4.9±2.2% to +7.4±1.0%). The highest aerosol absorption was

Vertical profile of aerosols in the Himalayan region using an ultralight aircraft platform

NASA Astrophysics Data System (ADS)

Singh, A.; Mahata, K.; Rupakheti, M.; Lawrence, M. G.; Junkermann, W.

2017-12-01

Indo-gangetic plain (IGP) and Himalayan foothills have large spatial and temporal heterogeneity in aerosols characteristics. Regional meteorology around 850-500 mb plays an important role in the transformation and transportation of aerosols from west Asia to IGP, into Himalayan foothill, as well to high-altitude region of the Himalayas. In order to quantify the vertical and horizontal variation of aerosol properties in the Himalayan , an airborne campaign was carried out in the Pokhara Valley/Nepal (83°50'-84°10' E, 25°7'-28°15' N, 815 masl ) in two phases: test flights during May 2016 and an intensive airborne sampling flight in December-January 2017. This paper provides an overview of airborne measurement campaign from the first phase of measurements in May 2016. A two-seater microlight aircraft (IKARUS C 42) was used as the aerial platform. This was deemed the feasible option in Nepal for an aerial campaign; technical specification of the aircraft include an approximately 6 hrs of flying time, short-take off run, > 100 kgs of payload, suitable for spiral upward and downward profiling. The instrument package consist of GRIMM 1.108 for particle size distribution from 0.3 to 20 um at 6 seconds time resolution, and TSI CPC 3375 for total ultrafine particle (UFP) concentration at 1 s. The package also includes a Magee Scientific Aethalometer (AE42) for aerosol absorption at seven different wavelengths. Meteorological parameters include temperature and dew point at a sampling rate of 1 Hz or higher. The paper provides a snapshot of observed vertical profile (from 800 to 4500masl) of aerosols size, number and black carbon over one of populated mountain valley in Nepal during the pre-monsoon season. During the airborne measurement, local fires- mostly agriculture burn were observed, however no large scale forest fire was captured. Sharp morning and afternoon gradients were observed in the vertical profile for aerosol number and size, mostly dominated by <400 nm. The

Vertical profile of tritium concentration in air during a chronic atmospheric HT release.

PubMed

Noguchi, Hiroshi; Yokoyama, Sumi

2003-03-01

The vertical profiles of tritium gas and tritiated water concentrations in air, which would have an influence on the assessment of tritium doses as well as on the environmental monitoring of tritium, were measured in a chronic tritium gas release experiment performed in Canada in 1994. While both of the profiles were rather uniform during the day because of atmospheric mixing, large gradients of the profiles were observed at night. The gradient coefficients of the profiles were derived from the measurements. Correlations were analyzed between the gradient coefficients and meteorological conditions: solar radiation, wind speed, and turbulent diffusivity. It was found that the solar radiation was highly correlated with the gradient coefficients of tritium gas and tritiated water profiles and that the wind speed and turbulent diffusivity showed weaker correlations with those of tritiated water profiles. A one-dimensional tritium transport model was developed to analyze the vertical diffusion of tritiated water re-emitted from the ground into the atmosphere. The model consists of processes of tritium gas deposition to soil including oxidation into tritiated water, reemission of tritiated water, dilution of tritiated water in soil by rain, and vertical diffusion of tritiated water in the atmosphere. The model accurately represents the accumulation of tritiated water in soil water and the time variations and vertical profiles of tritiated water concentrations in air.

Vertical Profiles of Aerosol Volume from High Spectral Resolution Infrared Transmission Measurements: Results

NASA Technical Reports Server (NTRS)

Eldering, Annmarie; Kahn, Brian H.; Mills, Franklin P.; Irion, Fredrick W.; Steele, Helen M.; Gunson, Michael R.

2004-01-01

The high-resolution infrared absorption spectra of the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment are utilized to derive vertical profiles of sulfate aerosol volume density and extinction coefficient. Following the eruption of Mt. Pinatubo in June 1991, the ATMOS spectra obtained on three Space Shuttle missions (1992, 1993, and 1994) provide a unique opportunity to study the global stratospheric sulfate aerosol layer shortly after a major volcanic eruption and periodically during the decay phase. Synthetic sulfate aerosol spectra are fit to the observed spectra, and a global fitting inversion routine is used to derive vertical profiles of sulfate aerosol volume density. Vertical profiles of sulfate aerosol volume density for the three missions over portions of the globe are presented, with the peak in aerosol volume density occurring from as low as 10 km (polar latitudes) to as high as 20 km (subtropical latitudes). Derived aerosol volume density is as high as 2-3.5 (mu)m(exp 3) per cubic centimeter +/-10% in 1992, decreasing to 0.2-0.5 (mu)m(exp 3) per cubic centimeter +/-20% in 1994, in agreement with other experiments. Vertical extinction profiles derived from ATMOS are compared with profiles from Improved Stratospheric And Mesospheric Sounder (ISAMS) and Cryogenic Limb Array Etalon Spectrometer (CLAES) that coincide in space and time and show good general agreement. The uncertainty of the ATMOS vertical profiles is similar to CLAES and consistently smaller than ISAMS at similar altitudes.

Modeling the CAPTEX Vertical Tracer Concentration Profiles.

NASA Astrophysics Data System (ADS)

Draxler, Roland R.; Stunder, Barbara J. B.

1988-05-01

Perfluorocarbon tracer concentration profiles measured by aircraft 600-900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

Vertical profiles of urban aerosol complex refractive index in the frame of ESQUIF airborne measurements

NASA Astrophysics Data System (ADS)

Raut, J.-C.; Chazette, P.

2007-07-01

A synergy between lidar, sunphotometer and in situ measurements has been applied to airborne observations performed during the Etude et Simulation de la QUalité de l'air en Ile-de-France (ESQUIF), enabling the retrieval of vertical profiles for the aerosol complex refractive index (ACRI) and single-scattering albedo with a vertical resolution of 200 m over Paris area. The averaged value over the entire planetary boundary layer (PBL) for the ACRI is close to 1.51(±0.02)-i0.017(±0.003) at 532 nm. The single-scattering albedo of the corresponding aerosols is found to be ~0.9 at the same wavelength. A good agreement is found with previous studies for urban aerosols. A comparison of vertical profiles of ACRI with simulations combining in situ measurements and relative humidity (RH) profiles has highlighted a modification in aerosol optical properties linked to their history and the origin of the air mass. The determination of ACRI in the atmospheric column enabled to retrieve vertical profiles of extinction coefficient in accordance with lidar profiles measurements.

Vertical profiles of urban aerosol complex refractive index in the frame of ESQUIF airborne measurements

NASA Astrophysics Data System (ADS)

Raut, J.-C.; Chazette, P.

2008-02-01

A synergy between lidar, sunphotometer and in situ measurements has been applied to airborne observations performed during the Etude et Simulation de la QUalité de l'air en Ile-de-France (ESQUIF), enabling the retrieval of vertical profiles for the aerosol complex refractive index (ACRI) and single-scattering albedo with a vertical resolution of 200 m over Paris area. The averaged value over the entire planetary boundary layer (PBL) for the ACRI is close to 1.51(±0.02)-i0.017(±0.003) at 532 nm. The single-scattering albedo of the corresponding aerosols is found to be ~0.9 at the same wavelength. A good agreement is found with previous studies for urban aerosols. A comparison of vertical profiles of ACRI with simulations combining in situ measurements and relative humidity (RH) profiles has highlighted a modification in aerosol optical properties linked to their history and the origin of the air mass. The determination of ACRI in the atmospheric column enabled to retrieve vertical profiles of extinction coefficient in accordance with lidar profiles measurements.

Vertical and Spatial Profiling of Arctic Black Carbon on the North Slope of Alaska 2015: Comparison of Model and Observation

NASA Astrophysics Data System (ADS)

Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

2015-12-01

One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic Cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, vertical profile information of BC is critical in reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the Department of Energy (DOE) Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Lastly, these aerosol and gas measurements provide an important dataset to assess the representativeness of ground sites at regional scales. Comparisons between observations and a global climate model (CAM5) simulations will be agumented with a discussion on the capability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the ability of the SP2 to partition rBC-containing particles into nascent or aged species allows an evaluation of how well the CAM5 model captures aging of long distant transported carbonaceous aerosols. Finally model sensitivity studies will be aso be presented that investigated the relative importance of the different emission sectors to the summer Arctic

Evaluation of vertical profiles to design continuous descent approach procedure

NASA Astrophysics Data System (ADS)

Pradeep, Priyank

The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft and Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of the air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data (BADA) of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK, EWR and LGA)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of

Atmospheric soundings by SPICAM occultation observations: aerosol and ozone vertical profiles

NASA Astrophysics Data System (ADS)

Montmessin, F.

2005-12-01

The SPICAM instrument is a highly versatile, dual spectrometer probing both the UV and the NIR spectral region and is currently flying around Mars onboard Mars Express. Since the beginning of MEx operations, SPICAM has collected about thousand atmospheric profiles while observing in a solar or a stellar occultation mode. UV spectra bear the signatures of several species; i.e carbon dioxide, ozone and aerosols, while infrared spectra potentially bring information on atmospheric condensates and on water vapor. This presentation will focus on the measured aerosol, ozone and water vapor profiles. For the aerosol, we will emphasize the numerous observations made in the polar night and will also discuss some high altitude clouds discovered in the southern hemisphere. Ozone and water vapor profiles will be presented along with some General Circulation Model comparisons. This work has been supported by CNES.

Vertical velocity and turbulence aspects during Mistral events as observed by UHF wind profilers

NASA Astrophysics Data System (ADS)

Caccia, J.; Guénard, V.; Benech, B.; Campistron, B.; Drobinski, P.

2004-11-01

The general purpose of this paper is to experimentally study mesoscale dynamical aspects of the Mistral in the coastal area located at the exit of the Rhône-valley. The Mistral is a northerly low-level flow blowing in southern France along the Rhône-valley axis, located between the French Alps and the Massif Central, towards the Mediterranean Sea. The experimental data are obtained by UHF wind profilers deployed during two major field campaigns, MAP (Mesoscale Alpine Program) in autumn 1999, and ESCOMPTE (Expérience sur Site pour COntraindre les Modèles de Pollution atmosphériques et de Transports d'Emission) in summer 2001. Thanks to the use of the time evolution of the vertical profile of the horizontal wind vector, recent works have shown that the dynamics of the Mistral is highly dependent on the season because of the occurrence of specific synoptic patterns. In addition, during summer, thermal forcing leads to a combination of sea breeze with Mistral and weaker Mistral due to the enhanced friction while, during autumn, absence of convective turbulence leads to substantial acceleration as low-level jets are generated in the stably stratified planetary boundary layer. At the exit of the Rhône valley, the gap flow dynamics dominates, whereas at the lee of the Alps, the dynamics is driven by the relative contribution of "flow around" and "flow over" mechanisms, upstream of the Alps. This paper analyses vertical velocity and turbulence, i.e. turbulent dissipation rate, with data obtained by the same UHF wind profilers during the same Mistral events. In autumn, the motions are found to be globally and significantly subsident, which is coherent for a dry, cold and stable flow approaching the sea, and the turbulence is found to be of pure dynamical origin (wind shears and mountain/lee wave breaking), which is coherent with non-convective situations. In summer, due to the ground heating and to the interactions with thermal circulation, the vertical motions are

Black carbon vertical profiles strongly affect its radiative forcing uncertainty

NASA Astrophysics Data System (ADS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.; Ghan, S. J.; Iversen, T.; Kinne, S.; Kirkevåg, A.; Lamarque, J.-F.; Lin, G.; Liu, X.; Penner, J.; Seland, Ø.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, K.; Zhang, K.

2012-11-01

The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom). Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

Black carbon vertical profiles strongly affect its radiative forcing uncertainty

NASA Astrophysics Data System (ADS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.; Ghan, S. J.; Iversen, T.; Kinne, S.; Kirkevåg, A.; Lamarque, J.-F.; Lin, G.; Liu, X.; Penner, J. E.; Seland, Ø.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, K.; Zhang, K.

2013-03-01

The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom). Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

Black Carbon Vertical Profiles Strongly Affect Its Radiative Forcing Uncertainty

NASA Technical Reports Server (NTRS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.;

Retrieving vertical ozone profiles from measurements of global spectral irradiance

NASA Astrophysics Data System (ADS)

Bernhard, Germar; Petropavlovskikh, Irina; Mayer, Bernhard

2017-12-01

A new method is presented to determine vertical ozone profiles from measurements of spectral global (direct Sun plus upper hemisphere) irradiance in the ultraviolet. The method is similar to the widely used Umkehr technique, which inverts measurements of zenith sky radiance. The procedure was applied to measurements of a high-resolution spectroradiometer installed near the centre of the Greenland ice sheet. Retrieved profiles were validated with balloon-sonde observations and ozone profiles from the space-borne Microwave Limb Sounder (MLS). Depending on altitude, the bias between retrieval results presented in this paper and MLS observations ranges between -5 and +3 %. The magnitude of this bias is comparable, if not smaller, to values reported in the literature for the standard Dobson Umkehr method. Total ozone columns (TOCs) calculated from the retrieved profiles agree to within 0.7±2.0 % (±1σ) with TOCs measured by the Ozone Monitoring Instrument on board the Aura satellite. The new method is called the Global-Umkehr method.

Estimation of surface-level PM concentration from satellite observation taking into account the aerosol vertical profiles and hygroscopicity.

PubMed

Kim, Kwanchul; Lee, Kwon H; Kim, Ji I; Noh, Youngmin; Shin, Dong H; Shin, Sung K; Lee, Dasom; Kim, Jhoon; Kim, Young J; Song, Chul H

2016-01-01

Surface-level PM10 distribution was estimated from the satellite aerosol optical depth (AOD) products, taking the account of vertical profiles and hygroscopicity of aerosols over Jeju, Korea during March 2008 and October 2009. In this study, MODIS AOD data from the Terra and Aqua satellites were corrected with aerosol extinction profiles and relative humidity data. PBLH (Planetary Boundary Layer Height) was determined from MPLNET lidar-derived aerosol extinction coefficient profiles. Through statistical analysis, better agreement in correlation (R = 0.82) between the hourly PM10 concentration and hourly average Sunphotometer AOD was the obtained when vertical fraction method (VFM) considering Haze Layer Height (HLH) and hygroscopic growth factor f(RH) was used. The validity of the derived relationship between satellite AOD and surface PM10 concentration clearly demonstrates that satellite AOD data can be utilized for remote sensing of spatial distribution of regional PM10 concentration. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The power of vertical geolocation of atmospheric profiles from GNSS radio occultation.

PubMed

Scherllin-Pirscher, Barbara; Steiner, Andrea K; Kirchengast, Gottfried; Schwärz, Marc; Leroy, Stephen S

2017-02-16

High-resolution measurements from Global Navigation Satellite System (GNSS) radio occultation (RO) provide atmospheric profiles with independent information on altitude and pressure. This unique property is of crucial advantage when analyzing atmospheric characteristics that require joint knowledge of altitude and pressure or other thermodynamic atmospheric variables. Here we introduce and demonstrate the utility of this independent information from RO and discuss the computation, uncertainty, and use of RO atmospheric profiles on isohypsic coordinates-mean sea level altitude and geopotential height-as well as on thermodynamic coordinates (pressure and potential temperature). Using geopotential height as vertical grid, we give information on errors of RO-derived temperature, pressure, and potential temperature profiles and provide an empirical error model which accounts for seasonal and latitudinal variations. The observational uncertainty of individual temperature/pressure/potential temperature profiles is about 0.7 K/0.15%/1.4 K in the tropopause region. It gradually increases into the stratosphere and decreases toward the lower troposphere. This decrease is due to the increasing influence of background information. The total climatological error of mean atmospheric fields is, in general, dominated by the systematic error component. We use sampling error-corrected climatological fields to demonstrate the power of having different and accurate vertical coordinates available. As examples we analyze characteristics of the location of the tropopause for geopotential height, pressure, and potential temperature coordinates as well as seasonal variations of the midlatitude jet stream core. This highlights the broad applicability of RO and the utility of its versatile vertical geolocation for investigating the vertical structure of the troposphere and stratosphere.

Determination of accurate vertical atmospheric profiles of extinction and turbulence

NASA Astrophysics Data System (ADS)

Hammel, Steve; Campbell, James; Hallenborg, Eric

2017-09-01

Our ability to generate an accurate vertical profile characterizing the atmosphere from the surface to a point above the boundary layer top is quite rudimentary. The region from a land or sea surface to an altitude of 3000 meters is dynamic and particularly important to the performance of many active optical systems. Accurate and agile instruments are necessary to provide measurements in various conditions, and models are needed to provide the framework and predictive capability necessary for system design and optimization. We introduce some of the path characterization instruments and describe the first work to calibrate and validate them. Along with a verification of measurement accuracy, the tests must also establish each instruments performance envelope. Measurement of these profiles in the field is a problem, and we will present a discussion of recent field test activity to address this issue. The Comprehensive Atmospheric Boundary Layer Extinction/Turbulence Resolution Analysis eXperiment (CABLE/TRAX) was conducted late June 2017. There were two distinct objectives for the experiment: 1) a comparison test of various scintillometers and transmissometers on a homogeneous horizontal path; 2) a vertical profile experiment. In this paper we discuss only the vertical profiling effort, and we describe the instruments that generated data for vertical profiles of absorption, scattering, and turbulence. These three profiles are the core requirements for an accurate assessment of laser beam propagation.

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.

Vertical profiles of black carbon concentration and particle number size distribution in the North China Plain

NASA Astrophysics Data System (ADS)

Ran, L.; Deng, Z.

2013-12-01

The vertical distribution of aerosols is of great importance to our understanding in the impacts of aerosols on radiation balance and climate, as well as air quality and public health. To better understand and estimate the effects of atmospheric components including trace gases and aerosols on atmospheric environment and climate, an intensive field campaign, Vertical Observations of trace Gases and Aerosols in the North China Plain (VOGA-NCP), was carried out from late July to early August 2013 over a rural site in the polluted NCP. During the campaign, vertical profiles of black carbon (BC) concentration and particle number size distribution were measured respectively by a micro-Aethalometer and an optical particle counter attached to a tethered balloon within 1000 m height. Meteorological parameters, including temperature, relative humidity, wind speed and wind direction, were measured simultaneously by a radiosonde also attached to the tethered balloon. Preliminary results showed distinct diurnal variations of the vertical distribution of aerosol total number concentration and BC concentration, following the development of the mixing layer. Generally, there was a well mixing of aerosols within the mixing layer and a sharp decrease above the mixing layer. Particularly, a small peak of BC concentrations was observed around 400-500 m height for several profiles. Further analysis would be needed to explain such phenomenon. It was also found that measured vertical profiles of BC using the filter-based method might be affected by the vertical distribution of relative humidity.

On vertical profile of ozone at Syowa

NASA Technical Reports Server (NTRS)

Chubachi, Shigeru

1994-01-01

The difference in the vertical ozone profile at Syowa between 1966-1981 and 1982-1988 is shown. The month-height cross section of the slope of the linear regressions between ozone partial pressure and 100-mb temperature is also shown. The vertically integrated values of the slopes are in close agreement with the slopes calculated by linear regression of Dobson total ozone on 100-mb temperature in the period of 1982-1988.

An analysis of the vertical structure equation for arbitrary thermal profiles

NASA Technical Reports Server (NTRS)

Cohn, Stephen E.; Dee, Dick P.

1989-01-01

The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations.

An analysis of the vertical structure equation for arbitrary thermal profiles

NASA Technical Reports Server (NTRS)

Cohn, Stephen E.; Dee, Dick P.

1987-01-01

The vertical structure equation is a singular Sturm-Liouville problem whose eigenfunctions describe the vertical dependence of the normal modes of the primitive equations linearized about a given thermal profile. The eigenvalues give the equivalent depths of the modes. The spectrum of the vertical structure equation and the appropriateness of various upper boundary conditions, both for arbitrary thermal profiles were studied. The results depend critically upon whether or not the thermal profile is such that the basic state atmosphere is bounded. In the case of a bounded atmosphere it is shown that the spectrum is always totally discrete, regardless of details of the thermal profile. For the barotropic equivalent depth, which corresponds to the lowest eigen value, upper and lower bounds which depend only on the surface temperature and the atmosphere height were obtained. All eigenfunctions are bounded, but always have unbounded first derivatives. It was proved that the commonly invoked upper boundary condition that vertical velocity must vanish as pressure tends to zero, as well as a number of alternative conditions, is well posed. It was concluded that the vertical structure equation always has a totally discrete spectrum under the assumptions implicit in the primitive equations.

Vertical Distribution of Aersols and Water Vapor Using CRISM Limb Observations

NASA Technical Reports Server (NTRS)

Smith, Michael D.; Wolff, Michael J.; Clancy, R. Todd

2011-01-01

Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Specifically, the observed radiance as a function of wavelength and height above the limb allows the vertical distribution of both dust and ice aerosols to be retrieved. These data serve as an important supplement to the aerosol profiling provided by the MRO/MCS instrument allowing independent validation and giving additional information on particle physical and scattering properties through multi-wavelength studies. A total of at least ten CRISM limb observations have been taken so far covering a full Martian year. Each set of limb observations nominally contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude over the Tharsis and Syrtis/Hellas regions, respectively. At each longitude, limb scans are spaced roughly 10 degrees apart in latitude, with a vertical spatial resolution on the limb of roughly 800 m. Radiative transfer modeling is used to model the observations. We compute synthetic CRISM limb spectra using a discrete-ordinates radiative transfer code that accounts for multiple scattering from aerosols and accounts for spherical geometry of the limb observations by integrating the source functions along curved paths in that coordinate system. Retrieved are 14-point vertical profiles for dust and water ice aerosols with resolution of 0.4 scale heights between one and six scale heights above the surface. After the aerosol retrieval is completed, the abundances of C02 (or surface pressure) and H20 gas are retrieved by matching the depth of absorption bands at 2000 nm for carbon dioxide and at 2600 run for water vapor. In addition to the column abundance of water vapor, limited information on its vertical structure can also be retrieved depending on the signal

Radial-vertical profiles of tropical cyclone derived from dropsondes

NASA Astrophysics Data System (ADS)

Ren, Yifang

The scopes of this thesis research are two folds: the first one is to the construct the intensity-based composite radial-vertical profiles of tropical cyclones (TC) using GPS-based dropsonde observations and the second one is to identify the major deficiencies of Mathur vortices against the dropsonde composites of TCs. The intensity-based dropsonde composites of TCs advances our understanding of the dynamic and thermal structure of TCs of different intensity along the radial direction in and above the boundary layer where lies the devastating high wind that causes property damages and storm surges. The identification of the major deficiencies of Mathur vortices in representing the radial-vertical profiles of TC of different intensity helps to improve numerical predictions of TCs since most operational TC forecast models need to utilize bogus vortices, such as Mathur vortices, to initialize TC forecasts and simulations. We first screen all available GPS dropsonde data within and round 35 named TCs over the tropical Atlantic basin from 1996 to 2010 and pair them with TC parameters derived from the best-track data provided by the National Hurricane Center (NHC) and select 1149 dropsondes that have continuous coverage in the lower troposphere. The composite radial-vertical profiles of tangential wind speed, temperature, mixing ratio and humidity are based for each TC category ranging from "Tropical Storm" (TS) to "Hurricane Category 1" (H1) through "Hurricane Category 5" (H5). The key findings of the dropsonde composites are: (i) all TCs have the maximum tangential wind within 1 km above the ground and a distance of 1-2 times of the radius of maximum wind (RMW) at the surface; (ii) all TCs have a cold ring surrounding the warm core near the boundary layer at a distance of 1-3 times of the RMW and the cold ring structure gradually diminishes at a higher elevation where the warm core structure prevails along the radial direction; (iii) the existence of such shallow cold

Importance of A Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

NASA Astrophysics Data System (ADS)

Johnson, M. S.; Sullivan, J. T.; Liu, X.; Zoogman, P.; Newchurch, M.; Kuang, S.; McGee, T. J.; Leblanc, T.

2017-12-01

Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME, GOME-2, and OMI. This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's operational GEOS-5 FP model and reanalysis data from MERRA2) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 km) and tropospheric (0-10 km) TOLNet observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3 retrievals in the troposphere and at the surface are presented. Results indicate that while the TB-Clim climatological dataset can replicate seasonally-averaged tropospheric O3 profiles, model-simulated profiles from a full CTM resulted in more accurate tropospheric and surface-level O3 retrievals from

Importance of a Priori Vertical Ozone Profiles for TEMPO Air Quality Retrievals

NASA Technical Reports Server (NTRS)

Johnson, Matthew S.; Sullivan, John; Liu, Xiong; Zoogman, Peter; Newchurch, Mike; Kuang, Shi; McGee, Thomas; Leblanc, Thierry

2017-01-01

Ozone (O3) is a toxic pollutant which plays a major role in air quality. Typically, monitoring of surface air quality and O3 mixing ratios is conducted using in situ measurement networks. This is partially due to high-quality information related to air quality being limited from space-borne platforms due to coarse spatial resolution, limited temporal frequency, and minimal sensitivity to lower tropospheric and surface-level O3. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite is designed to address the limitations of current space-based platforms and to improve our ability to monitor North American air quality. TEMPO will provide hourly data of total column and vertical profiles of O3 with high spatial resolution to be used as a near-real-time air quality product. TEMPO O3 retrievals will apply the Smithsonian Astrophysical Observatory profile algorithm developed based on work from GOME (Global Ozone Monitoring Experiment), GOME-2, and OMI (Ozone Monitoring Instrument). This algorithm is suggested to use a priori O3 profile information from a climatological data-base developed from long-term ozone-sonde measurements (tropopause-based (TB-Clim) O3 climatology). This study evaluates the TB-Clim dataset and model simulated O3 profiles, which could potentially serve as a priori O3 profile information in TEMPO retrievals, from near-real-time data assimilation model products (NASA GMAO's (Global Modeling and Assimilation Office) operational GEOS-5 (Goddard Earth Observing System, Version 5) FP (Forecast Products) model and reanalysis data from MERRA2 (Modern-Era Retrospective analysis for Research and Applications, Version 2)) and a full chemical transport model (CTM), GEOS-Chem. In this study, vertical profile products are evaluated with surface (0-2 kilometers) and tropospheric (0-10 kilometers) TOLNet (Tropospheric Ozone Lidar Network) observations and the theoretical impact of individual a priori profile sources on the accuracy of TEMPO O3

MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

EPA Science Inventory

U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a
Geopr...

A measurement system for vertical seawater profiles close to the air-sea interface

NASA Astrophysics Data System (ADS)

Sims, Richard P.; Schuster, Ute; Watson, Andrew J.; Yang, Ming Xi; Hopkins, Frances E.; Stephens, John; Bell, Thomas G.

2017-09-01

This paper describes a near-surface ocean profiler, which has been designed to precisely measure vertical gradients in the top 10 m of the ocean. Variations in the depth of seawater collection are minimized when using the profiler compared to conventional CTD/rosette deployments. The profiler consists of a remotely operated winch mounted on a tethered yet free-floating buoy, which is used to raise and lower a small frame housing sensors and inlet tubing. Seawater at the inlet depth is pumped back to the ship for analysis. The profiler can be used to make continuous vertical profiles or to target a series of discrete depths. The profiler has been successfully deployed during wind speeds up to 10 m s-1 and significant wave heights up to 2 m. We demonstrate the potential of the profiler by presenting measured vertical profiles of the trace gases carbon dioxide and dimethylsulfide. Trace gas measurements use an efficient microporous membrane equilibrator to minimize the system response time. The example profiles show vertical gradients in the upper 5 m for temperature, carbon dioxide and dimethylsulfide of 0.15 °C, 4 µatm and 0.4 nM respectively.

Vertical profiles of nitrous acid in the nocturnal urban atmosphere of Houston, TX

NASA Astrophysics Data System (ADS)

Wong, K. W.; Oh, H.-J.; Lefer, B.; Rappenglück, B.; Stutz, J.

2010-12-01

Nitrous acid (HONO) often plays an important role in tropospheric photochemistry as a major precursor of the hydroxyl radical (OH) in early morning hours and potentially during the day. However, the processes leading to formation of HONO and its vertical distribution at night, which can have a considerable impact on daytime ozone formation, are currently poorly characterized by observations and models. Long-path differential optical absorption spectroscopy (LP-DOAS) measurements of HONO during the 2006 TexAQS II Radical and Aerosol Measurement Project (TRAMP), near downtown Houston, TX, show nocturnal vertical profiles of HONO, with mixing ratios of up to 2.2 ppb near the surface and below 100 ppt aloft. Three nighttime periods of HONO, NO2 and O3 observations during TRAMP were used to perform model simulations of vertical mixing ratio profiles. By adjusting vertical mixing and NOx emissions the modeled NO2 and O3 mixing ratios showed very good agreement with the observations. Using a simple conversion of NO2 to HONO on the ground, direct HONO emissions, as well as HONO loss at the ground and on aerosol, the observed HONO profiles were reproduced well by the model. The unobserved increase of HONO to NO2 ratio (HONO/NO2) with altitude that was simulated by the initial model runs was found to be due to HONO uptake being too small on aerosol and too large on the ground. Refined model runs, with adjusted HONO uptake coefficients, showed much better agreement of HONO and HONO/NO2 for two typical nights, except during morning rush hour, when other HONO formation pathways are most likely active. One of the nights analyzed showed increase of HONO mixing ratios together with decreasing NO2 mixing ratios that the model was unable to reproduce, most likely due to the impact of weak precipitation during this night. HONO formation and removal rates averaged over the lowest 300 m of the atmosphere showed that NO2 to HONO conversion on the ground was the dominant source of HONO

Vertical profiles of nitrous acid in the nocturnal urban atmosphere of Houston, TX

NASA Astrophysics Data System (ADS)

Wong, K. W.; Oh, H.-J.; Lefer, B. L.; Rappenglück, B.; Stutz, J.

2011-04-01

Nitrous acid (HONO) often plays an important role in tropospheric photochemistry as a major precursor of the hydroxyl radical (OH) in early morning hours and potentially during the day. However, the processes leading to formation of HONO and its vertical distribution at night, which can have a considerable impact on daytime ozone formation, are currently poorly characterized by observations and models. Long-path differential optical absorption spectroscopy (LP-DOAS) measurements of HONO during the 2006 TexAQS II Radical and Aerosol Measurement Project (TRAMP), near downtown Houston, TX, show nocturnal vertical profiles of HONO, with mixing ratios of up to 2.2 ppb near the surface and below 100 ppt aloft. Three nighttime periods of HONO, NO2 and O3 observations during TRAMP were used to perform model simulations of vertical mixing ratio profiles. By adjusting vertical mixing and NOx emissions the modeled NO2 and O3 mixing ratios showed very good agreement with the observations. Using a simple conversion of NO2 to HONO on the ground, direct HONO emissions, as well as HONO loss at the ground and on aerosol, the observed HONO profiles were reproduced by the model for 1-2 and 7-8 September in the nocturnal boundary layer (NBL). The unobserved increase of HONO to NO2 ratio (HONO/NO2) with altitude that was simulated by the initial model runs was found to be due to HONO uptake being too small on aerosol and too large on the ground. Refined model runs, with adjusted HONO uptake coefficients, showed much better agreement of HONO and HONO/NO2 for two typical nights, except during morning rush hour, when other HONO formation pathways are most likely active. One of the nights analyzed showed an increase of HONO mixing ratios together with decreasing NO2 mixing ratios that the model was unable to reproduce, most likely due to the impact of weak precipitation during this night. HONO formation and removal rates averaged over the lowest 300 m of the atmosphere showed that NO2 to

Ozone vertical profile changes over South Pole

NASA Technical Reports Server (NTRS)

Oltmans, S. J.; Hofmann, D. J.; Komhyr, W. D.; Lathrop, J. A.

1994-01-01

Important changes in the ozone vertical profile over South Pole, Antarctica have occurred both during the recent period of measurements, 1986-1991, and since an earlier set of soundings was carried out from 1967-1971. From the onset of the 'ozone hole' over Antarctica in the early 1980s, there has been a tendency for years with lower spring ozone amounts to alternate with years with somewhat higher (although still depleted) ozone amounts. Beginning in 1989 there have been three consecutive years of strong depletion although the timing of the breakdown of the vortex has varied from year to year. Comparison of the vertical profiles between the two periods of study reveals the dramatic decreases in the ozone amounts in the stratosphere between 15-21 km during the spring. In addition, it appears that summer values are also now much lower in this altitude region.

ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, Vertical Air Motion (williams-vertair)

DOE Data Explorer

Williams, Christopher; Jensen, Mike

2012-11-06

This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

Vertical Profiling of Air Pollution at RAPCD

NASA Technical Reports Server (NTRS)

Newchurch, Michael J.; Fuller, Kirk A.; Bowdle, David A.; Johnson, Steven; Knupp, Kevin; Gillani, Noor; Biazar, Arastoo; Mcnider, Richard T.; Burris, John

2004-01-01

The interaction between local and regional pollution levels occurs at the interface of the Planetary Boundary Layer and the Free Troposphere. Measuring the vertical distribution of ozone, aerosols, and winds with high temporal and vertical resolution is essential to diagnose the nature of this interchange and ultimately for accurately forecasting ozone and aerosol pollution levels. The Regional Atmospheric Profiling Center for Discovery, RAPCD, was built and instrumented to address this critical issue. The ozone W DIAL lidar, Nd:YAG aerosol lidar, and 2.1 micron Doppler wind lidar, along with balloon- borne ECC ozonesondes form the core of the W C D instrumentation for addressing this problem. Instrumentation in the associated Mobile Integrated Profiling (MIPS) laboratory includes 91 5Mhz profiler, sodar, and ceilometer. The collocated Applied particle Optics and Radiometry (ApOR) laboratory hosts an FTIR along with MOUDI and optical particle counters. With MODELS-3 analysis by colleagues in the National Space Science and Technology Center on the UAH campus and the co- located National Weather Service Forecasting Office in Huntsville, AL we are developing a unique facility for advancing the state of the science of pollution forecasting.

Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

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

Wootton, Kent

2015-09-17

In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 ± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

Spectrometeric measurements of vertical profile and column abundance of NO2 at Zvenigorod, Russia: Fourteen years of observations

NASA Astrophysics Data System (ADS)

Gruzdev, A.; Elokhov, A.

Since 1990, NO2 measurements are carried out at Zvenigorod Research Station (56°N, 37°E), Moscow region, with the help of zenith viewing spectrophotometer in spectral range 435-450 nm. The instrument and method of observations were verified in comparison campaigns within the framework of the Network for Detection of Stratospheric Change. Measurements are done during morning and evening twilight at solar zenith angles 84-96°. Slant column NO2 abundances are derived from observed spectra taking into account O3 and NO2 absorption, single molecular and aerosol scattering, and the Ring effect. The NO2 abundances in the vertical column as well as vertical NO2 profiles are derived as solution of inverse mathematical problem (with Chahine method) using a spherical single scattering model and a one-dimensional photochemical model. Derived quantities are (1) NO2 abundances within 5-km thick layers in the stratosphere and troposphere, (2) NO2 abundance in the thin atmospheric near-surface layer and (3) columnar NO2 abundances in the troposphere (0-10 km) and the stratosphere (10-50 km) as integrals over appropriate layers. Results of measurements show variability of stratospheric and tropospheric NO2 at different time scales from the diurnal to the interannual scale. Out of the period affected by the Pinatubo eruption (1992-1994), a general decline of the stratospheric column NO2 abundance is occurring, superimposed by interannual variations. A linear, statistically significant, negative annual trend of about 12% per decade has been detected for both morning and evening stratospheric column NO2 abundances. For interpretation of the observed trend, a simple photochemical model is used, which takes into account the observed changes in N2O and stratospheric ozone abundances, and in temperature. The estimated model trend of the stratospheric column NO2 abundance in the extratropical Northern Hemisphere is about -5% per decade, which is less than observed. Dynamical variability

Global distribution of vertical wavenumber spectra in the lower stratosphere observed using high-vertical-resolution temperature profiles from COSMIC GPS radio occultation

NASA Astrophysics Data System (ADS)

Noersomadi; Tsuda, T.

2016-02-01

We retrieved temperature (T) profiles with a high vertical resolution using the full spectrum inversion (FSI) method from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) GPS radio occultation (GPS-RO) data from January 2007 to December 2009. We studied the characteristics of temperature perturbations in the stratosphere at 20-27 km altitude. This height range does not include a sharp jump in the background Brunt-Väisälä frequency squared (N2) near the tropopause, and it was reasonably stable regardless of season and latitude. We analyzed the vertical wavenumber spectra of gravity waves (GWs) with vertical wavelengths ranging from 0.5 to 3.5 km, and we integrated the (total) potential energy EpT. Another integration of the spectra from 0.5 to 1.75 km was defined as EpS for short vertical wavelength GWs, which was not studied with the conventional geometrical optics (GO) retrievals. We also estimated the logarithmic spectral slope (p) for the saturated portion of spectra with a linear regression fitting from 0.5 to 1.75 km.Latitude and time variations in the spectral parameters were investigated in two longitudinal regions: (a) 90-150° E, where the topography was more complicated, and (b) 170-230° E, which is dominated by oceans. We compared EpT, EpS, and p, with the mean zonal winds (U) and outgoing longwave radiation (OLR). We also show a ratio of EpS to EpT and discuss the generation source of EpS. EpT and p clearly showed an annual cycle, with their maximum values in winter at 30-50° N in region (a), and 50-70° N in region (b), which was related to the topography. At 30-50° N in region (b), EpT and p exhibited some irregular variations in addition to an annual cycle. In the Southern Hemisphere, we also found an annual oscillation in EpT and p, but it showed a time lag of about 2 months relative to U. Characteristics of EpTand p in the tropical region seem to be related to convective activity. The ratio of EpT to the

Vertical profiles of fine and coarse aerosol particles over Cyprus: Comparison between in-situ drone measurements and remote sensing observations

NASA Astrophysics Data System (ADS)

Mamali, Dimitra; Marinou, Eleni; Pikridas, Michael; Kottas, Michael; Binietoglou, Ioannis; Kokkalis, Panagiotis; Tsekeri, Aleksandra; Amiridis, Vasilis; Sciare, Jean; Keleshis, Christos; Engelmann, Ronny; Ansmann, Albert; Russchenberg, Herman W. J.; Biskos, George

2017-04-01

Vertical profiles of the aerosol mass concentration derived from light detection and ranging (lidar) measurements were compared to airborne dried optical particle counter (OPC MetOne; Model 212) measurements during the INUIT-BACCHUS-ACTRIS campaign. The campaign took place in April 2016 and its main focus was the study of aerosol dust particles. During the campaign the NOA Polly-XT Raman lidar located at Nicosia (35.08° N, 33.22° E) was providing round-the-clock vertical profiles of aerosol optical properties. In addition, an unmanned aerial vehicle (UAV) carrying an OPC flew on 7 days during the first morning hours. The flights were performed at Orounda (35.1018° N, 33.0944° E) reaching altitudes of 2.5 km a.s.l, which allows comparison with a good fraction of the recorded lidar data. The polarization lidar photometer networking method (POLIPHON) was used for the estimation of the fine (non-dust) and coarse (dust) mode aerosol mass concentration profiles. This method uses as input the particle backscatter coefficient and the particle depolarization profiles of the lidar at 532 nm wavelength and derives the aerosol mass concentration. The first step in this approach makes use of the lidar observations to separate the backscatter and extinction contributions of the weakly depolarizing non-dust aerosol components from the contributions of the strongly depolarizing dust particles, under the assumption of an externally mixed two-component aerosol. In the second step, sun photometer retrievals of the fine and the coarse modes aerosol optical thickness (AOT) and volume concentration are used to calculate the associated concentrations from the extinction coefficients retrieved from the lidar. The estimated aerosol volume concentrations were converted into mass concentration with an assumption for the bulk aerosol density, and compared with the OPC measurements. The first results show agreement within the experimental uncertainty. This project received funding from the

Generation of optimum vertical profiles for an advanced flight management system

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Waters, M. H.

1981-01-01

Algorithms for generating minimum fuel or minimum cost vertical profiles are derived and examined. The option for fixing the time of flight is included in the concepts developed. These algorithms form the basis for the design of an advanced on-board flight management system. The variations in the optimum vertical profiles (resulting from these concepts) due to variations in wind, takeoff mass, and range-to-destination are presented. Fuel savings due to optimum climb, free cruise altitude, and absorbing delays enroute are examined.

Observations of vertical velocities in the tropical upper troposphere and lower stratosphere using the Arecibo 430-MHz radar

NASA Technical Reports Server (NTRS)

Cornish, C. R.

1988-01-01

The first clear-air observations of vertical velocities in the tropical upper troposphere and lower stratosphere (8-22 km) using the Arecibo 430-MHz radar are presented. Oscillations in the vertical velocity near the Brunt-Vaisala period are observed in the lower stratosphere during the 12-hour observation period. Frequency power spectra from the vertical velocity time series show a slope between -0.5 and -1.0. Vertical wave number spectra computed from the height profiles of vertical velocities have slopes between -1.0 and -1.5. These observed slopes do not agree well with the slopes of +1/3 and -2.5 for frequency and vertical wave number spectra, respectively, predicted by a universal gravity-wave spectrum model. The spectral power of wave number spectra of a radial beam directed 15 deg off-zenith is enhanced by an order of magnitude over the spectral power levels of the vertical beam. This enhancement suggests that other geophysical processes besides gravity waves are present in the horizontal flow. The steepening of the wave number spectrum of the off-vertical beam in the lower stratosphere to near -2.0 is attributed to a quasi-inertial period wave, which was present in the horizontal flow during the observation period.

Variation of subsurface chlorophyll maximum layer from the vertical profiler and in-situ observation in the eastern coastal region of Korea (the East/Japan Sea)

NASA Astrophysics Data System (ADS)

Son, Y. T.; Chang, K. I.; Nam, S.; Kang, D. J.

2016-02-01

Coastal monitoring buoy (called it as ESROB) has been continually operated to monitor meteorological (wind, air temperature, air pressure, PAR) and oceanic properties (temperature, salinity, current, chlorophyll fluorescence, DO, turbidity) using equipment such as CTD, fluorometer and WQM (Water Quality Monitor) in the eastern coastal region of Korea (the East/Japan Sea) since April 2011. The ESROB produced temporal evolution of physical and biogeochemical parameters of the water column with high resolution of 10 min interval. In order to understand horizontal influence of physical and biogeochemical parameters on variation of subsurface chlorophyll maximum layer (SCM), interdisciplinary in-situ surveys with small R/V in the study area for about week were conducted in June/October 2014 and in May 2015. A wirewalker, a wave-driven vertically profiling platform (Rainville and Pinkel 2001), was also deployed at two points (about 30 m and 80 m water depth) along cross-shore direction with the ESROB for about one or two weeks with in-situ survey durations. The wirewalker was equipped with CTD, turbidity and chlorophyll a fluorometer profiler, which was completed approximately every 3 10 minute depending on sea surface state. The SCM was observed in almost every deployment nearest coast, except for June in 2014, with variation of semi- and diurnal time periods. Temporal evolution of the wirewalker showed that disappearance and reoccurrence of the SCM within the water column in October 2014, which was associated with vertical mixing induced by strong wind stress. Low salinity plume in the surface layer and shoaling of bottom cold water were concurrently observed after homogeneous water column, affecting another condition to the vertical distribution of chlorophyll a in this coastal region. Moreover in-situ observation with densely points and temporal interval for 1 day revealed that distribution with high concentration of chlorophyll a on isopycnal was association with

Computer programs for generation and evaluation of near-optimum vertical flight profiles

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Waters, M. H.; Patmore, L. C.

1983-01-01

Two extensive computer programs were developed. The first, called OPTIM, generates a reference near-optimum vertical profile, and it contains control options so that the effects of various flight constraints on cost performance can be examined. The second, called TRAGEN, is used to simulate an aircraft flying along an optimum or any other vertical reference profile. TRAGEN is used to verify OPTIM's output, examine the effects of uncertainty in the values of parameters (such as prevailing wind) which govern the optimum profile, or compare the cost performance of profiles generated by different techniques. A general description of these programs, the efforts to add special features to them, and sample results of their usage are presented.

Studying Vertical Microbiome Transmission from Mothers to Infants by Strain-Level Metagenomic Profiling.

PubMed

Asnicar, Francesco; Manara, Serena; Zolfo, Moreno; Truong, Duy Tin; Scholz, Matthias; Armanini, Federica; Ferretti, Pamela; Gorfer, Valentina; Pedrotti, Anna; Tett, Adrian; Segata, Nicola

2017-01-01

The gut microbiome becomes shaped in the first days of life and continues to increase its diversity during the first months. Links between the configuration of the infant gut microbiome and infant health are being shown, but a comprehensive strain-level assessment of microbes vertically transmitted from mother to infant is still missing. We collected fecal and breast milk samples from multiple mother-infant pairs during the first year of life and applied shotgun metagenomic sequencing followed by computational strain-level profiling. We observed that several specific strains, including those of Bifidobacterium bifidum , Coprococcus comes , and Ruminococcus bromii , were present in samples from the same mother-infant pair, while being clearly distinct from those carried by other pairs, which is indicative of vertical transmission. We further applied metatranscriptomics to study the in vivo gene expression of vertically transmitted microbes and found that transmitted strains of Bacteroides and Bifidobacterium species were transcriptionally active in the guts of both adult and infant. By combining longitudinal microbiome sampling and newly developed computational tools for strain-level microbiome analysis, we demonstrated that it is possible to track the vertical transmission of microbial strains from mother to infants and to characterize their transcriptional activity. Our work provides the foundation for larger-scale surveys to identify the routes of vertical microbial transmission and its influence on postinfancy microbiome development. IMPORTANCE Early infant exposure is important in the acquisition and ultimate development of a healthy infant microbiome. There is increasing support for the idea that the maternal microbial reservoir is a key route of microbial transmission, and yet much is inferred from the observation of shared species in mother and infant. The presence of common species, per se , does not necessarily equate to vertical transmission, as species

Studying Vertical Microbiome Transmission from Mothers to Infants by Strain-Level Metagenomic Profiling

PubMed Central

Manara, Serena; Truong, Duy Tin; Armanini, Federica; Ferretti, Pamela; Gorfer, Valentina; Pedrotti, Anna

2017-01-01

ABSTRACT The gut microbiome becomes shaped in the first days of life and continues to increase its diversity during the first months. Links between the configuration of the infant gut microbiome and infant health are being shown, but a comprehensive strain-level assessment of microbes vertically transmitted from mother to infant is still missing. We collected fecal and breast milk samples from multiple mother-infant pairs during the first year of life and applied shotgun metagenomic sequencing followed by computational strain-level profiling. We observed that several specific strains, including those of Bifidobacterium bifidum, Coprococcus comes, and Ruminococcus bromii, were present in samples from the same mother-infant pair, while being clearly distinct from those carried by other pairs, which is indicative of vertical transmission. We further applied metatranscriptomics to study the in vivo gene expression of vertically transmitted microbes and found that transmitted strains of Bacteroides and Bifidobacterium species were transcriptionally active in the guts of both adult and infant. By combining longitudinal microbiome sampling and newly developed computational tools for strain-level microbiome analysis, we demonstrated that it is possible to track the vertical transmission of microbial strains from mother to infants and to characterize their transcriptional activity. Our work provides the foundation for larger-scale surveys to identify the routes of vertical microbial transmission and its influence on postinfancy microbiome development. IMPORTANCE Early infant exposure is important in the acquisition and ultimate development of a healthy infant microbiome. There is increasing support for the idea that the maternal microbial reservoir is a key route of microbial transmission, and yet much is inferred from the observation of shared species in mother and infant. The presence of common species, per se, does not necessarily equate to vertical transmission, as

pCO2 Observations from a Vertical Profiler on the upper continental slope off Vancouver Island: Physical controls on biogeochemical processes.

NASA Astrophysics Data System (ADS)

Mihaly, S. F.

2016-02-01

We analyse two six month sets of data collected from a vertical profiler on Ocean Networks Canada's NEPTUNE observatory over the summer and early fall of 2012 and 2014. The profiler is in 400 m of water on the upper slope of the continental shelf. The site is away from direct influence of canyons, but is in a region of strong internal tide generation. Both seasonally varying semidiurnal internal tidal currents and diurnal shelf waves are observed. The near surface mean flow is weak and seasonally alternates between the California and Alaskan Currents. Mid-depth waters are influenced by the poleward flowing Californian undercurrent and the deep waters by seasonally varying wind-driven Ekman transport. The profiling package consists of a CTD, an oxygen optode, a pCO2 sensor, Chlorophyll fluorometer/turbidity, CDOM and is co-located with an upward-looking bottom-mounted 75kHz ADCP that measures currents to 30 m below sea surface. With these first deep-sea profiled time series measurements of pCO2, we endeavor to model how the local physical dynamics exert control over the variability of water properties over the slope and shelf and what the variability of the non-conservative tracers of pCO2 and O2 can tell us about the biogeochemistry of the region.

Shifts of radiocesium vertical profiles in sediments and their modelling in Japanese lakes.

PubMed

Fukushima, Takehiko; Komatsu, Eiji; Arai, Hiroyuki; Kamiya, Koichi; Onda, Yuichi

2018-02-15

Vertical profiles of radiocesium concentrations were measured in sediment cores collected at various times after the 2011 Fukushima nuclear accident in five Japanese lakes (Hinuma, Kasumigaura, Kitaura, Onogawa and Sohara) with different morphological and trophic characteristics in order to investigate the sedimentation-diffusion processes. In lakes where sediments had high porosities and experienced considerable wave action due to shallowness, we observed rapid penetration of radiocesium to a certain depth just after the accident, followed by downward movement of the peak depths. In contrast, gradual downward transfers of distinct peaks were found in other types of lakes. A one-dimensional differential sediment model with water-sediments interaction processes was constructed to describe the vertical shift of radiocesium profiles. Our proposed submodels relating to the length scales of the mixing using wind-induced stress and porosity of sediments were constructed based on one measurement of the vertical distribution of radiocesium in three lakes (Hinuma, Kasumigaura and Sohara). This model was then validated using samples from those lakes in different years, as well as from two other lakes. Good agreement was obtained. We discuss our findings, the limits of model application, and future research targets. Copyright © 2017 Elsevier B.V. All rights reserved.

GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra

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

Connor, Brian J.; Sherlock, Vanessa; Toon, Geoff

An algorithm for retrieval of vertical profiles from ground-based spectra in the near IR is described and tested. Known as GFIT2, the algorithm is primarily intended for CO 2, and is used exclusively for CO 2 in this paper. Retrieval of CO 2 vertical profiles from ground-based spectra is theoretically possible, would be very beneficial for carbon cycle studies and the validation of satellite measurements, and has been the focus of much research in recent years. GFIT2 is tested by application both to synthetic spectra and to measurements at two Total Carbon Column Observing Network (TCCON) sites. We demonstrate thatmore » there are approximately 3° of freedom for the CO 2 profile, and the algorithm performs as expected on synthetic spectra. We show that the accuracy of retrievals of CO 2 from measurements in the 1.61 μ (6220 cm -1) spectral band is limited by small uncertainties in calculation of the atmospheric spectrum. We investigate several techniques to minimize the effect of these uncertainties in calculation of the spectrum. These techniques are somewhat effective but to date have not been demonstrated to produce CO 2 profile retrievals with sufficient precision for applications to carbon dynamics. As a result, we finish by discussing ongoing research which may allow CO 2 profile retrievals with sufficient accuracy to significantly improve the scientific value of the measurements from that achieved with column retrievals.« less

GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra

DOE PAGES

Connor, Brian J.; Sherlock, Vanessa; Toon, Geoff; ...

2016-08-02

An algorithm for retrieval of vertical profiles from ground-based spectra in the near IR is described and tested. Known as GFIT2, the algorithm is primarily intended for CO 2, and is used exclusively for CO 2 in this paper. Retrieval of CO 2 vertical profiles from ground-based spectra is theoretically possible, would be very beneficial for carbon cycle studies and the validation of satellite measurements, and has been the focus of much research in recent years. GFIT2 is tested by application both to synthetic spectra and to measurements at two Total Carbon Column Observing Network (TCCON) sites. We demonstrate thatmore » there are approximately 3° of freedom for the CO 2 profile, and the algorithm performs as expected on synthetic spectra. We show that the accuracy of retrievals of CO 2 from measurements in the 1.61 μ (6220 cm -1) spectral band is limited by small uncertainties in calculation of the atmospheric spectrum. We investigate several techniques to minimize the effect of these uncertainties in calculation of the spectrum. These techniques are somewhat effective but to date have not been demonstrated to produce CO 2 profile retrievals with sufficient precision for applications to carbon dynamics. As a result, we finish by discussing ongoing research which may allow CO 2 profile retrievals with sufficient accuracy to significantly improve the scientific value of the measurements from that achieved with column retrievals.« less

Vertical Soil Profiling Using a Galvanic Contact Resistivity Scanning Approach

PubMed Central

Pan, Luan; Adamchuk, Viacheslav I.; Prasher, Shiv; Gebbers, Robin; Taylor, Richard S.; Dabas, Michel

2014-01-01

Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep) soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument. PMID:25057135

Impact of spatial inhomogeneities on stratospheric species vertical profiles from remote-sensing balloon-borne instruments

NASA Astrophysics Data System (ADS)

Berthet, Gwenael; Renard, Jean-Baptiste; Catoire, Valery; Huret, Nathalie; Lefevre, Franck; Hauchecorne, Alain; Chartier, Michel; Robert, Claude

Remote-sensing balloon observations have recurrently revealed high concentrations of polar stratospheric NO2 in particular in the lower stratosphere as can be seen in various published vertical profiles. A balloon campaign dedicated to the investigation of this problem through comparisons between remote-sensing (SALOMON) and in situ (SPIRALE) measurements of NO2 inside the polar vortex was conducted in January 2006. The published results show unexpected strong enhancements in the slant column densities of NO2 with respect to the elevation angle and displacement of the balloon. These fluctuations result from NO2 spatial inhomogeneities located above the balloon float altitude resulting from mid-latitude air intrusion as revealed by Potential Vorticity (PV) maps. The retrieval of the NO2 vertical profile is subsequently biased in the form of artificial excesses of NO2 concentrations. A direct implication is that the differences previously observed between measurements of NO2 and OClO and model results are probably mostly due to the improper inversion of NO2 in presence of either perturbed dynamical conditions or when mesospheric production events occur as recently highlighted from ENVISAT data. Through the occurrence of such events, we propose to re-examine formerly published high-latitude profiles from the remote-sensing instruments AMON and SALOMON using in parallel PV maps from the MIMOSA advection contour model and the REPROBUS CTM outputs. Mid-latitude profiles of NO2 will also be investigated since they are likely to be biased if presence of air from other latitudes was present at the time of the observations.

Vertical profiles of aerosol mass concentration derived by unmanned airborne in situ and remote sensing instruments during dust events

NASA Astrophysics Data System (ADS)

Mamali, Dimitra; Marinou, Eleni; Sciare, Jean; Pikridas, Michael; Kokkalis, Panagiotis; Kottas, Michael; Binietoglou, Ioannis; Tsekeri, Alexandra; Keleshis, Christos; Engelmann, Ronny; Baars, Holger; Ansmann, Albert; Amiridis, Vassilis; Russchenberg, Herman; Biskos, George

2018-05-01

In situ measurements using unmanned aerial vehicles (UAVs) and remote sensing observations can independently provide dense vertically resolved measurements of atmospheric aerosols, information which is strongly required in climate models. In both cases, inverting the recorded signals to useful information requires assumptions and constraints, and this can make the comparison of the results difficult. Here we compare, for the first time, vertical profiles of the aerosol mass concentration derived from light detection and ranging (lidar) observations and in situ measurements using an optical particle counter on board a UAV during moderate and weak Saharan dust episodes. Agreement between the two measurement methods was within experimental uncertainty for the coarse mode (i.e. particles having radii > 0.5 µm), where the properties of dust particles can be assumed with good accuracy. This result proves that the two techniques can be used interchangeably for determining the vertical profiles of aerosol concentrations, bringing them a step closer towards their systematic exploitation in climate models.

Vertical velocity variance in the mixed layer from radar wind profilers

USGS Publications Warehouse

Eng, K.; Coulter, R.L.; Brutsaert, W.

2003-01-01

Vertical velocity variance data were derived from remotely sensed mixed layer turbulence measurements at the Atmospheric Boundary Layer Experiments (ABLE) facility in Butler County, Kansas. These measurements and associated data were provided by a collection of instruments that included two 915 MHz wind profilers, two radio acoustic sounding systems, and two eddy correlation devices. The data from these devices were available through the Atmospheric Boundary Layer Experiment (ABLE) database operated by Argonne National Laboratory. A signal processing procedure outlined by Angevine et al. was adapted and further built upon to derive vertical velocity variance, w_pm???2, from 915 MHz wind profiler measurements in the mixed layer. The proposed procedure consisted of the application of a height-dependent signal-to-noise ratio (SNR) filter, removal of outliers plus and minus two standard deviations about the mean on the spectral width squared, and removal of the effects of beam broadening and vertical shearing of horizontal winds. The scatter associated with w_pm???2 was mainly affected by the choice of SNR filter cutoff values. Several different sets of cutoff values were considered, and the optimal one was selected which reduced the overall scatter on w_pm???2 and yet retained a sufficient number of data points to average. A similarity relationship of w_pm???2 versus height was established for the mixed layer on the basis of the available data. A strong link between the SNR and growth/decay phases of turbulence was identified. Thus, the mid to late afternoon hours, when strong surface heating occurred, were observed to produce the highest quality signals.

Estimating vertical profiles of water-cloud droplet effective radius from SWIR satellite measurements via a statistical model derived from CloudSat observations

NASA Astrophysics Data System (ADS)

Nagao, T. M.; Murakami, H.; Nakajima, T. Y.

2017-12-01

This study proposes an algorithm to estimate vertical profiles of cloud droplet effective radius (CDER-VP) for water clouds from shortwave infrared (SWIR) measurements of Himawari-8/AHI via a statistical model of CDER-VP derived from CloudSat observation. Several similar algorithms in previous studies utilize a spectral radiance matching on the assumption of simultaneous observations of CloudSat and Aqua/MODIS. However, our algorithm does not assume simultaneous observations with CloudSat. First, in advance, a database (DB) of CDER-VP is prepared by the following procedure: TOA radiances at 0.65, 2.3 and 10.4-μm bands of the AHI are simulated using CDER-VP and cloud optical depth vertical profile (COD-VP) contained in the CloudSat 2B-CWC-RVOD and 2B-TAU products. Cloud optical thickness (COT), Column-CDER and cloud top height (CTH) are retrieved from the simulated radiances using a traditional retrieval algorithm with vertically homogeneous cloud model (1-SWIR VHC method). The CDER-VP is added to the DB by using the COT and Column-CDER retrievals as a key of the DB. Then by using principal component (PC) analysis, up to three PC vectors of the CDER-VPs in the DB are extracted. Next, the algorithm retrieves CDER-VP from actual AHI measurements by the following procedure: First, COT, Column-CDER and CTH are retrieved from TOA radiances at 0.65, 2.3 and 10.4-μm bands of the AHI using by 1-SWIR VHC method. Then, the PC vectors of CDER-VP is fetched from the DB using the COT and Column-CDER retrievals as the key of the DB. Finally, using coefficients of the PC vectors of CDER-VP as variables for retrieval, CDER-VP, COT and CTH are retrieved from TOA radiances at 0.65, 1.6, 2.3, 3.9 and 10.4-μm bands of the AHI based on optimal estimation method with iterative radiative transfer calculation. The simulation result showed the CDER-VP retrieval errors were almost smaller than 3 - 4 μm. The CDER retrieval errors at the cloud base were almost larger than the others (e

Latitudinal Variations In Vertical Cloud Structure Of Jupiter As Determined By Ground- based Observation With Multispectral Imaging

NASA Astrophysics Data System (ADS)

Sato, T.; Kasaba, Y.; Takahashi, Y.; Murata, I.; Uno, T.; Tokimasa, N.; Sakamoto, M.

2008-12-01

We conducted ground-based observation of Jupiter with the liquid crystal tunable filter (LCTF) and EM-CCD camera in two methane absorption bands (700-757nm, 872-950nm at 3 nm step: total of 47 wavelengths) to derive detailed Jupiter's vertical cloud structure. The 2-meter reflector telescope at Nishi-Harima astronomical observatory in Japan was used for our observation on 26-30 May, 2008. After a series of image processing (composition of high quality images in each wavelength and geometry calibration), we converted observed intensity to absolute reflectivity at each pixel using standard star. As a result, we acquired Jupiter's data cubes with high-spatial resolution (about 1") and narrow band imaging (typically 7nm) in each methane absorption band by superimposing 30 Jupiter's images obtained in short exposure time (50 ms per one image). These data sets enable us to probe different altitudes of Jupiter from 100 mbar down to 1bar level with higher vertical resolution than using convectional interference filters. To interpret observed center-limb profiles, we developed radiative transfer code based on layer adding doubling algorithm to treat multiple scattering of solar light theoretically and extracted information on aerosol altitudes and optical properties using two-cloud model. First, we fit 5 different profiles simultaneously in continuum data (745-757 nm) to retrieve information on optical thickness of haze and single scattering albedo of cloud. Second, we fit 15 different profiles around 727nm methane absorption band and 13 different profiles around 890 nm methane absorption band to retrieve information on the aerosol altitude location and optical thickness of cloud. In this presentation, we present the results of these modeling simulations and discuss the latitudinal variations of Jupiter's vertical cloud structure.

Radially Magnetized Protoplanetary Disk: Vertical Profile

NASA Astrophysics Data System (ADS)

Russo, Matthew; Thompson, Christopher

2015-11-01

This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field Br ˜ (10-4-10-2)(r/ AU)-2 G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ˜1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10-8 M⊙ yr-1 are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper.

Application of a new vertical profiling tool (ESASS) for sampling groundwater quality during hollow-stem auger drilling

USGS Publications Warehouse

Harte, Philip T.; Flanagan, Sarah M.

2011-01-01

A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth-specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305-m long screen auger during hollow-stem auger drilling. With ESASS, the water column in the flights above the screen auger is separated from the water in the screen auger by a specially designed removable plug and collar. The tool fits inside an auger of standard inner diameter (82.55 mm). The novel design of the system constituted by the plug, collar, and A-rod allows the plug to be retrieved using conventional drilling A-rods. After retrieval, standard-diameter (50.8 mm) observation wells can be installed within the hollow-stem augers. Testing of ESASS was conducted at one waste-disposal site with tetrachloroethylene (PCE) contamination and at two reference sites with no known waste-disposal history. All three sites have similar geology and are underlain by glacial, stratified-drift deposits. For the applications tested, ESASS proved to be a useful tool in vertical profiling of groundwater quality. At the waste site, PCE concentrations measured with ESASS profiling at several depths were comparable (relative percent difference <25%) to PCE concentrations sampled from wells. Vertical profiling with ESASS at the reference sites illustrated the vertical resolution achievable in the profile system; shallow groundwater quality varied by a factor of five in concentration of some constituents (nitrate and nitrite) over short (0.61 m) distances.

A method for retrieving vertical ozone profiles from limb scattered measurements

NASA Astrophysics Data System (ADS)

Wang, Zijun; Chen, Shengbo; Yang, Chunyan; Jin, Lihua

2011-10-01

A two-step method is employed in this study to retrieve vertical ozone profiles using scattered measurements from the limb of the atmosphere. The combination of the Differential Optical Absorption Spectroscopy (DOAS) and the Multiplicative Algebraic Reconstruction Technique (MART) is proposed. First, the limb radiance, measured over a range of tangent heights, is processed using the DOAS technique to recover the effective column densities of atmospheric ozone. Second, these effective column densities along the lines of sight (LOSs) are inverted using the MART coupled with a forward model SCIATRAN (radiative transfer model for SCIAMACHY) to derive the ozone profiles. This method is applied to Optical Spectrograph and Infra Red Imager System (OSIRIS) radiance, using the wavelength windows 571-617 nm. Vertical ozone profiles between 10 and 48 km are derived with a vertical resolution of 1 km. The results illustrate a good agreement with the cloud-free coincident SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) ozone measurements, with deviations less than ±10% (±5% for altitudes from 17 to 47 km). Furthermore, sensitivities of retrieved ozone to aerosol, cloud parameters and NO2 concentration are also investigated.

K-band observations of boxy bulges - I. Morphology and surface brightness profiles

NASA Astrophysics Data System (ADS)

Bureau, M.; Aronica, G.; Athanassoula, E.; Dettmar, R.-J.; Bosma, A.; Freeman, K. C.

2006-08-01

In this first paper of a series on the structure of boxy and peanut-shaped (B/PS) bulges, Kn-band observations of a sample of 30 edge-on spiral galaxies are described and discussed. Kn-band observations best trace the dominant luminous galactic mass and are minimally affected by dust. Images, unsharp-masked images, as well as major-axis and vertically summed surface brightness profiles are presented and discussed. Galaxies with a B/PS bulge tend to have a more complex morphology than galaxies with other bulge types, more often showing centred or off-centred X structures, secondary maxima along the major-axis and spiral-like structures. While probably not uniquely related to bars, those features are observed in three-dimensional N-body simulations of barred discs and may trace the main bar orbit families. The surface brightness profiles of galaxies with a B/PS bulge are also more complex, typically containing three or more clearly separated regions, including a shallow or flat intermediate region (Freeman Type II profiles). The breaks in the profiles offer evidence for bar-driven transfer of angular momentum and radial redistribution of material. The profiles further suggest a rapid variation of the scaleheight of the disc material, contrary to conventional wisdom but again as expected from the vertical resonances and instabilities present in barred discs. Interestingly, the steep inner region of the surface brightness profiles is often shorter than the isophotally thick part of the galaxies, itself always shorter than the flat intermediate region of the profiles. The steep inner region is also much more prominent along the major-axis than in the vertically summed profiles. Similarly to other recent work but contrary to the standard `bulge + disc' model (where the bulge is both thick and steep), we thus propose that galaxies with a B/PS bulge are composed of a thin concentrated disc (a disc-like bulge) contained within a partially thick bar (the B/PS bulge), itself

TOLNet Data Format for Lidar Ozone Profile & Surface Observations

NASA Astrophysics Data System (ADS)

Chen, G.; Aknan, A. A.; Newchurch, M.; Leblanc, T.

2015-12-01

The Tropospheric Ozone Lidar Network (TOLNet) is an interagency initiative started by NASA, NOAA, and EPA in 2011. TOLNet currently has six Lidars and one ozonesonde station. TOLNet provides high-resolution spatio-temporal measurements of tropospheric (surface to tropopause) ozone and aerosol vertical profiles to address fundamental air-quality science questions. The TOLNet data format was developed by TOLNet members as a community standard for reporting ozone profile observations. The development of this new format was primarily based on the existing NDAAC (Network for the Detection of Atmospheric Composition Change) format and ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) format. The main goal is to present the Lidar observations in self-describing and easy-to-use data files. The TOLNet format is an ASCII format containing a general file header, individual profile headers, and the profile data. The last two components repeat for all profiles recorded in the file. The TOLNet format is both human and machine readable as it adopts standard metadata entries and fixed variable names. In addition, software has been developed to check for format compliance. To be presented is a detailed description of the TOLNet format protocol and scanning software.

Relationships among cloud occurrence frequency, overlap, and effective thickness derived from CALIPSO and CloudSat merged cloud vertical profiles

NASA Astrophysics Data System (ADS)

Kato, Seiji; Sun-Mack, Sunny; Miller, Walter F.; Rose, Fred G.; Chen, Yan; Minnis, Patrick; Wielicki, Bruce A.

2010-01-01

A cloud frequency of occurrence matrix is generated using merged cloud vertical profiles derived from the satellite-borne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and cloud profiling radar. The matrix contains vertical profiles of cloud occurrence frequency as a function of the uppermost cloud top. It is shown that the cloud fraction and uppermost cloud top vertical profiles can be related by a cloud overlap matrix when the correlation length of cloud occurrence, which is interpreted as an effective cloud thickness, is introduced. The underlying assumption in establishing the above relation is that cloud overlap approaches random overlap with increasing distance separating cloud layers and that the probability of deviating from random overlap decreases exponentially with distance. One month of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat data (July 2006) support these assumptions, although the correlation length sometimes increases with separation distance when the cloud top height is large. The data also show that the correlation length depends on cloud top hight and the maximum occurs when the cloud top height is 8 to 10 km. The cloud correlation length is equivalent to the decorrelation distance introduced by Hogan and Illingworth (2000) when cloud fractions of both layers in a two-cloud layer system are the same. The simple relationships derived in this study can be used to estimate the top-of-atmosphere irradiance difference caused by cloud fraction, uppermost cloud top, and cloud thickness vertical profile differences.

Satellite-derived vertical profiles of temperature and dew point for mesoscale weather forecast

NASA Astrophysics Data System (ADS)

Masselink, Thomas; Schluessel, P.

1995-12-01

Weather forecast-models need spatially high resolutioned vertical profiles of temperature and dewpoint for their initialisation. These profiles can be supplied by a combination of data from the Tiros-N Operational Vertical Sounder (TOVS) and the imaging Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA polar orbiting sate!- lites. In cloudy cases the profiles derived from TOVS data only are of insufficient accuracy. The stanthrd deviations from radiosonde ascents or numerical weather analyses likely exceed 2 K in temperature and 5Kin dewpoint profiles. It will be shown that additional cloud information as retrieved from AVHIRR allows a significant improvement in theaccuracy of vertical profiles. The International TOVS Processing Package (ITPP) is coupled to an algorithm package called AVHRR Processing scheme Over cLouds, Land and Ocean (APOLLO) where parameters like cloud fraction and cloud-top temperature are determined with higher accuracy than obtained from TOVS retrieval alone. Furthermore, a split-window technique is applied to the cloud-free AVHRR imagery in order to derive more accurate surface temperatures than can be obtained from the pure TOVS retrieval. First results of the impact of AVHRR cloud detection on the quality of the profiles are presented. The temperature and humidity profiles of different retrieval approaches are validated against analyses of the European Centre for Medium-Range Weatherforecasts.

Improvement of vertical profiles of raindrop size distribution from micro rain radar using 2D video disdrometer measurements

NASA Astrophysics Data System (ADS)

Adirosi, E.; Baldini, L.; Roberto, N.; Gatlin, P.; Tokay, A.

2016-03-01

A measurement scheme aimed at investigating precipitation properties based on collocated disdrometer and profiling instruments is used in many experimental campaigns. Raindrop size distribution (RSD) estimated by disdrometer is referred to the ground level; the collocated profiling instrument is supposed to provide complementary estimation at different heights of the precipitation column above the instruments. As part of the Special Observation Period 1 of the HyMeX (Hydrological Cycle in the Mediterranean Experiment) project, conducted between 5 September and 6 November 2012, a K-band vertically pointing micro rain radar (MRR) and a 2D video disdrometer (2DVD) were installed close to each other at a site in the historic center of Rome (Italy). The raindrop size distributions collected by 2D video disdrometer are considered to be fairly accurate within the typical sizes of drops. Vertical profiles of raindrop sizes up to 1085 m are estimated from the Doppler spectra measured by the micro rain radar with a height resolution of 35 m. Several issues related to vertical winds, attenuation correction, Doppler spectra aliasing, and range-Doppler ambiguity limit the performance of MRR in heavy precipitation or in convection, conditions that frequently occur in late summer or in autumn in Mediterranean regions. In this paper, MRR Doppler spectra are reprocessed, exploiting the 2DVD measurements at ground to estimate the effects of vertical winds at 105 m (the most reliable MRR lower height), in order to provide a better estimation of vertical profiles of raindrop size distribution from MRR spectra. Results show that the reprocessing procedure leads to a better agreement between the reflectivity computed at 105 m from the reprocessed MRR spectra and that obtained from the 2DVD data. Finally, vertical profiles of MRR-estimated RSDs and their relevant moments (namely median volume diameter and reflectivity) are presented and discussed in order to investigate the

RADIALLY MAGNETIZED PROTOPLANETARY DISK: VERTICAL PROFILE

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

Russo, Matthew; Thompson, Christopher

2015-11-10

This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiencesmore » the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field B{sub r} ∼ (10{sup −4}–10{sup −2})(r/ AU){sup −2} G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ∼1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10{sup −8} M{sub ⊙} yr{sup −1} are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper.« less

Mesoscale kinematics derived from X-band Doppler radar observations of convective versus stratiform precipitation and comparison with GPS radiosonde profiles

NASA Astrophysics Data System (ADS)

Deshpande, Sachin M.; Dhangar, N.; Das, S. K.; Kalapureddy, M. C. R.; Chakravarty, K.; Sonbawne, S.; Konwar, M.

2015-11-01

Single Doppler analysis techniques known as velocity azimuth display (VAD) and volume velocity processing (VVP) are used to analyze kinematics of mesoscale flow such as horizontal wind and divergence using X-band Doppler weather radar observations, for selected cases of convective, stratiform, and shallow cloud systems near tropical Indian sites Pune (18.58°N, 73.92°E, above sea level (asl) 560 m) and Mandhardev (18.51°N, 73.85°E, asl 1297 m). The vertical profiles of horizontal wind estimated from radar VVP/VAD methods agree well with GPS radiosonde profiles, with the low-level jet at about 1.5 km during monsoon season well depicted in both. The vertical structure and temporal variability of divergence and reflectivity profiles are indicative of the dynamical and microphysical characteristics of shallow convective, deep convective, and stratiform cloud systems. In shallow convective systems, vertical development of reflectivity profiles is limited below 5 km. In deep convective systems, reflectivity values as large as 55 dBZ were observed above freezing level. The stratiform system shows the presence of a reflectivity bright band (~35 dBZ) near the melting level. The diagnosed vertical profiles of divergence in convective and stratiform systems are distinct. In shallow convective conditions, convergence was seen below 4 km with divergence above. Low-level convergence and upper level divergence are observed in deep convective profiles, while stratiform precipitation has midlevel convergence present between lower level and upper level divergence. The divergence profiles in stratiform precipitation exhibit intense shallow layers of "melting convergence" at 0°C level, near 4.5 km altitude, with a steep gradient on the both sides of the peak. The level of nondivergence in stratiform situations is lower than that in convective situations. These observed vertical structures of divergence are largely indicative of latent heating profiles in the atmosphere, an

Application of a new vertical profiling tool (ESASS) for sampling groundwater quality during hollow-stem auger drilling

USGS Publications Warehouse

Harte, P.T.; Flanagan, S.M.

2011-01-01

A new tool called ESASS (Enhanced Screen Auger Sampling System) was developed by the U.S. Geological Survey. The use of ESASS, because of its unique U.S. patent design (U.S. patent no. 7,631,705 B1), allows for the collection of representative, depth-specific groundwater samples (vertical profiling) in a quick and efficient manner using a 0.305-m long screen auger during hollow-stem auger drilling. With ESASS, the water column in the flights above the screen auger is separated from the water in the screen auger by a specially designed removable plug and collar. The tool fits inside an auger of standard inner diameter (82.55 mm). The novel design of the system constituted by the plug, collar, and A-rod allows the plug to be retrieved using conventional drilling A-rods. After retrieval, standard-diameter (50.8 mm) observation wells can be installed within the hollow-stem augers. Testing of ESASS was conducted at one waste-disposal site with tetrachloroethylene (PCE) contamination and at two reference sites with no known waste-disposal history. All three sites have similar geology and are underlain by glacial, stratified-drift deposits. For the applications tested, ESASS proved to be a useful tool in vertical profiling of groundwater quality. At the waste site, PCE concentrations measured with ESASS profiling at several depths were comparable (relative percent difference <25%) to PCE concentrations sampled from wells. Vertical profiling with ESASS at the reference sites illustrated the vertical resolution achievable in the profile system; shallow groundwater quality varied by a factor of five in concentration of some constituents (nitrate and nitrite) over short (0.61 m) distances. Ground Water Monitoring & Remediation ?? 2011, National Ground Water Association. No claim to original US government works.

Measuring vertical oxygen profiles in the hyporheic zone using planar optodes

NASA Astrophysics Data System (ADS)

Vieweg, M.; Fleckenstein, J. H.; Schmidt, C.

2012-04-01

On of the key parameters, controlling biogeochemical reactions in the hyporheic zone (HZ) is the distribution of oxygen. A reliable measurement of the vertical oxygen distribution is an important tool to understand the dynamic fluctuations of the aerobic zone within the HZ. With repeated measurements of continuous profiles, mixing of surface water and groundwater as well as the consumption of oxygen can be evaluated. We present a novel approach for the in situ measurements of vertical oxygen distribution in the riverbed using a planar optode. The luminescence based optode measurement enables a non invasive measurement without consumption of oxygen, no creation of preferential flow paths and only minimal disturbance of the flow field. Possible atmospheric contamination by pumping pore water into a vessel can be avoided and the readings are independent of flow velocity. A self manufactured planar optode is wrapped around an acrylic tube and installed in the riverbed. The measurement is performed by vertically moving a profiler-piston inside the acrylic tube. The piston holds a robust polymer optical fibre which emits a modulated light signal through the acrylic glass to the optode-foil and transmits the induced luminescence signal back to a commercially available trace oxygen meter. Temperature compensation is accomplished using a depth-oriented temperature probe nearby and processing the raw data within a Matlab script. Robust and unbiased oxygen profiles are obtained by averaging multiple consecutive measurements. To ensure a constant velocity of the profiler for replicating the exact measuring depths, an electric motor device is used. First results at our test site show a variable oxygen profile down to 40 cm depth which is strongly influenced by stream level and upwelling groundwater conditions. The measured oxygen profiles will serve as input parameter for a 3D solute transport and chemical reaction subsurface model of the HZ.

More vertical etch profile using a Faraday cage in plasma etching

NASA Astrophysics Data System (ADS)

Cho, Byeong-Ok; Hwang, Sung-Wook; Ryu, Jung-Hyun; Moon, Sang Heup

1999-05-01

Scanning electron microscope images of sidewalls obtained by plasma etching of an SiO2 film with and without a Faraday cage have been compared. When the substrate film is etched in the Faraday cage, faceting is effectively suppressed and the etch profile becomes more vertical regardless of the process conditions. This is because the electric potential in the cage is nearly uniform and therefore distortion of the electric field at the convex corner of a microfeature is prevented. The most vertical etch profile is obtained when the cage is used in fluorocarbon plasmas, where faceting is further suppressed due to the decrease in the chemical sputtering yield and the increase in the radical/ion flux on the substrate.

Vertical Position and Current Profile Measurements by Faraday-effect Polarimetry On EAST tokamak

NASA Astrophysics Data System (ADS)

Ding, Weixing; Liu, H. Q.; Jie, Y. X.; Brower, D. L.; Qian, J. P.; Zou, Z. Y.; Lian, H.; Wang, S. X.; Luo, Z. P.; Xiao, B. J.; Ucla Team; Asipp Team

2017-10-01

A primary goal for ITER and prospective fusion power reactors is to achieve controlled long-pulse/steady-state burning plasmas. For elongated divertor plasmas, both the vertical position and current profile have to be precisely controlled to optimize performance and prevent disruptions. An eleven-channel laser-based POlarimeter-INTerferometer (POINT) system has been developed for measuring the internal magnetic field in the EAST tokamak and can be used to obtain the plasma current profile and vertical position. Current profiles are determined from equilibrium reconstruction including internal magnetic field measurements as internal constraints. Horizontally-viewing chords at/near the mid-plane allow us to determine plasma vertical position non-inductively with subcentimeter spatial resolution and time response up to 1 s. The polarimeter-based position measurement, which does not require equilibrium reconstruction, is benchmarked against conventional flux loop measurements and can be exploited for feedback control. Work supported by US DOE through Grants No. DE-FG02-01ER54615 and No. DC-SC0010469.

Wind-Wave Effects on Vertical Mixing in Chesapeake Bay, USA: comparing observations to second-moment closure predictions.

NASA Astrophysics Data System (ADS)

Fisher, A. W.; Sanford, L. P.; Scully, M. E.

2016-12-01

Coherent wave-driven turbulence generated through wave breaking or nonlinear wave-current interactions, e.g. Langmuir turbulence (LT), can significantly enhance the downward transfer of momentum, kinetic energy, and dissolved gases in the oceanic surface layer. There are few observations of these processes in the estuarine or coastal environments, where wind-driven mixing may co-occur with energetic tidal mixing and strong density stratification. This presents a major challenge for evaluating vertical mixing parameterizations used in modeling estuarine and coastal dynamics. We carried out a large, multi-investigator study of wind-driven estuarine dynamics in the middle reaches of Chesapeake Bay, USA, during 2012-2013. The center of the observational array was an instrumented turbulence tower with both atmospheric and marine turbulence sensors as well as rapidly sampled temperature and conductivity sensors. For this paper, we examined the impacts of surface gravity waves on vertical profiles of turbulent mixing and compared our results to second-moment turbulence closure predictions. Wave and turbulence measurements collected from the vertical array of Acoustic Doppler Velocimeters (ADVs) provided direct estimates of the dominant terms in the TKE budget and the surface wave field. Observed dissipation rates, TKE levels, and turbulent length scales are compared to published scaling relations and used in the calculation of second-moment nonequilibrium stability functions. Results indicate that in the surface layer of the estuary, where elevated dissipation is balanced by vertical divergence in TKE flux, existing nonequilibrium stability functions underpredict observed eddy viscosities. The influences of wave breaking and coherent wave-driven turbulence on modeled and observed stability functions will be discussed further in the context of turbulent length scales, TKE and dissipation profiles, and the depth at which the wave-dominated turbulent transport layer

Modeling of Aerosol Vertical Profiles Using GIS and Remote Sensing

PubMed Central

Wong, Man Sing; Nichol, Janet E.; Lee, Kwon Ho

2009-01-01

The use of Geographic Information Systems (GIS) and Remote Sensing (RS) by climatologists, environmentalists and urban planners for three dimensional modeling and visualization of the landscape is well established. However no previous study has implemented these techniques for 3D modeling of atmospheric aerosols because air quality data is traditionally measured at ground points, or from satellite images, with no vertical dimension. This study presents a prototype for modeling and visualizing aerosol vertical profiles over a 3D urban landscape in Hong Kong. The method uses a newly developed technique for the derivation of aerosol vertical profiles from AERONET sunphotometer measurements and surface visibility data, and links these to a 3D urban model. This permits automated modeling and visualization of aerosol concentrations at different atmospheric levels over the urban landscape in near-real time. Since the GIS platform permits presentation of the aerosol vertical distribution in 3D, it can be related to the built environment of the city. Examples are given of the applications of the model, including diagnosis of the relative contribution of vehicle emissions to pollution levels in the city, based on increased near-surface concentrations around weekday rush-hour times. The ability to model changes in air quality and visibility from ground level to the top of tall buildings is also demonstrated, and this has implications for energy use and environmental policies for the tall mega-cities of the future. PMID:22408531

Modeling of Aerosol Vertical Profiles Using GIS and Remote Sensing.

PubMed

Wong, Man Sing; Nichol, Janet E; Lee, Kwon Ho

2009-01-01

The use of Geographic Information Systems (GIS) and Remote Sensing (RS) by climatologists, environmentalists and urban planners for three dimensional modeling and visualization of the landscape is well established. However no previous study has implemented these techniques for 3D modeling of atmospheric aerosols because air quality data is traditionally measured at ground points, or from satellite images, with no vertical dimension. This study presents a prototype for modeling and visualizing aerosol vertical profiles over a 3D urban landscape in Hong Kong. The method uses a newly developed technique for the derivation of aerosol vertical profiles from AERONET sunphotometer measurements and surface visibility data, and links these to a 3D urban model. This permits automated modeling and visualization of aerosol concentrations at different atmospheric levels over the urban landscape in near-real time. Since the GIS platform permits presentation of the aerosol vertical distribution in 3D, it can be related to the built environment of the city. Examples are given of the applications of the model, including diagnosis of the relative contribution of vehicle emissions to pollution levels in the city, based on increased near-surface concentrations around weekday rush-hour times. The ability to model changes in air quality and visibility from ground level to the top of tall buildings is also demonstrated, and this has implications for energy use and environmental policies for the tall mega-cities of the future.

GOSAT TIR radiometric validation toward simultaneous GHG column and profile observation

NASA Astrophysics Data System (ADS)

Kataoka, F.; Knuteson, R. O.; Kuze, A.; Shiomi, K.; Suto, H.; Saitoh, N.

2015-12-01

The Greenhouse gases Observing SATellite (GOSAT) was launched on January 2009 and continues its operation for more than six years. The thermal and near infrared sensor for carbon observation Fourier-Transform Spectrometer (TANSO-FTS) onboard GOSAT measures greenhouse gases (GHG), such as CO2 and CH4, with wide and high resolution spectra from shortwave infrared (SWIR) to thermal infrared (TIR). This instrument has the advantage of being able to measure simultaneously the same field of view in different spectral ranges. The combination of column-GHG form SWIR band and vertical profile-GHG from TIR band provide better understanding and distribution of GHG, especially in troposphere. This work describes the radiometric validation and sensitivity analysis of TANSO-FTS TIR spectra, especially CO2, atmospheric window and CH4 channels with forward calculation. In this evaluation, we used accurate in-situ dataset of the HIPPO (HIAPER Pole-to-Pole Observation) airplane observation data and GOSAT vicarious calibration and validation campaign data in Railroad Valley, NV. The HIPPO aircraft campaign had taken accurate atmospheric vertical profile dataset (T, RH, O3, CO2, CH4, N2O, CO) approximately pole-to-pole from the surface to the tropopause over the ocean. We implemented these dataset for forward calculation and made the spectral correction model with respect to wavenumber and internal calibration blackbody temperature The GOSAT vicarious calibration campaign have conducted every year since 2009 near summer solstice in Railroad Valley, where high-temperature desert site. In this campaign, we have measured temperature and humidity by a radiosonde and CO2, CH4 and O3 profile by the AJAX airplane at the time of the GOSAT overpass. Sometimes, the GHG profiles over the Railroad Valley show the air mass advection in mid-troposphere depending on upper wind. These advections bring the different concentration of GHG in lower and upper troposphere. Using these cases, we made

Large-scale vertical velocity, diabatic heating and drying profiles associated with seasonal and diurnal variations of convective systems observed in the GoAmazon2014/5 experiment

DOE PAGES

Tang, Shuaiqi; Xie, Shaocheng; Zhang, Yunyan; ...

2016-11-16

This study describes the characteristics of large-scale vertical velocity, apparent heating source ( Q 1) and apparent moisture sink ( Q 2) profiles associated with seasonal and diurnal variations of convective systems observed during the two intensive operational periods (IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during the Green Ocean Amazon (GoAmazon2014/5) experiment. The derived large-scale fields have large diurnal variations according to convective activity in the GoAmazon region and the morning profiles show distinct differences between the dry and wetmore » seasons. In the wet season, propagating convective systems originating far from the GoAmazon region are often seen in the early morning, while in the dry season they are rarely observed. Afternoon convective systems due to solar heating are frequently seen in both seasons. Accordingly, in the morning, there is strong upward motion and associated heating and drying throughout the entire troposphere in the wet season, which is limited to lower levels in the dry season. In the afternoon, both seasons exhibit weak heating and strong moistening in the boundary layer related to the vertical convergence of eddy fluxes. Here, a set of case studies of three typical types of convective systems occurring in Amazonia – i.e., locally occurring systems, coastal-occurring systems and basin-occurring systems – is also conducted to investigate the variability of the large-scale environment with different types of convective systems.« less

Large-scale vertical velocity, diabatic heating and drying profiles associated with seasonal and diurnal variations of convective systems observed in the GoAmazon2014/5 experiment

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

Tang, Shuaiqi; Xie, Shaocheng; Zhang, Yunyan

2016-01-01

This study describes the characteristics of large-scale vertical velocity, apparent heating source ( Q 1) and apparent moisture sink ( Q 2) profiles associated with seasonal and diurnal variations of convective systems observed during the two intensive operational periods (IOPs) that were conducted from 15 February to 26 March 2014 (wet season) and from 1 September to 10 October 2014 (dry season) near Manaus, Brazil, during the Green Ocean Amazon (GoAmazon2014/5) experiment. The derived large-scale fields have large diurnal variations according to convective activity in the GoAmazon region and the morning profiles show distinct differences between the dry and wetmore » seasons. In the wet season, propagating convective systems originating far from the GoAmazon region are often seen in the early morning, while in the dry season they are rarely observed. Afternoon convective systems due to solar heating are frequently seen in both seasons. Accordingly, in the morning, there is strong upward motion and associated heating and drying throughout the entire troposphere in the wet season, which is limited to lower levels in the dry season. In the afternoon, both seasons exhibit weak heating and strong moistening in the boundary layer related to the vertical convergence of eddy fluxes. A set of case studies of three typical types of convective systems occurring in Amazonia – i.e., locally occurring systems, coastal-occurring systems and basin-occurring systems – is also conducted to investigate the variability of the large-scale environment with different types of convective systems.« less

High-Latitude Topside Ionospheric Vertical Electron-Density-Profile Changes in Response to Large Magnetic Storms

NASA Technical Reports Server (NTRS)

Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

2015-01-01

Large magnetic-storm induced changes have been detected in high-latitude topside vertical electron-density profiles Ne(h). The investigation was based on the large database of topside Ne(h) profiles and digital topside ionograms from the International Satellites for Ionospheric Studies (ISIS) program available from the NASA Space Physics Data Facility (SPDF) at http://spdf.gsfc.nasa.gov/isis/isis-status.html. This large database enabled Ne(h) profiles to be obtained when an ISIS satellite passed through nearly the same region of space before, during, and after a major magnetic storm. A major goal was to relate the magnetic-storm induced high-latitude Ne(h) profile changes to solar-wind parameters. Thus an additional data constraint was to consider only storms where solar-wind data were available from the NASA/SPDF OMNIWeb database. Ten large magnetic storms (with Dst less than -100 nT) were identified that satisfied both the Ne(h) profile and the solar-wind data constraints. During five of these storms topside ionospheric Ne(h) profiles were available in the high-latitude northern hemisphere and during the other five storms similar ionospheric data were available in the southern hemisphere. Large Ne(h) changes were observed during each one of these storms. Our concentration in this paper is on the northern hemisphere. The data coverage was best for the northern-hemisphere winter. Here Ne(h) profile enhancements were always observed when the magnetic local time (MLT) was between 00 and 03 and Ne(h) profile depletions were always observed between 08 and 10 MLT. The observed Ne(h) deviations were compared with solar-wind parameters, with appropriate time shifts, for four storms.

Local fluctuations of ozone from 16 km to 45 km deduced from in situ vertical ozone profile

NASA Technical Reports Server (NTRS)

Moreau, G.; Robert, C.

1994-01-01

A vertical ozone profile obtained by an in situ ozone sonde from 16 km to 45 km, has allowed to observe local ozone concentration variations. These variations can be observed, thanks to a fast measurement system based on a UV absorption KrF excimer laser beam in a multipass cell. Ozone standard deviation versus altitude calculated from the mean is derived. Ozone variations or fluctuations are correlated with the different dynamic zones of the stratosphere.

Balloon-borne observations of the development and vertical structure of the Antarctic ozone hole in 1986

NASA Technical Reports Server (NTRS)

Hofmann, D. J.; Harder, J. W.; Rolf, S. R.; Rosen, J. M.

1987-01-01

The vertical distribution of ozone measured at McMurdo Station, Antarctica using balloon-borne sensors on 33 occasions during November 6, 1986 - August 25, 1986 is described. These observations suggest a highly structured cavity confined to the 12-20 km altitude region. In the 17-19 km altitude range, the ozone volume mixing ratio declined from about 2 ppm at the end of August to about 0.5 ppm by mid-October. The average decay in this region can be described as exponential with a half life of about 25 days. While total ozone, as obtained from profile integration, declined only about 35 percent, the integrated ozone between 14 and 18 km declined more than 70 percent. Vertical ozone profiles in the vortex revealed unusual structure with major features from 1 to 5 km thick which had suffered ozone depletions as great as 90 percent.

Vertical profiles of black carbon measured by a micro-aethalometer in summer in the North China Plain

NASA Astrophysics Data System (ADS)

Ran, Liang; Deng, Zhaoze; Xu, Xiaobin; Yan, Peng; Lin, Weili; Wang, Ying; Tian, Ping; Wang, Pucai; Pan, Weilin; Lu, Daren

2016-08-01

Black carbon (BC) is a dominant absorber in the visible spectrum and a potent factor in climatic effects. Vertical profiles of BC were measured using a micro-aethalometer attached to a tethered balloon during the Vertical Observations of trace Gases and Aerosols (VOGA) field campaign, in summer 2014 at a semirural site in the North China Plain (NCP). The diurnal cycle of BC vertical distributions following the evolution of the mixing layer (ML) was investigated for the first time in the NCP region. Statistical parameters including identified mixing height (Hm) and average BC mass concentrations within the ML (Cm) and in the free troposphere (Cf) were obtained for a selected dataset of 67 vertical profiles. Hm was usually lower than 0.2 km in the early morning and rapidly rose thereafter due to strengthened turbulence. The maximum height of the ML was reached in the late afternoon. The top of a full developed ML exceeded 1 km on sunny days in summer, while it stayed much lower on cloudy days. The sunset triggered the collapse of the ML, and a stable nocturnal boundary layer (NBL) gradually formed. Accordingly, the highest level Cm was found in the early morning and the lowest was found in the afternoon. In the daytime, BC was almost uniformly distributed within the ML and significantly decreased above the ML. During the field campaign, Cm averaged about 5.16 ± 2.49 µg m-3, with a range of 1.12 to 14.49 µg m-3, comparable with observational results in many polluted urban areas such as Milan in Italy and Shanghai in China. As evening approached, BC gradually built up near the surface and exponentially declined with height. In contrast to the large variability found both in Hm and Cm, Cf stayed relatively unaffected through the day. Cf was less than 10 % of the ground level under clean conditions, while it amounted to half of the ground level in some polluted cases. In situ measurements of BC vertical profiles would hopefully have an important implication for

Analysis and high resolution modelling of black carbon vertical profiles measured over three Italian valleys

NASA Astrophysics Data System (ADS)

Gandolfi, Ilaria; Curci, Gabriele; Falasca, Serena; Ferrero, Luca

2017-04-01

Analysis and high resolution modelling of black carbon vertical profiles measured over three Italian valleys Ilaria Gandolfi1,2, Gabriele Curci1,2, Serena Falasca1,2, Luca Ferrero3 1 Department of Physical and Chemical Sciences, University of L'Aquila, L'Aquila, Italy 2 Center of Excellence CETEMPS, University of L'Aquila, L'Aquila, Italy 3 POLARIS Research Centre, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy Last decades were characterized by a growing interest in aerosols: mainly for their effect on human health and on the energy balance of solar and planetary radiation, thus their role in climate change. In this study, we analyze the evolution of vertical profile of black carbon (BC) through tethered balloon observations and chemistry-transport modelling. Black carbon is regarded as the second most important anthropogenic climate forcing agent and its concentration varies significantly depending on the altitude and the sources on the territory. In winter of 2010 University Of Milan Bicocca conducted three intensive measurements campaigns over three Italian basin valleys (Terni, Po Valley, Passiria Valley). The choice of the valleys was made taking into consideration the orography and the river basin structure. The measurement campaign was based on a helium-filled tethered balloon, on which the instrumentation for the analysis has been mounted; the instrumentation consisted on a meteorological station, an OPC, a cascade impactor and a micro-Aethalometer. Subsequently, at University of L'Aquila simulations were produced to help interpretation of these vertical aerosol profiles (mass, composition and distribution) and related optical properties (scattering, absorption) using a chemistry-transport model (WRF-CHIMERE) at high horizontal resolution (1 km). The analysis focused primarily on the calculation of the heating rate and of the Direct Radiative Effect (DRE), and on the analysis of the

Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

NASA Astrophysics Data System (ADS)

Kudo, Rei; Nishizawa, Tomoaki; Aoyagi, Toshinori

2016-07-01

The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR

Vertical profile of fog microphysics : a case study

NASA Astrophysics Data System (ADS)

Burnet, Frédéric; Brilouet, Pierre-Etienne; Mazoyer, Marie; Bourrianne, Thierry; Etcheberry, Jean-Michel; Gaillard, Brigitte; Legain, Dominique; Tzanos, Diane; Barrié, Joel; Barrau, Sébastien; Defoy, Stephan

2016-04-01

The occurrence and development of fogs result from the non-linear interaction of competing radiative, thermodynamic, microphysical and dynamical processes and the forecasting of their life cycle still remains a challenging issue. Several field campaigns have been carried out at the SIRTA observatory in the Paris suburb area (France). These experiments have shown that fog events exhibit large differences of the microphysical properties and various evolutions during their life cycle. To better understand relationships between the different processes and to validate numerical simulations it is necessary however to document the vertical profile of the fog microphysics. A CDP (Cloud Droplet Spectrometer) from DMT (Droplet Measurement Technology, Boulder, CO) has been modified to allow measurements of the droplet size distribution in fog layers with a tethered balloon. This instrumental set-up has been used during a field campaign during the winter 2013-214 in the Landes area in the South West of France. To validate the vertical profiles provided by the modified CDP, a mast was equipped with microphysical instruments at 2 altitude levels with an another CDP at 24 m and a Fog Monitor FM100 at 42 m. The instrumental set-up deployed during this campaign is presented. Data collected during a fog event that occurred during the night of 5-6 March 2014 are analysed. We show that microphysical properties such as droplet number concentration, LWC and mean droplet size, exhibit different time evolution during the fog life cycle depending on the altitude level. Droplet size distribution measurements are also investigated. They reveal sharp variations along the vertical close to the top of the fog layer. In addition it is shown that the shape of the size distributions at the top follows a time evolution typical of a quasi-adiabatic droplet growth.

Retrieval of ozone profiles from OMPS limb scattering observations

NASA Astrophysics Data System (ADS)

Arosio, Carlo; Rozanov, Alexei; Malinina, Elizaveta; Eichmann, Kai-Uwe; von Clarmann, Thomas; Burrows, John P.

2018-04-01

This study describes a retrieval algorithm developed at the University of Bremen to obtain vertical profiles of ozone from limb observations performed by the Ozone Mapper and Profiler Suite (OMPS). This algorithm is based on the technique originally developed for use with data from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument. As both instruments make limb measurements of the scattered solar radiation in the ultraviolet (UV) and visible (Vis) spectral ranges, an underlying objective of the study is to obtain consolidated and consistent ozone profiles from the two satellites and to produce a combined data set. The retrieval algorithm uses radiances in the UV and Vis wavelength ranges normalized to the radiance at an upper tangent height to obtain ozone concentrations in the altitude range of 12-60 km. Measurements at altitudes contaminated by clouds in the instrument field of view are identified and filtered out. An independent aerosol retrieval is performed beforehand and its results are used to account for the stratospheric aerosol load in the ozone inversion. The typical vertical resolution of the retrieved profiles varies from ˜ 2.5 km at lower altitudes ( < 30 km) to ˜ 1.5 km (about 45 km) and becomes coarser at upper altitudes. The retrieval errors resulting from the measurement noise are estimated to be 1-4 % above 25 km, increasing to 10-30 % in the upper troposphere. OMPS data are processed for the whole of 2016. The results are compared with the NASA product and validated against profiles derived from passive satellite observations or measured in situ by balloon-borne sondes. Between 20 and 60 km, OMPS ozone profiles typically agree with data from the Microwave Limb Sounder (MLS) v4.2 within 5-10 %, whereas in the lower altitude range the bias becomes larger, especially in the tropics. The comparison of OMPS profiles with ozonesonde measurements shows differences within ±5 % between 13 and 30 km at

Microwave Radiometer and Lidar Synergy for High Vertical Resolution Thermodynamic Profiling in a Cloudy Scenario

NASA Astrophysics Data System (ADS)

Barrera Verdejo, M.; Crewell, S.; Loehnert, U.; Di Girolamo, P.

2016-12-01

Continuous monitoring of thermodynamic atmospheric profiles is important for many applications, e.g. assessment of atmospheric stability and cloud formation. Nowadays there is a wide variety of ground-based sensors for atmospheric profiling. However, no single instrument is able to simultaneously provide measurements with complete vertical coverage, high vertical and temporal resolution, and good performance under all weather conditions. For this reason, instrument synergies of a wide range of complementary measurements are more and more considered for improving the quality of atmospheric observations. The current work presents synergetic use of a microwave radiometer (MWR) and Raman lidar (RL) within a physically consistent optimal estimation approach. On the one hand, lidar measurements provide humidity and temperature measurements with a high vertical resolution albeit with limited vertical coverage, due to overlapping function problems, sunlight contamination and the presence of clouds. On the other hand, MWRs obtain humidity, temperature and cloud information throughout the troposphere, with however only a very limited vertical resolution. The benefits of MWR+RL synergy have been previously demonstrated for clear sky cases. This work expands this approach to cloudy scenarios. Consistent retrievals of temperature, absolute and relative humidity as well as liquid water path are analyzed. In addition, different measures are presented to demonstrate the improvements achieved via the synergy compared to individual retrievals, e.g. degrees of freedom or theoretical error. We also demonstrate that, compared to the lidar, the higher temporal resolution of the MWR presents a strong advantage for capturing the high temporal variability of the liquid water cloud.. Finally, the results are compared with independent information sources, e.g. GPS or radiosondes, showing good consistency. The study demonstrates the benefits of the sensor combination, being especially strong

Vertical and Lateral Electron Content in the Martian Ionosphere

NASA Astrophysics Data System (ADS)

Paetzold, M. P.; Peter, K.; Bird, M. K.; Häusler, B.; Tellmann, S.

2016-12-01

The radio-science experiment MaRS (Mars Express Radio Science) on the Mars Express spacecraft sounds the neutral atmosphere and ionosphere of Mars since 2004. Approximately 800 vertical profiles of the ionospheric electron density have been acquired until today. The vertical electron content (TEC) is easily computed from the vertical electron density profile by integrating along the altitude. The TEC is typically a fraction of a TEC unit (1E16 m^-2) and depends on the solar zenith angle. The magnitude of the TEC is however fully dominated by the electron density contained in the main layer M2. The contributions by the M1 layer below M2 or the topside is marginal. MaRS is using two radio frequencies for the sounding of the ionosphere. The directly observed differential Doppler from the two received frequencies is a measure of the lateral electron content that means along the ray path and perpendicular to the vertical electron density profile. Combining both the vertical electron density profile, the vertical TEC and the directly observed lateral TEC describes the lateral electron density distribution in the ionosphere.

Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

NASA Astrophysics Data System (ADS)

Barrera-Verdejo, María; Crewell, Susanne; Löhnert, Ulrich; Orlandi, Emiliano; Di Girolamo, Paolo

2016-08-01

Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g., assessment of atmospheric stability and cloud formation. Nowadays there are a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution, albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWRs) receive water vapor information throughout the troposphere, though their vertical resolution is poor. In this work, we present an MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an optimal estimation method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information, taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a 2-month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyze the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty is reduced above the last usable lidar range by a factor of ˜ 2 with respect to the case where only RL measurements are used. The analysis in terms of degrees of freedom per signal reveal that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using

Observations of and Influences on Low-Latitude Vertical Plasma Drifts

NASA Astrophysics Data System (ADS)

Miller, E. S.; Chartier, A.; Paxton, L. J.

2016-12-01

Many workers have suggested that the morphology (position and relative intensities) of the crests of the equatorial ionization anomaliesis related to the time history of the equatorial vertical drift. In this work, we compare observations of the vertical drift using an HF radiosignals of opportunity in the Central Pacific with UV 135.6-nm observations of the equatorial anomalies from the DMSP/SSUSI andTIMED/GUVI instruments. Furthermore, we explore the role of E region density in modulating the vertical plasma drift using a passive HFsounding experiment in the Caribbean. Coupling between nighttime medium-scale traveling ionospheric disturbances (MSTIDs) and sporadic-Elayers has been suggested as a growth-rate-increasing process. While we observe sporadic-E in the local hemisphere coincident to increases in thealtitude of the F-region altitude, we also observe uplifts without sporadic-E in the local hemisphere. Apart from the trivial explanation that sporadic-E is occurring in the conjugate hemisphere, another possible explanation is that the E region may enhance the vertical drift, but is not required to produce enhanced vertical drifts. These studies represent fruitful areas of future intersection between ground-based observations and ICON and GOLD science.

Simulating CO2 profiles using NIES TM and comparison with HIAPER Pole-to-Pole Observations

NASA Astrophysics Data System (ADS)

Song, C.; Maksyutov, S.; Belikov, D.; Takagi, H.; Shu, J.

2015-03-01

We present a study on validation of the National Institute for Environmental Studies Transport Model (NIES TM) by comparing to observed vertical profiles of atmospheric CO2. The model uses a hybrid sigma-isentropic (σ-θ) vertical coordinate that employs both terrain-following and isentropic parts switched smoothly in the stratosphere. The model transport is driven by reanalyzed meteorological fields and designed to simulate seasonal and diurnal cycles, synoptic variations, and spatial distributions of atmospheric chemical constituents in the troposphere. The model simulations were run for biosphere, fossil fuel, air-ocean exchange, biomass burning and inverse correction fluxes of carbon dioxide (CO2) by GOSAT Level 4 product. We compared the NIES TM simulated fluxes with data from the HIAPER Pole-to-Pole Observations (HIPPO) Merged 10 s Meteorology, Atmospheric Chemistry, and Aerosol Data, including HIPPO-1, HIPPO-2 and HIPPO-3 from 128.0° E to -84.0° W, and 87.0° N to -67.2° S. The simulation results were compared with CO2 observations made in January and November 2009, and March and April 2010. The analysis attests that the model is good enough to simulate vertical profiles with errors generally within 1-2 ppmv, except for the lower stratosphere in the Northern Hemisphere high latitudes.

High-latitude topside ionospheric vertical electron density profile changes in response to large magnetic storms

NASA Astrophysics Data System (ADS)

Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

2016-05-01

Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst < -100 nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial and/or temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100 km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

High-Latitude Topside Ionospheric Vertical Electron Density Profile Changes in Response to Large Magnetic Storms

NASA Technical Reports Server (NTRS)

Benson, Robert F.; Fainberg, Joseph; Osherovich, Vladimir A.; Truhlik, Vladimir; Wang, Yongli; Bilitza, Dieter; Fung, Shing F.

2016-01-01

Large magnetic-storm-induced changes were detected in high-latitude topside vertical electron density profiles Ne(h) in a database of profiles and digital topside ionograms, from the International Satellites for Ionospheric Studies (ISIS) program, that enabled Ne(h) profiles to be obtained in nearly the same region of space before, during, and after a major magnetic storm (Dst -100nT). Storms where Ne(h) profiles were available in the high-latitude Northern Hemisphere had better coverage of solar wind parameters than storms with available Ne(h) profiles in the high-latitude Southern Hemisphere. Large Ne(h) changes were observed during all storms, with enhancements and depletions sometimes near a factor of 10 and 0.1, respectively, but with substantial differences in the responses in the two hemispheres. Large spatial andor temporal Ne(h) changes were often observed during Dst minimum and during the storm recovery phase. The storm-induced Ne(h) changes were the most pronounced and consistent in the Northern Hemisphere in that large enhancements were observed during winter nighttime and large depletions during winter and spring daytime. The limited available cases suggested that these Northern Hemisphere enhancements increased with increases of the time-shifted solar wind velocity v, magnetic field B, and with more negative values of the B components except for the highest common altitude (1100km) of the profiles. There was also some evidence suggesting that the Northern Hemisphere depletions were related to changes in the solar wind parameters. Southern Hemisphere storm-induced enhancements and depletions were typically considerably less with depletions observed during summer nighttime conditions and enhancements during summer daytime and fall nighttime conditions.

How well can we Measure the Vertical Profile of Tropospheric Aerosol Extinction?

NASA Technical Reports Server (NTRS)

Schmid, Beat; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.

2005-01-01

The recent Department of Energy Atmospheric Radiation Measurement (ARM) Aerosol Intensive Operations Period (MOP, May 2003) yielded one of the best measurement sets obtained to-date to assess our ability to measure the vertical profile of ambient aerosol extinction sigma(sub ep)(lambda) in the lower troposphere. During one month, a heavily instrumented aircraft with well characterized aerosol sampling ability carrying well proven and new aerosol instrumentation, devoted most of the 60 available flight hours to flying vertical profiles over the heavily instrumented ARM Southern Great Plains (SGP) Climate Research Facility (CRF). This allowed us to compare vertical extinction profiles obtained from 6 different instuments: airborne Sun photometer (AATS-14), airborne nephelometer/absorption photometer, airborne cavity ring-down system, ground-based Raman lidar and 2 ground-based elastic backscatter lidars. We find the in-situ measured sigma(sub ep)(lambda) to be lower than the AATS-14 derived values. Bias differences are 0.002 - 0.004 K/m equivalent to 12-17% in the visible, or 45% in the near-infrared. On the other hand, we find that with respect to AATS-14, the lidar sigma(sub ep)(lambda) are higher. An unnoticed loss of sensitivity of the Raman lidar had occurred leading up to AIOP and we expect better agreement from the recently restored system looking at the collective results from 6 field campaigns conducted since 1996, airborne in situ measurements of sigma(sub ep)(lambda) tend to be biased slightly low (17% at visible wavelengths) when compared to airborne Sun photometer sigma(sub ep)(lambda). On the other hand, sigma(sub ep)(lambda) values derived from lidars tend to have no or positive biases. From the bias differences we conclude that the typical systematic error associated with measuring the tropospheric vertical profile of the ambient aerosol extinction with current state of-the art instrumentation is 15-20% at visible wavelengths and potentially larger in

Vertically-resolved profiles of mass concentrations and particle backscatter coefficients of Asian dust plumes derived from lidar observations of silicon dioxide.

PubMed

Noh, Youngmin; Müller, Detlef; Shin, Sung-Kyun; Shin, Dongho; Kim, Young J

2016-01-01

This study presents a method to retrieve vertically-resolved profiles of dust mass concentrations by analyzing Raman lidar signals of silicon dioxide (quartz) at 546nm. The observed particle plumes consisted of mixtures of East Asian dust with anthropogenic pollution. Our method for the first time allows for extracting the contribution of the aerosol component "pure dust" contained in the aerosol type "polluted dust". We also propose a method that uses OPAC (Optical Properties of Aerosols and Clouds) and the mass concentrations profiles of dust in order to derive profiles of backscatter coefficients of pure dust in mixed dust/pollution plumes. The mass concentration of silicon dioxide (quartz) in the atmosphere can be estimated from the backscatter coefficient of quartz. The mass concentration of dust is estimated by the weight percentage (38-77%) of mineral quartz in Asian dust. The retrieved dust mass concentrations are classified into water soluble, nucleation, accumulation, mineral-transported and coarse mode according to OPAC. The mass mixing ratio of 0.018, 0.033, 0.747, 0.130 and 0.072, respectively, is used. Dust extinction coefficients at 550nm were calculated by using OPAC and prescribed number concentrations for each of the 5 components. Dust backscatter coefficients were calculated from the dust extinction coefficients on the basis of a lidar ratio of 45±3sr at 532nm. We present results of quartz-Raman measurements carried out on the campus of the Gwangju Institute of Science and Technology (35.10°N, 126.53°E) on 15, 16, and 21 March 2010. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retrieval of carbon dioxide vertical profiles from solar occultation observations and associated error budgets for ACE-FTS and CASS-FTS

NASA Astrophysics Data System (ADS)

Sioris, C. E.; Boone, C. D.; Nassar, R.; Sutton, K. J.; Gordon, I. E.; Walker, K. A.; Bernath, P. F.

2014-07-01

An algorithm is developed to retrieve the vertical profile of carbon dioxide in the 5 to 25 km altitude range using mid-infrared solar occultation spectra from the main instrument of the ACE (Atmospheric Chemistry Experiment) mission, namely the Fourier transform spectrometer (FTS). The main challenge is to find an atmospheric phenomenon which can be used for accurate tangent height determination in the lower atmosphere, where the tangent heights (THs) calculated from geometric and timing information are not of sufficient accuracy. Error budgets for the retrieval of CO2 from ACE-FTS and the FTS on a potential follow-on mission named CASS (Chemical and Aerosol Sounding Satellite) are calculated and contrasted. Retrieved THs have typical biases of 60 m relative to those retrieved using the ACE version 3.x software after revisiting the temperature dependence of the N2 CIA (collision-induced absorption) laboratory measurements and accounting for sulfate aerosol extinction. After correcting for the known residual high bias of ACE version 3.x THs expected from CO2 spectroscopic/isotopic inconsistencies, the remaining bias for tangent heights determined with the N2 CIA is -20 m. CO2 in the 5-13 km range in the 2009-2011 time frame is validated against aircraft measurements from CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container), CONTRAIL (Comprehensive Observation Network for Trace gases by Airline), and HIPPO (HIAPER Pole-to-Pole Observations), yielding typical biases of -1.7 ppm in the 5-13 km range. The standard error of these biases in this vertical range is 0.4 ppm. The multi-year ACE-FTS data set is valuable in determining the seasonal variation of the latitudinal gradient which arises from the strong seasonal cycle in the Northern Hemisphere troposphere. The annual growth of CO2 in this time frame is determined to be 2.6 ± 0.4 ppm year-1, in agreement with the currently accepted global growth rate based on

Off-Nadir Hyperspectral Sensing for Estimation of Vertical Profile of Leaf Chlorophyll Content within Wheat Canopies

PubMed Central

Huang, Wenjiang; Zhou, Xianfeng; Ye, Huichun; Dong, Yingying

2017-01-01

Monitoring the vertical profile of leaf chlorophyll (Chl) content within winter wheat canopies is of significant importance for revealing the real nutritional status of the crop. Information on the vertical profile of Chl content is not accessible to nadir-viewing remote or proximal sensing. Off-nadir or multi-angle sensing would provide effective means to detect leaf Chl content in different vertical layers. However, adequate information on the selection of sensitive spectral bands and spectral index formulas for vertical leaf Chl content estimation is not yet available. In this study, all possible two-band and three-band combinations over spectral bands in normalized difference vegetation index (NDVI)-, simple ratio (SR)- and chlorophyll index (CI)-like types of indices at different viewing angles were calculated and assessed for their capability of estimating leaf Chl for three vertical layers of wheat canopies. The vertical profiles of Chl showed top-down declining trends and the patterns of band combinations sensitive to leaf Chl content varied among different vertical layers. Results indicated that the combinations of green band (520 nm) with NIR bands were efficient in estimating upper leaf Chl content, whereas the red edge (695 nm) paired with NIR bands were dominant in quantifying leaf Chl in the lower layers. Correlations between published spectral indices and all NDVI-, SR- and CI-like types of indices and vertical distribution of Chl content showed that reflectance measured from 50°, 30° and 20° backscattering viewing angles were the most promising to obtain information on leaf Chl in the upper-, middle-, and bottom-layer, respectively. Three types of optimized spectral indices improved the accuracy for vertical leaf Chl content estimation. The optimized three-band CI-like index performed the best in the estimation of vertical distribution of leaf Chl content, with R2 of 0.84–0.69, and RMSE of 5.37–5.56 µg/cm2 from the top to the bottom layers

Off-Nadir Hyperspectral Sensing for Estimation of Vertical Profile of Leaf Chlorophyll Content within Wheat Canopies.

PubMed

Kong, Weiping; Huang, Wenjiang; Casa, Raffaele; Zhou, Xianfeng; Ye, Huichun; Dong, Yingying

2017-11-23

Monitoring the vertical profile of leaf chlorophyll (Chl) content within winter wheat canopies is of significant importance for revealing the real nutritional status of the crop. Information on the vertical profile of Chl content is not accessible to nadir-viewing remote or proximal sensing. Off-nadir or multi-angle sensing would provide effective means to detect leaf Chl content in different vertical layers. However, adequate information on the selection of sensitive spectral bands and spectral index formulas for vertical leaf Chl content estimation is not yet available. In this study, all possible two-band and three-band combinations over spectral bands in normalized difference vegetation index (NDVI)-, simple ratio (SR)- and chlorophyll index (CI)-like types of indices at different viewing angles were calculated and assessed for their capability of estimating leaf Chl for three vertical layers of wheat canopies. The vertical profiles of Chl showed top-down declining trends and the patterns of band combinations sensitive to leaf Chl content varied among different vertical layers. Results indicated that the combinations of green band (520 nm) with NIR bands were efficient in estimating upper leaf Chl content, whereas the red edge (695 nm) paired with NIR bands were dominant in quantifying leaf Chl in the lower layers. Correlations between published spectral indices and all NDVI-, SR- and CI-like types of indices and vertical distribution of Chl content showed that reflectance measured from 50°, 30° and 20° backscattering viewing angles were the most promising to obtain information on leaf Chl in the upper-, middle-, and bottom-layer, respectively. Three types of optimized spectral indices improved the accuracy for vertical leaf Chl content estimation. The optimized three-band CI-like index performed the best in the estimation of vertical distribution of leaf Chl content, with R² of 0.84-0.69, and RMSE of 5.37-5.56 µg/cm² from the top to the bottom layers

Potential of collocated radiometer and wind profiler observations for monsoon studies

NASA Astrophysics Data System (ADS)

Balaji, B.; Prabha, Thara V.; Jaya Rao, Y.; Kiran, T.; Dinesh, G.; Chakravarty, Kaustav; Sonbawne, S. M.; Rajeevan, M.

2017-09-01

Collocated observations from microwave radiometer and wind profiler are used in a pilot study during the monsoon period to derive information on the thermodynamics and winds and association with rainfall characteristics. These instruments were operated throughout the monsoon season of 2015. Continuous vertical profiles of winds, temperature and humidity show significant promise for understanding the low-level jet, its periodicity and its association with moisture transport, clouds and precipitation embedded within the monsoon large-scale convection. Observations showed mutually beneficial in explaining variability that are part of the low frequency oscillations and the diurnal variability during monsoon. These observations highlight the importance of locally driven convective systems, in the presence of weak moisture transport over the area. The episodic moisture convergence showed a periodicity of 9 days which matches with the subsequent convection and precipitation and thermodynamic regimes. Inferences from the diurnal cycle of moisture transport and the convective activity, relationship with the low-level jet characteristics and thermodynamics are also illustrated.

Vertical profiles of aerosol absorption coefficient from micro-Aethalometer data and Mie calculation over Milan.

PubMed

Ferrero, L; Mocnik, G; Ferrini, B S; Perrone, M G; Sangiorgi, G; Bolzacchini, E

2011-06-15

Vertical profiles of aerosol number-size distribution and black carbon (BC) concentration were measured between ground-level and 500m AGL over Milan. A tethered balloon was fitted with an instrumentation package consisting of the newly-developed micro-Aethalometer (microAeth® Model AE51, Magee Scientific, USA), an optical particle counter, and a portable meteorological station. At the same time, PM(2.5) samples were collected both at ground-level and at a high altitude sampling site, enabling particle chemical composition to be determined. Vertical profiles and PM(2.5) data were collected both within and above the mixing layer. Absorption coefficient (b(abs)) profiles were calculated from the Aethalometer data: in order to do so, an optical enhancement factor (C), accounting for multiple light-scattering within the filter of the new microAeth® Model AE51, was determined for the first time. The value of this parameter C (2.05±0.03 at λ=880nm) was calculated by comparing the Aethalometer attenuation coefficient and aerosol optical properties determined from OPC data along vertical profiles. Mie calculations were applied to the OPC number-size distribution data, and the aerosol refractive index was calculated using the effective medium approximation applied to aerosol chemical composition. The results compare well with AERONET data. The BC and b(abs) profiles showed a sharp decrease at the mixing height (MH), and fairly constant values of b(abs) and BC were found above the MH, representing 17±2% of those values measured within the mixing layer. The BC fraction of aerosol volume was found to be lower above the MH: 48±8% of the corresponding ground-level values. A statistical mean profile was calculated, both for BC and b(abs), to better describe their behaviour; the model enabled us to compute their average behaviour as a function of height, thus laying the foundations for valid parametrizations of vertical profile data which can be useful in both remote sensing

Interpretation of nitric oxide profile observed in January 1992 over Kiruna

NASA Astrophysics Data System (ADS)

Kondo, Y.; Kawa, S. R.; Lary, D.; Sugita, T.; Douglass, Anne R.; Lutman, E.; Koike, M.; Deshler, T.

1996-05-01

NO mixing ratios measured from Kiruna (68°N, 20°E), Sweden, on January 22, 1992, revealed values much smaller than those observed at midlatitude near equinox and had a sharper vertical gradient around 25 km. Location of the measurements was close to the terminator and near the edge of the polar vortex, which is highly distorted from concentric flow by strong planetary wave activities. These conditions necessitate accurate calculation, properly taking into account the transport and photochemical processes, in order to quantitatively explain the observed NO profile. A three-dimensional chemistry and transport model (CTM) and a trajectory model (TM) were used to interpret the profile observations within their larger spatial, temporal, and chemical context. The NOy profile calculated by the CTM is in good agreement with that observed on January 31, 1992. In addition, model NOy profiles show small variabilities depending on latitudes, and they change little between January 22 and 31. The TM uses the observed NOy values. The NO values calculated by the CTM and TM agree with observations up to 27 km. Between 20 and 27 km the NO values calculated by the trajectory model including only gas phase chemistry are much larger than those including heterogeneous chemistry, indicating that NO mixing ratios were reduced significantly by heterogeneous chemistry on sulfuric acid aerosols. Very little sunlight to generate NOx from HNO3 was available, also causing the very low NO values. The good agreement between the observed and modeled NO profiles indicates that models can reproduce the photochemical and transport processes in the region where NO values have a sharp horizontal gradient. Moreover, CTM and TM model results show that even when the NOy gradients are weak, the model NO depends upon accurate calculation of the transport and insolation for several days.

Comparison of stratospheric NO2 profiles above Kiruna, Sweden retrieved from ground-based zenith sky DOAS measurements, SAOZ balloon measurements and SCIAMACHY limb observations

NASA Astrophysics Data System (ADS)

Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Pukite, Janis; Van Roozendael, Michel; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

2015-04-01

Stratospheric NO2 not only destroys ozone but acts as a buffer against halogen catalyzed ozone loss by converting halogen species into stable nitrates. These two roles of stratospheric NO2 depend on the altitude. Hence, the objective of this study is to investigate the vertical distribution of stratospheric NO2. We compare the NO2 profiles derived from the zenith sky DOAS with those obtained from, SAOZ balloon measurements and satellite limb observations. Vertical profiles of stratospheric NO2 are retrieved from ground-based zenith sky DOAS observations operated at Kiruna, Sweden (68.84°N, 20.41°E) since 1996. To determine the profile of stratospheric NO2 measured from ground-based zenith sky DOAS, we apply the Optimal Estimation Method (OEM) to retrieval of vertical profiles of stratospheric NO2 which has been developed by IASB-BIRA. The basic principle behind this profiling approach is the dependence of the mean scattering height on solar zenith angle (SZA). We compare the retrieved profiles to two additional datasets of stratospheric NO2 profile. The first one is derived from satellite limb observations by SCIAMACHY (Scanning Imaging Absorption spectrometer for Atmospheric CHartographY) on EnviSAT. The second is derived from the SAOZ balloon measurements (using a UV/Visible spectrometer) performed at Kiruna in Sweden.

Use of temperature profiles beneath streams to determine rates of vertical ground-water flow and vertical hydraulic conductivity

USGS Publications Warehouse

Lapham, Wayne W.

1989-01-01

The use of temperature profiles beneath streams to determine rates of vertical ground-water flow and effective vertical hydraulic conductivity of sediments was evaluated at three field sites by use of a model that numerically solves the partial differential equation governing simultaneous vertical flow of fluid and heat in the Earth. The field sites are located in Hardwick and New Braintree, Mass., and in Dover, N.J. In New England, stream temperature varies from about 0 to 25 ?C (degrees Celsius) during the year. This stream-temperature fluctuation causes ground-water temperatures beneath streams to fluctuate by more than 0.1 ?C during a year to a depth of about 35 ft (feet) in fine-grained sediments and to a depth of about 50 ft in coarse-grained sediments, if ground-water velocity is 0 ft/d (foot per day). Upward flow decreases the depth affected by stream-temperature fluctuation, and downward flow increases the depth. At the site in Hardwick, Mass., ground-water flow was upward at a rate of less than 0.01 ft/d. The maximum effective vertical hydraulic conductivity of the sediments underlying this site is 0.1 ft/d. Ground-water velocities determined at three locations at the site in New Braintree, Mass., where ground water discharges naturally from the underlying aquifer to the Ware River, ranged from 0.10 to 0.20 ft/d upward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.4 to 17.1 ft/d. Ground-water velocities determined at three locations at the Dover, N.J., site, where infiltration from the Rockaway River into the underlying sediments occurs because of pumping, were 1.5 ft/d downward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.2 to 2.5 ft/d. Independent estimates of velocity at two of the three sites are in general agreement with the velocities determined using temperature profiles. The estimates of velocities and conductivities derived from the

Improving Vertical Jump Profiles Through Prescribed Movement Plans.

PubMed

Mayberry, John K; Patterson, Bryce; Wagner, Phil

2018-06-01

Mayberry, JK, Patterson, B, and Wagner, P. Improving vertical jump profiles through prescribed movement plans. J Strength Cond Res 32(6): 1619-1626, 2018-Developing practical, reliable, and valid methods for monitoring athlete wellness and injury risk is an important goal for trainers, athletes, and coaches. Previous studies have shown that the countermovement vertical jump (CMJ) test is both a reliable and valid metric for evaluating an athlete's condition. This study examines the effectiveness of prescribed workouts on improving the quality of movement during CMJ. The data set consists of 2,425 pairs of CMJ scans for high school, college, and professional athletes training at a privately owned facility. During each scan, a force plate recorded 3 ground reaction force (GRF) measurements known to impact CMJ performance: eccentric rate of force development (ERFD), average vertical concentric force (AVCF), and concentric vertical impulse (CVI). After an initial scan, coaches either assigned the athlete a specific 1- or 2-strength movement plan (treatment group) or instructed the athlete to choose their own workouts (control group) before returning for a follow-up scan. A multivariate analysis of covariance (MANCOVA) revealed significant differences in changes to GRF measurements between athletes in the 2 groups after adjusting for the covariates sex, sport, time between scans, and rounds of workout completed. A principal component analysis of GRF measurements further identified 4 primary groups of athlete needs and the results provide recommendations for effective workout plans targeting each group. In particular, split squats increase CVI and decrease ERFD/AVCF; deadlifts increase AVCF and decrease CVI; alternating squats/split squats increase ERFD/CVI and decrease AVCF; and alternating squats/deadlifts increase ERFD/AVCF and decrease CVI.

Comparison of the GOSAT TANSO-FTS TIR CH volume mixing ratio vertical profiles with those measured by ACE-FTS, ESA MIPAS, IMK-IAA MIPAS, and 16 NDACC stations

NASA Astrophysics Data System (ADS)

Olsen, Kevin S.; Strong, Kimberly; Walker, Kaley A.; Boone, Chris D.; Raspollini, Piera; Plieninger, Johannes; Bader, Whitney; Conway, Stephanie; Grutter, Michel; Hannigan, James W.; Hase, Frank; Jones, Nicholas; de Mazière, Martine; Notholt, Justus; Schneider, Matthias; Smale, Dan; Sussmann, Ralf; Saitoh, Naoko

2017-10-01

The primary instrument on the Greenhouse gases Observing SATellite (GOSAT) is the Thermal And Near infrared Sensor for carbon Observations (TANSO) Fourier transform spectrometer (FTS). TANSO-FTS uses three short-wave infrared (SWIR) bands to retrieve total columns of CO2 and CH4 along its optical line of sight and one thermal infrared (TIR) channel to retrieve vertical profiles of CO2 and CH4 volume mixing ratios (VMRs) in the troposphere. We examine version 1 of the TANSO-FTS TIR CH4 product by comparing co-located CH4 VMR vertical profiles from two other remote-sensing FTS systems: the Canadian Space Agency's Atmospheric Chemistry Experiment FTS (ACE-FTS) on SCISAT (version 3.5) and the European Space Agency's Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat (ESA ML2PP version 6 and IMK-IAA reduced-resolution version V5R_CH4_224/225), as well as 16 ground stations with the Network for the Detection of Atmospheric Composition Change (NDACC). This work follows an initial inter-comparison study over the Arctic, which incorporated a ground-based FTS at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka, Canada, and focuses on tropospheric and lower-stratospheric measurements made at middle and tropical latitudes between 2009 and 2013 (mid-2012 for MIPAS). For comparison, vertical profiles from all instruments are interpolated onto a common pressure grid, and smoothing is applied to ACE-FTS, MIPAS, and NDACC vertical profiles. Smoothing is needed to account for differences between the vertical resolution of each instrument and differences in the dependence on a priori profiles. The smoothing operators use the TANSO-FTS a priori and averaging kernels in all cases. We present zonally averaged mean CH4 differences between each instrument and TANSO-FTS with and without smoothing, and we examine their information content, their sensitive altitude range, their correlation, their a priori dependence, and the variability within

Experimental study of vertical stress profiles of a confined granular bed under static and dynamic conditions.

PubMed

Mandato, S; Cuq, B; Ruiz, T

2012-07-01

In a wet agglomeration process inside a low shear mixer, the blade function is to induce i) homogenization of the liquid sprayed on the powder surface and ii) a stress field able to transfer the mechanical energy at the particle scale. In this work we study the mechanical state of a confined powder bed through the analysis of stress distributions (by force measurements) in a rectangular cell in two cases: for a classical model powder (i.e. glass beads) and a complex powder (i.e. wheat semolina). Two types of vertical stress profiles are obtained according to the type of measurements carried out in the powder bed, either locally (at different positions in the cell) or globally (at the entire base). The global vertical stress profile follows Janssen's model and the local vertical stress profile highlights a critical length, identified as the percolation threshold of the force network, and a shielding length near the bottom, which is similar to an influence length of the side walls. In the context of wet agglomeration, the results allow to consider the role of the characteristic lengths in the mixing bowl under vertical mechanical solicitation.

The Design of Ocean Turbulence Measurement with a Free Fall Vertical Profiler

NASA Astrophysics Data System (ADS)

Luan, Xin; Xin, Jia; Zhu, Tieyi; Yang, Hua; Teng, Yuru; Song, Dalei

2018-03-01

The newly designed instrument Free Fall Vertical Profiler (FFVP) developed by Ocean University of China (OUC) had been deployed in the Western Pacific in March 08, 2017 and succeed to collect turbulence signals about 350-m-deep water. According to the requirements of turbulence measurement, the mechanical design was developed for turbulence platform to achieve stability and good flow tracking. By analysing the Heading, Pitch and Roll, the results suggested that the platform satisfies the requirements of stability. The power spectrum of the cleaned shear signals using the noise correction algorithm match well with the theoretical Nasmyth spectrum and the rate of turbulence dissipation are approximately 10-8 W/kg. In general, the FFVP was rationally designed and provided a good measurement platform for turbulence observation.

Quantitative precipitation estimation in complex orography using quasi-vertical profiles of dual polarization radar variables

NASA Astrophysics Data System (ADS)

Montopoli, Mario; Roberto, Nicoletta; Adirosi, Elisa; Gorgucci, Eugenio; Baldini, Luca

2017-04-01

. To avoid facing such a complexity, especially with a view to operational implementation, we propose to look at the features of the vertical profile of rain (VPR), i.e. after performing the rain estimation. This procedure allows characterizing a single variable (i.e. rain) when dealing with vertical extrapolations. Some case studies of severe thunderstorms that hit the mountainous area surrounding Rome in Italy causing floodings and damages and observed by the research C-band polarization agility Doppler radar named Polar 55C, managed by the Institute of Atmospheric Sciences and Climate (ISAC) at the National Research Council of Italy (CNR), are used to support the concept of VPR. Our results indicate that the combined algorithm, which merges together the differential phase shift (Kdp), the reflectivity factor at horizontal polarization (Zhh), and differential reflectivity (Zdr), once accurately processed, performs best among those tested that make use of Zhh alone, Kdp alone, and Zhh and Zdr pair. Improvements from 25% to 80% are found for the total rain accumulations in terms of normalized bias when the VPR extrapolation is applied.

Vertical and horizontal seismometric observations of tides

NASA Astrophysics Data System (ADS)

Lambotte, S.; Rivera, L.; Hinderer, J.

2006-01-01

Tidal signals have been largely studied with gravimeters, strainmeters and tiltmeters, but can also be retrieved from digital records of the output of long-period seismometers, such as STS-1, particularly if they are properly isolated. Horizontal components are often noisier than the vertical ones, due to sensitivity to tilt at long periods. Hence, horizontal components are often disturbed by local effects such as topography, geology and cavity effects, which imply a strain-tilt coupling. We use series of data (duration larger than 1 month) from several permanent broadband seismological stations to examine these disturbances. We search a minimal set of observable signals (tilts, horizontal and vertical displacements, strains, gravity) necessary to reconstruct the seismological record. Such analysis gives a set of coefficients (per component for each studied station), which are stable over years and then can be used systematically to correct data from these disturbances without needing heavy numerical computation. A special attention is devoted to ocean loading for stations close to oceans (e.g. Matsushiro station in Japon (MAJO)), and to pressure correction when barometric data are available. Interesting observations are made for vertical seismometric components; in particular, we found a pressure admittance between pressure and data 10 times larger than for gravimeters for periods larger than 1 day, while this admittance reaches the usual value of -3.5 nm/s 2/mbar for periods below 3 h. This observation may be due to instrumental noise, but the exact mechanism is not yet understood.

Observing the Vertical Dimensions of Singapore's Urban Heat Island

NASA Astrophysics Data System (ADS)

Chow, W. T. L.; Ho, D. X. Q.

2015-12-01

In numerous cities, measurements of urban warmth in most urban heat island (UHI) studies are generally constrained towards surface or near-surface (<2 m above ground) levels across horizontal variations in land use and land cover. However, there has been hitherto limited attention towards the measurement of vertical temperature profiles extending from the urban surface through to the urban boundary layer. Knowledge of these profiles, through how they vary over different local urban morphologies, and develop with respect to synoptic meteorological conditions, are important towards several aspects of UHI research; these include validating modelling urban canopy lapse rate profiles or estimating the growth of urban plumes. In this study, we utilised temperature sensors attached onto remote controlled aerial quadcopter platforms to measure urban temperature and humidity profiles in Singapore, which is a rapidly urbanizing major tropical metropolis. These profiles were measured from the surface to ~100 m above ground level, a height which includes all of the urban canopy and parts of the urban boundary layer. Initial results indicate significant variations in stability measured over different land uses (e.g. urban park, high-rise residential, commercial); these profiles are also temporally dynamic, depending on the time of day and larger-scale weather conditions.

Development of a Climatology of Vertically Complete Wind Profiles from Doppler Radar Wind Profiler Systems

NASA Technical Reports Server (NTRS)

Barbre, Robert E., Jr.

2015-01-01

This paper describes in detail the QC and splicing methodology for KSC's 50- and 915-MHz DRWP measurements that generates an extensive archive of vertically complete profiles from 0.20-18.45 km. The concurrent POR from each archive extends from April 2000 to December 2009. MSFC NE applies separate but similar QC processes to each of the 50- and 915-MHz DRWP archives. DRWP literature and data examination provide the basis for developing and applying the automated and manual QC processes on both archives. Depending on the month, the QC'ed 50- and 915-MHz DRWP archives retain 52-65% and 16-30% of the possible data, respectively. The 50- and 915-MHz DRWP QC archives retain 84-91% and 85-95%, respectively, of all the available data provided that data exist in the non- QC'ed archives. Next, MSFC NE applies an algorithm to splice concurrent measurements from both DRWP sources. Last, MSFC NE generates a composite profile from the (up to) five available spliced profiles to effectively characterize boundary layer winds and to utilize all possible 915-MHz DRWP measurements at each timestamp. During a given month, roughly 23,000-32,000 complete profiles exist from 0.25-18.45 km from the composite profiles' archive, and approximately 5,000- 27,000 complete profiles exist from an archive utilizing an individual 915-MHz DRWP. One can extract a variety of profile combinations (pairs, triplets, etc.) from this sample for a given application. The sample of vertically complete DRWP wind measurements not only gives launch vehicle customers greater confidence in loads and trajectory assessments versus using balloon output, but also provides flexibility to simulate different DOL situations across applicable altitudes. In addition to increasing sample size and providing more flexibility for DOL simulations in the vehicle design phase, the spliced DRWP database provides any upcoming launch vehicle program with the capability to utilize DRWP profiles on DOL to compute vehicle steering

The vertical structure of tangential winds in tropical cyclones: Observations, theory, and numerical simulations

NASA Astrophysics Data System (ADS)

Stern, Daniel P.

The vertical structure of the tangential wind field in tropical cyclones is investigated through observations, theory, and numerical simulations. First, a dataset of Doppler radar wind swaths obtained from NOAA/AOML/HRD is used to create azimuthal mean tangential wind fields for 7 storms on 17 different days. Three conventional wisdoms of vertical structure are reexamined: the outward slope of the Radius of Maximum Winds (RMW) decreases with increasing intensity, the slope increases with the size of the RMW, and the RMW is a surface of constant absolute angular momentum (M). The slopes of the RMW and of M surfaces are objectively determined. The slopes are found to increase linearly with the size of the low-level RMW, and to be independent of the intensity of the storm. While the RMW is approximately an M surface, M systematically decreases with height along the RMW. The steady-state analytical theory of Emanuel (1986) is shown to make specific predictions regarding the vertical structure of tropical cyclones. It is found that in this model, the slope of the RMW is a linear function of its size and is independent of intensity, and that the RMW is almost exactly an M surface. A simple time-dependent model which is governed by the same assumptions as the analytical theory yields the same results. Idealized hurricane simulations are conducted using the Weather Research and Forecasting (WRF) model. The assumptions of Emanuel's theory, slantwise moist neutrality and thermal wind balance, are both found to be violated. Nevertheless, the vertical structure of the wind field itself is generally well predicted by the theory. The percentage rate at which the winds decay with height is found to be nearly independent of both size and intensity, in agreement with observations and theory. Deviations from this decay profile are shown to be due to gradient wind imbalance. The slope of the RMW increases linearly with its size, but is systematically too large compared to

Parameterization of Cirrus Cloud Vertical Profiles and Geometrical Thickness Using CALIPSO and CloudSat Data

NASA Astrophysics Data System (ADS)

Khatri, P.; Iwabuchi, H.; Saito, M.

2017-12-01

High-level cirrus clouds, which normally occur over more than 20% of the globe, are known to have profound impacts on energy budget and climate change. The scientific knowledge regarding the vertical structure of such high-level cirrus clouds and their geometrical thickness are relatively poorer compared to low-level water clouds. Knowledge regarding cloud vertical structure is especially important in passive remote sensing of cloud properties using infrared channels or channels strongly influenced by gaseous absorption when clouds are geometrically thick and optically thin. Such information is also very useful for validating cloud resolving numerical models. This study analyzes global scale data of ice clouds identified by Cloud profiling Radar (CPR) onboard CloudSat and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard CALIPSO to parameterize (i) vertical profiles of ice water content (IWC), cloud-particle effective radius (CER), and ice-particle number concentration for varying ice water path (IWP) values and (ii) the relation of cloud geometrical thickness (CGT) with IWP and CER for varying cloud top temperature (CTT) values. It is found that the maxima in IWC and CER profile shifts towards cloud base with the increase of IWP. Similarly, if the cloud properties remain same, CGT shows an increasing trend with the decrease of CTT. The implementation of such cloud vertical inhomogeneity parameterization in the forward model used in the Integrated Cloud Analysis System ICAS (Iwabuchi et al., 2016) generally shows increase of brightness temperatures in infrared channels compared to vertically homogeneous cloud assumption. The cloud vertical inhomogeneity is found to bring noticeable changes in retrieved cloud properties. Retrieved CER and cloud top height become larger for optically thick cloud. We will show results of comparison of cloud properties retrieved from infrared measurements and active remote sensing.

Coastal water monitoring using a vertical profiler

NASA Astrophysics Data System (ADS)

Kim, Dong Guk; Seo, Seongbong; Park, Young-Gyu; Min, Hong Sik

2017-04-01

Using a profiler system, the Aqualog, composed of a moored wire and a carrier in which a CTD was installed, we have been monitoring coastal water in Korea since August 2016. With this monitoring system, we were able to observe rapid warming of surface water that resulted in large damage to fish farms. The profiles showed that the warming was associated with low salinity water due to the fresh water discharge from the Yangtze River. We also observed change in water properties due to a typhoon. Along the Korean coast there are many aquafarms, which are becoming more vulnerable to environmental change. With the data from the profiler we would be able to help the aquafarms to sustain.

Vertical radar profiles for the calibration of unsaturated flow models under dynamic water table conditions

NASA Astrophysics Data System (ADS)

Cassiani, G.; Gallotti, L.; Ventura, V.; Andreotti, G.

2003-04-01

The identification of flow and transport characteristics in the vadose zone is a fundamental step towards understanding the dynamics of contaminated sites and the resulting risk of groundwater pollution. Borehole radar has gained popularity for the monitoring of moisture content changes, thanks to its apparent simplicity and its high resolution characteristics. However, cross-hole radar requires closely spaced (a few meters), plastic-cased boreholes, that are rarely available as a standard feature in sites of practical interest. Unlike cross-hole applications, Vertical Radar Profiles (VRP) require only one borehole, with practical and financial benefits. High-resolution, time-lapse VRPs have been acquired at a crude oil contaminated site in Trecate, Northern Italy, on a few existing boreholes originally developed for remediation via bioventing. The dynamic water table conditions, with yearly oscillations of roughly 5 m from 6 to 11 m bgl, offers a good opportunity to observe via VRP a field scale drainage-imbibition process. Arrival time inversion has been carried out using a regularized tomographic algorithm, in order to overcome the noise introduced by first arrival picking. Interpretation of the vertical profiles in terms of moisture content has been based on standard models (Topp et al., 1980; Roth et al., 1990). The sedimentary sequence manifests itself as a cyclic pattern in moisture content over most of the profiles. We performed preliminary Richards' equation simulations with time varying later table boundary conditions, in order to estimate the unsaturated flow parameters, and the results have been compared with laboratory evidence from cores.

Sensitive monitoring of iodine species in sea water using capillary electrophoresis: vertical profiles of dissolved iodine in the Pacific Ocean.

PubMed

Huang, Zhuo; Ito, Kazuaki; Morita, Isamu; Yokota, Kuriko; Fukushi, Keiichi; Timerbaev, Andrei R; Watanabe, Shuichi; Hirokawa, Takeshi

2005-08-01

Using a novel high-sensitivity capillary electrophoretic method, vertical distributions of iodate, iodide, total inorganic iodine, dissolved organic iodine and total iodine in the North Pacific Ocean (0-5500 m) were determined without any sample pre-treatment other than UV irradiation before total iodine analysis. An extensive set of data demonstrated that the iodine behaviour in the ocean water collected during a cruise in the North Pacific Ocean in February-March 2003 was not conservative but correlated with variations in concentrations of dissolved oxygen and nutrient elements such as silicon, nitrogen and phosphorus. This suggests that the vertical distribution of iodine is associated with biological activities. The dissolved organic iodine was found in the euphotic zone in accord with observations elsewhere in the oceans. The vertical profile of dissolved organic iodine also appears to be related to biogeochemical activity. The concentrations of all measured iodine species vary noticeably above 1000 m but only minor latitudinal changes occur below 1000 m and slight vertical alterations can be observed below 2400 m. These findings are thought to reflect the stratification of nutrients and iodine species with different biological activities in the water column.

Observing the Great Plains Low-Level Jet Using the Aircraft Communications Addressing and Reporting System (ACARS): A Comparison with Boundary Layer Profiler Observations

NASA Astrophysics Data System (ADS)

Skinner, P. S.; Basu, S.

2009-12-01

Wind resources derived from the nocturnal low-level jet of the Great Plains of the United States are a driving factor in the proliferation of wind energy facilities across the region. Accurate diagnosis and forecasting of the low-level jet is important to not only assess the wind resource but to estimate the potential for shear-induced stress generation on turbine rotors. This study will examine the utility of Aircraft Communications Addressing and Reporting System (ACARS) observations in diagnosing low-level jet events across the Texas Panhandle. ACARS observations from Lubbock International Airport (KLBB) will be compared to observations from a 915 MHZ Doppler radar vertical boundary-layer profiler with 60m vertical resolution located at the field experiment site of Texas Tech University. The ability of ACARS data to adequately observe low-level jet events during the spring and summer of 2009 will be assessed and presented.

Seasonal changes in the tropospheric carbon monoxide profile over the remote Southern Hemisphere evaluated using multi-model simulations and aircraft observations

NASA Astrophysics Data System (ADS)

Fisher, J. A.; Wilson, S. R.; Zeng, G.; Williams, J. E.; Emmons, L. K.; Langenfelds, R. L.; Krummel, P. B.; Steele, L. P.

2015-03-01

The combination of low anthropogenic emissions and large biogenic sources that characterizes the Southern Hemisphere (SH) leads to significant differences in atmospheric composition relative to the better studied Northern Hemisphere. This unique balance of sources poses significant challenges for global models. Carbon monoxide (CO) in particular is difficult to simulate in the SH due to the increased importance of secondary chemical production associated with the much more limited primary emissions. Here, we use aircraft observations from the 1991-2000 Cape Grim Overflight Program (CGOP) and the 2009-2011 HIAPER (High-performance Instrumented Airborne Platform for Environmental Research) Pole-to-Pole Observations (HIPPO), together with model output from the SH Model Intercomparison Project, to elucidate the drivers of CO vertical structure in the remote SH. Observed CO vertical profiles from Cape Grim are remarkably consistent with those observed over the southern mid-latitudes Pacific 10-20 years later, despite major differences in time periods, flight locations, and sampling strategies between the two data sets. These similarities suggest the processes driving observed vertical gradients are coherent across much of the remote SH and have not changed significantly over the past 2 decades. Model ability to simulate CO profiles reflects the interplay between biogenic emission sources, the chemical mechanisms that drive CO production from these sources, and the transport that redistributes this CO throughout the SH. The four chemistry-climate and chemical transport models included in the intercomparison show large variability in their abilities to reproduce the observed CO profiles. In particular, two of the four models significantly underestimate vertical gradients in austral summer and autumn, which we find are driven by long-range transport of CO produced from oxidation of biogenic compounds. Comparisons between the models show that more complex chemical

A Direct Detection 1.6μm DIAL with Three Wavelengths for Measurements of Vertical CO2 Concentration and Temperature Profiles in the Atmosphere

NASA Astrophysics Data System (ADS)

Nagasawa, C.; Abo, M.; Shibata, Y.; Nagai, T.; Tsukamoto, M.

2012-12-01

We report the new 1.6 μm DIAL system that can measure the temperature profiles with the CO2 concentration profiles in the atmosphere because of improvement of measurement accuracy of the CO2 density and mixing ratio (ppm). We have developed a direct detection 1.6 μm differential absorption lidar (DIAL) technique to perform range-resolved measurements of vertical CO2 concentration profiles in the atmosphere [Sakaizawa et al. 2009]. Our 1.6 μm DIAL system consists of the Optical Parametric Generator (OPG) transmitter that excited by the LD pumped Nd:YAG laser with high repetition rate (500 Hz) and the receiving optics that included the near-infrared photomultiplier tube with high quantum efficiency operating at the photon counting mode and the telescope with larger aperture than that of the coherent detection method. Laser beams of three wavelengths around a CO2 absorption line is transmitted alternately to the atmosphere for measurements of CO2 concentration and temperature profiles. Moreover, a few retrieval algorithms of CO2-DIAL are also performed for improvement of measurement accuracy. The accurate vertical CO2 profiles in the troposphere are highly desirable in the inverse techniques to improve quantification and understanding of the global budget of CO2 and also global climate changes [Stephens et al. 2007]. In comparison with the ground-based monitoring network, CO2 measurements for vertical profiles in the troposphere have been limited to campaign-style aircraft and commercial airline observations with the limited spatial and temporal coverage. This work was financially supported by the System Development Program for Advanced Measurement and Analysis of the Japan Science and Technology Agency. References Sakaizawa, D., C. Nagasawa, T. Nagai, M. Abo, Y. Shibata, H. Nagai, M. Nakazato, and T. Sakai, Development of a 1.6μm differential absorption lidar with a quasi-phase-matching optical parametric oscillator and photon-counting detector for the vertical

Analysis and characterization of the vertical wind profile in UAE

NASA Astrophysics Data System (ADS)

Lee, W.; Ghedira, H.; Ouarda, T.; Gherboudj, I.

2011-12-01

In this study, temporal and spatial analysis of the vertical wind profiles in the UAE has been performed to estimate wind resource potential. Due to the very limited number of wind masts (only two wind masts in the UAE, operational for less than three years), the wind potential analysis will be mainly derived from numerical-based models. Additional wind data will be derived from the UAE met stations network (at 10 m elevation) managed by the UAE National Center of Meteorology and Seismology. However, since wind turbines are generally installed at elevations higher than 80 m, it is vital to extrapolate wind speed correctly from low heights to wind turbine hub heights to predict potential wind energy properly. To do so, firstly two boundary layer based models, power law and logarithmic law, were tested to find the best fitting model. Power law is expressed as v/v0 =(H/H0)^α and logarithmic law is represented as v/v0 =[ln(H/Z0))/(ln(H0/Z0)], where V is the wind speed [m/s] at height H [m] and V0 is the known wind speed at a reference height H0. The exponent (α) coefficient is an empirically derived value depending on the atmospheric stability and z0 is the roughness coefficient length [m] that depends on topography, land roughness and spacing. After testing the two models, spatial and temporal analysis for wind profile was performed. Many studies about wind in different regions have shown that wind profile parameters have hourly, monthly and seasonal variations. Therefore, it can be examined whether UAE wind characteristics follow general wind characteristics observed in other regions or have specific wind features due to its regional condition. About 3 years data from August 2008 to February 2011 with 10-minutes resolution were used to derive monthly variation. The preliminary results(Fig.1) show that during that period, wind profile parameters like alpha from power law and roughness length from logarithmic law have monthly variation. Both alpha and roughness have

The use of vertical seismic profiles in seismic investigations of the earth

USGS Publications Warehouse

Balch, Alfred H.; Lee, M.W.; Miller, J.J.; Ryder, Robert T.

1982-01-01

During the past 8 years, the U.S. Geological Survey has conducted an extensive investigation on the use of vertical seismic profiles (VSP) in a variety of seismic exploration applications. Seismic sources used were surface air guns, vibrators, explosives, marine air guns, and downhole air guns. Source offsets have ranged from 100 to 7800 ft. Well depths have been from 1200 to over 10,000 ft. We have found three specific ways in which VSPs can be applied to seismic exploration. First, seismic events observed at the surface of the ground can be traced, level by level, to their point of origin within the earth. Thus, one can tie a surface profile to a well log with an extraordinarily high degree of confidence. Second, one can establish the detectability of a target horizon, such as a porous zone. One can determine (either before or after surface profiling) whether or not a given horizon or layered sequence returns a detectable reflection to the surface. The amplitude and character of the reflection can also be observed. Third, acoustic properties of a stratigraphic sequence can be measured and sometimes correlated to important exploration parameters. For example, sometimes a relationship between apparent attenuation and sand percentage can be established. The technique shows additional promise of aiding surface exploration indirectly through studies of the evolution of the seismic pulse, studies of ghosts and multiples, and studies of seismic trace inversion techniques. Nearly all current seismic data‐processing techniques are adaptable to the processing of VSP data, such as normal moveout (NMO) corrections, stacking, single‐and multiple‐channel filtering, deconvolution, and wavelet shaping.

Analysis of photonic spot profile converter and bridge structure on SOI platform for horizontal and vertical integration

NASA Astrophysics Data System (ADS)

Majumder, Saikat; Jha, Amit Kr.; Biswas, Aishik; Banerjee, Debasmita; Ganguly, Dipankar; Chakraborty, Rajib

2017-08-01

Horizontal spot size converter required for horizontal light coupling and vertical bridge structure required for vertical integration are designed on high index contrast SOI platform in order to form more compact integrated photonic circuits. Both the structures are based on the concept of multimode interference. The spot size converter can be realized by successive integration of multimode interference structures with reducing dimension on horizontal plane, whereas the optical bridge structure consists of a number of vertical multimode interference structure connected by single mode sections. The spot size converter can be modified to a spot profile converter when the final single mode waveguide is replaced by a slot waveguide. Analysis have shown that by using three multimode sections in a spot size converter, an Gaussian input having spot diameter of 2.51 μm can be converted to a spot diameter of 0.25 μm. If the output single mode section is replaced by a slot waveguide, this input profile can be converted to a flat top profile of width 50 nm. Similarly, vertical displacement of 8μm is possible by using a combination of two multimode sections and three single mode sections in the vertical bridge structure. The analyses of these two structures are carried out for both TE and TM modes at 1550 nm wavelength using the semi analytical matrix method which is simple and fast in computation time and memory. This work shows that the matrix method is equally applicable for analysis of horizontally as well as vertically integrated photonic circuit.

The vertical profile of radar reflectivity of convective cells: A strong indicator of storm intensity and lightning probability?

NASA Technical Reports Server (NTRS)

Zipser, Edward J.; Lutz, Kurt R.

1994-01-01

Reflectivity data from Doppler radars are used to construct vertical profiles of radar reflectivity (VPRR) of convective cells in mesoscale convective systems (MCSs) in three different environmental regimes. The National Center for Atmospheric Research CP-3 and CP-4 radars are used to calculate median VPRR for MCSs in the Oklahoma-Kansas Preliminary Regional Experiment for STORM-Central in 1985. The National Oceanic and Atmospheric Administration-Tropical Ocean Global Atmosphere radar in Darwin, Australia, is used to calculate VPRR for MCSs observed both in oceanic, monsoon regimes and in continental, break period regimes during the wet seasons of 1987/88 and 1988/89. The midlatitude and tropical continental VPRRs both exhibit maximum reflectivity somewhat above the surface and have a gradual decrease in reflectivity with height above the freezing level. In sharp contrast, the tropical oceanic profile has a maximum reflectivity at the lowest level and a very rapid decrease in reflectivity with height beginning just above the freezing level. The tropical oceanic profile in the Darwin area is almost the same shape as that for two other tropical oceanic regimes, leading to the conclustion that it is characteristic. The absolute values of reflectivity in the 0 to 20 C range are compared with values in the literature thought to represent a threshold for rapid storm electrification leading to lightning, about 40 dBZ at -10 C. The large negative vertical gradient of reflectivity in this temperature range for oceanic storms is hypothesized to be a direct result of the characteristically weaker vertical velocities observed in MCSs over tropical oceans. It is proposed, as a necessary condition for rapid electrification, that a convective cell must have its updraft speed exceed some threshold value. Based upon field program data, a tentative estimate for the magnitude of this threshold is 6-7 m/s for mean speed and 10-12 m/s for peak speed.

Decoding the origins of vertical land motions observed today at coasts

NASA Astrophysics Data System (ADS)

Pfeffer, J.; Spada, G.; Mémin, A.; Boy, J.-P.; Allemand, P.

2017-07-01

In recent decades, geodetic techniques have allowed detecting vertical land motions and sea-level changes of a few millimetres per year, based on measurements taken at the coast (tide gauges), on board of satellite platforms (satellite altimetry) or both (Global Navigation Satellite System). Here, contemporary vertical land motions are analysed from January 1993 to July 2013 at 849 globally distributed coastal sites. The vertical displacement of the coastal platform due to surface mass changes is modelled using elastic and viscoelastic Green's functions. Special attention is paid to the effects of glacial isostatic adjustment induced by past and present-day ice melting. Various rheological and loading parameters are explored to provide a set of scenarios that could explain the coastal observations of vertical land motions globally. In well-instrumented regions, predicted vertical land motions explain more than 80 per cent of the variance observed at scales larger than a few hundred kilometres. Residual vertical land motions show a strong local variability, especially in the vicinity of plate boundaries due to the earthquake cycle. Significant residual signals are also observed at scales of a few hundred kilometres over nine well-instrumented regions forming observation windows on unmodelled geophysical processes. This study highlights the potential of our multitechnique database to detect geodynamical processes, driven by anthropogenic influence, surface mass changes (surface loading and glacial isostatic adjustment) and tectonic activity (including the earthquake cycle, sediment and volcanic loading, as well as regional tectonic constraints). Future improvements should be aimed at densifying the instrumental network and at investigating more thoroughly the uncertainties associated with glacial isostatic adjustment models.

Comparing the cloud vertical structure derived from several methods based on measured atmospheric profiles and active surface measurements

NASA Astrophysics Data System (ADS)

Costa-Surós, M.; Calbó, J.; González, J. A.; Long, C. N.

2013-06-01

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, is an important characteristic in order to describe the impact of clouds in a changing climate. In this work several methods to estimate the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering number and position of cloud layers, with a ground based system which is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ on the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study these methods are applied to 125 radiosonde profiles acquired at the ARM Southern Great Plains site during all seasons of year 2009 and endorsed by GOES images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The overall agreement for the methods ranges between 44-88%; four methods produce total agreements around 85%. Further tests and improvements are applied on one of these methods. In addition, we attempt to make this method suitable for low resolution vertical profiles, which could be useful in atmospheric modeling. The total agreement, even when using low resolution profiles, can be improved up to 91% if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

Retrieval of vertical aerosol- and trace gas profiles in the Antarctic troposphere using helicopter-borne MAX-DOAS measurements

NASA Astrophysics Data System (ADS)

Nasse, Jan-Marcus; Zielcke, Johannes; Buxmann, Joelle; Frieß, Udo; Platt, Ulrich

2014-05-01

BrO and aerosol vertical profiles obtained from the helicopter-borne observations, discuss the vertical resolution, error budget and information content of the measurements, and compare the data with profiles from our co-located ship-borne MAX-DOAS instrument.

Vertical tilts of tropospheric waves - Observations and theory

NASA Technical Reports Server (NTRS)

Ebisuzaki, Wesley

1991-01-01

Two methods are used to investigate the vertical tilts of planetary waves as functions of zonal wavenumber and frequency. The vertical tilts are computed by cross-spectral analysis of the geopotential heights at different pressures. In the midlatitude troposphere, the eastward-moving waves had a westward tilt with height, as expected, but the westward-moving waves with frequencies higher than 0.2/d showed statistically significant eastward vertical tilts. For a free Rossby wave, this implies that the Eliassen-Palm flux is downward along with its energy propagation. A downward energy propagation suggests an upper-level source of these waves. It is proposed that the eastward-tilting waves were forced by the nonlinear interaction of stationary waves and baroclinically unstable cyclone-scale waves. The predicted vertical tilt and phase speed were consistent with the observations. In addition, simulations of a general circulation model were analyzed. In the control run, eastward-tilting waves disappeared when the sources of stationary waves were removed. This is consistent with the present theory.

Double Bright Band Observations with High-Resolution Vertically Pointing Radar, Lidar, and Profiles

NASA Technical Reports Server (NTRS)

Emory, Amber E.; Demoz, Belay; Vermeesch, Kevin; Hicks, Michael

2014-01-01

On 11 May 2010, an elevated temperature inversion associated with an approaching warm front produced two melting layers simultaneously, which resulted in two distinct bright bands as viewed from the ER-2 Doppler radar system, a vertically pointing, coherent X band radar located in Greenbelt, MD. Due to the high temporal resolution of this radar system, an increase in altitude of the melting layer of approximately 1.2 km in the time span of 4 min was captured. The double bright band feature remained evident for approximately 17 min, until the lower atmosphere warmed enough to dissipate the lower melting layer. This case shows the relatively rapid evolution of freezing levels in response to an advancing warm front over a 2 h time period and the descent of an elevated warm air mass with time. Although observations of double bright bands are somewhat rare, the ability to identify this phenomenon is important for rainfall estimation from spaceborne sensors because algorithms employing the restriction of a radar bright band to a constant height, especially when sampling across frontal systems, will limit the ability to accurately estimate rainfall.

Double bright band observations with high-resolution vertically pointing radar, lidar, and profilers

NASA Astrophysics Data System (ADS)

Emory, Amber E.; Demoz, Belay; Vermeesch, Kevin; Hicks, Micheal

2014-07-01

On 11 May 2010, an elevated temperature inversion associated with an approaching warm front produced two melting layers simultaneously, which resulted in two distinct bright bands as viewed from the ER-2 Doppler radar system, a vertically pointing, coherent X band radar located in Greenbelt, MD. Due to the high temporal resolution of this radar system, an increase in altitude of the melting layer of approximately 1.2 km in the time span of 4 min was captured. The double bright band feature remained evident for approximately 17 min, until the lower atmosphere warmed enough to dissipate the lower melting layer. This case shows the relatively rapid evolution of freezing levels in response to an advancing warm front over a 2 h time period and the descent of an elevated warm air mass with time. Although observations of double bright bands are somewhat rare, the ability to identify this phenomenon is important for rainfall estimation from spaceborne sensors because algorithms employing the restriction of a radar bright band to a constant height, especially when sampling across frontal systems, will limit the ability to accurately estimate rainfall.

The vertical structure of convectively-driven cloud microphysics and its dependency on atmospheric conditions: An investigation through observations and modeling

NASA Astrophysics Data System (ADS)

van Diedenhoven, B.; Fridlind, A. M.; Sinclair, K.; Ackerman, A. S.

2016-12-01

It is generally observed that ice crystal sizes decrease as a function of altitude within clouds. This dependency is often explained as resulting from size sorting owing to the greater fall speeds of larger particles, but may also be related to dependence of ice diffusional growth on available water vapor and temperature, or other factors. Furthermore, the vertical variation of ice sizes is expected to be affected by the glaciation temperature of convectively-driven clouds. Realistic modeling of ice formation, growth and sedimentation is crucial to reliably represent vertical structures of ice clouds and cloud evolution in general. In this presentation we use remote sensing observations of glaciation temperature and ice effective radius obtained with airborne instruments to explore how their vertical dependencies vary with atmospheric conditions, such as humidity and wind profiles. Our focus will be on convectively-driven clouds. Subsequently, we test the ability of a quasi-idealized cloud permitting model to reproduce these dependencies of ice formation and size to atmospheric conditions, applying various ice growth and multiplication assumptions. The goal of this study is to identify variables that determine the vertical structure of cold clouds that can be used to evaluate model simulations.

Hemispheric aerosol vertical profiles: anthropogenic impacts on optical depth and cloud nuclei.

PubMed

Clarke, Antony; Kapustin, Vladimir

2010-09-17

Understanding the effect of anthropogenic combustion upon aerosol optical depth (AOD), clouds, and their radiative forcing requires regionally representative aerosol profiles. In this work, we examine more than 1000 vertical profiles from 11 major airborne campaigns in the Pacific hemisphere and confirm that regional enhancements in aerosol light scattering, mass, and number are associated with carbon monoxide from combustion and can exceed values in unperturbed regions by more than one order of magnitude. Related regional increases in a proxy for cloud condensation nuclei (CCN) and AOD imply that direct and indirect aerosol radiative effects are coupled issues linked globally to aged combustion. These profiles constrain the influence of combustion on regional AOD and CCN suitable for challenging climate model performance and informing satellite retrievals.

Measurements of Aerosol Vertical Profiles and Optical Properties during INDOEX 1999 Using Micro-Pulse Lidars

NASA Technical Reports Server (NTRS)

Welton, Ellsworth J.; Voss, Kenneth J.; Quinn, Patricia K.; Flatau, Piotr J.; Markowicz, Krzysztof; Campbell, James R.; Spinhirne, James D.; Gordon, Howard R.; Johnson, James E.; Starr, David OC. (Technical Monitor)

2001-01-01

Micro-pulse lidar systems (MPL) were used to measure aerosol properties during the Indian Ocean Experiment (INDOEX) 1999 field phase. Measurements were made from two platforms: the NOAA ship RN Ronald H. Brown, and the Kaashidhoo Climate Observatory (KCO) in the Maldives. Sunphotometers were used to provide aerosol optical depths (AOD) needed to calibrate the MPL. This study focuses on the height distribution and optical properties (at 523 nm) of aerosols observed during the campaign. The height of the highest aerosols (top height) was calculated and found to be below 4 km for most of the cruise. The marine boundary layer (MBL) top was calculated and found to be less than 1 km. MPL results were combined with air mass trajectories, radiosonde profiles of temperature and humidity, and aerosol concentration and optical measurements. Humidity varied from approximately 80% near the surface to 50% near the top height during the entire cruise. The average value and standard deviation of aerosol optical parameters were determined for characteristic air mass regimes. Marine aerosols in the absence of any continental influence were found to have an AOD of 0.05 +/- 0.03, an extinction-to-backscatter ratio (S-ratio) of 33 +/- 6 sr, and peak extinction values around 0.05/km (near the MBL top). The marine results are shown to be in agreement with previously measured and expected values. Polluted marine areas over the Indian Ocean, influenced by continental aerosols, had AOD values in excess of 0.2, S-ratios well above 40 sr, and peak extinction values approximately 0.20/km (near the MBL top). The polluted marine results are shown to be similar to previously published values for continental aerosols. Comparisons between MPL derived extinction near the ship (75 m) and extinction calculated at ship-level using scattering measured by a nephelometer and absorption using a PSAP were conducted. The comparisons indicated that the MPL algorithm (using a constant S-ratio throughout the

Effects of pressing schedule on formation of vertical density profile for MDF panels

Treesearch

Zhiyong Cai; James H. Muehl; Jerrold E. Winandy

2006-01-01

A fundamental understanding of mat consolidation during hot pressing will help to optimize the medium-density fiberboard (MDF) manufacturing process by increasing productivity, improving product quality, and enhancing durability. Effects of panel density, fiber moisture content (MC), and pressing schedule on formation of vertical density profile (VDP) during hot...

Vertical Coupling and Observable Effects of Evanescent Acoustic-Gravity Waves in the Mesosphere and Thermosphere

NASA Astrophysics Data System (ADS)

Snively, J. B.

2017-12-01

Our understanding of acoustic-gravity wave (AGW) dynamics at short periods ( minutes to hour) and small scales ( 10s to 100s km) in the mesosphere, thermosphere, and ionosphere (MTI) has benefited considerably from horizontally- and vertically-resolved measurements of layered species. These include, for example, imagery of the mesopause ( 80-100 km) airglow layers and vertical profiles of the sodium layer via lidar [e.g., Taylor and Hapgood, PSS, 36(10), 1988; Miller et al., PNAS, 112(49), 2015; Cao et al., JGR, 121, 2016]. In the thermosphere-ionosphere, AGW perturbations are also revealed in electron density profiles [Livneh et al., JGR, 112, 2007] and maps of total electron content (TEC) from global positioning system (GPS) receivers [Nishioka et al., GRL, 40(21), 2013]. To the extent that AGW signatures in layered species can be quantified, and the ambient atmospheric state measured or estimated, numerical models enable investigations of dynamics at intermediate altitudes that cannot readily be measured (e.g., above and below the 80-100 km mesopause region). Here, new 2D and 3D versions of the Model for Acoustic-Gravity Wave Interactions and Coupling (MAGIC) [e.g., Snively and Pasko, JGR, 113(A6), 2008, and references therein] are introduced and applied to investigate spectra of short-period AGW that can pass through the mesopause region to reach and impact the thermosphere. Simulation case studies are constructed to investigate both their signatures through the hydroxyl airglow layer [e.g., Snively et al., JGR 115(A11), 2010] and their effects above. These waves, with large vertical wavelengths and fast horizontal phase speeds, also include those that may be subject to evanescence at mesopause or in the middle-thermosphere, with potential for ducting or dissipation between where static stability is higher. Despite complicating interpretations of momentum fluxes, evanescence plays an under-appreciated role in vertical coupling by AGW [Walterscheid and Hecht

Seismic anisotropy in gas-hydrate- and gas-bearing sediments on the Blake Ridge, from a walkaway vertical seismic profile

USGS Publications Warehouse

Pecher, I.A.; Holbrook, W.S.; Sen, M.K.; Lizarralde, D.; Wood, W.T.; Hutchinson, D.R.; Dillon, William P.; Hoskins, H.; Stephen, R.A.

2003-01-01

We present results from an analysis of anisotropy in marine sediments using walkaway vertical seismic profiles from the Blake Ridge, offshore South Carolina. We encountered transverse isotropy (TI) with a vertical symmetry axis in a gas-hydrate-bearing unit of clay and claystone with Thomsen parameters ?? = 0.05 ?? 0.02 and ?? = 0.04 ?? 0.06. TI increased to ?? = 0.16 ?? 0.04 and ?? = 0.19 ?? 0.12 in the underlying gas zone. Rock physics modeling suggests that the observed TI is caused by a partial alignment of clay particles rather than high-velocity gas-hydrate veins. Similarly, the increase of TI in the gas zone is not caused by thin low-velocity gas layers but rather, we speculate, by the sharp contrast between seismic properties of an anisotropic sediment frame and elongated gas-bearing pore voids. Our results underscore the significance of anisotropy for integrating near-vertical and wide-angle seismic data.

Observations of Dust Using the NASA Geoscience Laser Altimeter System (GLAS): New New Measurements of Aerosol Vertical Distribution From Space

NASA Technical Reports Server (NTRS)

Welton, Ellsworth; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis; Hart, William

2003-01-01

On January 12, 2003 NASA launched the first satellite-based lidar, the Geoscience Laser -Altimeter System (GLAS), onboard the ICESat spacecraft. The GLAS atmospheric measurements introduce a fundamentally new and important tool for understanding the atmosphere and climate. In the past, aerosols have only been studied from space using images gathered by passive sensors. Analysis of this passive data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth's climate. However, these images do not show the aerosol's vertical distribution. As a result, a key piece of information has been missing. The measurements now obtained by GLAS will provide information on the vertical distribution of aerosols and clouds, and improve our ability to study their transport processes and aerosol-cloud interactions. Here we show an overview of GLAS, provide an update of its current status, and present initial observations of dust profiles. In particular, a strategy of characterizing the height profile of dust plumes over source regions will be presented.

Experimental observation of the influence of furnace temperature profile on convection and segregation in the vertical Bridgman crystal growth technique

NASA Technical Reports Server (NTRS)

Neugebauer, G. T.; Wilcox, W. R.

1990-01-01

Azulene-doped naphtalene was directionally solidified using the vertical Bridgman-Stockbarger technique. Doping homogeneity and convection are determined as a function of the temperature profile in the furnace and the freezing rate. Convective velocities are two orders of magnitude lower when the temperature increases with height. The cross sectional variation in azulene concentration tends to be asymmetric. Neither rotation of the ampoule nor deliberate introduction of thermal asymmetries during solidification had a significant influence on cross sectional variations in doping. It is predicted that slow directional solidification under microgravity conditions can produce greater inhomogeneities than on earth. Thus when low freezing rates are necessary in order to avoid constitutional supercooling, it may be necessary to combine microgravity and magnetic fields in order to achieve homogeneous crystals.

Global-mean BC lifetime as an indicator of model skill? Constraining the vertical aerosol distribution using aircraft observations

NASA Astrophysics Data System (ADS)

Lund, M. T.; Samset, B. H.; Skeie, R. B.; Berntsen, T.

2017-12-01

Several recent studies have used observations from the HIPPO flight campaigns to constrain the modeled vertical distribution of black carbon (BC) over the Pacific. Results indicate a relatively linear relationship between global-mean atmospheric BC residence time, or lifetime, and bias in current models. A lifetime of less than 5 days is necessary for models to reasonably reproduce these observations. This is shorter than what many global models predict, which will in turn affect their estimates of BC climate impacts. Here we use the chemistry-transport model OsloCTM to examine whether this relationship between global BC lifetime and model skill also holds for a broader a set of flight campaigns from 2009-2013 covering both remote marine and continental regions at a range of latitudes. We perform four sets of simulations with varying scavenging efficiency to obtain a spread in the modeled global BC lifetime and calculate the model error and bias for each campaign and region. Vertical BC profiles are constructed using an online flight simulator, as well by averaging and interpolating monthly mean model output, allowing us to quantify sampling errors arising when measurements are compared with model output at different spatial and temporal resolutions. Using the OsloCTM coupled with a microphysical aerosol parameterization, we investigate the sensitivity of modeled BC vertical distribution to uncertainties in the aerosol aging and scavenging processes in more detail. From this, we can quantify how model uncertainties in the BC life cycle propagate into uncertainties in its climate impacts. For most campaigns and regions, a short global-mean BC lifetime corresponds with the lowest model error and bias. On an aggregated level, sampling errors appear to be small, but larger differences are seen in individual regions. However, we also find that model-measurement discrepancies in BC vertical profiles cannot be uniquely attributed to uncertainties in a single process or

Vertical temperature profile and mesospheric winds retrieval on Mars from CO ;millimeter observations. Comparison with general circulation model predictions

NASA Astrophysics Data System (ADS)

Cavalié, T.; Billebaud, F.; Encrenaz, T.; Dobrijevic, M.; Brillet, J.; Forget, F.; Lellouch, E.

2008-10-01

Aims: We have recorded high spectral resolution spectra and derived precise atmospheric temperature profiles and wind velocities in the atmosphere of Mars. We have compared observations of the planetary mean thermal profile and mesospheric wind velocities on the disk, obtained with our millimetric observations of CO rotational lines, to predictions from the Laboratoire de Météorologie Dynamique (LMD) Mars General Circulation Model, as provided through the Mars Climate Database (MCD) numerical tool. Methods: We observed the atmosphere of Mars at CO(1-0) and CO(2-1) wavelengths with the IRAM 30-m antenna in June 2001 and November 2005. We retrieved the mean thermal profile of the planet from high and low spectral resolution data with an inversion method detailed here. High spectral resolution spectra were used to derive mesospheric wind velocities on the planetary disk. We also report here the use of 13CO(2-1) line core shifts to measure wind velocities at 40 km. Results: Neither the Mars Year 24 (MY24) nor the Dust Storm scenario from the Mars Climate Database (MCD) provides satisfactory fits to the 2001 and 2005 data when retrieving the thermal profiles. The Warm scenario only provides good fits for altitudes lower than 30 km. The atmosphere is warmer than predicted up to 60 km and then becomes colder. Dust loading could be the reason for this mismatch. The MCD MY24 scenario predicts a thermal inversion layer between 40 and 60 km, which is not retrieved from the high spectral resolution data. Our results are generally in agreement with other observations from 10 to 40 km in altitude, but our results obtained from the high spectral resolution spectra differ in the 40-70 km layer, where the instruments are the most sensitive. The wind velocities we retrieve from our 12CO observations confirm MCD predictions for 2001 and 2005. Velocities obtained from 13CO observations are consistent with MCD predictions in 2001, but are lower than predicted in 2005.

Retrieving Vertical Air Motion and Raindrop Size Distributions from Vertically Pointing Doppler Radars

NASA Astrophysics Data System (ADS)

Williams, C. R.; Chandra, C. V.

2017-12-01

The vertical evolution of falling raindrops is a result of evaporation, breakup, and coalescence acting upon those raindrops. Computing these processes using vertically pointing radar observations is a two-step process. First, the raindrop size distribution (DSD) and vertical air motion need to be estimated throughout the rain shaft. Then, the changes in DSD properties need to be quantified as a function of height. The change in liquid water content is a measure of evaporation, and the change in raindrop number concentration and size are indicators of net breakup or coalescence in the vertical column. The DSD and air motion can be retrieved using observations from two vertically pointing radars operating side-by-side and at two different wavelengths. While both radars are observing the same raindrop distribution, they measure different reflectivity and radial velocities due to Rayleigh and Mie scattering properties. As long as raindrops with diameters greater than approximately 2 mm are in the radar pulse volumes, the Rayleigh and Mie scattering signatures are unique enough to estimate DSD parameters using radars operating at 3- and 35-GHz (Williams et al. 2016). Vertical decomposition diagrams (Williams 2016) are used to explore the processes acting on the raindrops. Specifically, changes in liquid water content with height quantify evaporation or accretion. When the raindrops are not evaporating, net raindrop breakup and coalescence are identified by changes in the total number of raindrops and changes in the DSD effective shape as the raindrops. This presentation will focus on describing the DSD and air motion retrieval method using vertical profiling radar observations from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) central facility in Northern Oklahoma.

Local ensemble transform Kalman filter for ionospheric data assimilation: Observation influence analysis during a geomagnetic storm event

NASA Astrophysics Data System (ADS)

Durazo, Juan A.; Kostelich, Eric J.; Mahalov, Alex

2017-09-01

We propose a targeted observation strategy, based on the influence matrix diagnostic, that optimally selects where additional observations may be placed to improve ionospheric forecasts. This strategy is applied in data assimilation observing system experiments, where synthetic electron density vertical profiles, which represent those of Constellation Observing System for Meteorology, Ionosphere, and Climate/Formosa satellite 3, are assimilated into the Thermosphere-Ionosphere-Electrodynamics General Circulation Model using the local ensemble transform Kalman filter during the 26 September 2011 geomagnetic storm. During each analysis step, the observation vector is augmented with five synthetic vertical profiles optimally placed to target electron density errors, using our targeted observation strategy. Forecast improvement due to assimilation of augmented vertical profiles is measured with the root-mean-square error (RMSE) of analyzed electron density, averaged over 600 km regions centered around the augmented vertical profile locations. Assimilating vertical profiles with targeted locations yields about 60%-80% reduction in electron density RMSE, compared to a 15% average reduction when assimilating randomly placed vertical profiles. Assimilating vertical profiles whose locations target the zonal component of neutral winds (Un) yields on average a 25% RMSE reduction in Un estimates, compared to a 2% average improvement obtained with randomly placed vertical profiles. These results demonstrate that our targeted strategy can improve data assimilation efforts during extreme events by detecting regions where additional observations would provide the largest benefit to the forecast.

Comparing the cloud vertical structure derived from several methods based on measured atmospheric profiles and active surface measurements

NASA Astrophysics Data System (ADS)

Costa-Surós, M.; Calbó, J.; González, J. A.; Long, C. N.

2014-04-01

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, is an important characteristic in order to describe the impact of clouds on climate. In this work several methods to estimate the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering number and position of cloud layers, with a ground based system which is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ on the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study these methods are applied to 193 radiosonde profiles acquired at the ARM Southern Great Plains site during all seasons of year 2009 and endorsed by GOES images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The perfect agreement (i.e. when the whole CVS is correctly estimated) for the methods ranges between 26-64%; the methods show additional approximate agreement (i.e. when at least one cloud layer is correctly assessed) from 15-41%. Further tests and improvements are applied on one of these methods. In addition, we attempt to make this method suitable for low resolution vertical profiles, like those from the outputs of reanalysis methods or from the WMO's Global Telecommunication System. The perfect agreement, even when using low resolution profiles, can be improved up to 67% (plus 25% of approximate agreement) if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

Temperature and Relative Humidity Vertical Profiles within Planetary Boundary Layer in Winter Urban Airshed

NASA Astrophysics Data System (ADS)

Bendl, Jan; Hovorka, Jan

2017-12-01

The planetary boundary layer is a dynamic system with turbulent flow where horizontal and vertical air mixing depends mainly on the weather conditions and geomorphology. Normally, air temperature from the Earth surface decreases with height but inversion situation may occur, mainly during winter. Pollutant dispersion is poor during inversions so air pollutant concentration can quickly rise, especially in urban closed valleys. Air pollution was evaluated by WHO as a human carcinogen (mostly by polycyclic aromatic hydrocarbons) and health effects are obvious. Knowledge about inversion layer height is important for estimation of the pollution impact and it can give us also information about the air pollution sources. Temperature and relative humidity vertical profiles complement ground measurements. Ground measurements were conducted to characterize comprehensively urban airshed in Svermov, residential district of the city of Kladno, about 30 km NW of Prague, from the 2nd Feb. to the 3rd of March 2016. The Svermov is an air pollution hot-spot for long time benzo[a]pyrene (B[a]P) limit exceedances, reaching the highest B[a]P annual concentration in Bohemia - west part of the Czech Republic. Since the Svermov sits in a shallow valley, frequent vertical temperature inversion in winter and low emission heights of pollution sources prevent pollutant dispersal off the valley. Such orography is common to numerous small settlements in the Czech Republic. Ground measurements at the sports field in the Svermov were complemented by temperature and humidity vertical profiles acquired by a Vaisala radiosonde positioned at tethered He-filled balloon. Total number of 53 series of vertical profiles up to the height of 300 m was conducted. Meteorology parameters were acquired with 4 Hz frequency. The measurements confirmed frequent early-morning and night formation of temperature inversion within boundary layer up to the height of 50 m. This rather shallow inversion had significant

Vertical suspsended sediment fluxes observed from ocean gliders

NASA Astrophysics Data System (ADS)

Merckelbach, Lucas; Carpenter, Jeffrey

2016-04-01

Many studies trying to understand a coastal system in terms of sediment transport paths resort to numerical modelling - combining circulation models with sediment transport models. Two aspects herein are crucial: sediment fluxes across the sea bed-water column interface, and the subsequent vertical mixing by turbulence. Both aspects are highly complex and have relatively short time scales, so that the processes involved are implemented in numerical models as parameterisations. Due to the effort required to obtain field observations of suspended sediment concentrations (and other parameters), measurements are scarce, which makes the development and tuning of parameterisations a difficult task. Ocean gliders (autonomous underwater vehicles propelled by a buoyancy engine) provide a platform complementing more traditional methods of sampling. In this work we present observations of suspended sediment concentration (SSC) and dissipation rate taken by two gliders, each equipped with optical sensors and a microstructure sensor, along with current observations from a bottom mounted ADCP, all operated in the German Bight sector of the North Sea in Summer 2014. For about two weeks of a four-week experiment, the gliders were programmed to fly in a novel way as Lagrangian profilers to water depths of about 40 m. The benefit of this approach is that the rate of change of SSC - and other parameters - is local to the water column, as opposed to an unknown composition of temporal and spatial variability when gliders are operated in the usual way. Therefore, vertical sediment fluxes can be calculated without the need of the - often dubious - assumption that spatial variability can be neglected. During the experiment the water column was initially thermally stratified, with a cross-pycnocline diffusion coefficient estimated at 7\\cdot10-5 m2 s-1. Halfway through the experiment the remnants of tropical storm Bertha arrived at the study site and caused a complete mixing of the water

Relative humidity vertical profiling using lidar-based synergistic methods in the framework of the Hygra-CD campaign

NASA Astrophysics Data System (ADS)

Labzovskii, Lev D.; Papayannis, Alexandros; Binietoglou, Ioannis; Banks, Robert F.; Baldasano, Jose M.; Toanca, Florica; Tzanis, Chris G.; Christodoulakis, John

2018-02-01

Accurate continuous measurements of relative humidity (RH) vertical profiles in the lower troposphere have become a significant scientific challenge. In recent years a synergy of various ground-based remote sensing instruments have been successfully used for RH vertical profiling, which has resulted in the improvement of spatial resolution and, in some cases, of the accuracy of the measurement. Some studies have also suggested the use of high-resolution model simulations as input datasets into RH vertical profiling techniques. In this paper we apply two synergetic methods for RH profiling, including the synergy of lidar with a microwave radiometer and high-resolution atmospheric modeling. The two methods are employed for RH retrieval between 100 and 6000 m with increased spatial resolution, based on datasets from the HygrA-CD (Hygroscopic Aerosols to Cloud Droplets) campaign conducted in Athens, Greece from May to June 2014. RH profiles from synergetic methods are then compared with those retrieved using single instruments or as simulated by high-resolution models. Our proposed technique for RH profiling provides improved statistical agreement with reference to radiosoundings by 27 % when the lidar-radiometer (in comparison with radiometer measurements) approach is used and by 15 % when a lidar model is used (in comparison with WRF-model simulations). Mean uncertainty of RH due to temperature bias in RH profiling was ˜ 4.34 % for the lidar-radiometer and ˜ 1.22 % for the lidar-model methods. However, maximum uncertainty in RH retrievals due to temperature bias showed that lidar-model method is more reliable at heights greater than 2000 m. Overall, our results have demonstrated the capability of both combined methods for daytime measurements in heights between 100 and 6000 m when lidar-radiometer or lidar-WRF combined datasets are available.

The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds.

PubMed

Miller, Daniel J; Zhang, Zhibo; Ackerman, Andrew S; Platnick, Steven; Baum, Bryan A

2016-04-27

Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness ( τ ) and effective radius ( r e ) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5-10 g/m 2 . In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic r e profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques.

The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds

PubMed Central

Miller, Daniel J.; Zhang, Zhibo; Ackerman, Andrew S.; Platnick, Steven; Baum, Bryan A.

2018-01-01

Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness (τ) and effective radius (re) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5–10 g/m2. In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic re profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques. PMID:29637042

The vertical profile of winds on Titan.

PubMed

Bird, M K; Allison, M; Asmar, S W; Atkinson, D H; Avruch, I M; Dutta-Roy, R; Dzierma, Y; Edenhofer, P; Folkner, W M; Gurvits, L I; Johnston, D V; Plettemeier, D; Pogrebenko, S V; Preston, R A; Tyler, G L

2005-12-08

One of Titan's most intriguing attributes is its copious but featureless atmosphere. The Voyager 1 fly-by and occultation in 1980 provided the first radial survey of Titan's atmospheric pressure and temperature and evidence for the presence of strong zonal winds. It was realized that the motion of an atmospheric probe could be used to study the winds, which led to the inclusion of the Doppler Wind Experiment on the Huygens probe. Here we report a high resolution vertical profile of Titan's winds, with an estimated accuracy of better than 1 m s(-1). The zonal winds were prograde during most of the atmospheric descent, providing in situ confirmation of superrotation on Titan. A layer with surprisingly slow wind, where the velocity decreased to near zero, was detected at altitudes between 60 and 100 km. Generally weak winds (approximately 1 m s(-1)) were seen in the lowest 5 km of descent.

Ozone profile intercomparison based on simultaneous observations between 20 and 40 km

NASA Technical Reports Server (NTRS)

Aimedieu, P.; Krueger, A. J.; Robbins, D. E.; Simon, P. C.

1983-01-01

The vertical distribution of stratospheric ozone has been simultaneously measured by means of five different instruments carried on the same balloon payload. The launches were performed from Gap during the intercomparison campaign conducted in June 1981 in southern France. Data obtained between altitudes of 20 and 40 km are compared and discussed. Vertical profiles deduced from Electrochemical Concentration Cell sondes launched from the same location by small balloons and from short Umkehr measurements made at Mt Chiran (France) are also included in this comparison. Systematic differences of the order of 20 percent between ozone profiles deduced from solar u.v. absorption and in situ techniques are found.

Vertical profiles of aerosol and black carbon in the Arctic: a seasonal phenomenology along 2 years (2011-2012) of field campaigns

NASA Astrophysics Data System (ADS)

Ferrero, Luca; Cappelletti, David; Busetto, Maurizio; Mazzola, Mauro; Lupi, Angelo; Lanconelli, Christian; Becagli, Silvia; Traversi, Rita; Caiazzo, Laura; Giardi, Fabio; Moroni, Beatrice; Crocchianti, Stefano; Fierz, Martin; Močnik, Griša; Sangiorgi, Giorgia; Perrone, Maria G.; Maturilli, Marion; Vitale, Vito; Udisti, Roberto; Bolzacchini, Ezio

2016-10-01

We present results from a systematic study of vertical profiles of aerosol number size distribution and black carbon (BC) concentrations conducted in the Arctic, over Ny-Ålesund (Svalbard). The campaign lasted 2 years (2011-2012) and resulted in 200 vertical profiles measured by means of a tethered balloon (up to 1200 m a.g.l.) during the spring and summer seasons. In addition, chemical analysis of filter samples, aerosol size distribution and a full set of meteorological parameters were determined at ground. The collected experimental data allowed a classification of the vertical profiles into different typologies, which allowed us to describe the seasonal phenomenology of vertical aerosol properties in the Arctic. During spring, four main types of profiles were found and their behavior was related to the main aerosol and atmospheric dynamics occurring at the measuring site. Background conditions generated homogenous profiles. Transport events caused an increase of aerosol concentration with altitude. High Arctic haze pollution trapped below thermal inversions promoted a decrease of aerosol concentration with altitude. Finally, ground-based plumes of locally formed secondary aerosol determined profiles with decreasing aerosol concentration located at different altitude as a function of size. During the summer season, the impact from shipping caused aerosol and BC pollution plumes to be constrained close to the ground, indicating that increasing shipping emissions in the Arctic could bring anthropogenic aerosol and BC in the Arctic summer, affecting the climate.

Improved observations of turbulence dissipation rates from wind profiling radars

DOE PAGES

McCaffrey, Katherine; Bianco, Laura; Wilczak, James M.

2017-07-20

Observations of turbulence dissipation rates in the planetary boundary layer are crucial for validation of parameterizations in numerical weather prediction models. However, because dissipation rates are difficult to obtain, they are infrequently measured through the depth of the boundary layer. For this reason, demonstrating the ability of commonly used wind profiling radars (WPRs) to estimate this quantity would be greatly beneficial. During the XPIA field campaign at the Boulder Atmospheric Observatory, two WPRs operated in an optimized configuration, using high spectral resolution for increased accuracy of Doppler spectral width, specifically chosen to estimate turbulence from a vertically pointing beam. Multiplemore » post-processing techniques, including different numbers of spectral averages and peak processing algorithms for calculating spectral moments, were evaluated to determine the most accurate procedures for estimating turbulence dissipation rates using the information contained in the Doppler spectral width, using sonic anemometers mounted on a 300 m tower for validation. Furthermore, the optimal settings were determined, producing a low bias, which was later corrected. Resulting estimations of turbulence dissipation rates correlated well ( R 2 = 0.54 and 0.41) with the sonic anemometers, and profiles up to 2 km from the 449 MHz WPR and 1 km from the 915 MHz WPR were observed.« less

Improved observations of turbulence dissipation rates from wind profiling radars

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

McCaffrey, Katherine; Bianco, Laura; Wilczak, James M.

Observations of turbulence dissipation rates in the planetary boundary layer are crucial for validation of parameterizations in numerical weather prediction models. However, because dissipation rates are difficult to obtain, they are infrequently measured through the depth of the boundary layer. For this reason, demonstrating the ability of commonly used wind profiling radars (WPRs) to estimate this quantity would be greatly beneficial. During the XPIA field campaign at the Boulder Atmospheric Observatory, two WPRs operated in an optimized configuration, using high spectral resolution for increased accuracy of Doppler spectral width, specifically chosen to estimate turbulence from a vertically pointing beam. Multiplemore » post-processing techniques, including different numbers of spectral averages and peak processing algorithms for calculating spectral moments, were evaluated to determine the most accurate procedures for estimating turbulence dissipation rates using the information contained in the Doppler spectral width, using sonic anemometers mounted on a 300 m tower for validation. Furthermore, the optimal settings were determined, producing a low bias, which was later corrected. Resulting estimations of turbulence dissipation rates correlated well ( R 2 = 0.54 and 0.41) with the sonic anemometers, and profiles up to 2 km from the 449 MHz WPR and 1 km from the 915 MHz WPR were observed.« less

Estimating vertical velocity and radial flow from Doppler radar observations of tropical cyclones

NASA Astrophysics Data System (ADS)

Lee, J. L.; Lee, W. C.; MacDonald, A. E.

2006-01-01

The mesoscale vorticity method (MVM) is used in conjunction with the ground-based velocity track display (GBVTD) to derive the inner-core vertical velocity from Doppler radar observations of tropical cyclone (TC) Danny (1997). MVM derives the vertical velocity from vorticity variations in space and in time based on the mesoscale vorticity equation. The use of MVM and GBVTD allows us to derive good correlations among the eye-wall maximum wind, bow-shaped updraught and echo east of the eye-wall in Danny. Furthermore, we demonstrate the dynamically consistent radial flow can be derived from the vertical velocity obtained from MVM using the wind decomposition technique that solves the Poisson equations over a limited-area domain. With the wind decomposition, we combine the rotational wind which is obtained from Doppler radar wind observations and the divergent wind which is inferred dynamically from the rotational wind to form the balanced horizontal wind in TC inner cores, where rotational wind dominates the divergent wind. In this study, we show a realistic horizontal and vertical structure of the vertical velocity and the induced radial flow in Danny's inner core. In the horizontal, the main eye-wall updraught draws in significant surrounding air, converging at the strongest echo where the maximum updraught is located. In the vertical, the main updraught tilts vertically outwards, corresponding very well with the outward-tilting eye-wall. The maximum updraught is located at the inner edge of the eye-wall clouds, while downward motions are found at the outer edge. This study demonstrates that the mesoscale vorticity method can use high-temporal-resolution data observed by Doppler radars to derive realistic vertical velocity and the radial flow of TCs. The vorticity temporal variations crucial to the accuracy of the vorticity method have to be derived from a high-temporal-frequency observing system such as state-of-the-art Doppler radars.

New Insights on "Next Day" Ozone Increases in the Northeastern U.S. using Continuous Vertical Profiles of Ozone

NASA Astrophysics Data System (ADS)

Sullivan, J. T.; McGee, T. J.; Rabenhorst, S. D.; Delgado, R.; Dreessen, J.; Sumnicht, G. K.; Twigg, L.

2016-12-01

A unique multi-day air quality event occurred throughout the Mid-Atlantic region from June 9-12, 2015. The June event was coupled to the advection of widespread smoke and debris from western Canada throughout the region. Observations indicated that the aged smoke impacted the Planetary Boundary Layer (PBL) and greatly enhanced ozone concentrations at the surface. Many ground sites in the region, particularly in Maryland, recorded 8-hr ozone concentrations that were in exceedance of the 75 ppb EPA National Ambient Air Quality Standard (NAAQS). After the high O3 episode occurred, a nocturnal low-level jet developed throughout the Mid-Atlantic region, which was spatially correlated with next day high O3 at several sites within the New England region. During this event, nearly continuous vertical profiles of ozone are presented at Beltsville, MD from the NASA Goddard Space Flight Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL), which has been developed and validated within the Tropospheric Ozone Lidar Network (TOLNet). Lidar observations reveal a well-mixed polluted PBL, nocturnal residual layer, and subsequent mixing down of the residual layer in the morning. Additional measurements of surface ozone, aerosol lidar profiles, wind profiles, and balloon borne profiles are also presented. Model output and trajectory analyses are also presented to illustrate the complex flow regimes that occurred during the daytime and nighttime to help redistribute the polluted air mass.

Vertical Structure of Ice Cloud Layers From CloudSat and CALIPSO Measurements and Comparison to NICAM Simulations

NASA Technical Reports Server (NTRS)

Ham, Seung-Hee; Sohn, Byung-Ju; Kato, Seiji; Satoh, Masaki

2013-01-01

The shape of the vertical profile of ice cloud layers is examined using 4 months of CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) global measurements taken on January, April, July, and October 2007. Ice clouds are selected using temperature profiles when the cloud base is located above the 253K temperature level. The obtained ice water content (IWC), effective radius, or extinction coefficient profiles are normalized by their layer mean values and are expressed in the normalized vertical coordinate, which is defined as 0 and 1 at the cloud base and top heights, respectively. Both CloudSat and CALIPSO observations show that the maximum in the IWC and extinction profiles shifts toward the cloud bottom, as the cloud depth increases. In addition, clouds with a base reaching the surface in a high-latitude region show that the maximum peak of the IWC and extinction profiles occurs near the surface, which is presumably due to snow precipitation. CloudSat measurements show that the seasonal difference in normalized cloud vertical profiles is not significant, whereas the normalized cloud vertical profile significantly varies depending on the cloud type and the presence of precipitation. It is further examined if the 7 day Nonhydrostatic Icosahedral Atmospheric Model (NICAM) simulation results from 25 December 2006 to 1 January 2007 generate similar cloud profile shapes. NICAM IWC profiles also show maximum peaks near the cloud bottom for thick cloud layers and maximum peaks at the cloud bottom for low-level clouds near the surface. It is inferred that oversized snow particles in the NICAM cloud scheme produce a more vertically inhomogeneous IWC profile than observations due to quick sedimentation.

Vertical distribution of Martian aerosols from SPICAM/Mars-Express limb observations

NASA Astrophysics Data System (ADS)

Fedorova, A.; Korablev, O.; Bertaux, J.-L.; Rodin, A.; Perrier, S.; Moroz, V. I.

Limb spectroscopic observations provide invaluable information about vertical distribution of main atmospheric components in the Martian atmosphere, in particular vertical distribution and structure of aerosols, which play an important role in the heat balance of the planet. Only limited set of successful limb spectroscopic observations have been carried out on Mars so far, including those by MGS/TES spectrometer and Thermoscan and Auguste experiments of Phobos mission. Currently SPICAM instrument onboard Mars-Express spacecraft has accomplished several sequences of limb observations. First analysis of limb sounding data received by SPICAM IR and UV channels, which imply the presence of fine, deep, optically thin aerosol fraction extended over broad range of altitudes, is presented.

Wintertime characteristics of aerosols over middle Indo-Gangetic Plain: Vertical profile, transport and radiative forcing

NASA Astrophysics Data System (ADS)

Kumar, M.; Raju, M. P.; Singh, R. K.; Singh, A. K.; Singh, R. S.; Banerjee, T.

2017-01-01

Winter-specific characteristics of airborne particulates over middle Indo-Gangetic Plain (IGP) were evaluated in terms of aerosol chemical and micro-physical properties under three-dimensional domain. Emphases were made for the first time to identify intra-seasonal variations of aerosols sources, horizontal and vertical transport, effects of regional meteorology and estimating composite aerosol short-wave radiative forcing over an urban region (25°10‧-25°19‧N; 82°54‧-83°4‧E) at middle-IGP. Space-borne passive (Aqua and Terra MODIS, Aura OMI) and active sensor (CALIPSO-CALIOP) based observations were concurrently used with ground based aerosol mass measurement for entire winter and pre-summer months (December, 1, 2014 to March, 31, 2015). Exceptionally high aerosol mass loading was recorded for both PM10 (267.6 ± 107.0 μg m- 3) and PM2.5 (150.2 ± 89.4 μg m- 3) typically exceeding national standard. Aerosol type was mostly dominated by fine particulates (particulate ratio: 0.61) during pre to mid-winter episodes before being converted to mixed aerosol types (ratio: 0.41-0.53). Time series analysis of aerosols mass typically identified three dissimilar aerosol loading episodes with varying attributes, well resemble to that of previous year's observation representing its persisting nature. Black carbon (9.4 ± 3.7 μg m- 3) was found to constitute significant proportion of fine particulates (2-27%) with a strong diurnal profile. Secondary inorganic ions also accounted a fraction of particulates (PM2.5: 22.5%; PM10: 26.9%) having SO4- 2, NO3- and NH4+ constituting major proportion. Satellite retrieved MODIS-AOD (0.01-2.30) and fine mode fractions (FMF: 0.01-1.00) identified intra-seasonal variation with transport of aerosols from upper to middle-IGP through continental westerly. Varying statistical association of columnar and surface aerosol loading both in terms of fine (r; PM2.5: MODIS-AOD: 0.51) and coarse particulates (PM10: MODIS-AOD: 0.53) was

Dissipation Rate of Turbulent Kinetic Energy in Diel Vertical Migrations: Comparison of ANSYS Fluent Model to Measurements

NASA Astrophysics Data System (ADS)

Dean, Cayla; Soloviev, Alexander; Hirons, Amy; Frank, Tamara; Wood, Jon

2015-04-01

Recent studies suggest that diel vertical migrations of zooplankton may have an impact on ocean mixing, though details are not completely clear. A strong sound scattering layer of zooplankton undergoing diel vertical migrations was observed in Saanich Inlet, British Colombia, Canada by Kunze et al. (2006). In this study, a shipboard 200-kHz echosounder was used to track vertical motion of the sound scattering layer, and microstructure profiles were collected to observe turbulence. An increase of dissipation rate of turbulent kinetic energy by four to five orders of magnitude was measured during diel vertical migrations of zooplankton in one case (but not observed during other cases). A strong sound scattering layer undergoing diel vertical migration was also observed in the Straits of Florida via a bottom mounted acoustic Doppler current profiler at 244 m isobath. A 3-D non-hydrostatic computational fluid dynamics model with Lagrangian particle injections (a proxy for migrating zooplankton) via a discrete phase model was used to simulate the effect of diel vertical migrations on the turbulence for both Saanich Inlet and the Straits of Florida. The model was initialized with idealized (but based on observation) density and velocity profiles. Particles, with buoyancy adjusted to serve as a proxy for vertically swimming zooplankton, were injected to simulate diel vertical migration cycles. Results of models run with extreme concentrations of particles showed an increase in dissipation rate of turbulent kinetic energy of approximately five orders of magnitude over background turbulence during migration of particles in both Saanich Inlet and the Straits of Florida cases (though direct relation of the turbulence produced by buoyant particles and swimming organisms isn't straightforward). This increase was quantitatively consistent, with turbulence measurements by Kunze et al. (2006). When 10 times fewer particles were injected into the model, the effect on dissipation

Relation of Cloud Occurrence Frequency, Overlap, and Effective Thickness Derived from CALIPSO and CloudSat Merged Cloud Vertical Profiles

NASA Technical Reports Server (NTRS)

Kato, Seiji; Sun-Mack, Sunny; Miller, Walter F.; Rose, Fred G.; Chen, Yan; Minnis, Patrick; Wielicki, Bruce A.

2009-01-01

A cloud frequency of occurrence matrix is generated using merged cloud vertical profile derived from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Cloud Profiling Radar (CPR). The matrix contains vertical profiles of cloud occurrence frequency as a function of the uppermost cloud top. It is shown that the cloud fraction and uppermost cloud top vertical pro les can be related by a set of equations when the correlation distance of cloud occurrence, which is interpreted as an effective cloud thickness, is introduced. The underlying assumption in establishing the above relation is that cloud overlap approaches the random overlap with increasing distance separating cloud layers and that the probability of deviating from the random overlap decreases exponentially with distance. One month of CALIPSO and CloudSat data support these assumptions. However, the correlation distance sometimes becomes large, which might be an indication of precipitation. The cloud correlation distance is equivalent to the de-correlation distance introduced by Hogan and Illingworth [2000] when cloud fractions of both layers in a two-cloud layer system are the same.

Lightning Nitrogen Oxides (LNOx) Vertical Profile Quantification and 10 Year Trend Analysis using Ozone Monitoring Instrument (OMI) Satellite Measurements, Air Quality Station (AQS) Surface Measurements, The National Lightning Detection Network (NLDN), and Simulated by Cloud Resolving Chemical Transport Model (REAM Cloud)

NASA Astrophysics Data System (ADS)

Smeltzer, C. D.; Wang, Y.; Koshak, W. J.

2014-12-01

Vertical profiles and emission lifetimes of lightning nitrogen oxides (LNOx) are derived using the Ozone Monitoring Instrument (OMI). Approximately 200 million flashes, over a 10 year climate period, from the United States National Lighting Detection Network (NLDN), are aggregated with OMI cloud top height to determine the vertical LNOx structure. LNOx lifetime is determined as function of LNOx signal in a 36 kilometer vertical column from the time of the last known flash to depletion of the LNOx signal. Environmental Protection Agency (EPA) Air Quality Station (AQS) surface data further support these results by demonstrating as much as a 200% increase in surface level NO2 during strong thunderstorm events and a lag as long as 5 to 8 hours from the lightning event to the peak surface event, indicating a evolutional process. Analysis of cloud resolving chemical transport model (REAM Cloud) demonstrates that C-shaped LNOx profiles, which agree with OMI vertical profile observations, evolve due to micro-scale convective meteorology given inverted C-shaped LNOx emission profiles as determined from lightning radio telemetry. It is shown, both in simulations and in observations, that the extent to which the LNOx vertical distribution is C-shaped and the lifetime of LNOx is proportional to the shear-strength of the thunderstorm. Micro-scale convective meteorology is not adequately parameterized in global scale and regional scale chemical transport models (CTM). Therefore, these larger scale CTMs ought to use a C-shape emissions profile to best reproduce observations until convective parameterizations are updated. These findings are used to simulate decadal LNOx and lightning ozone climatology over the Continental United States (CONUS) from 2004-2014.

Comparing the cloud vertical structure derived from several methods based on radiosonde profiles and ground-based remote sensing measurements

NASA Astrophysics Data System (ADS)

Costa-Surós, M.; Calbó, J.; González, J. A.; Long, C. N.

2014-08-01

The cloud vertical distribution and especially the cloud base height, which is linked to cloud type, are important characteristics in order to describe the impact of clouds on climate. In this work, several methods for estimating the cloud vertical structure (CVS) based on atmospheric sounding profiles are compared, considering the number and position of cloud layers, with a ground-based system that is taken as a reference: the Active Remote Sensing of Clouds (ARSCL). All methods establish some conditions on the relative humidity, and differ in the use of other variables, the thresholds applied, or the vertical resolution of the profile. In this study, these methods are applied to 193 radiosonde profiles acquired at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site during all seasons of the year 2009 and endorsed by Geostationary Operational Environmental Satellite (GOES) images, to confirm that the cloudiness conditions are homogeneous enough across their trajectory. The perfect agreement (i.e., when the whole CVS is estimated correctly) for the methods ranges between 26 and 64%; the methods show additional approximate agreement (i.e., when at least one cloud layer is assessed correctly) from 15 to 41%. Further tests and improvements are applied to one of these methods. In addition, we attempt to make this method suitable for low-resolution vertical profiles, like those from the outputs of reanalysis methods or from the World Meteorological Organization's (WMO) Global Telecommunication System. The perfect agreement, even when using low-resolution profiles, can be improved by up to 67% (plus 25% of the approximate agreement) if the thresholds for a moist layer to become a cloud layer are modified to minimize false negatives with the current data set, thus improving overall agreement.

High-resolution vertical velocities and their power spectrum observed with the MAARSY radar - Part 1: frequency spectrum

NASA Astrophysics Data System (ADS)

Li, Qiang; Rapp, Markus; Stober, Gunter; Latteck, Ralph

2018-04-01

The Middle Atmosphere Alomar Radar System (MAARSY) installed at the island of Andøya has been run for continuous probing of atmospheric winds in the upper troposphere and lower stratosphere (UTLS) region. In the current study, we present high-resolution wind measurements during the period between 2010 and 2013 with MAARSY. The spectral analysis applying the Lomb-Scargle periodogram method has been carried out to determine the frequency spectra of vertical wind velocity. From a total of 522 days of observations, the statistics of the spectral slope have been derived and show a dependence on the background wind conditions. It is a general feature that the observed spectra of vertical velocity during active periods (with wind velocity > 10 m s-1) are much steeper than during quiet periods (with wind velocity < 10 m s-1). The distribution of spectral slopes is roughly symmetric with a maximum at -5/3 during active periods, whereas a very asymmetric distribution with a maximum at around -1 is observed during quiet periods. The slope profiles along altitudes reveal a significant height dependence for both conditions, i.e., the spectra become shallower with increasing altitudes in the upper troposphere and maintain roughly a constant slope in the lower stratosphere. With both wind conditions considered together the general spectra are obtained and their slopes are compared with the background horizontal winds. The comparisons show that the observed spectra become steeper with increasing wind velocities under quiet conditions, approach a spectral slope of -5/3 at a wind velocity of 10 m s-1 and then roughly maintain this slope (-5/3) for even stronger winds. Our findings show an overall agreement with previous studies; furthermore, they provide a more complete climatology of frequency spectra of vertical wind velocities under different wind conditions.

The thermal structure of Titan’s upper atmosphere, I: Temperature profiles from Cassini INMS observations

NASA Astrophysics Data System (ADS)

Snowden, D.; Yelle, R. V.; Cui, J.; Wahlund, J.-E.; Edberg, N. J. T.; Ågren, K.

2013-09-01

We derive vertical temperature profiles from Ion Neutral Mass Spectrometer (INMS) N2 density measurements from 32 Cassini passes. We find that the average temperature of Titan’s thermosphere varies significantly from pass-to-pass between 112 and 175 K. The temperatures from individual temperature profiles also varies considerably, with many passes exhibiting wave-like temperature perturbations and large temperature gradients. Wave-like temperature perturbations have wavelengths between 150 and 420 km and amplitudes between 3% and 22% and vertical wave power spectra of the INMS data and HASI data have a slope between -2 and -3, which is consistent with vertically propagating atmospheric waves. The lack of a strong correlation between temperature and latitude, longitude, solar zenith angle, or local solar time indicates that the thermal structure of Titan’s thermosphere is not primarily determined by the absorption of solar EUV flux. At N2 densities greater than 108 cm-3, Titan’s thermosphere is colder when Titan is observed in Saturn’s magnetospheric lobes compared to Saturn’s plasma sheet as proposed by Westlake et al. (Westlake, J.H. et al. [2011]. J. Geophys. Res. 116, A03318. http://dx.doi.org/10.1029/2010JA016251). This apparent correlation suggests that magnetospheric particle precipitation causes the temperature variability in Titan’s thermosphere; however, at densities smaller than 108 cm-3 the lobe passes are hotter than the plasma sheet passes and we find no correlation between the temperature of Titan’s thermosphere and ionospheric signatures of enhanced particle precipitation, which suggests that the correlation is not indicative of a physical connection. The temperature of Titan’s thermosphere also may have decreased by ∼10 K around mid-2007. Finally, we classify the vertical temperature profiles to show which passes are hot and cold and which passes have the largest temperature variations. In a companion paper (Part II), we estimate

The effect of sediment thermal conductivity on vertical groundwater flux estimates

NASA Astrophysics Data System (ADS)

Sebok, Eva; Müller, Sascha; Engesgaard, Peter; Duque, Carlos

2015-04-01

present. Using the measured sediment thermal conductivity for the different model layers instead of a homogeneous distribution did not result in a better fit between observed and simulated sediment temperature profiles. The estimated groundwater fluxes however were greatly affected by using the measured thermal conductivities resulting in changes of ± 45% in estimated vertical fluxes.

Constraints on vertical transport near the polar summer mesopause from PMC observations and modelling

NASA Astrophysics Data System (ADS)

Wilms, H.; Rapp, M.; Kirsch, A.

2016-12-01

The comparison of microphysical simulations of polar mesospheric cloud properties with ground based and satellite borne observations suggests that vertical wind variance imposed by gravity waves is an important prerequisite to realistically model PMC properties. This paper reviews the available observational evidence of vertical wind measurements at the polar summer mesopause (including their frequency content). Corresponding results are compared to vertical wind variance from several global models and implications for the transport of trace constituents in this altitude region are discussed.

Using Distributed Temperature Sensing for measuring vertical temperature profiles and air temperature variance in the roughness sublayer above a forest canopy

NASA Astrophysics Data System (ADS)

Schilperoort, B.; Coenders, M.; Savenije, H. H. G.

2017-12-01

In recent years, the accuracy and resolution of Distributed Temperature Sensing (DTS) machines has increased enough to expand its use in atmospheric sciences. With DTS the temperature of a fiber optic (FO) cable can be measured with a high frequency (1 Hz) and high resolution (0.30 m), for cable lengths up to kilometers. At our measurement site, a patch of 26 to 30 m tall Douglas Fir in mixed forest, we placed FO cables vertically along a 48 m tall flux tower. This gives a high resolution vertical temperature profile above, through, and below the canopy. By using a `bare' FO cable, with a diameter of 0.25 mm, we are able to measure variations in air temperature at a very small timescale, and are able to measure a vertical profile of the air temperature variance. The vertical temperature profiles can be used to study the formation of the stable boundary layer above and in the canopy at a high resolution. It also shows that a stable layer can develop below the canopy, which is not limited to night time conditions but also occurs during daytime. The high frequency measurements can be used to study the gradient of the variance of air temperature over the height. To study how the flux tower itself affects temperature variance measurements, the `bare' FO cable can be placed horizontally under a support structure away from the flux tower. Lastly, by using the hot-wire anemometer principle with DTS, the measurements can be expanded to also include vertical wind profile.

GPM and TRMM Radar Vertical Profiles and Impact on Large-scale Variations of Surface Rain

NASA Astrophysics Data System (ADS)

Wang, J. J.; Adler, R. F.

2017-12-01

Previous studies by the authors using Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) data have shown that TRMM Precipitation Radar (PR) and GPM Dual-Frequency Precipitation Radar (DPR) surface rain estimates do not have corresponding amplitudes of inter-annual variations over the tropical oceans as do passive microwave observations by TRMM Microwave Imager (TMI) and GPM Microwave Imager (GMI). This includes differences in surface temperature-rainfall variations. We re-investigate these relations with the new GPM Version 5 data with an emphasis on understanding these differences with respect to the DPR vertical profiles of reflectivity and rainfall and the associated convective and stratiform proportions. For the inter-annual variation of ocean rainfall from both passive microwave (TMI and GMI) and active microwave (PR and DPR) estimates, it is found that for stratiform rainfall both TMI-PR and GMI-DPR show very good correlation. However, the correlation of GMI-DPR is much higher than TMI-PR in convective rainfall. The analysis of vertical profile of PR and DPR rainfall during the TRMM and GPM overlap period (March-August, 2014) reveals that PR and DPR have about the same rainrate at 4km and above, but PR rainrate is more than 10% lower that of DPR at the surface. In other words, it seems that convective rainfall is better defined with DPR near surface. However, even though the DPR results agree better with the passive microwave results, there still is a significant difference, which may be a result of DPR retrieval error, or inherent passive/active retrieval differences. Monthly and instantaneous GMI and DPR data need to be analyzed in details to better understand the differences.

Vertical Profile of Aerosol Properties at Pico Mountain, Azores

NASA Astrophysics Data System (ADS)

Wright, K.; Mazzoleni, C.; Mazzoleni, L. R.; Dzepina, K.; Hueber, J.; China, S.; Sharma, N.

2013-12-01

Pico Mountain (2325m asl) is a dormant volcano in the archipelago of the Azores1500 km west of Lisbon, Portugal in the North Atlantic. It differs from typical mountain ranges such as the Alps or the Rockies, which are large and present a complex orography. Pico Mountain has a simple cone-like structure with only one main peak and is thousands of kilometers away from any other significant mountain range. In summer months, it is typical for air masses to move around the mountain rather than traveling up its face. This implies that often the peak of the mountain lies above the marine boundary layer in the free troposphere, while the lower part of the mountain is affected by marine clouds and marine air-masses. An atmospheric monitoring station, the Pico Mountain Observatory was established in 2001 in the summit caldera of the volcano at 2225m above sea level. The observatory is far from large populations or pollution sources, which makes the station ideal to study atmospheric gases and aerosols transported over long-ranges in the free troposphere. The station is reachable only by foot following a steep and strenuous hiking trail. In the summer of 2013 we began to collect vertical profiles of aerosol by carrying an instrumented backpack up to the summit of the mountain, with the goal of studying the vertical structure of atmospheric aerosols from the marine boundary layer to the free troposphere. The backpack was carried from the base of trail at 1200m asl. The backpack was equipped with the following instruments: 1. Nephelometer to measure light scattering from aerosol 2. 2-size optical particle counter (300-500 nm) 3. Portable micro-aethalometer to measure absorbing aerosols 4. SEM/TEM sampler to collect particles for off-line electron microscopy analysis 5. Battery powered data logger to measure relative humidity, temperature and pressure 6. GPS tracking device We provide a preliminary analysis of data collected in 2013 to gain insight on the vertical distribution

A New Airborne Lidar for Remote Sensing of Canopy Fluorescence and Vertical Profile

NASA Astrophysics Data System (ADS)

Ounis, A.; Bach, J.; Mahjoub, A.; Daumard, F.; Moya, I.; Goulas, Y.

2016-06-01

We report the development of a new lidar system for airborne remote sensing of chlorophyll fluorescence (ChlF) and vertical profile of canopies. By combining laserinduced fluorescence (LIF), sun-induced fluorescence (SIF) and canopy height distribution, the new instrument will low the simultaneous assessment of gross primary production (GPP), photosynthesis efficiency and above ground carbon stocks. Technical issues of the lidar development are discussed and expected performances are presented.

Constraining the 0-20 km Vertical Profile of Water Vapor in the Martian Atmosphere with MGS-TES Limb Sounding

NASA Astrophysics Data System (ADS)

McConnochie, T. H.; Smith, M. D.; McDonald, G. D.

2016-12-01

The vertical profile of water vapor in the lower atmosphere of Mars is a crucial but poorly-measured detail of the water cycle. Most of our existing water vapor data sets (e.g. Smith, 2002, JGR 107; Smith et al., 2009, JGR 114; Maltagliati et al., 2011, Icarus 213) rely on the traditional assumption of uniform mass mixing from the surface up to a saturation level, but GCM models (Richardson et al., 2002, JGR 107; Navarro et al., 2014, JGR 119) imply that this is not the case in at least some important seasons and locations. For example at the equator during northern summer the water vapor mixing ratio in aforementioned GCMs increases upwards by a factor of two to three in the bottom scale height. This might influence the accuracy of existing precipitable water column (PWC) data sets. Even if not, the correct vertical distribution is critical for determining the extent to which high-altitude cold trapping interferes with inter-hemispheric transport, and its details in the lowest scale heights will be a critical test of the accuracy of modeled water vapor transport. Meanwhile attempts to understand apparent interactions of water vapor with surface soils (e.g. Ojha et al. 2015, Nature Geoscience 8; Savijärvi et al., 2016, Icarus 265) need an estimate for the amount of water vapor in the boundary layer, and existing PWC data sets can't provide this unless the lower atmospheric vertical distribution is known or constrained. Maltagliati et al. (2013, Icarus 223) have obtained vertical profiles of water vapor at higher altitudes with SPICAM on Mars Express, but these are commonly limited to altitudes greater 20 km and they never extend below 10 km. We have previously used Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) limb-sounding to measure the vertical profile of water vapor (e.g. McConnochie and Smith, 2009, Fall AGU #P54B-06), but these preliminary results were clearly not quantitatively accurate in the lower atmosphere. We will present improved TES

Seasonal changes in the tropospheric carbon monoxide profile over the remote Southern Hemisphere evaluated using multi-model simulations and aircraft observations

NASA Astrophysics Data System (ADS)

Fisher, J. A.; Wilson, S. R.; Zeng, G.; Williams, J. E.; Emmons, L. K.; Langenfelds, R. L.; Krummel, P. B.; Steele, L. P.

2014-11-01

We use aircraft observations from the 1991-2000 Cape Grim Overflight Program and the 2009-2011 HIAPER Pole-to-Pole Observations (HIPPO), together with output from four chemical transport and chemistry-climate models, to better understand the vertical distribution of carbon monoxide (CO) in the remote Southern Hemisphere. Observed CO vertical gradients at Cape Grim vary from 1.6 ppbv km-1 in austral autumn to 2.2 ppbv km-1 in austral spring. CO vertical profiles from Cape Grim are remarkably consistent with those observed over the southern mid-latitudes Pacific during HIPPO, despite major differences in time periods, flight locations, and sampling strategies between the two datasets. Using multi-model simulations from the Southern Hemisphere Model Intercomparison Project (SHMIP), we find that observed CO vertical gradients in austral winter-spring are well-represented in models and can be attributed to primary CO emissions from biomass burning. In austral summer-autumn, inter-model variability in simulated gradients is much larger, and two of the four SHMIP models significantly underestimate the Cape Grim observations. Sensitivity simulations show that CO vertical gradients at this time of year are driven by long-range transport of secondary CO of biogenic origin, implying a large sensitivity of the remote Southern Hemisphere troposphere to biogenic emissions and chemistry. Inter-model variability in summer-autumn gradients can be explained by differences in both the chemical mechanisms that drive secondary production of CO from biogenic sources and the vertical transport that redistributes this CO throughout the Southern Hemisphere. This suggests that the CO vertical gradient in the remote Southern Hemisphere provides a sensitive test of the chemistry and transport processes that define the chemical state of the background atmosphere.

Validation of ionospheric electron density profiles inferred from GPS occultation observations of the GPS/MET experiment

NASA Astrophysics Data System (ADS)

Kawakami, Todd Mori

In April of 1995, the launch of the GPS Meteorology Experiment (GPS/MET) onboard the Orbview-1 satellite, formerly known as Microlab-1, provided the first technology demonstration of active limb sounding of the Earth's atmosphere with a low Earth orbiting spacecraft utilizing the signals transmitted by the satellites of the Global Positioning System (GPS). Though the experiment's primary mission was to probe the troposphere and stratosphere, GPS/MET was also capable of making radio occultation observations of the ionosphere. The application of the GPS occultation technique to the upper atmosphere created a unique opportunity to conduct ionospheric research with an unprecedented global distribution of observations. For operational support requirements, the Abel transform could be employed to invert the horizontal TEC profiles computed from the L1 and L2 phase measurements observed by GPS/MET into electron density profiles versus altitude in near real time. The usefulness of the method depends on how effectively the TEC limb profiles can be transformed into vertical electron density profiles. An assessment of GPS/MET's ability to determine electron density profiles needs to be examined to validate the significance of the GPS occultation method as a new and complementary ionospheric research tool to enhance the observational databases and improve space weather modeling and forecasting. To that end, simulations of the occultation observations and their inversions have been conducted to test the Abel transform algorithm and to provide qualitative information about the type and range of errors that might be experienced during the processing of real data. Comparisons of the electron density profiles inferred from real GPS/MET observations are then compared with coincident in situ measurements from the satellites of Defense Meteorological Satellite Program (DMSP) and ground-based remote sensing from digisonde and incoherent scatter radar facilities. The principal focus of

Vertical Profiles of Aerosol Optical Properties Over Central Illinois and Comparison with Surface and Satellite Measurements

NASA Technical Reports Server (NTRS)

Sheridan P. J.; Andrews, E.; Ogren, J A.; Tackett, J. L.; Winker, D. M.

2012-01-01

Between June 2006 and September 2009, an instrumented light aircraft measured over 400 vertical profiles of aerosol and trace gas properties over eastern and central Illinois. The primary objectives of this program were to (1) measure the in situ aerosol properties and determine their vertical and temporal variability and (2) relate these aircraft measurements to concurrent surface and satellite measurements. Underflights of the CALIPSO satellite show reasonable agreement in a majority of retrieved profiles between aircraft-measured extinction at 532 nm (adjusted to ambient relative humidity) and CALIPSO-retrieved extinction, and suggest that routine aircraft profiling programs can be used to better understand and validate satellite retrieval algorithms. CALIPSO tended to overestimate the aerosol extinction at this location in some boundary layer flight segments when scattered or broken clouds were present, which could be related to problems with CALIPSO cloud screening methods. The in situ aircraft-collected aerosol data suggest extinction thresholds for the likelihood of aerosol layers being detected by the CALIOP lidar. These statistical data offer guidance as to the likelihood of CALIPSO's ability to retrieve aerosol extinction at various locations around the globe.

Observed and Modeled HOCl Profiles in the Midlatitude Stratosphere: Implication for Ozone Loss

NASA Technical Reports Server (NTRS)

Kovalenko, L. J.; Jucks, K. W.; Salawitch, R. J.; Toon, G. C.; Blavier, J. F.; Johnson, D. G.; Kleinbohl, A.; Livesey, N. J .; Margitan, J. J.; Pickett, H. M.;

Retrieval of Precipitation Profiles from Multiresolution, Multifrequency, Active and Passive Microwave Observations

NASA Technical Reports Server (NTRS)

Grecu, Mircea; Anagnostou, Emmanouil N.; Olson, William S.; Starr, David OC. (Technical Monitor)

2002-01-01

In this study, a technique for estimating vertical profiles of precipitation from multifrequency, multiresolution active and passive microwave observations is investigated using both simulated and airborne data. The technique is applicable to the Tropical Rainfall Measuring Mission (TRMM) satellite multi-frequency active and passive observations. These observations are characterized by various spatial and sampling resolutions. This makes the retrieval problem mathematically more difficult and ill-determined because the quality of information decreases with decreasing resolution. A model that, given reflectivity profiles and a small set of parameters (including the cloud water content, the intercept drop size distribution, and a variable describing the frozen hydrometeor properties), simulates high-resolution brightness temperatures is used. The high-resolution simulated brightness temperatures are convolved at the real sensor resolution. An optimal estimation procedure is used to minimize the differences between simulated and observed brightness temperatures. The retrieval technique is investigated using cloud model synthetic and airborne data from the Fourth Convection And Moisture Experiment. Simulated high-resolution brightness temperatures and reflectivities and airborne observation strong are convolved at the resolution of the TRMM instruments and retrievals are performed and analyzed relative to the reference data used in observations synthesis. An illustration of the possible use of the technique in satellite rainfall estimation is presented through an application to TRMM data. The study suggests improvements in combined active and passive retrievals even when the instruments resolutions are significantly different. Future work needs to better quantify the retrievals performance, especially in connection with satellite applications, and the uncertainty of the models used in retrieval.

Vertical density profile and internal bond strength of wet-formed particleboard bonded with cellulose nanofibrils

Treesearch

John F. Hunt; Weiqi Leng; Mehdi Tajvidi

2017-01-01

In this study, the effects of cellulose nanofibrils (CNFs) ratio, press program, particle size, and density on the vertical density profile (VDP) and internal bond (IB) strength of the wet-formed particleboard were investigated. Results revealed that the VDP was significantly influenced by the press program. Pressing using a constant pressure (CP) press program...

Vertical profile of tropospheric ozone derived from synergetic retrieval using three different wavelength ranges, UV, IR, and microwave: sensitivity study for satellite observation

NASA Astrophysics Data System (ADS)

Sato, Tomohiro O.; Sato, Takao M.; Sagawa, Hideo; Noguchi, Katsuyuki; Saitoh, Naoko; Irie, Hitoshi; Kita, Kazuyuki; Mahani, Mona E.; Zettsu, Koji; Imasu, Ryoichi; Hayashida, Sachiko; Kasai, Yasuko

2018-03-01

We performed a feasibility study of constraining the vertical profile of the tropospheric ozone by using a synergetic retrieval method on multiple spectra, i.e., ultraviolet (UV), thermal infrared (TIR), and microwave (MW) ranges, measured from space. This work provides, for the first time, a quantitative evaluation of the retrieval sensitivity of the tropospheric ozone by adding the MW measurement to the UV and TIR measurements. Two observation points in East Asia (one in an urban area and one in an ocean area) and two observation times (one during summer and one during winter) were assumed. Geometry of line of sight was nadir down-looking for the UV and TIR measurements, and limb sounding for the MW measurement. The retrieval sensitivities of the ozone profiles in the upper troposphere (UT), middle troposphere (MT), and lowermost troposphere (LMT) were estimated using the degree of freedom for signal (DFS), the pressure of maximum sensitivity, reduction rate of error from the a priori error, and the averaging kernel matrix, derived based on the optimal estimation method. The measurement noise levels were assumed to be the same as those for currently available instruments. The weighting functions for the UV, TIR, and MW ranges were calculated using the SCIATRAN radiative transfer model, the Line-By-Line Radiative Transfer Model (LBLRTM), and the Advanced Model for Atmospheric Terahertz Radiation Analysis and Simulation (AMATERASU), respectively. The DFS value was increased by approximately 96, 23, and 30 % by adding the MW measurements to the combination of UV and TIR measurements in the UT, MT, and LMT regions, respectively. The MW measurement increased the DFS value of the LMT ozone; nevertheless, the MW measurement alone has no sensitivity to the LMT ozone. The pressure of maximum sensitivity value for the LMT ozone was also increased by adding the MW measurement. These findings indicate that better information on LMT ozone can be obtained by adding constraints

Study of seasonal and long-term vertical deformation in Nepal based on GPS and GRACE observations

NASA Astrophysics Data System (ADS)

Zhang, Tengxu; Shen, WenBin; Pan, Yuanjin; Luan, Wei

2018-02-01

Lithospheric deformation signal can be detected by combining data from continuous global positioning system (CGPS) and satellite observations from the Gravity Recovery and Climate Experiment (GRACE). In this paper, we use 2.5- to 19-year-long time series from 35 CGPS stations to estimate vertical deformation rates in Nepal, which is located in the southern side of the Himalaya. GPS results were compared with GRACE observations. Principal component analysis was conducted to decompose the time series into three-dimensional principal components (PCs) and spatial eigenvectors. The top three high-order PCs were calculated to correct common mode errors. Both GPS and GRACE observations showed significant seasonal variations. The observed seasonal GPS vertical variations are in good agreement with those from the GRACE-derived results, particularly for changes in surface pressure, non-tidal oceanic mass loading, and hydrologic loading. The GPS-observed rates of vertical deformation obtained for the region suggest both tectonic impact and mass decrease. The rates of vertical crustal deformation were estimated by removing the GRACE-derived hydrological vertical rates from the GPS measurements. Most of the sites located in the southern part of the Main Himalayan Thrust subsided, whereas the northern part mostly showed an uplift. These results may contribute to the understanding of secular vertical crustal deformation in Nepal.

Vertical structure of precipitating shallow echoes observed from TRMM during Indian summer monsoon

NASA Astrophysics Data System (ADS)

Kumar, Shailendra

2017-08-01

The present study explores the properties of precipitating shallow echoes (PSEs) over the tropical areas (30°S-30°N) during Indian summer monsoon season using attenuated corrected radar reflectivity factor (Ze) measured by the Tropical Rainfall Measuring Mission satellite. Radar echoes observed in study are less than the freezing height, so they belong to warm precipitation. Radar echoes with at least 0.75 km wide are considered for finding the shallow echoes climatology. Western Ghats and adjoining ocean (Arabian sea) have the highest PSEs followed by Myanmar and Burma coast, whereas the overall west coast of Latin America consists of the lowest PSEs. Tropical oceanic areas contain fewer PSEs compared to coastal areas. Average vertical profiles show nearly similar Ze characteristics which peaks between 1.5 and 2 km altitude with model value 32-34 dBZ. Slope of Ze is higher for intense PSEs as radar reflectivity decreases more rapidly in intense PSEs.

Variation of Equatorial F-region Vertical Neutral Wind and Neutral Temperature during Geomagnetic Storms: Brazil FPI Observations

NASA Astrophysics Data System (ADS)

Sheng, C.; De La Garza, J. L.; Deng, Y.; Makela, J. J.; Fisher, D. J.; Meriwether, J. W.; Mesquita, R.

2015-12-01

An accurate description of vertical neutral winds in the thermosphere is essential to understand how the upper atmosphere responds to the geomagnetic storms. However, vertical wind measurements are difficult to obtain and there are still limited data. Recent observation deployments now permit substantial progress on this issue. In this paper, neutral vertical wind data from Brazil FPI observations at around 240 km altitude during 2009 to 2015 are used for the study of the equatorial vertical wind and neutral temperature variation during geomagnetic activity times. First, the observations during several particular storm periods will be analyzed. Secondly, Epoch analysis will be used to bin all the observed events together to investigate the climatological features of vertical wind and temperature during storms. The results will give us an unprecedented view of the nighttime vertical wind and neutral temperature variations at low latitudes, which is critical to specify the dynamics of the upper atmosphere.

Modification of Turbulent Pipe Flow Equations to Estimate the Vertical Velocity Profiles Under Woody Debris Jams

NASA Astrophysics Data System (ADS)

Cervania, A.; Knack, I. M. W.

2017-12-01

The presence of woody debris (WD) jams in rivers and streams increases the risk of backwater flooding and reduces the navigability of a channel, but adds fish and macroinvertebrate habitat to the stream. When designing river engineering projects engineers use hydraulic models to predict flow behavior around these obstructions. However, the complexities of flow through and beneath WD jams are still poorly understood. By increasing the ability to predict flow behavior around WD jams, landowners and engineers are empowered to develop sustainable practices regarding the removal or placement of WD in rivers and flood plains to balance the desirable and undesirable effects to society and the environment. The objective of this study is to address some of this knowledge gap by developing a method to estimate the vertical velocity profile of flow under WD jams. When flow passes under WD jams, it becomes affected by roughness elements on all sides, similar to turbulent flows in pipe systems. Therefore, the method was developed using equations that define the velocity profiles of turbulent pipe flows: the law of the wall, the logarithmic law, and the velocity defect law. Flume simulations of WD jams were conducted and the vertical velocity profiles were measured along the centerline. A calculated velocity profile was fit to the measured profile through the calibration of eight parameters. An optimal value or range of values have been determined for several of these parameters using cross-validation techniques. The results indicate there may be some promise to using this method in hydraulic models.

The Tropical Convective Spectrum. Part 1; Archetypal Vertical Structures

NASA Technical Reports Server (NTRS)

Boccippio, Dennis J.; Petersen, Walter A.; Cecil, Daniel J.

2005-01-01

A taxonomy of tropical convective and stratiform vertical structures is constructed through cluster analysis of 3 yr of Tropical Rainfall Measuring Mission (TRMM) "warm-season" (surface temperature greater than 10 C) precipitation radar (PR) vertical profiles, their surface rainfall, and associated radar-based classifiers (convective/ stratiform and brightband existence). Twenty-five archetypal profile types are identified, including nine convective types, eight stratiform types, two mixed types, and six anvil/fragment types (nonprecipitating anvils and sheared deep convective profiles). These profile types are then hierarchically clustered into 10 similar families, which can be further combined, providing an objective and physical reduction of the highly multivariate PR data space that retains vertical structure information. The taxonomy allows for description of any storm or local convective spectrum by the profile types or families. The analysis provides a quasi-independent corroboration of the TRMM 2A23 convective/ stratiform classification. The global frequency of occurrence and contribution to rainfall for the profile types are presented, demonstrating primary rainfall contribution by midlevel glaciated convection (27%) and similar depth decaying/stratiform stages (28%-31%). Profiles of these types exhibit similar 37- and 85-GHz passive microwave brightness temperatures but differ greatly in their frequency of occurrence and mean rain rates, underscoring the importance to passive microwave rain retrieval of convective/stratiform discrimination by other means, such as polarization or texture techniques, or incorporation of lightning observations. Close correspondence is found between deep convective profile frequency and annualized lightning production, and pixel-level lightning occurrence likelihood directly tracks the estimated mean ice water path within profile types.

Observations and a model of undertow over the inner continental shelf

USGS Publications Warehouse

Lentz, Steven J.; Fewings, Melanie; Howd, Peter; Fredericks, Janet; Hathaway, Kent

2008-01-01

Onshore volume transport (Stokes drift) due to surface gravity waves propagating toward the beach can result in a compensating Eulerian offshore flow in the surf zone referred to as undertow. Observed offshore flows indicate that wave-driven undertow extends well offshore of the surf zone, over the inner shelves of Martha’s Vineyard, Massachusetts, and North Carolina. Theoretical estimates of the wave-driven offshore transport from linear wave theory and observed wave characteristics account for 50% or more of the observed offshore transport variance in water depths between 5 and 12 m, and reproduce the observed dependence on wave height and water depth.During weak winds, wave-driven cross-shelf velocity profiles over the inner shelf have maximum offshore flow (1–6 cm s−1) and vertical shear near the surface and weak flow and shear in the lower half of the water column. The observed offshore flow profiles do not resemble the parabolic profiles with maximum flow at middepth observed within the surf zone. Instead, the vertical structure is similar to the Stokes drift velocity profile but with the opposite direction. This vertical structure is consistent with a dynamical balance between the Coriolis force associated with the offshore flow and an along-shelf “Hasselmann wave stress” due to the influence of the earth’s rotation on surface gravity waves. The close agreement between the observed and modeled profiles provides compelling evidence for the importance of the Hasselmann wave stress in forcing oceanic flows. Summer profiles are more vertically sheared than either winter profiles or model profiles, for reasons that remain unclear.

A large-scale intercomparison of stratospheric vertical distributions of NO2 and BrO retrieved from the SCIAMACHY limb measurements and ground-based twilight observations

NASA Astrophysics Data System (ADS)

Rozanov, Alexei; Hendrick, Francois; Lotz, Wolfhardt; van Roozendael, Michel; Bovensmann, Heinrich; Burrows, John P.

This study is devoted to the intercomparison of NO2 and BrO vertical profiles obtained from the satellite and ground-based measurements. Although, the ground-based observations are performed only at selected locations, they have a great potential to be used for the validation of satellite measurements since continuous long-term measurement series performed with the same instruments are available. Thus, long-term trends in the observed species can be analyzed and intercompared. Previous intercomparisons of the vertical distributions of NO2 and BrO retrieved from SCIAMACHY limb measurements at the University of Bremen and obtained at IASB-BIRA by applying a profiling technique to ground-based zenith-sky DOAS observations have shown a good agreement between the results of completely different measurement techniques. However, only a relatively short time period of one year was analyzed so far which do not allow investigating seasonal variations and trends. Furthermore, some minor discrepancies are still to be analyzed. In the current study, several years datasets obtained at Observatoire de Haute-Provence (OHP) in France and in Harestua in Norway will be compared to the retrievals of SCIAMACHY limb measurements. Seasonal and annual variations will be analyzed and possible reasons for the remaining discrepancies will be discussed.

Near Real Time Vertical Profiles of Clouds and Aerosols from the Cloud-Aerosol Transport System (CATS) on the International Space Station

NASA Astrophysics Data System (ADS)

Yorks, J. E.; McGill, M. J.; Nowottnick, E. P.

2015-12-01

Plumes from hazardous events, such as ash from volcanic eruptions and smoke from wildfires, can have a profound impact on the climate system, human health and the economy. Global aerosol transport models are very useful for tracking hazardous plumes and predicting the transport of these plumes. However aerosol vertical distributions and optical properties are a major weakness of global aerosol transport models, yet a key component of tracking and forecasting smoke and ash. The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar designed to provide vertical profiles of clouds and aerosols while also demonstrating new in-space technologies for future Earth Science missions. CATS has been operating on the Japanese Experiment Module - Exposed Facility (JEM-EF) of the International Space Station (ISS) since early February 2015. The ISS orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three-day repeat cycle. The ISS orbit also provides CATS with excellent coverage over the primary aerosol transport tracks, mid-latitude storm tracks, and tropical convection. Data from CATS is used to derive properties of clouds and aerosols including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The measurements of atmospheric clouds and aerosols provided by the CATS payload have demonstrated several science benefits. CATS provides near-real-time observations of cloud and aerosol vertical distributions that can be used as inputs to global models. The infrastructure of the ISS allows CATS data to be captured, transmitted, and received at the CATS ground station within several minutes of data collection. The CATS backscatter and vertical feature mask are part of a customized near real time (NRT) product that the CATS processing team produces within 6 hours of collection. The continuous near real time CATS data

Estimation of the vertical profile of sulfur dioxide injection into the atmosphere by a volcanic eruption using satellite column measurements and inverse transport modeling

NASA Astrophysics Data System (ADS)

Eckhardt, S.; Prata, A. J.; Seibert, P.; Stebel, K.; Stohl, A.

2008-07-01

An analytical inversion method has been developed to estimate the vertical profile of SO2 emissions from volcanic eruptions. The method uses satellite-observed total SO2 columns and an atmospheric transport model (FLEXPART) to exploit the fact that winds change with altitude thus, the position and shape of the volcanic plume bear information on its emission altitude. The method finds the vertical emission distribution which minimizes the total difference between simulated and observed SO2 columns while also considering a priori information. We have tested the method with the eruption of Jebel at Tair, Yemen, on 30 September 2007 for which a comprehensive observational data set from various satellite instruments (AIRS, OMI, SEVIRI, CALIPSO) is available. Using satellite data from the first 24 h after the eruption for the inversion, we found an emission maximum near 16 km above sea level (a.s.l.), and secondary maxima near 5, 9, 12 and 14 km a.s.l. 60% of the emission occurred above the tropopause. The emission profile obtained in the inversion was then used to simulate the transport of the plume over the following week. The modeled plume agrees very well with SO2 total columns observed by OMI, and its altitude agrees with CALIPSO aerosol observations to within 1 2 km. The inversion result is robust against various changes in both the a priori and the observations. Even when using only SEVIRI data from the first 15 h after the eruption, the emission profile was reasonably well estimated. The method is computationally very fast. It is therefore suitable for implementation within an operational environment, such as the Volcanic Ash Advisory Centers, to predict the threat posed by volcanic ash for air traffic. It could also be helpful for assessing the sulfur input into the stratosphere, be it in the context of volcanic processes or also for proposed geo-engineering techniques to counteract global warming.

Estimation of the vertical profile of sulfur dioxide injection into the atmosphere by a volcanic eruption using satellite column measurements and inverse transport modeling

NASA Astrophysics Data System (ADS)

Eckhardt, S.; Prata, A. J.; Seibert, P.; Stebel, K.; Stohl, A.

2008-02-01

An analytical inversion method has been developed to estimate the vertical profile of SO2 emissions from volcanic eruptions. The method uses satellite-observed total SO2 columns and an atmospheric transport model (FLEXPART) to exploit the fact that winds change with altitude - thus, the position and shape of the volcanic plume bear information on its emission altitude. The method finds the vertical emission distribution which minimizes the total difference between simulated and observed SO2 columns while also considering a priori information. We have tested the method with the eruption of Jebel at Tair on 30 September 2007 for which a comprehensive observational data set from various satellite instruments (AIRS, OMI, SEVIRI, CALIPSO) is available. Using satellite data from the first 24 h after the eruption for the inversion, we found an emission maximum near 16 km above sea level (asl), and secondary maxima near 5, 9, 12 and 14 km a.s.l. 60% of the emission occurred above the tropopause. The emission profile obtained in the inversion was then used to simulate the transport of the plume over the following week. The modeled plume agrees very well with SO2 total columns observed by OMI, and its altitude and width agree mostly within 1-2 km with CALIPSO observations of stratospheric aerosol produced from the SO2. The inversion result is robust against various changes in both the a priori and the observations. Even when using only SEVIRI data from the first 15 h after the eruption, the emission profile was reasonably well estimated. The method is computationally very fast. It is therefore suitable for implementation within an operational environment, such as the Volcanic Ash Advisory Centers, to predict the threat posed by volcanic ash for air traffic. It could also be helpful for assessing the sulfur input into the stratosphere, be it in the context of volcanic processes or also for proposed geo-engineering techniques to counteract global warming.

How Well do State-of-the-Art Techniques Measuring the Vertical Profile of Tropospheric Aerosol Extinction Compare?

NASA Technical Reports Server (NTRS)

Schmid, B.; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.;

The vertical variability of hyporheic fluxes inferred from riverbed temperature data

NASA Astrophysics Data System (ADS)

Cranswick, Roger H.; Cook, Peter G.; Shanafield, Margaret; Lamontagne, Sebastien

2014-05-01

We present detailed profiles of vertical water flux from the surface to 1.2 m beneath the Haughton River in the tropical northeast of Australia. A 1-D numerical model is used to estimate vertical flux based on raw temperature time series observations from within downwelling, upwelling, neutral, and convergent sections of the hyporheic zone. A Monte Carlo analysis is used to derive error bounds for the fluxes based on temperature measurement error and uncertainty in effective thermal diffusivity. Vertical fluxes ranged from 5.7 m d-1 (downward) to -0.2 m d-1 (upward) with the lowest relative errors for values between 0.3 and 6 m d-1. Our 1-D approach provides a useful alternative to 1-D analytical and other solutions because it does not incorporate errors associated with simplified boundary conditions or assumptions of purely vertical flow, hydraulic parameter values, or hydraulic conditions. To validate the ability of this 1-D approach to represent the vertical fluxes of 2-D flow fields, we compare our model with two simple 2-D flow fields using a commercial numerical model. These comparisons showed that: (1) the 1-D vertical flux was equivalent to the mean vertical component of flux irrespective of a changing horizontal flux; and (2) the subsurface temperature data inherently has a "spatial footprint" when the vertical flux profiles vary spatially. Thus, the mean vertical flux within a 2-D flow field can be estimated accurately without requiring the flow to be purely vertical. The temperature-derived 1-D vertical flux represents the integrated vertical component of flux along the flow path intersecting the observation point. This article was corrected on 6 JUN 2014. See the end of the full text for details.

Retrieval of carbon dioxide vertical profiles from solar occultation observations and associated error budgets for ACE-FTS and CASS-FTS

NASA Astrophysics Data System (ADS)

Sioris, C. E.; Boone, C. D.; Nassar, R.; Sutton, K. J.; Gordon, I. E.; Walker, K. A.; Bernath, P. F.

2014-02-01

An algorithm is developed to retrieve the vertical profile of carbon dioxide in the 5 to 25 km altitude range using mid-infrared solar occultation spectra from the main instrument of the ACE (Atmospheric Chemistry Experiment) mission, namely the Fourier Transform Spectrometer (FTS). The main challenge is to find an atmospheric phenomenon which can be used for accurate tangent height determination in the lower atmosphere, where the tangent heights (THs) calculated from geometric and timing information is not of sufficient accuracy. Error budgets for the retrieval of CO2 from ACE-FTS and the FTS on a potential follow-on mission named CASS (Chemical and Aerosol Sounding Satellite) are calculated and contrasted. Retrieved THs are typically within 60 m of those retrieved using the ACE version 3.x software after revisiting the temperature dependence of the N2 CIA (Collision-Induced Absorption) laboratory measurements and accounting for sulfate aerosol extinction. After correcting for the known residual high bias of ACE version 3.x THs expected from CO2 spectroscopic/isotopic inconsistencies, the remaining bias for tangent heights determined with the N2 CIA is -20m. CO2 in the 5-13 km range in the 2009-2011 time frame is validated against aircraft measurements from CARIBIC, CONTRAIL and HIPPO, yielding typical biases of -1.7 ppm in the 5-13 km range. The standard error of these biases in this vertical range is 0.4 ppm. The multi-year ACE-FTS dataset is valuable in determining the seasonal variation of the latitudinal gradient which arises from the strong seasonal cycle in the Northern Hemisphere troposphere. The annual growth of CO2 in this time frame is determined to be 2.5 ± 0.7 ppm yr-1, in agreement with the currently accepted global growth rate based on ground-based measurements.

New insights about cloud vertical structure from CloudSat and CALIPSO observations

NASA Astrophysics Data System (ADS)

Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin

2017-09-01

Active cloud observations from A-Train's CloudSat and CALIPSO satellites offer new opportunities to examine the vertical structure of hydrometeor layers. We use the 2B-CLDCLASS-LIDAR merged CloudSat-CALIPSO product to examine global aspects of hydrometeor vertical stratification. We group the data into major cloud vertical structure (CVS) classes based on our interpretation of how clouds in three standard atmospheric layers overlap and provide their global frequency of occurrence. The two most frequent CVS classes are single-layer (per our definition) low and high clouds that represent 53% of cloudy skies, followed by high clouds overlying low clouds, and vertically extensive clouds that occupy near-contiguously a large portion of the troposphere. The prevalence of these configurations changes seasonally and geographically, between daytime and nighttime, and between continents and oceans. The radiative effects of the CVS classes reveal the major radiative warmers and coolers from the perspective of the planet as a whole, the surface, and the atmosphere. Single-layer low clouds dominate planetary and atmospheric cooling and thermal infrared surface warming. We also investigate the consistency between passive and active views of clouds by providing the CVS breakdowns of Moderate Resolution Imaging Spectroradiometer cloud regimes for spatiotemporally coincident MODIS-Aqua (also on the A-Train) and CloudSat-CALIPSO daytime observations. When the analysis is expanded for a more in-depth look at the most heterogeneous of the MODIS cloud regimes, it ultimately confirms previous interpretations of their makeup that did not have the benefit of collocated active observations.

Evidence of horizontal and vertical transport of water in the Southern Hemisphere tropical tropopause layer (TTL) from high-resolution balloon observations

NASA Astrophysics Data System (ADS)

Khaykin, Sergey M.; Pommereau, Jean-Pierre; Riviere, Emmanuel D.; Held, Gerhard; Ploeger, Felix; Ghysels, Melanie; Amarouche, Nadir; Vernier, Jean-Paul; Wienhold, Frank G.; Ionov, Dmitry

2016-09-01

High-resolution in situ balloon measurements of water vapour, aerosol, methane and temperature in the upper tropical tropopause layer (TTL) and lower stratosphere are used to evaluate the processes affecting the stratospheric water budget: horizontal transport (in-mixing) and hydration by cross-tropopause overshooting updrafts. The obtained in situ evidence of these phenomena are analysed using satellite observations by Aura MLS (Microwave Limb Sounder) and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) together with trajectory and transport modelling performed using CLaMS (Chemical Lagrangian Model of the Stratosphere) and HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model. Balloon soundings were conducted during March 2012 in Bauru, Brazil (22.3° S) in the frame of the TRO-Pico campaign for studying the impact of convective overshooting on the stratospheric water budget. The balloon payloads included two stratospheric hygrometers: FLASH-B (Fluorescence Lyman-Alpha Stratospheric Hygrometer for Balloon) and Pico-SDLA instrument as well as COBALD (Compact Optical Backscatter Aerosol Detector) sondes, complemented by Vaisala RS92 radiosondes. Water vapour vertical profiles obtained independently by the two stratospheric hygrometers are in excellent agreement, ensuring credibility of the vertical structures observed. A signature of in-mixing is inferred from a series of vertical profiles, showing coincident enhancements in water vapour (of up to 0.5 ppmv) and aerosol at the 425 K (18.5 km) level. Trajectory analysis unambiguously links these features to intrusions from the Southern Hemisphere extratropical stratosphere, containing more water and aerosol, as demonstrated by MLS and CALIPSO global observations. The in-mixing is successfully reproduced by CLaMS simulations, showing a relatively moist filament extending to 20° S. A signature of local cross-tropopause transport of water is observed in a particular

a Comparitive Study Using Geometric and Vertical Profile Features Derived from Airborne LIDAR for Classifying Tree Genera

NASA Astrophysics Data System (ADS)

Ko, C.; Sohn, G.; Remmel, T. K.

2012-07-01

We present a comparative study between two different approaches for tree genera classification using descriptors derived from tree geometry and those derived from the vertical profile analysis of LiDAR point data. The different methods provide two perspectives for processing LiDAR point clouds for tree genera identification. The geometric perspective analyzes individual tree crowns in relation to valuable information related to characteristics of clusters and line segments derived within crowns and overall tree shapes to highlight the spatial distribution of LiDAR points within the crown. Conversely, analyzing vertical profiles retrieves information about the point distributions with respect to height percentiles; this perspective emphasizes of the importance that point distributions at specific heights express, accommodating for the decreased point density with respect to depth of canopy penetration by LiDAR pulses. The targeted species include white birch, maple, oak, poplar, white pine and jack pine at a study site northeast of Sault Ste. Marie, Ontario, Canada.

Retrieval of Vertical LAI Profiles Over Tropical Rain Forests using Waveform Lidar at La Selva, Costa Rica

NASA Technical Reports Server (NTRS)

Tang, Hao; Dubayah, Ralph; Swatantra, Anu; Hofton, Michelle; Sheldon, Sage; Clark, David B.; Blair, Bryan

2012-01-01

This study explores the potential of waveform lidar in mapping the vertical and spatial distributions of leaf area index (LAI) over the tropical rain forest of La Selva Biological Station in Costa Rica. Vertical profiles of LAI were derived at 0.3 m height intervals from the Laser Vegetation Imaging Sensor (LVIS) data using the Geometric Optical and Radiative Transfer (GORT) model. Cumulative LAI profiles obtained from LVIS were validated with data from 55 ground to canopy vertical transects using a modular field tower to destructively sample all vegetation. Our results showed moderate agreement between lidar and field derived LAI (r2=0.42, RMSE=1.91, bias=-0.32), which further improved when differences between lidar and tower footprint scales (r2=0.50, RMSE=1.79, bias=0.27) and distance of field tower from lidar footprint center (r2=0.63, RMSE=1.36, bias=0.0) were accounted for. Next, we mapped the spatial distribution of total LAI across the landscape and analyzed LAI variations over different land cover types. Mean values of total LAI were 1.74, 5.20, 5.41 and 5.62 over open pasture, secondary forests, regeneration forests after selective-logging and old-growth forests respectively. Lastly, we evaluated the sensitivities of our LAI retrieval model to variations in canopy/ground reflectance ratio and to waveform noise such as induced by topographic slopes. We found for both, that the effects were not significant for moderate LAI values (about 4). However model derivations of LAI might be inaccurate in areas of high-slope and high LAI (about 8) if ground return energies are low. This research suggests that large footprint waveform lidar can provide accurate vertical LAI profile estimates that do not saturate even at the high LAI levels in tropical rain forests and may be a useful tool for understanding the light transmittance within these canopies.

Vertical profiles of ozone, carbon monoxide, and dew-point temperature obtained during GTE/CITE 1, October-November 1983. [Chemical Instrumentation Test and Evaluation

NASA Technical Reports Server (NTRS)

Fishman, Jack; Gregory, Gerald L.; Sachse, Glen W.; Beck, Sherwin M.; Hill, Gerald F.

1987-01-01

A set of 14 pairs of vertical profiles of ozone and carbon monoxide, obtained with fast-response instrumentation, is presented. Most of these profiles, which were measured in the remote troposphere, also have supporting fast-response dew-point temperature profiles. The data suggest that the continental boundary layer is a source of tropospheric ozone, even in October and November, when photochemical activity should be rather small. In general, the small-scale vertical variability between CO and O3 is in phase. At low latitudes this relationship defines levels in the atmosphere where midlatitude air is being transported to lower latitudes, since lower dew-point temperatures accompany these higher CO and O3 concentrations. A set of profiles which is suggestive of interhemispheric transport is also presented. Independent meteorological analyses support these interpretations.

Development of the Vertical Electro Magnetic Profiling (VEMP) method

NASA Astrophysics Data System (ADS)

Miura, Yasuo; Osato, Kazumi; Takasugi, Shinji; Muraoka, Hirofumi; Yasukawa, Kasumi

1996-09-01

As a part of the "Deep-Seated Geothermal Resources Survey (DSGR)" project being undertaken by the New Energy and Industrial Technology Development Organization (NEDO), the "Vertical Electro Magnetic Profiling (VEMP)" method is being developed to accurately obtain deep resistivity structures. The VEMP method takes multi-frequency three-component magnetic field data in an open hole well using controlled source transmitters emitted at the surface (either loop or grounded-wire sources). Numerical simulations using EM3D have demonstrated that phase data of the VEMP method is not only very sensitive to the general resistivity structure, but will also indicate the presence of deeper anomalies. Forward modelling was used to determine the required transmitter moments for various grounded-wire and loop sources for a field test using the WD-1 well in the Kakkonda geothermal area. VEMP logging of the WD-1 well was carried out in May 1994 and the processed field data matches the computer simulations quite well.

Vertical profiles of lung deposited surface area concentration of particulate matter measured with a drone in a street canyon.

PubMed

Kuuluvainen, Heino; Poikkimäki, Mikko; Järvinen, Anssi; Kuula, Joel; Irjala, Matti; Dal Maso, Miikka; Keskinen, Jorma; Timonen, Hilkka; Niemi, Jarkko V; Rönkkö, Topi

2018-05-23

The vertical profiles of lung deposited surface area (LDSA) concentration were measured in an urban street canyon in Helsinki, Finland, by using an unmanned aerial system (UAS) as a moving measurement platform. The street canyon can be classified as an avenue canyon with an aspect ratio of 0.45 and the UAS was a multirotor drone especially modified for emission measurements. In the experiments of this study, the drone was equipped with a small diffusion charge sensor capable of measuring the alveolar LDSA concentration of particles. The drone measurements were conducted during two days on the same spatial location at the kerbside of the street canyon by flying vertically from the ground level up to an altitude of 50 m clearly above the rooftop level (19 m) of the nearest buildings. The drone data were supported by simultaneous measurements and by a two-week period of measurements at nearby locations with various instruments. The results showed that the averaged LDSA concentrations decreased approximately from 60 μm 2 /cm 3 measured close to the ground level to 36-40 μm 2 /cm 3 measured close to the rooftop level of the street canyon, and further to 16-26 μm 2 /cm 3 measured at 50 m. The high-resolution measurement data enabled an accurate analysis of the functional form of vertical profiles both in the street canyon and above the rooftop level. In both of these regions, exponential fits were used and the parameters obtained from the fits were thoroughly compared to the values found in literature. The results of this study indicated that the role of turbulent mixing caused by traffic was emphasized compared to the street canyon vortex as a driving force of the dispersion. In addition, the vertical profiles above the rooftop level showed a similar exponential decay compared to the profiles measured inside the street canyon. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vertical Distribution Characteristics of PM2.5 Observed by a Mobile Vehicle Lidar in Tianjin, China in 2016

NASA Astrophysics Data System (ADS)

Lyu, Lihui; Dong, Yunsheng; Zhang, Tianshu; Liu, Cheng; Liu, Wenqing; Xie, Zhouqing; Xiang, Yan; Zhang, Yi; Chen, Zhenyi; Fan, Guangqiang; Zhang, Leibo; Liu, Yang; Shi, Yuchen; Shu, Xiaowen

2018-02-01

We present mobile vehicle lidar observations in Tianjin, China during the spring, summer, and winter of 2016. Mobile observations were carried out along the city border road of Tianjin to obtain the vertical distribution characteristics of PM2.5. Hygroscopic growth was not considered since relative humidity was less than 60% during the observation experiments. PM2.5 profile was obtained with the linear regression equation between the particle extinction coefficient and PM2.5 mass concentration. In spring, the vertical distribution of PM2.5 exhibited a hierarchical structure. In addition to a layer of particles that gathered near the ground, a portion of particles floated at 0.6-2.5-km height. In summer and winter, the fine particles basically gathered below 1 km near the ground. In spring and summer, the concentration of fine particles in the south was higher than that in the north because of the influence of south wind. In winter, the distribution of fine particles was opposite to that measured during spring and summer. High concentrations of PM2.5 were observed in the rural areas of North Tianjin with a maximum of 350 μg m-3 on 13 December 2016. It is shown that industrial and ship emissions in spring and summer and coal combustion in winter were the major sources of fine particles that polluted Tianjin. The results provide insights into the mechanisms of haze formation and the effects of meteorological conditions during haze-fog pollution episodes in the Tianjin area.

Visual observations of the vertical distribution of plankton throughout the water column above Broken Spur vent field, Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Vereshchaka, A. L.; Vinogradov, G. M.

1999-09-01

Visual observations were made in September 1997 during the 39 cruise of R/V "Akademik Mstislav Keldysh" with 2 deep-sea manned submersibles "Mir" aboard. During 4 dives the following plankton countings were made: 3 vertical throughout the water column during the day, 2 vertical in the upper 1000 m at night, and 1 oblique in the plume area during the day. Biomass profiles are represented for each dive for all abundant animal groups: copepods, euphausiids+decapods+mysids, chaetognaths, medusae, ctenophores, siphonophores, cyclothones, myctophides, radiolarians, and the total zooplankton. Plankton distribution shows 2 aggregations, one within the main pycnocline and the other near the plume; Gelatinous animals and radiolarians dominate in both aggregations by biomass and make a significant contribution to the plankton biomass throughout the water column. Oblique counting indicates the presence of aggregations of animals near the upper and lower borders of the plume and biomass depletion within the plume core.

Determination of precipitation profiles from airborne passive microwave radiometric measurements

NASA Technical Reports Server (NTRS)

Kummerow, Christian; Hakkarinen, Ida M.; Pierce, Harold F.; Weinman, James A.

1991-01-01

This study presents the first quantitative retrievals of vertical profiles of precipitation derived from multispectral passive microwave radiometry. Measurements of microwave brightness temperature (Tb) obtained by a NASA high-altitude research aircraft are related to profiles of rainfall rate through a multichannel piecewise-linear statistical regression procedure. Statistics for Tb are obtained from a set of cloud radiative models representing a wide variety of convective, stratiform, and anvil structures. The retrieval scheme itself determines which cloud model best fits the observed meteorological conditions. Retrieved rainfall rate profiles are converted to equivalent radar reflectivity for comparison with observed reflectivities from a ground-based research radar. Results for two case studies, a stratiform rain situation and an intense convective thunderstorm, show that the radiometrically derived profiles capture the major features of the observed vertical structure of hydrometer density.

ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, 449 MHz Profiler(williams-449_prof)

DOE Data Explorer

Williams, Christopher; Jensen, Mike

2012-11-06

This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

Influence of Saharan dust outbreaks and atmospheric stability upon vertical profiles of size-segregated aerosols and water vapor

NASA Astrophysics Data System (ADS)

Giménez, Joaquín; Pastor, Carlos; Castañer, Ramón; Nicolás, José; Crespo, Javier; Carratalá, Adoración

2010-01-01

Vertical profiles of aerosols and meteorological parameters were obtained using a hot air balloon and motorized paraglider. They were studied under anticyclonic conditions in four different contexts. Three flights occurred near sunrise, and one took place in the central hours of the day. The effects of North African dust intrusions were analyzed, whose entrance to the study area took place above the Stable Boundary Layer (SBL) in flight 1 and below it in flight 2. These flights have been compared with a non-intrusion situation (flight 3). A fourth flight characterized the profiles in the central hours of the day with a well-formed Convective Boundary Layer (CBL). With respect to the particle number distribution, the results show that not all sizes increase within the presence of an intrusion; during the first flight the smallest particles were not affected. The particle sizes affected in the second flight fell within the 0.35-2.5 μm interval. Under situations of convective dynamics, the reduction percentage of the particle number concentration reduces with increasing altitude, independently of their size, with respect to stability conditions. The negative vertical gradient for aerosols and water vapor, characteristic of a highly stable SBL (flight 3) becomes a constant profile within a CBL (flight 4). There are two situations that seem to alter the negative vertical gradient of the water vapor mixing ratio within the SBL: the presence of an intrusion and the possible stratification of the SBL based on different degrees of stability.

First Comparison of Remote Vertical Profiles of Refractory Black Carbon between the Atlantic and Pacific Basins on Global Scales

NASA Astrophysics Data System (ADS)

Katich, J. M.; Schwarz, J. P.

2016-12-01

The NASA Atmospheric Tomography Mission (ATom) provides a first opportunity to obtain vertical profiles of refractory black carbon (rBC) mass mixing ratios over global scale ( 65S - 85 N latitude) in the remote atmosphere over both the Pacific and Atlantic basins. A NOAA single-particle soot photometer (SP2) will fly on the NASA DC-8 research aircraft over July/August of 2016, obtaining near- continuous vertical profiling ( 0.3 to 12 km) over most of the Earth's latitude range, akin to the NSF HIPPO campaign that occurred only over the Pacific basin during 2009-2011. HIPPO analysis suggested both that high altitude rBC mass mixing ratios (MMRs) were likely zonally well mixed, and that global model estimates of remote rBC MMR throughout the upper troposphere globally, and not just over the Pacific, were likely biased high. Here we will present an initial analysis of the new, more complete data set in which Atlantic rBC profiles will be used to assess these prior suppositions.

An Orbital "Virtual Radar" from TRMM Passive Microwave and Lightning Observations

NASA Technical Reports Server (NTRS)

Boccippio, Dennis J.

2004-01-01

The retrieval of vertical structure from joint passive microwave and lightning observations is demonstrated. Three years of data from the TRMM (Tropical Rainfall Measuring Mission) are used as a training dataset for regression and classification neural networks; the TMI (TRMM Microwave Imager) and LIS (Lightning Imaging Sensor) provide the inputs, the PR (Precipitation Radar) provides the training targets. Both vertical reflectivity profile categorization (into 9 convective, 7 stratiform, 2 mixed and 6 anvil types) and geophysical parameters (surface rainfall, vertically integrated liquid (VIL), ice water content (IWC) and echo tops) are retrieved. Retrievals are successful over both land and ocean surfaces. The benefit of using lightning observations as inputs to these retrievals is quantitatively demonstrated; lightning essentially provides an additional convective/stratiform discriminator, and is most important for isolation of midlevel (tops in the mixed phase region) convective profile types (this is because high frequency passive microwave observations already provide good convective/stratiform discrimination for deep convective profiles). This is highly relevant as midlevel convective profiles account for an extremely large fraction of tropical rainfall, and yet are most difficult to discriminate from comparable-depth stratiform profile types using passive microwave observations alone.

The potential of LIRIC to validate the vertical profiles of the aerosol mass concentration estimated by an air quality model

NASA Astrophysics Data System (ADS)

Siomos, Nikolaos; Filoglou, Maria; Poupkou, Anastasia; Liora, Natalia; Dimopoulos, Spyros; Melas, Dimitris; Chaikovsky, Anatoli; Balis, Dimitris

2015-04-01

Vertical profiles of the aerosol mass concentration derived by a retrieval algorithm that uses combined sunphotometer and LIDAR data (LIRIC) were used in order to validate the mass concentration profiles estimated by the air quality model CAMx. LIDAR and CIMEL measurements of the Laboratory of Atmospheric Physics of the Aristotle University of Thessaloniki were used for this validation.The aerosol mass concentration profiles of the fine and coarse mode derived by CAMx were compared with the respective profiles derived by the retrieval algorithm. For the coarse mode particles, forecasts of the Saharan dust transportation model BSC-DREAM8bV2 were also taken into account. Each of the retrieval algorithm's profiles were matched to the models' profile with the best agreement within a time window of four hours before and after the central measurement. OPAC, a software than can provide optical properties of aerosol mixtures, was also employed in order to calculate the angstrom exponent and the lidar ratio values for 355nm and 532nm for each of the model's profiles aiming in a comparison with the angstrom exponent and the lidar ratio values derived by the retrieval algorithm for each measurement. The comparisons between the fine mode aerosol concentration profiles resulted in a good agreement between CAMx and the retrieval algorithm, with the vertical mean bias error never exceeding 7 μgr/m3. Concerning the aerosol coarse mode concentration profiles both CAMx and BSC-DREAM8bV2 values are severely underestimated, although, in cases of Saharan dust transportation events there is an agreement between the profiles of BSC-DREAM8bV2 model and the retrieval algorithm.

Characteristic Vertical Profiles of Cloud Water Composition in Marine Stratocumulus Clouds and Relationships With Precipitation

NASA Astrophysics Data System (ADS)

MacDonald, Alexander B.; Dadashazar, Hossein; Chuang, Patrick Y.; Crosbie, Ewan; Wang, Hailong; Wang, Zhen; Jonsson, Haflidi H.; Flagan, Richard C.; Seinfeld, John H.; Sorooshian, Armin

2018-04-01

This study uses airborne cloud water composition measurements to characterize the vertical structure of air-equivalent mass concentrations of water-soluble species in marine stratocumulus clouds off the California coast. A total of 385 cloud water samples were collected in the months of July and August between 2011 and 2016 and analyzed for water-soluble ionic and elemental composition. Three characteristic profiles emerge: (i) a reduction of concentration with in-cloud altitude for particulate species directly emitted from sources below cloud without in-cloud sources (e.g., Cl- and Na+), (ii) an increase of concentration with in-cloud altitude (e.g., NO2- and formate), and (iii) species exhibiting a peak in concentration in the middle of cloud (e.g., non-sea-salt SO42-, NO3-, and organic acids). Vertical profiles of rainout parameters such as loss frequency, lifetime, and change in concentration with respect to time show that the scavenging efficiency throughout the cloud depth depends strongly on the thickness of the cloud. Thin clouds exhibit a greater scavenging loss frequency at cloud top, while thick clouds have a greater scavenging loss frequency at cloud base. The implications of these results for treatment of wet scavenging in models are discussed.

Characteristic Vertical Profiles of Cloud Water Composition in Marine Stratocumulus Clouds and Relationships With Precipitation

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

MacDonald, Alexander B.; Dadashazar, Hossein; Chuang, Patrick Y.

This study uses airborne cloud water composition measurements to characterize the vertical structure of air-equivalent mass concentrations of water-soluble species in marine stratocumulus clouds off the California coast. A total of 385 cloud water samples were collected in the months of July and August between 2011 and 2016 and analyzed for water-soluble ionic and elemental composition. Three characteristic profiles emerge: (i) a reduction of concentration with in-cloud altitude for particulate species directly emitted from sources below cloud without in-cloud sources (e.g., Cl-, Na+); (ii) an increase of concentration with in-cloud altitude (e.g., NO2-, formate); and (iii) species exhibiting a peakmore » in concentration in the middle of cloud (e.g., non-sea salt SO42-, NO3-, organic acids). Vertical profiles of rainout parameters such as loss frequency, lifetime, and change in concentration with respect to time show that the scavenging efficiency throughout the cloud depth depends strongly on the thickness of the cloud. Thin clouds exhibit a greater scavenging loss frequency at cloud top, while thick clouds have a greater scavenging loss frequency at cloud base. The implications of these results for treatment of wet scavenging in models are discussed.« less

Vertical profiles in NO3 and N2O5 measured from an aircraft: Results from the NOAA P-3 and surface platforms during the New England Air Quality Study 2004

NASA Astrophysics Data System (ADS)

Brown, Steven S.; Dubé, William P.; Osthoff, Hans D.; Stutz, Jochen; Ryerson, Thomas B.; Wollny, Adam G.; Brock, Charles A.; Warneke, Carsten; de Gouw, Joost A.; Atlas, Eliot; Neuman, J. Andrew; Holloway, John S.; Lerner, Brian M.; Williams, Eric J.; Kuster, William C.; Goldan, Paul D.; Angevine, Wayne M.; Trainer, Michael; Fehsenfeld, Frederick C.; Ravishankara, A. R.

2007-11-01

The nocturnal nitrogen oxides, NO3 and N2O5, are important to the chemical transformation and transport of NOx, O3 and VOC. Their concentrations, sources and sinks are known to be vertically stratified in the nighttime atmosphere. In this paper, we report vertical profiles for NO3 and N2O5 measured from an aircraft (the NOAA P-3) as part of the New England Air Quality Study in July and August 2004. The aircraft data are compared to surface measurements made in situ from a ship and by long-path DOAS. Consistent with previous, vertically resolved studies of NO3 and N2O5, the aircraft measurements show that these species occur at larger concentrations and are longer lived aloft than they are at the surface. The array of in situ measurements available on the P-3 allows for investigation of the mechanisms that give rise to the observed vertical gradients. Selected vertical profiles from this campaign illustrate the role of biogenic VOC, particularly isoprene and dimethyl sulfide, both within and above the nocturnal and/or marine boundary layer. Gradients in relative humidity and aerosol surface may also create a vertical gradient in the rate of N2O5 hydrolysis. Low-altitude intercepts of power plant plumes showed strong vertical stratification, with plume depths of 80 m. The efficiency of N2O5 hydrolysis within these plumes was an important factor determining the low-level NOx and O3 transport or loss at night. Averages of nocturnal O3, NO2, NO3 and N2O5 binned according to altitude were consistent with the trends from individual profiles. While production rates of NO3 peaked near the surface, lifetimes of NO3 and N2O5 were maximum aloft, particularly in the free troposphere. Variability in NO3 and N2O5 was large and exceeded that of NO2 or O3 because of inhomogeneous distribution of NOx emissions and NO3 and N2O5 sinks.

Convection Fingerprints on the Vertical Profiles of Q1 and Q2

NASA Astrophysics Data System (ADS)

Chang, C.; Lin, H.; Chou, C.

2013-12-01

Different types of tropical convection left their fingerprints on vertical structures of apparent heat source (Q1) and apparent moisture sink (Q2). Profile of deep convection on condensation heating and drying has been well-documented, yet direct assessment of shallow convection remains to be explored. Shallow convection prevails over subtropical ocean, where large-scale subsidence is primarily balanced by radiative cooling and moistening due to surface evaporation instead of moist convection. In this study a united framework is designed to investigate the vertical structures of tropical marine convections in three reanalysis data, including ERA-Interim, MERRA, and CFSR. It starts by sorting and binning data from the lightest to the heaviest rain. Then the differences between two neighboring bins are used to examine the direct effects for precipitation change, in light of the fact that non-convective processes would change slowly from bin to bin. It is shown that all three reanalyses reveal the shallow convective processes in light rain bins, featured by re-evaporating and detraining at the top of boundary layer and lower free troposphere. For heavy rain bins, three reanalyses mainly differ in their numbers and altitudes of heating and drying peaks, implying no universal agreement has been reached on partitioning of cloud populations. Coherent variations in temperature, moisture, and vertical motion are also discussed. This approach permits a systematical survey and comparison of tropical convection in GCM-type models, and preliminary studies of three reanalyses suggest certain degree of inconsistency in simulated convective feedback to large-scale heat and moisture budgets.

Variability of O3 and NO2 profile shapes during DISCOVER-AQ: Implications for satellite observations and comparisons to model-simulated profiles

NASA Astrophysics Data System (ADS)

Flynn, Clare Marie; Pickering, Kenneth E.; Crawford, James H.; Weinheimer, Andrew J.; Diskin, Glenn; Thornhill, K. Lee; Loughner, Christopher; Lee, Pius; Strode, Sarah A.

2016-12-01

To investigate the variability of in situ profile shapes under a variety of meteorological and pollution conditions, results are presented of an agglomerative hierarchical cluster analysis of the in situ O3 and NO2 profiles for each of the four campaigns of the NASA DISCOVER-AQ mission. Understanding the observed profile variability for these trace gases is useful for understanding the accuracy of the assumed profile shapes used in satellite retrieval algorithms as well as for understanding the correlation between satellite column observations and surface concentrations. The four campaigns of the DISCOVER-AQ mission took place in Maryland during July 2011, the San Joaquin Valley of California during January-February 2013, the Houston, Texas, metropolitan region during September 2013, and the Denver-Front Range region of Colorado during July-August 2014. Several distinct profile clusters emerged for the California, Texas, and Colorado campaigns for O3, indicating significant variability of O3 profile shapes, while the Maryland campaign presented only one distinct O3 cluster. In contrast, very few distinct profile clusters emerged for NO2 during any campaign for this particular clustering technique, indicating the NO2 profile behavior was relatively uniform throughout each campaign. However, changes in NO2 profile shape were evident as the boundary layer evolved through the day, but they were apparently not significant enough to yield more clusters. The degree of vertical mixing (as indicated by temperature lapse rate) associated with each cluster exerted an important influence on the shapes of the median cluster profiles for O3, as well as impacted the correlations between the associated column and surface data for each cluster for O3. The correlation analyses suggest satellites may have the best chance to relate to surface O3 under the conditions encountered during the Maryland campaign Clusters 1 and 2, which include deep, convective boundary layers and few

Combining Satellite Microwave Radiometer and Radar Observations to Estimate Atmospheric Latent Heating Profiles

NASA Technical Reports Server (NTRS)

Grecu, Mircea; Olson, William S.; Shie, Chung-Lin; L'Ecuyer, Tristan S.; Tao, Wei-Kuo

2009-01-01

In this study, satellite passive microwave sensor observations from the TRMM Microwave Imager (TMI) are utilized to make estimates of latent + eddy sensible heating rates (Q1-QR) in regions of precipitation. The TMI heating algorithm (TRAIN) is calibrated, or "trained" using relatively accurate estimates of heating based upon spaceborne Precipitation Radar (PR) observations collocated with the TMI observations over a one-month period. The heating estimation technique is based upon a previously described Bayesian methodology, but with improvements in supporting cloud-resolving model simulations, an adjustment of precipitation echo tops to compensate for model biases, and a separate scaling of convective and stratiform heating components that leads to an approximate balance between estimated vertically-integrated condensation and surface precipitation. Estimates of Q1-QR from TMI compare favorably with the PR training estimates and show only modest sensitivity to the cloud-resolving model simulations of heating used to construct the training data. Moreover, the net condensation in the corresponding annual mean satellite latent heating profile is within a few percent of the annual mean surface precipitation rate over the tropical and subtropical oceans where the algorithm is applied. Comparisons of Q1 produced by combining TMI Q1-QR with independently derived estimates of QR show reasonable agreement with rawinsonde-based analyses of Q1 from two field campaigns, although the satellite estimates exhibit heating profile structure with sharper and more intense heating peaks than the rawinsonde estimates. 2

Infiltration pattern in a regolith-fractured bedrock profile: field observation of a dye stain pattern

NASA Astrophysics Data System (ADS)

Kim, Jae Gon; Lee, Gyoo Ho; Lee, Jin-Soo; Chon, Chul-Min; Kim, Tack Hyun; Ha, Kyoochul

2006-02-01

We examined the infiltration pattern of water in a regolith-bedrock profile consisting of two overburdens (OB1 and OB2), a buried rice paddy soil (PS), two texturally distinctive weathered materials (WM1 and WM2) and a fractured sedimentary rock (BR), using a Brilliant Blue FCF dye tracer. A black-coloured coating in conducting fractures in WM1, WM2 and BR was analysed by X-ray diffraction and scanning electron microscopy. The dye tracer penetrated to greater than 2 m depth in the profile. The macropore flow and saturated interflow were the major infiltration patterns in the profile. Macropore flow and saturated interflow were observed along fractures in WM1, WM2 and BR and at the dipping interfaces of PS-WM1, PS-WM2 and PS-BR respectively. Heterogeneous matrix flow occurred in upper overburden (OB1) and PS. Compared with OB1, the coarser textured OB2 acted as a physical barrier for vertical flow of water. The PS with low bulk density and many fine roots was another major conducting route of water in the profile. Manganese oxide and iron oxide were positively identified in the black coating material and had low crystallinity and high surface area, indicating their high reactivity with conducting contaminants.

Eddy Vertical Structure Observed by Deepgliders: Evidence for the Enstrophy Inertial Range Cascade in Geostrophic Turbulence

NASA Astrophysics Data System (ADS)

Eriksen, C. C.

2016-12-01

Full water column temperature and salinity profiles and estimates of average current collected with Deepgliders were used to analyze vertical structure of mesoscale features in the western North Atlantic Ocean. Fortnightly repeat surveys over a 58 km by 58 km region centered at the Bermuda Atlantic Time Series (BATS) site southeast of Bermuda were carried out for 3 and 9 months in successive years. In addition, a section from Bermuda along Line W across the Gulf Stream to the New England Continental Slope and a pair of sections from Bermuda to the Bahamas were carried out. Absolute geostrophic current estimates constructed from these measurements and projected upon flat bottom resting ocean dynamic modes for the regions indicate nearly equal kinetic energy in the barotropic mode and first baroclinic mode. An empirical orthogonal mode decomposition of dynamic mode amplitudes demonstrates strong coupling of the barotropic and first baroclinic modes, a result resembling those reported for the Polymode experiment 3 decades ago. Higher baroclinic modes are largely independent of one another. Energy in baroclinic modes varies in inverse proportion to mode number cubed, a result predicted for an enstrophy inertial range cascade of geostrophic turbulence, believed newly detected by these observations. This (mode number)-3 dependence is found at BATS and across the Gulf Stream and Sargasso Sea. On two occasions, submesoscale anticyclones were detected at BATS whose vertical structure closely resembled the second baroclinic mode. Anomalously cold and fresh water within their cores (by as much as 3.5°C and 0.5 in salinity) suggests they were of subpolar (likely Labrador Sea) origin. These provided temporary perturbations to the vertical mode number energy spectrum.

Impact of fugitive sources and meteorological parameters on vertical distribution of particulate matter over the industrial agglomeration.

PubMed

Štrbová, Kristína; Raclavská, Helena; Bílek, Jiří

2017-12-01

The aim of the study was to characterize vertical distribution of particulate matter, in an area well known by highest air pollution levels in Europe. A balloon filled with helium with measuring instrumentation was used for vertical observation of air pollution over the fugitive sources in Moravian-Silesian metropolitan area during spring and summer. Synchronously, selected meteorological parameters were recorded together with particulate matter for exploration its relationship with particulate matter. Concentrations of particulate matter in the vertical profile were significantly higher in the spring than in the summer. Significant effect of fugitive sources was observed up to the altitude ∼255 m (∼45 m above ground) in both seasons. The presence of inversion layer was observed at the altitude ∼350 m (120-135 m above ground) at locations with major source traffic load. Both particulate matter concentrations and number of particles for the selected particle sizes decreased with increasing height. Strong correlation of particulate matter with meteorological parameters was not observed. The study represents the first attempt to assess the vertical profile over the fugitive emission sources - old environmental burdens in industrial region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Observations of tropospheric phase scintillations at 5 GHz on vertical paths

NASA Technical Reports Server (NTRS)

Armstrong, J. W.; Sramek, R. A.

1982-01-01

The article presents observations of turbulence-induced tropospheric phase fluctuations measured at 5 GHz on the near-vertical paths relevant to many astronomical and geophysical measurements. The data are summarized as phase power spectra, structure functions, and Allan variances. Comparisons to other microwave observations indicate relatively good agreement in both the level and shape of the power spectrum of these tropospheric phase fluctuations. Implications for precision Doppler tracking of spacecraft and geodesy/radio interferometry are discussed.

Vertical distribution of ozone at the terminator on Mars

NASA Astrophysics Data System (ADS)

Maattanen, Anni; Lefevre, Franck; Guilbon, Sabrina; Listowski, Constantino; Montmessin, Franck

2016-10-01

The SPICAM/Mars Express UV solar occultation dataset gives access to the ozone vertical distribution via the ozone absorption in the Hartley band (220-280 nm). We present the retrieved ozone profiles and compare them to the LMD Mars Global Climate Model (LMD-MGCM) results.Due to the photochemical reactivity of ozone, a classical comparison of local density profiles is not appropriate for solar occultations that are acquired at the terminator, and we present here a method often used in the Earth community. The principal comparison is made via the slant profiles (integrated ozone concentration on the line-of-sight), since the spherical symmetry hypothesis made in the onion-peeling vertical inversion method is not valid for photochemically active species (e.g., ozone) around terminator. For each occultation, we model the ozone vertical and horizontal distribution with high solar zenith angle (or local time) resolution around the terminator and then integrate the model results following the lines-of-sight of the occultation to construct the modeled slant profile. We will also discuss the difference of results between the above comparison method and a comparison using the local density profiles, i.e., the observed ones inverted by using the spherical symmetry hypothesis and the modeled ones extracted from the LMD-MGCM exactly at the terminator. The method and the results will be presented together with the full dataset.SPICAM is funded by the French Space Agency CNES and this work has received funding from the European Union's Horizon 2020 Programme (H2020-Compet-08-2014) under grant agreement UPWARDS-633127.

Lidar Observations of the Vertical Structure of Ozone and Aerosol during Wintertime High-Ozone Episodes Associated with Oil and Gas Exploration in the Uintah Basin

NASA Astrophysics Data System (ADS)

Senff, C. J.; Langford, A. O.; Banta, R. M.; Alvarez, R. J.; Weickmann, A.; Sandberg, S.; Marchbanks, R. D.; Brewer, A.; Hardesty, R. M.

2013-12-01

The Uintah Basin in northeast Utah has been experiencing extended periods of poor air quality in the winter months including very high levels of surface ozone. To investigate the causes of these wintertime ozone pollution episodes, two comprehensive studies were undertaken in January/February of 2012 and 2013. As part of these Uintah Basin Ozone Studies (UBOS), NOAA deployed its ground-based, scanning Tunable Optical Profiler for Aerosol and oZone (TOPAZ) lidar to document the vertical structure of ozone and aerosol backscatter from near the surface up to about 3 km above ground level (AGL). TOPAZ, along with a comprehensive set of chemistry and meteorological measurements, was situated in both years at the Horse Pool site at the northern edge of a large concentration of gas producing wells in the eastern part of the Uintah Basin. The 2012 study was characterized by unusually warm and snow-free condition and the TOPAZ lidar observed deep boundary layers (BL) and mostly well-mixed vertical ozone profiles at or slightly above tropospheric background levels. During UBOS 2013, winter weather conditions in the Uintah Basin were more typical with snow-covered ground and a persistent, shallow cold-pool layer. The TOPAZ lidar characterized with great temporal and spatial detail the evolution of multiple high-ozone episodes as well as cleanout events caused by the passage of synoptic-scale storm systems. Despite the snow cover, the TOPAZ observations show well-mixed afternoon ozone and aerosol profiles up to about 100 m AGL. After several days of pollutant buildup, BL ozone values reached 120-150 ppbv. Above the mixed layer, ozone values gradually decreased to tropospheric background values of around 50 ppbv throughout the several-hundred-meter-deep cold-pool layer and then stayed constant above that up to about 3 km AGL. During the ozone episodes, the lidar observations show no indication of either vertical or horizontal transport of high ozone levels to the surface, thus

One year of vertical wind profiles measurements at a Mediterranean coastal site of South Italy

NASA Astrophysics Data System (ADS)

Calidonna, Claudia Roberta; Avolio, Elenio; Federico, Stefano; Gullì, Daniel; Lo Feudo, Teresa; Sempreviva, Anna Maria

2015-04-01

In order to develop wind farms projects is challenging to site them on coastal areas both onshore and offshore as suitable sites. Developing projects need high quality databases under a wide range of atmospheric conditions or high resolution models that could resolve the effect of the coastal discontinuity in the surface properties. New parametrizations are important and high quality databases are also needed for formulating them. Ground-based remote sensing devices such as lidars have been shown to be functional for studying the evolution of the vertical wind structure coastal atmospheric boundary layer both on- and offshore. Here, we present results from a year of vertical wind profiles, wind speed and direction, monitoring programme at a site located in the Italian Calabria Region, Central Mediterranean, 600m from the Thyrrenian coastline, where a Lidar Doppler, ZephIr (ZephIr ltd) has been operative since July 2013. The lidar monitors wind speed and direction from 10m up to 300m at 10 vertical levels with an average of 10 minutes and it is supported by a metmast providing: Atmospheric Pressure, Solar Radiation, Precipitation, Relative Humidity, Temperature,Wind Speed and Direction at 10m. We present the characterization of wind profiles during one year period according to the time of the day to transition periods night/day/night classified relating the local scale, breeze scale, to the large scale conditions. The dataset is also functional for techniques for short-term prediction of wind for the renewable energy integration in the distribution grids. The site infrastructure is funded within the Project "Infrastructure of High Technology for Environmental and Climate Monitoring" (I-AMICA) (PONa3_00363) by the Italian National Operative Program (PON 2007-2013) and European Regional Development Fund. Real-time data are show on http://www.i-amica.it/i-amica/?page_id=1122.

Inversely Estimating the Vertical Profile of the Soil CO2 Production Rate in a Deciduous Broadleaf Forest Using a Particle Filtering Method

PubMed Central

Sakurai, Gen; Yonemura, Seiichiro; Kishimoto-Mo, Ayaka W.; Murayama, Shohei; Ohtsuka, Toshiyuki; Yokozawa, Masayuki

2015-01-01

Carbon dioxide (CO2) efflux from the soil surface, which is a major source of CO2 from terrestrial ecosystems, represents the total CO2 production at all soil depths. Although many studies have estimated the vertical profile of the CO2 production rate, one of the difficulties in estimating the vertical profile is measuring diffusion coefficients of CO2 at all soil depths in a nondestructive manner. In this study, we estimated the temporal variation in the vertical profile of the CO2 production rate using a data assimilation method, the particle filtering method, in which the diffusion coefficients of CO2 were simultaneously estimated. The CO2 concentrations at several soil depths and CO2 efflux from the soil surface (only during the snow-free period) were measured at two points in a broadleaf forest in Japan, and the data were assimilated into a simple model including a diffusion equation. We found that there were large variations in the pattern of the vertical profile of the CO2 production rate between experiment sites: the peak CO2 production rate was at soil depths around 10 cm during the snow-free period at one site, but the peak was at the soil surface at the other site. Using this method to estimate the CO2 production rate during snow-cover periods allowed us to estimate CO2 efflux during that period as well. We estimated that the CO2 efflux during the snow-cover period (about half the year) accounted for around 13% of the annual CO2 efflux at this site. Although the method proposed in this study does not ensure the validity of the estimated diffusion coefficients and CO2 production rates, the method enables us to more closely approach the “actual” values by decreasing the variance of the posterior distribution of the values. PMID:25793387

Longitudinal Differences of Ionospheric Vertical Density Distribution and Equatorial Electrodynamics

NASA Technical Reports Server (NTRS)

Yizengaw, E.; Zesta, E.; Moldwin, M. B.; Damtie, B.; Mebrahtu, A.; Valledares, C.E.; Pfaff, R. F.

2012-01-01

Accurate estimation of global vertical distribution of ionospheric and plasmaspheric density as a function of local time, season, and magnetic activity is required to improve the operation of space-based navigation and communication systems. The vertical density distribution, especially at low and equatorial latitudes, is governed by the equatorial electrodynamics that produces a vertical driving force. The vertical structure of the equatorial density distribution can be observed by using tomographic reconstruction techniques on ground-based global positioning system (GPS) total electron content (TEC). Similarly, the vertical drift, which is one of the driving mechanisms that govern equatorial electrodynamics and strongly affect the structure and dynamics of the ionosphere in the low/midlatitude region, can be estimated using ground magnetometer observations. We present tomographically reconstructed density distribution and the corresponding vertical drifts at two different longitudes: the East African and west South American sectors. Chains of GPS stations in the east African and west South American longitudinal sectors, covering the equatorial anomaly region of meridian approx. 37 deg and 290 deg E, respectively, are used to reconstruct the vertical density distribution. Similarly, magnetometer sites of African Meridian B-field Education and Research (AMBER) and INTERMAGNET for the east African sector and South American Meridional B-field Array (SAMBA) and Low Latitude Ionospheric Sensor Network (LISN) are used to estimate the vertical drift velocity at two distinct longitudes. The comparison between the reconstructed and Jicamarca Incoherent Scatter Radar (ISR) measured density profiles shows excellent agreement, demonstrating the usefulness of tomographic reconstruction technique in providing the vertical density distribution at different longitudes. Similarly, the comparison between magnetometer estimated vertical drift and other independent drift observation

Characteristics of aerosol vertical profiles in Tsukuba, Japan, and their impacts on the evolution of the atmospheric boundary layer

NASA Astrophysics Data System (ADS)

Kudo, Rei; Aoyagi, Toshinori; Nishizawa, Tomoaki

2018-05-01

Vertical profiles of the aerosol physical and optical properties, with a focus on seasonal means and on transport events, were investigated in Tsukuba, Japan, by a synergistic remote sensing method that uses lidar and sky radiometer data. The retrieved aerosol vertical profiles of the springtime mean and five transport events were input to our developed one-dimensional atmospheric model, and the impacts of the aerosol vertical profiles on the evolution of the atmospheric boundary layer (ABL) were studied by numerical sensitivity experiments. The characteristics of the aerosol vertical profiles in Tsukuba are as follows: (1) the retrieval results in the spring showed that aerosol optical thickness at 532 nm in the free atmosphere (FA) was 0.13, greater than 0.08 in the ABL owing to the frequent occurrence of transported aerosols in the FA. In other seasons, optical thickness in the FA was almost the same as that in the ABL. (2) The aerosol optical and physical properties in the ABL showed a dependency on the extinction coefficient. With an increase in the extinction coefficient from 0.00 to 0.24 km-1, the Ångström exponent increased from 0.0 to 2.0, the single-scattering albedo increased from 0.87 to 0.99, and the asymmetry factor decreased from 0.75 to 0.50. (3) The large variability in the physical and optical properties of aerosols in the FA were attributed to transport events, during which the transported aerosols consisted of varying amounts of dust and smoke particles depending on where they originated (China, Mongolia, or Russia). The results of the numerical sensitivity experiments using the aerosol vertical profiles of the springtime mean and five transport events in the FA are as follows: (1) numerical sensitivity experiments based on simulations conducted with and without aerosols showed that aerosols caused the net downward radiation and the sensible and latent heat fluxes at the surface to decrease. The decrease in temperature in the ABL (-0.2 to -0

Vertical structure of tropospheric winds on gas giants

NASA Astrophysics Data System (ADS)

Scott, R. K.; Dunkerton, T. J.

2017-04-01

Zonal mean zonal velocity profiles from cloud-tracking observations on Jupiter and Saturn are used to infer latitudinal variations of potential temperature consistent with a shear stable potential vorticity distribution. Immediately below the cloud tops, density stratification is weaker on the poleward and stronger on the equatorward flanks of midlatitude jets, while at greater depth the opposite relation holds. Thermal wind balance then yields the associated vertical shears of midlatitude jets in an altitude range bounded above by the cloud tops and bounded below by the level where the latitudinal gradient of static stability changes sign. The inferred vertical shear below the cloud tops is consistent with existing thermal profiling of the upper troposphere. The sense of the associated mean meridional circulation in the upper troposphere is discussed, and expected magnitudes are given based on existing estimates of the radiative timescale on each planet.

Ground-Based Remote or In Situ Measurement of Vertical Profiles of Wind in the Lower Troposphere

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

Clifton, Andrew; Newman, Jennifer

Knowledge of winds in the lower troposphere is essential for a range of applications, including weather forecasting, transportation, natural hazards, and wind energy. This presentation focuses on the measurement of vertical profiles of wind in the lower troposphere for wind energy applications. This presentation introduces the information that wind energy site development and operations require, how it used, and the benefits and problems of current measurements from in-situ measurements and remote sensing. The development of commercial Doppler wind lidar systems over the last 10 years are shown, along with the lessons learned from this experience. Finally, potential developments in windmore » profiling aimed at reducing uncertainty and increasing data availability are introduced.« less

Correction of Electron Density Profiles in the Low Ionosphere Based on the Data of Vertical Sounding with the IRI Model

NASA Astrophysics Data System (ADS)

Denisenko, P. F.; Maltseva, O. A.; Sotsky, V. V.

2018-03-01

The method of correcting the daytime vertical profiles of electron plasma frequency in the low ionosphere from International Refererence Ionosphere (IRI) model in accordance with the measured data of the virtual heights and absorption of signal radiowaves (method A1) reflected from the bottom of E-region at vertical sounding (VS) is presented. The method is based on the replacement of the IRI model profile by an approximation of analytical dependence with parameters determined according to VS data and partially by the IRI model. The method is tested by the results of four joint ground-based and rocket experiments carried out in the 1970s at midlatitudes of the European part of Russia upon the launches of high-altitude geophysical rockets of the Vertical series. It is shown that the consideration of both virtual reflection heigths and absorption makes it possible to obtain electron density distributions that show the best agreement with the rocket measurements made at most height ranges in the D- and E-regions. In additional, the obtained distributions account more adequately than the IRI model for the contributions of D- and E-regions to absorption of signals reflected above these regions.

A Method for Evaluation of Model-Generated Vertical Profiles of Meteorological Variables

DTIC Science & Technology

2016-03-01

3 2.1 RAOB Soundings and WRF Output for Profile Generation 3 2.2 Height-Based Profiles 5 2.3 Pressure-Based Profiles 5 3. Comparisons 8 4...downward arrow. The blue lines represent sublayers with sublayer means indicated by red triangles. Circles indicate the observations or WRF output...9 Table 3 Sample of differences in listed variables derived from WRF and RAOB data

Vertical Gravimeter Array Observations and Their Performance in Groundwater-Level Monitoring

NASA Astrophysics Data System (ADS)

Tanaka, T.; Honda, R.

2018-03-01

The gravitational effects of the atmosphere and subsurface water are significant obstacles to observing gravity variations on the sub-μGal (1 μGal = 10 nm/s2) scale. The goal of this study is to detect changes in gravity that are caused by mass redistributions deep underground related to seismological phenomena by reducing environmental gravity effects using multiple gravimeters belowground and aboveground, which we term a "vertical gravimeter array." Based on an evaluation of the responses to atmospheric effects and rainfall events identified in observations made with individual relative gravimeters, the vertical gravimeter array succeeds in stacking the target signals from deep underground and in reducing errors due to rainfall or free groundwater and atmospheric effects. To enable accurate interpretation, we introduce a physical approach that is based on attraction and loading deformation effects for atmospheric reduction using state-of-the-art gridded weather data products. Changes in the water levels of confined groundwater can be regarded as a signal from deep underground, and a response coefficient of approximately -15 μGal/m was obtained. In addition, the response coefficient of the free groundwater level was determined to be approximately 5 μGal/m. Such array observations are expected to contribute to monitoring crustal activity and hydrological studies.

Vertical profiles of the 3-D wind velocity retrieved from multiple wind lidars performing triple range-height-indicator scans

DOE PAGES

Debnath, Mithu; Iungo, G. Valerio; Ashton, Ryan; ...

2017-02-06

Vertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved withmore » good accuracy. Furthermore, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.« less

Mitigating the negative impacts of tall wind turbines on bats: Vertical activity profiles and relationships to wind speed

PubMed Central

Nusslé, Sébastien; Miltner, Daniela; Kohle, Oliver; Glaizot, Olivier; Braunisch, Veronika; Obrist, Martin K.; Arlettaz, Raphaël

2018-01-01

Wind turbines represent a source of hazard for bats, especially through collision with rotor blades. With increasing technical development, tall turbines (rotor-swept zone 50–150 m above ground level) are becoming widespread, yet we lack quantitative information about species active at these heights, which impedes proposing targeted mitigation recommendations for bat-friendly turbine operation. We investigated vertical activity profiles of a bat assemblage, and their relationships to wind speed, within a major valley of the European Alps where tall wind turbines are being deployed. To monitor bat activity we installed automatic recorders at sequentially increasing heights from ground level up to 65 m, with the goal to determine species-specific vertical activity profiles and to link them to wind speed. Bat call sequences were analysed with an automatic algorithm, paying particular attention to mouse-eared bats (Myotis myotis and Myotis blythii) and the European free-tailed bat (Tadarida teniotis), three locally rare species. The most often recorded bats were the Common pipistrelle (Pipistrellus pipistrellus) and Savi’s pipistrelle (Hypsugo savii). Mouse-eared bats were rarely recorded, and mostly just above ground, appearing out of risk of collision. T. teniotis had a more evenly distributed vertical activity profile, often being active at rotor level, but its activity at that height ceased above 5 ms-1 wind speed. Overall bat activity in the rotor-swept zone declined with increasing wind speed, dropping below 5% above 5.4 ms-1. Collision risk could be drastically reduced if nocturnal operation of tall wind turbines would be restricted to wind speeds above 5 ms-1. Such measure should be implemented year-round because T. teniotis remains active in winter. This operational restriction is likely to cause only small energy production losses at these tall wind turbines, although further analyses are needed to assess these losses precisely. PMID:29561851

Mitigating the negative impacts of tall wind turbines on bats: Vertical activity profiles and relationships to wind speed.

PubMed

Wellig, Sascha D; Nusslé, Sébastien; Miltner, Daniela; Kohle, Oliver; Glaizot, Olivier; Braunisch, Veronika; Obrist, Martin K; Arlettaz, Raphaël

2018-01-01

Wind turbines represent a source of hazard for bats, especially through collision with rotor blades. With increasing technical development, tall turbines (rotor-swept zone 50-150 m above ground level) are becoming widespread, yet we lack quantitative information about species active at these heights, which impedes proposing targeted mitigation recommendations for bat-friendly turbine operation. We investigated vertical activity profiles of a bat assemblage, and their relationships to wind speed, within a major valley of the European Alps where tall wind turbines are being deployed. To monitor bat activity we installed automatic recorders at sequentially increasing heights from ground level up to 65 m, with the goal to determine species-specific vertical activity profiles and to link them to wind speed. Bat call sequences were analysed with an automatic algorithm, paying particular attention to mouse-eared bats (Myotis myotis and Myotis blythii) and the European free-tailed bat (Tadarida teniotis), three locally rare species. The most often recorded bats were the Common pipistrelle (Pipistrellus pipistrellus) and Savi's pipistrelle (Hypsugo savii). Mouse-eared bats were rarely recorded, and mostly just above ground, appearing out of risk of collision. T. teniotis had a more evenly distributed vertical activity profile, often being active at rotor level, but its activity at that height ceased above 5 ms-1 wind speed. Overall bat activity in the rotor-swept zone declined with increasing wind speed, dropping below 5% above 5.4 ms-1. Collision risk could be drastically reduced if nocturnal operation of tall wind turbines would be restricted to wind speeds above 5 ms-1. Such measure should be implemented year-round because T. teniotis remains active in winter. This operational restriction is likely to cause only small energy production losses at these tall wind turbines, although further analyses are needed to assess these losses precisely.

Vertical Distribution of Black and Brown Carbon over Shanghai during Winter

NASA Astrophysics Data System (ADS)

Zheng, M.; Yan, C.; Wang, D.; Fu, Q.

2016-12-01

Carbonaceous aerosols (i.e., black carbon, BC, and organic aerosol, OA) have significant impact on Earth's energy budget by scattering and absorbing solar radiation. Extensive carbonaceous aerosols have been emitted in mainland China. It is essential to study the column burden of carbonaceous aerosol and associated light absorption to better understand its radiative forcing. In this study, a tethered balloon-based field campaign was conducted over a Chinese megacity, Shanghai, in December of 2015, with the primary goal to investigate the vertical profile of air pollutants within the lower troposphere, especially during the polluted days. A 7-wavelength Aethalometer (AE-31) were adopted in the observation to obtain vertical profiles of atmospheric carbonaceous aerosols within the lower troposphere. Light absorption by black and brown carbon, the light absorbing organic components, were distinguished and separated based on difference between light absorption at 450 nm versus 880 nm. Light absorption of brown carbon relative to black carbon were also estimated to pose the importance of brown carbon. Besides, diurnal variation of black and brown carbon vertical profiles would also be discussed, with consideration of variation of height of planetary boundary layer.

Vertical Moist Thermodynamic Structure and Spatial-Temporal Evolution of the MJO in AIRS Observations

NASA Technical Reports Server (NTRS)

Tian, Baijun; Waliser, Duane E.; Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Yung, Yuk L.; Wang, Bin

2006-01-01

The atmospheric moisture and temperature profiles from the Atmospheric Infrared Sounder (AIRS)/Advanced Microwave Sounding Unit on the NASA Aqua mission, in combination with the precipitation from the Tropical Rainfall Measuring Mission (TRMM), are employed to study the vertical moist thermodynamic structure and spatial-temporal evolution of the Madden-Julian oscillation (MJO). The AIRS data indicate that, in the Indian Ocean and western Pacific, the temperature anomaly exhibits a trimodal vertical structure: a warm (cold) anomaly in the free troposphere (800-250 hPa) and a cold (warm) anomaly near the tropopause (above 250 hPa) and in the lower troposphere (below 800 hPa) associated with enhanced (suppressed) convection. The AIRS moisture anomaly also shows markedly different vertical structures as a function of longitude and the strength of convection anomaly. Most significantly, the AIRS data demonstrate that, over the Indian Ocean and western Pacific, the enhanced (suppressed) convection is generally preceded in both time and space by a low-level warm and moist (cold and dry) anomaly and followed by a low-level cold and dry (warm and moist) anomaly. The MJO vertical moist thermodynamic structure from the AIRS data is in general agreement, particularly in the free troposphere, with previous studies based on global reanalysis and limited radiosonde data. However, major differences in the lower-troposphere moisture and temperature structure between the AIRS observations and the NCEP reanalysis are found over the Indian and Pacific Oceans, where there are very few conventional data to constrain the reanalysis. Specifically, the anomalous lower-troposphere temperature structure is much less well defined in NCEP than in AIRS for the western Pacific, and even has the opposite sign anomalies compared to AIRS relative to the wet/dry phase of the MJO in the Indian Ocean. Moreover, there are well-defined eastward-tilting variations of moisture with height in AIRS over the

Measuring large-scale vertical motion in the atmosphere with dropsondes

NASA Astrophysics Data System (ADS)

Bony, Sandrine; Stevens, Bjorn

2017-04-01

Large-scale vertical velocity modulates important processes in the atmosphere, including the formation of clouds, and constitutes a key component of the large-scale forcing of Single-Column Model simulations and Large-Eddy Simulations. Its measurement has also been a long-standing challenge for observationalists. We will show that it is possible to measure the vertical profile of large-scale wind divergence and vertical velocity from aircraft by using dropsondes. This methodology was tested in August 2016 during the NARVAL2 campaign in the lower Atlantic trades. Results will be shown for several research flights, the robustness and the uncertainty of measurements will be assessed, ands observational estimates will be compared with data from high-resolution numerical forecasts.

Sulfur dioxide in the Venus atmosphere: I. Vertical distribution and variability

NASA Astrophysics Data System (ADS)

Vandaele, A. C.; Korablev, O.; Belyaev, D.; Chamberlain, S.; Evdokimova, D.; Encrenaz, Th.; Esposito, L.; Jessup, K. L.; Lefèvre, F.; Limaye, S.; Mahieux, A.; Marcq, E.; Mills, F. P.; Montmessin, F.; Parkinson, C. D.; Robert, S.; Roman, T.; Sandor, B.; Stolzenbach, A.; Wilson, C.; Wilquet, V.

2017-10-01

Recent observations of sulfur containing species (SO2, SO, OCS, and H2SO4) in Venus' mesosphere have generated controversy and great interest in the scientific community. These observations revealed unexpected spatial patterns and spatial/temporal variability that have not been satisfactorily explained by models. Sulfur oxide chemistry on Venus is closely linked to the global-scale cloud and haze layers, which are composed primarily of concentrated sulfuric acid. Sulfur oxide observations provide therefore important insight into the on-going chemical evolution of Venus' atmosphere, atmospheric dynamics, and possible volcanism. This paper is the first of a series of two investigating the SO2 and SO variability in the Venus atmosphere. This first part of the study will focus on the vertical distribution of SO2, considering mostly observations performed by instruments and techniques providing accurate vertical information. This comprises instruments in space (SPICAV/SOIR suite on board Venus Express) and Earth-based instruments (JCMT). The most noticeable feature of the vertical profile of the SO2 abundance in the Venus atmosphere is the presence of an inversion layer located at about 70-75 km, with VMRs increasing above. The observations presented in this compilation indicate that at least one other significant sulfur reservoir (in addition to SO2 and SO) must be present throughout the 70-100 km altitude region to explain the inversion in the SO2 vertical profile. No photochemical model has an explanation for this behaviour. GCM modelling indicates that dynamics may play an important role in generating an inflection point at 75 km altitude but does not provide a definitive explanation of the source of the inflection at all local times or latitudes The current study has been carried out within the frame of the International Space Science Institute (ISSI) International Team entitled 'SO2 variability in the Venus atmosphere'.

Modeling the MJO rain rates using parameterized large scale dynamics: vertical structure, radiation, and horizontal advection of dry air

NASA Astrophysics Data System (ADS)

Wang, S.; Sobel, A. H.; Nie, J.

2015-12-01

Two Madden Julian Oscillation (MJO) events were observed during October and November 2011 in the equatorial Indian Ocean during the DYNAMO field campaign. Precipitation rates and large-scale vertical motion profiles derived from the DYNAMO northern sounding array are simulated in a small-domain cloud-resolving model using parameterized large-scale dynamics. Three parameterizations of large-scale dynamics --- the conventional weak temperature gradient (WTG) approximation, vertical mode based spectral WTG (SWTG), and damped gravity wave coupling (DGW) --- are employed. The target temperature profiles and radiative heating rates are taken from a control simulation in which the large-scale vertical motion is imposed (rather than directly from observations), and the model itself is significantly modified from that used in previous work. These methodological changes lead to significant improvement in the results.Simulations using all three methods, with imposed time -dependent radiation and horizontal moisture advection, capture the time variations in precipitation associated with the two MJO events well. The three methods produce significant differences in the large-scale vertical motion profile, however. WTG produces the most top-heavy and noisy profiles, while DGW's is smoother with a peak in midlevels. SWTG produces a smooth profile, somewhere between WTG and DGW, and in better agreement with observations than either of the others. Numerical experiments without horizontal advection of moisture suggest that that process significantly reduces the precipitation and suppresses the top-heaviness of large-scale vertical motion during the MJO active phases, while experiments in which the effect of cloud on radiation are disabled indicate that cloud-radiative interaction significantly amplifies the MJO. Experiments in which interactive radiation is used produce poorer agreement with observation than those with imposed time-varying radiative heating. Our results highlight the

A model for the vertical sound speed and absorption profiles in Titan's atmosphere based on Cassini-Huygens data.

PubMed

Petculescu, Andi; Achi, Peter

2012-05-01

Measurements of thermodynamic quantities in Titan's atmosphere during the descent of Huygens in 2005 are used to predict the vertical profiles for the speed and intrinsic attenuation (or absorption) of sound. The calculations are done using one author's previous model modified to accommodate non-ideal equations of state. The vertical temperature profile places the tropopause about 40 km above the surface. In the model, a binary nitrogen-methane composition is assumed for Titan's atmosphere, quantified by the methane fraction measured by the gas chromatograph/mass spectrometer (GCMS) onboard Huygens. To more accurately constrain the acoustic wave number, the variation of thermophysical properties (specific heats, viscosity, and thermal conductivity) with altitude is included via data extracted from the NIST Chemistry WebBook [URL webbook.nist.gov, National Institute of Standards and Technology Chemistry WebBook (Last accessed 10/20/2011)]. The predicted speed of sound profile fits well inside the spread of the data recorded by Huygens' active acoustic sensor. In the N(2)-dominated atmosphere, the sound waves have negligible relaxational dispersion and mostly classical (thermo-viscous) absorption. The cold and dense environment of Titan can sustain acoustic waves over large distances with relatively small transmission losses, as evidenced by the small absorption. A ray-tracing program is used to assess the bounds imposed by the zonal wind-measured by the Doppler Wind Experiment on Huygens-on long-range propagation.

Profiler Support for Operations at Space Launch Ranges

NASA Technical Reports Server (NTRS)

Merceret, Francis; Wilfong, Timothy; Lambert, Winifred; Short, David; Decker, Ryan; Ward, Jennifer

2006-01-01

Accurate vertical wind profiles are essential to successful launch or landing. Wind changes can make it impossible to fly a desired trajectory or avoid dangerous vehicle loads, possibly resulting in loss of mission. Balloons take an hour to generate a profile up to 20 km, but major wind changes can occur in 20 minutes. Wind profilers have the temporal response to detect such last minute hazards. They also measure the winds directly overhead while balloons blow downwind. At the Eastern Range (ER), altitudes from 2 to 20 km are sampled by a 50-MHz profiler every 4 minutes. The surface to 3 km is sampled by five 915-MHz profilers every 15 minutes. The Range Safety office assesses the risk of potential toxic chemical dispersion. They use observational data and model output to estimate the spatial extent and concentration of substances dispersed within the boundary layer. The ER uses 915-MHz profilers as both a real time observation system and as input to dispersion models. The WR has similar plans. Wind profilers support engineering analyses for the Space Shuttle. The 50-IVl11z profiler was used recently to analyze changes in the low frequency wind and low vertical wavenumber content of wind profiles in the 3 to 15 km region of the atmosphere. The 915-MHz profiler network was used to study temporal wind change within the boundary layer.

Airborne in situ vertical profiling of HDO / H216O in the subtropical troposphere during the MUSICA remote sensing validation campaign

NASA Astrophysics Data System (ADS)

Dyroff, C.; Sanati, S.; Christner, E.; Zahn, A.; Balzer, M.; Bouquet, H.; McManus, J. B.; Gonzalez-Ramos, Y.; Schneider, M.

2015-05-01

Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as δD(H2O) were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Δ(δD) ≈10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote sensing measurements of δD(H2O) as a means to validate the remote sensing humidity and δD(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δD(H2O) correlations we were able to identify different layers of air masses with specific isotopic signatures. The results are discussed.

Airborne in situ vertical profiling of HDO/H216O in the subtropical troposphere during the MUSICA remote sensing validation campaign

NASA Astrophysics Data System (ADS)

Dyroff, C.; Sanati, S.; Christner, E.; Zahn, A.; Balzer, M.; Bouquet, H.; McManus, J. B.; González-Ramos, Y.; Schneider, M.

2015-01-01

Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as δ D(H2O were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Δ(δ D) ≈ 10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote-sensing measurements of δ D(H2O) as a means to validate the remote sensing humidity and δ D(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δ D(H2O) correlations we were able to identify different layers of airmasses with specific isotopic signatures. The results are discussed.

Vertical profile of H 2SO 4 vapor at 70-110 km on Venus and some related problems

NASA Astrophysics Data System (ADS)

Krasnopolsky, Vladimir A.

2011-09-01

The vertical profile of H 2SO 4 vapor is calculated using current atmospheric and thermodynamic data. The atmospheric data include the H 2O profiles observed at 70-112 km by the SOIR solar occultations, the SPICAV-UV profiles of the haze extinction at 220 nm, the VeRa temperature profiles, and a typical profile of eddy diffusion. The thermodynamic data are the saturated vapor pressures of H 2O and H 2SO 4 and chemical potentials of these species in sulfuric acid solutions. The calculated concentration of sulfuric acid in the cloud droplets varies from 85% at 70 km to a minimum of 70% at 90 km and then gradually increasing to 90-100% at 110 km. The H 2SO 4 vapor mixing ratio is ˜10 -12 at 70 and 110 km with a deep minimum of 3 × 10 -18 at 88 km. The H 2O-H 2SO 4 system matches the local thermodynamic equilibrium conditions up to 87 km. The column photolysis rate of H 2SO 4 is 1.6 × 10 5 cm -2 s -1 at 70 km and 23 cm -2 s -1 at 90 km. The calculated abundance of H 2SO 4 vapor at 90-110 km and its photolysis rate are smaller than those presented in the recent model by Zhang et al. (Zhang, X., Liang, M.C., Montmessin, F., Bertaux, J.L., Parkinson, C., Yung, Y.L. [2010]. Nat. Geosci. 3, 834-837) by factors of 10 6 and 10 9, respectively. Assumptions of 100% sulfuric acid, local thermodynamic equilibrium, too warm atmosphere, supersaturation of H 2SO 4 (impossible for a source of SO X), and cross sections for H 2SO 4·H 2O (impossible above the pure H 2SO 4) are the main reasons of this huge difference. Significant differences and contradictions between the SPICAV-UV, SOIR, and ground-based submillimeter observations of SO X at 70-110 km are briefly discussed and some weaknesses are outlined. The possible source of high altitude SO X on Venus remains unclear and probably does not exist.

OPTIM: Computer program to generate a vertical profile which minimizes aircraft fuel burn or direct operating cost. User's guide

NASA Technical Reports Server (NTRS)

1983-01-01

A profile of altitude, airspeed, and flight path angle as a function of range between a given set of origin and destination points for particular models of transport aircraft provided by NASA is generated. Inputs to the program include the vertical wind profile, the aircraft takeoff weight, the costs of time and fuel, certain constraint parameters and control flags. The profile can be near optimum in the sense of minimizing: (1) fuel, (2) time, or (3) a combination of fuel and time (direct operating cost (DOC)). The user can also, as an option, specify the length of time the flight is to span. The theory behind the technical details of this program is also presented.

Light hydrocarbons vertical profiles and fluxes in a french rural area

NASA Astrophysics Data System (ADS)

Kanakidou, M.; Bonsang, B.; Lambert, G.

By means of manned hot air balloon flights, in July 1986, an experiment was conducted in a rural area of southwest France in order to determine the production at ground level of non-methane hydrocarbons in the C 2-C 6 range. Flux determinations were based on vertical profiles before and after the development of a temperature inversion layer which allowed the measurement of the NMHC accumulation close to ground level. The main species produced in the late afternoon were acetylene, propane, ethene, propene and ethane with production rates of the order of 0.5 to 2 × 10 -4g of C m -2 h -1. Isoprene was found to be the main other unsaturated species also produced. The fluxes and the atmospheric content of the air column before the inversion are consistent with an average OH radical concentration of 2 × 10 6 cm -3.

Tethered balloon-based particle number concentration, and size distribution vertical profiles within the lower troposphere of Shanghai

NASA Astrophysics Data System (ADS)

Zhang, Kun; Wang, Dongfang; Bian, Qinggen; Duan, Yusen; Zhao, Mengfei; Fei, Dongnian; Xiu, Guangli; Fu, Qingyan

2017-04-01

A tethered balloon-based measurement campaign of particle number concentration (PNC) and particle number size distribution (PNSD) in the size range of 15.7-661.2 nm was conducted within the lower troposphere of 1000 m in Shanghai, a Chinese megacity, during December of 2015. The meteorological conditions, PNC, and PNSD were synchronously measured at the ground-based station as well as by the tethered balloon. On ground level, the 88.2 nm particles were found to have the highest PNC. The Pearson correlation analysis based on the ground level data showed NO2 had a strong correlation with PNC. The synchronous measurement of PNC and PNSD at the ground station and on the tethered balloon showed that the 15.7-200 nm particles had higher PNC on ground level, but the PNC of 200-661.2 nm particles was higher at 400 m. One haze event (Dec 22nd-Dec 23rd) was selected for detailed discussion on the variation of vertical profiles of PNSD and PNC. The vertical distribution of characteristics of PNC and PNSD were observed and compared. Results indicated that the highest MaxDm (the diameter with the highest PNC) during those three launches all appeared at a high altitude, usually above 300 m. Compared to the clean days, the relatively bigger MaxDm at each height in the haze days also indicated regional transport of pollutants might contribute to more to that haze event.

Surface influence upon vertical profiles in the nocturnal boundary layer

NASA Astrophysics Data System (ADS)

Garratt, J. R.

1983-05-01

Near-surface wind profiles in the nocturnal boundary layer, depth h, above relatively flat, tree-covered terrain are described in the context of the analysis of Garratt (1980) for the unstable atmospheric boundary layer. The observations at two sites imply a surface-based transition layer, of depth z *, within which the observed non-dimensional profiles Φ M 0 are a modified form of the inertial sub-layer relation Φ _M ( {{z L}} = ( {{{1 + 5_Z } L}} ) according to Φ _M^{{0}} ˜eq ( {{{1 + 5z} L}} )exp [ { - 0.7( {{{1 - z} z}_ * } )] , where z is height above the zero-plane displacement and L is the Monin-Obukhov length. At both sites the depth z * is significantly smaller than the appropriate neutral value ( z * N ) found from the previous analysis, as might be expected in the presence of a buoyant sink for turbulent kinetic energy.

The vertical structure of the F ring of Saturn from ring-plane crossings

NASA Astrophysics Data System (ADS)

Scharringhausen, Britt R.; Nicholson, Philip D.

2013-11-01

We present a photometric model of the rings of Saturn which includes the main rings and an F ring, inclined to the main rings, with a Gaussian vertical profile of optical depth. This model reproduces the asymmetry in brightness between the east and west ansae of the rings of Saturn that was observed by the Hubble Space Telescope (HST) within a few hours after the Earth ring-plane crossing (RPX) of 10 August 1995. The model shows that during this observation the inclined F ring unevenly blocked the east and west ansae of the main rings. The brightness asymmetry produced by the model is highly sensitive to the vertical thickness and radial optical depth of the F ring. The F-ring model that best matches the observations has a vertical full width at half maximum of 13 ± 7 km and an equivalent depth of 10 ± 4 km. The model also reproduces the shape of the HST profiles of ring brightness vs. distance from Saturn, both before and after the time of ring-plane crossing. Smaller asymmetries observed before the RPX, when the Earth was on the dark side of the rings, cannot be explained by blocking of the main rings by the F ring or vice versa and are probably instead due to the intrinsic longitudinal variation exhibited by the F ring.

Vertical Profiles of Phosphine and Ammonia on Saturn Derived from the First Cassini RSS Occultation Observation Using Forward Modeling

NASA Astrophysics Data System (ADS)

Mohammed, P. N.; Steffes, P. G.; Kliore, A. J.; Anabtawi, A.; Asmar, S. W.; Barbinis, E.; Goltz, G.; Johnston, D.; Marouf, E. A.

2005-08-01

The results from the first Cassini Radio Science Subsystem(RSS) occultation, which occurred at the Rev 7 periapse, are being used to derive profiles of the atmospheric constituents encountered by the three frequency (S-, X-, and Ka-band) radio link. A computer model has been developed to simulate ray paths and the ray path parameters in the atmosphere of Saturn encountered during occultation (see Mohammed and Steffes, Bull. Amer. Astron. Soc., 36, no. 4, 1107, 2004). This forward model, which can be used on any oblate planet, will be used to determine the refractive defocusing and derive the profiles of phosphine and ammonia using data observed at Ka-band (32 GHz or 9.3 mm), X-band (8.4 GHz or 3.6 cm) and S-band (2.3 GHz or 13 cm). The results of laboratory measurements of the 9 mm opacity of phosphine and ammonia (Mohammed and Steffes, ICARUS 166, 425-435, 2003) and the centimeter wavelength opacity of these constituents measured under simulated conditions for Saturn (see, e.g., Hoffman et. al. ICARUS 152, 172-184, 2001) were incorporated into the forward radio occultation model used in these derivations.

Evaluating vertical concentration profile of carbon source released from slow-releasing carbon source tablets and in situ biological nitrate denitrification activity

NASA Astrophysics Data System (ADS)

Yeum, Y.; HAN, K.; Yoon, J.; Lee, J. H.; Song, K.; Kang, J. H.; Park, C. W.; Kwon, S.; Kim, Y.

2017-12-01

Slow-releasing carbon source tablets were manufactured during the design of a small-scale in situ biological denitrification system to reduce high-strength nitrate (> 30 mg N/L) from a point source such as livestock complexes. Two types of slow-releasing tablets, precipitating tablet (PT, apparent density of 2.0 g/mL) and floating tablet (FT), were prepared to achieve a vertically even distribution of carbon source (CS) in a well and an aquifer. Hydroxypropyl methylcellulose (HPMC) was used to control the release rate, and microcrystalline cellulose pH 101 (MCC 101) was added as a binder. The #8 sand was used as a precipitation agent for the PTs, and the floating agents for the FTs were calcium carbonate and citric acid. FTs floated within 30 min. and remained in water because of the buoyance from carbon dioxide, which formed during the acid-base reaction between citric acid and calcium carbonate. The longevities of PTs with 300 mg of HPMC and FTs with 400 mg of HPMC were 25.4 days and 37.3 days, respectively. We assessed vertical CS profile in a continuous flowing physical aquifer model (release test, RT) and its efficiency on biological nitrate denitrification (denitrification test, DT). During the RT, PTs, FTs and a tracer (as 1 mg rhodamine B/L) were initially injected into a well of physical aquifer model (PAM). Concentrations of CS and the tracer were monitored along the streamline in the PAM to evaluate vertical profile of CS. During the DT, the same experiment was performed as RT, except continuous injection of solution containing 30 mg N/L into the PAM to evaluate biological denitrification activity. As a result of RT, temporal profiles of CS were similar at 3 different depths of monitoring wells. These results suggest that simultaneous addition of PT and FT be suitable for achieving a vertically even distribution of the CS in the injection well and an aquifer. In DT, similar profile of CS was detected in the injection well, and nitrate was biologically

Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories

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

Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien

Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid

Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories

DOE PAGES

Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien; ...

2017-05-16

Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid

From the chlorophyll a in the surface layer to its vertical profile: a Greenland Sea relationship for satellite applications

NASA Astrophysics Data System (ADS)

Cherkasheva, A.; Nöthig, E.-M.; Bauerfeind, E.; Melsheimer, C.; Bracher, A.

2013-04-01

Current estimates of global marine primary production range over a factor of two. Improving these estimates requires an accurate knowledge of the chlorophyll vertical profiles, since they are the basis for most primary production models. At high latitudes, the uncertainty in primary production estimates is larger than globally, because here phytoplankton absorption shows specific characteristics due to the low-light adaptation, and in situ data and ocean colour observations are scarce. To date, studies describing the typical chlorophyll profile based on the chlorophyll in the surface layer have not included the Arctic region, or, if it was included, the dependence of the profile shape on surface concentration was neglected. The goal of our study was to derive and describe the typical Greenland Sea chlorophyll profiles, categorized according to the chlorophyll concentration in the surface layer and further monthly resolved profiles. The Greenland Sea was chosen because it is known to be one of the most productive regions of the Arctic and is among the regions in the Arctic where most chlorophyll field data are available. Our database contained 1199 chlorophyll profiles from R/Vs Polarstern and Maria S. Merian cruises combined with data from the ARCSS-PP database (Arctic primary production in situ database) for the years 1957-2010. The profiles were categorized according to their mean concentration in the surface layer, and then monthly median profiles within each category were calculated. The category with the surface layer chlorophyll (CHL) exceeding 0.7 mg C m-3 showed values gradually decreasing from April to August. A similar seasonal pattern was observed when monthly profiles were averaged over all the surface CHL concentrations. The maxima of all chlorophyll profiles moved from the greater depths to the surface from spring to late summer respectively. The profiles with the smallest surface values always showed a subsurface chlorophyll maximum with its median

Seasonal ozone vertical profiles over North America using the AQMEII group of air quality models: model inter-comparison and stratospheric intrusion

EPA Science Inventory

This study utilizes simulations for the North American domain from four modeling groups that participated in the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) to evaluate seasonal ozone vertical profiles simulated for the year 2010 against ozo...

Measurements of Vertical Profiles of Turbulence, Temperature, Ozone, Aerosols, and BrO over Sea Ice and Tundra Snowpack during BROMEX

NASA Astrophysics Data System (ADS)

Shepson, P.; Caulton, D.; Cambaliza, M. L.; Dhaniyala, S.; Fuentes, J. D.; General, S.; Halfacre, J. W.; Nghiem, S. V.; Perez Perez, L.; Peterson, P. K.; Platt, U.; Pohler, D.; Pratt, K. A.; Simpson, W. R.; Stirm, B.; Walsh, S. J.; Zielcke, J.

2012-12-01

During the BROMEX field campaign of March 2012, we conducted measurements of boundary layer structure, ozone, BrO and aerosol, from a light, twin-engine aircraft during eleven flights originating from Barrow, AK. Flights were conducted over the sea ice in the Beaufort and Chukchi Seas, and over the tundra from Barrow to the Brooks Range, with vertical profiles covering altitudes from the surface to 3.5km in the free troposphere. Flights over the course of one month allowed a variety of sea ice conditions, including open water, nilas, first year sea ice, and frost flowers, to be examined over the Chukchi Sea. Atmospheric turbulence was measured using a calibrated turbulence probe, which will enable characterization of both the structure and turbulence of the Arctic boundary layer. Ozone was measured using a 2B UV absorption instrument. A GRIMM optical particle counter was used to measure 0.25-4 μm sized aerosol particles. The MAX-DOAS instrument enabled measurements of BrO vertical profiles. The aircraft measurements can be used to connect the surface measurements of ozone and BrO from the "Icelander" buoys, and the surface sites at Barrow, with those measured on the aircraft. Here we will discuss the spatial variability/coherence in these data. A major question that will be addressed using these data is the extent to which bromine is activated through reactions at the snowpack/ice surface versus the surface of aerosols. Here we will present a preliminary analysis of the relationships between snow/ice surface types, aerosol size-resolved number concentrations, and the vertical profiles of ozone and BrO.

In situ observations of the influence of a large onshore wind farm on near-surface temperature, turbulence intensity and wind speed profiles

NASA Astrophysics Data System (ADS)

Smith, Craig M.; Barthelmie, R. J.; Pryor, S. C.

2013-09-01

Observations of wakes from individual wind turbines and a multi-megawatt wind energy installation in the Midwestern US indicate that directly downstream of a turbine (at a distance of 190 m, or 2.4 rotor diameters (D)), there is a clear impact on wind speed and turbulence intensity (TI) throughout the rotor swept area. However, at a downwind distance of 2.1 km (26 D downstream of the closest wind turbine) the wake of the whole wind farm is not evident. There is no significant reduction of hub-height wind speed or increase in TI especially during daytime. Thus, in high turbulence regimes even very large wind installations may have only a modest impact on downstream flow fields. No impact is observable in daytime vertical potential temperature gradients at downwind distances of >2 km, but at night the presence of the wind farm does significantly decrease the vertical gradients of potential temperature (though the profile remains stably stratified), largely by increasing the temperature at 2 m.

Constraints on Southern Ocean CO2 Fluxes and Seasonality from Atmospheric Vertical Gradients Observed on Multiple Airborne Campaigns

NASA Astrophysics Data System (ADS)

McKain, K.; Sweeney, C.; Stephens, B. B.; Long, M. C.; Jacobson, A. R.; Basu, S.; Chatterjee, A.; Weir, B.; Wofsy, S. C.; Atlas, E. L.; Blake, D. R.; Montzka, S. A.; Stern, R.

2017-12-01

The Southern Ocean plays an important role in the global carbon cycle and climate system, but net CO2 flux into the Southern Ocean is difficult to measure and model because it results from large opposing and seasonally-varying fluxes due to thermal forcing, biological uptake, and deep-water mixing. We present an analysis to constrain the seasonal cycle of net CO2 exchange with the Southern Ocean, and the magnitude of summer uptake, using the vertical gradients in atmospheric CO2 observed during three aircraft campaigns in the southern polar region. The O2/N2 Ratio and CO2 Airborne Southern Ocean Study (ORCAS) was an airborne campaign that intensively sampled the atmosphere at 0-13 km altitude and 45-75 degrees south latitude in the austral summer (January-February) of 2016. The global airborne campaigns, the HIAPER Pole-to-Pole Observations (HIPPO) study and the Atmospheric Tomography Mission (ATom), provide additional measurements over the Southern Ocean from other seasons and multiple years (2009-2011, 2016-2017). Derivation of fluxes from measured vertical gradients requires robust estimates of the residence time of air in the polar tropospheric domain, and of the contribution of long-range transport from northern latitudes outside the domain to the CO2 gradient. We use diverse independent approaches to estimate both terms, including simulations using multiple transport and flux models, and observed gradients of shorter-lived tracers with specific sources regions and well-known loss processes. This study demonstrates the utility of aircraft profile measurements for constraining large-scale air-sea fluxes for the Southern Ocean, in contrast to those derived from the extrapolation of sparse ocean and atmospheric measurements and uncertain flux parameterizations.

A new MesosphEO dataset of temperature profiles from 35 to 85 km using Rayleigh scattering at limb from GOMOS/ENVISAT daytime observations

NASA Astrophysics Data System (ADS)

Hauchecorne, A.; Blanot, L.; Wing, R., Jr.; Keckhut, P.; Khaykin, S. M.

2017-12-01

The scattering of sunlight by the Earth atmosphere above the top of the stratospheric layer, about 30-35 km altitude, is only due to Rayleigh scattering by atmospheric molecules. Its intensity is then directly proportional to the atmospheric density. It is then possible to retrieve a temperature profile in absolute value using the hydrostatic equation and the perfect gas law, assuming that the temperature is known from a climatological model at the top of the density profile. This technique is applied to Rayleigh lidar observations since more than 35 years (Hauchecorne and Chanin, 1980). The GOMOS star occultation spectrometer observed the sunlight scattering at limb during daytime to remove it from the star spectrum. In the frame of the ESA funded MesosphEO project, GOMOS Rayleigh scattering profiles in the spectral range 400-460 nm have been used to retrieve temperature profiles from 35 to 85 km with a 2-km vertical resolution. A dataset of more than 310 thousands profiles from 2002 to 2012 is available for climatology and atmospheric dynamics studies. The validation of this dataset using NDACC Rayleigh lidars and MLS-AURA and SABER-TIMED will be presented. Preliminary results on the variability of the upper stratosphere and the mesosphere will be shown. We propose to apply this technique in the future to ALTIUS observations. The Rayleigh scattering technique can be applied to any sounder observing the day-time limb on the near-UV and visible spectrum.

Observing relationships between lightning and cloud profiles by means of a satellite-borne cloud radar

NASA Astrophysics Data System (ADS)

Buiat, Martina; Porcù, Federico; Dietrich, Stefano

2017-01-01

Cloud electrification and related lightning activity in thunderstorms have their origin in the charge separation and resulting distribution of charged iced particles within the cloud. So far, the ice distribution within convective clouds has been investigated mainly by means of ground-based meteorological radars. In this paper we show how the products from Cloud Profiling Radar (CPR) on board CloudSat, a polar satellite of NASA's Earth System Science Pathfinder (ESSP), can be used to obtain information from space on the vertical distribution of ice particles and ice content and relate them to the lightning activity. The analysis has been carried out, focusing on 12 convective events over Italy that crossed CloudSat overpasses during significant lightning activity. The CPR products considered here are the vertical profiles of cloud ice water content (IWC) and the effective radius (ER) of ice particles, which are compared with the number of strokes as measured by a ground lightning network (LINET). Results show a strong correlation between the number of strokes and the vertical distribution of ice particles as depicted by the 94 GHz CPR products: in particular, cloud upper and middle levels, high IWC content and relatively high ER seem to be favourable contributory causes for CG (cloud to ground) stroke occurrence.

Vertical distributions of fluorescent aerosol over the Eastern U.S.

NASA Astrophysics Data System (ADS)

Perring, A. E.; Robinson, E. S.; Schwarz, J. P.; Gao, R. S.

2016-12-01

The prevalence of bioaerosol in the atmosphere is relevant to atmospheric chemistry, microbial ecology and climate. These particles can act as effective cloud condensation nuclei (CCN) and ice nuclei (IN), representing a potential feedback between vegetation and precipitation. As bioaerosol frequently account for a substantial fraction of coarse mode aerosol in the boundary layer, they may have significant impacts on mixed-phase and/or cirrus cloud formation and climate. Very few measurements are available, however, to constrain loadings of bioaerosol in the free troposphere. Here we present vertical profiles of fluorescent aerosol concentration as a proxy for bioaerosol. The data were obtained over the eastern U.S. during the summer of 2016 using a Wide Band Integrated Bioaerosol Sensor (WIBS) installed aboard a NOAA Twin Otter research aircraft. The airspeed and inlet configuration were chosen to permit efficient sampling of aerosol with diameters of up to 10 μm. Vertical profiles extend from 1000 to 17,500 feet AGL, spanning a temperature range relevant to ice formation. 100 hours of data cover a latitude range from 30N to 46N and target a variety of potential bioaerosol source regions including forests, croplands, the Gulf of Mexico, and Lake Michigan. Observed vertical profiles are compared to expected loadings based on current model parameterizations and implications are discussed.

High resolution humidity, temperature and aerosol profiling with MeteoSwiss Raman lidar

NASA Astrophysics Data System (ADS)

Dinoev, Todor; Arshinov, Yuri; Bobrovnikov, Sergei; Serikov, Ilya; Calpini, Bertrand; van den Bergh, Hubert; Parlange, Marc B.; Simeonov, Valentin

2010-05-01

Meteorological services rely, in part, on numerical weather prediction (NWP). Twice a day radiosonde observations of water vapor provide the required data for assimilation but this time resolution is insufficient to resolve certain meteorological phenomena. High time resolution temperature profiles from microwave radiometers are available as well but have rather low vertical resolution. The Raman LIDARs are able to provide temperature and humidity profiles with high time and range resolution, suitable for NWP model assimilation and validation. They are as well indispensible tools for continuous aerosol profiling for high resolution atmospheric boundary layer studies. To improve the database available for direct meteorological applications the Swiss meteo-service (MeteoSwiss), the Swiss Federal Institute of Technology in Lausanne (EPFL) and the Swiss National Science Foundation (SNSF) initiated a project to design and build an automated Raman lidar for day and night vertical profiling of tropospheric water vapor with the possibility to further upgrade it with an aerosol and temperature channels. The project was initiated in 2004 and RALMO (Raman Lidar for meteorological observations) was inaugurated in August 2008 at MeteoSwiss aerological station at Payerne. RALMO is currently operational and continuously profiles water vapor mixing ratio, aerosol backscatter ratio and aerosol extinction. The instrument is a fully automated, self-contained, eye-safe Raman lidar operated at 355 nm. Narrow field-of-view multi-telescope receiver and narrow band detection allow day and night-time vertical profiling of the atmospheric humidity. The rotational-vibrational Raman lidar responses from water vapor and nitrogen are spectrally separated by a high-throughput fiber coupled diffraction grating polychromator. The elastic backscatter and pure-rotational Raman lidar responses (PRR) from oxygen and nitrogen are spectrally isolated by a double grating polychromator and are used to

Sampling the Vertical Moisture Structure of an Atmospheric River Event Using Airborne GPS Radio Occultation Profiling

NASA Astrophysics Data System (ADS)

Haase, J. S.; Malloy, K.; Murphy, B.; Sussman, J.; Zhang, W.

2015-12-01

Atmospheric rivers (ARs) are of high concern in California, bringing significant rain to the region over extended time periods of up to 5 days, potentially causing floods, and more importantly, contributing to the Sierra snowpack that provides much of the regional water resources. The CalWater project focuses on predicting the variability of the West Coast water supply, including improving AR forecasting. Unfortunately, data collection over the ocean remains a challenge and impacts forecasting accuracy. One novel technique to address this issue includes airborne GPS radio occultation (ARO), using broadcast GPS signals from space to measure the signal ray path bending angle and refractivity to retrieve vertical water vapor profiles. The Global Navigation Satellite System Instrument System for Multistatic and Occultation Sensing (GISMOS) system was developed for this purpose for recording and processing high-sample rate (10MHz) signals in the lower troposphere. Previous studies (Murphy et al, 2014) have shown promising results in acquiring airborne GPS RO data, comparing it to dropsondes and numerical weather models. CalWater launched a field campaign in the beginning of 2015 which included testing GISMOS ARO on the NOAA GIV aircraft for AR data acquisition, flying into the February 6th AR event that brought up to 35 cm of rain to central California. This case study will compare airborne GPS RO refractivity profiles to the NCEP-NCAR final reanalysis model and dropsonde profiles. We will show the data distribution and explain the sampling characteristics, providing high resolution vertical information to the sides of the aircraft in a manner complementary to dropsondes beneath the flight track. We will show how this method can provide additional reliable data during the development of AR storms.

Experimental observation of the influence of furnace temperature profile on convection and segregation in the vertical Bridgman crystal growth technique

NASA Technical Reports Server (NTRS)

Neugebauer, G. T.; Wilcox, William R.

1992-01-01

Azulene-doped naphthalene was directionally solidified during the vertical Bridgman-Stockbarger technique. Doping homogeneity and convection were determined as a function of the temperature profile in the furnace and the freezing rate. Convection velocities were two orders of magnitude lower when the temperature increased with height. Rarely was the convection pattern axisymmetric, even though the temperature varied less than 0.1 K around the circumference of the growth ampoule. Correspondingly the cross sectional variation in azulene concentration tended to be asymmetric, especially when the temperature increased with height. This cross sectional variation changed dramatically along the ingot, reflecting changes in convection presumably due to the decreasing height of the melt. Although there was large scatter and irreproducibility in the cross sectional variation in doping, this variation tended to be least when the growth rate was low and the convection was vigorous. It is expected that compositional variations would also be small at high growth rates with weak convection and flat interfaces, although this was not investigated in the present experiments. Neither rotation of the ampoule nor deliberate introduction of thermal asymmetries during solidification had a significant influence on cross sectional variations in doping. It is predicted that slow directional solidification under microgravity conditions could produce greater inhomogeneities than on Earth. Combined use of microgravity and magnetic fields would be required to achieve homogeneity when it is necessary to freeze slowly in order to avoid constitutional supercooling.

A comparison of selected vertical wind measurement techniques on basis of the EUCAARI IMPACT observations

NASA Astrophysics Data System (ADS)

Arabas, S.; Baehr, C.; Boquet, M.; Dufournet, Y.; Pawlowska, H.; Siebert, H.; Unal, C.

2009-04-01

The poster presents a comparison of selected methods for determination of the vertical wind in the boundary layer used during the EUCAARI IMPACT campaign that took place in May 2008 in The Netherlands. The campaign covered a monthlong intensified ground-based and airborne measurements in the vicinity of the CESAR observatory in Cabauw. Ground-based vertical wind remote sensing was carried out using the Leosphere WindCube WLS70 IR Doppler lidar, Vaisala LAP3000 radar wind-profiler and the TUDelft TARA S-band radar. In-situ airborne measurements were performed using an ultrasonic anemometer (on the ACTOS helicopter underhung platform) and a 5-hole pressure probe (on the SAFIRE ATR-42 airplane radome). Several in-situ anemometers were deployed on the 200-meter high tower of the CESAR observatory. A summary of the characteristics and principles of the considered techniques is presented. A comparison of the results obtained from different platforms depicts the capabilities of each technique and highlights the time, space and velocity resolutions.

Temperature-profile methods for estimating percolation rates in arid environments

USGS Publications Warehouse

Constantz, Jim; Tyler, Scott W.; Kwicklis, Edward

2003-01-01

Percolation rates are estimated using vertical temperature profiles from sequentially deeper vadose environments, progressing from sediments beneath stream channels, to expansive basin-fill materials, and finally to deep fractured bedrock underlying mountainous terrain. Beneath stream channels, vertical temperature profiles vary over time in response to downward heat transport, which is generally controlled by conductive heat transport during dry periods, or by advective transport during channel infiltration. During periods of stream-channel infiltration, two relatively simple approaches are possible: a heat-pulse technique, or a heat and liquid-water transport simulation code. Focused percolation rates beneath stream channels are examined for perennial, seasonal, and ephemeral channels in central New Mexico, with estimated percolation rates ranging from 100 to 2100 mm d−1 Deep within basin-fill and underlying mountainous terrain, vertical temperature gradients are dominated by the local geothermal gradient, which creates a profile with decreasing temperatures toward the surface. If simplifying assumptions are employed regarding stratigraphy and vapor fluxes, an analytical solution to the heat transport problem can be used to generate temperature profiles at specified percolation rates for comparison to the observed geothermal gradient. Comparisons to an observed temperature profile in the basin-fill sediments beneath Frenchman Flat, Nevada, yielded water fluxes near zero, with absolute values <10 mm yr−1 For the deep vadose environment beneath Yucca Mountain, Nevada, the complexities of stratigraphy and vapor movement are incorporated into a more elaborate heat and water transport model to compare simulated and observed temperature profiles for a pair of deep boreholes. Best matches resulted in a percolation rate near zero for one borehole and 11 mm yr−1 for the second borehole.

Profile of capillary bridges between two vertically stacked cylindrical fibers under gravitational effect

NASA Astrophysics Data System (ADS)

Sun, Xiaohang; Lee, Hoon Joo; Michielsen, Stephen; Wilusz, Eugene

2018-05-01

Although profiles of axisymmetric capillary bridges between two cylindrical fibers have been extensively studied, little research has been reported on capillary bridges under external forces such as the gravitational force. This is because external forces add significant complications to the Laplace-Young equation, making it difficult to predict drop profiles based on analytical approaches. In this paper, simulations of capillary bridges between two vertically stacked cylindrical fibers with gravitational effect taken into consideration are studied. The asymmetrical structure of capillary bridges that are hard to predict based on analytical approaches was studied via a numerical approach based on Surface Evolver (SE). The axial and the circumferential spreading of liquids on two identical fibers in the presence of gravitational effects are predicted to determine when the gravitational effects are significant or can be neglected. The effect of liquid volume, equilibrium contact angle, the distance between two fibers and fiber radii. The simulation results were verified by comparing them with experimental measurements. Based on SE simulations, curves representing the spreading of capillary bridges along the two cylindrical fibers were obtained. The gravitational effect was scaled based on the difference of the spreading on upper and lower fibers.

Estimating snow water equivalent from GPS vertical site-position observations in the western United States

PubMed Central

Ouellette, Karli J; de Linage, Caroline; Famiglietti, James S

2013-01-01

[1] Accurate estimation of the characteristics of the winter snowpack is crucial for prediction of available water supply, flooding, and climate feedbacks. Remote sensing of snow has been most successful for quantifying the spatial extent of the snowpack, although satellite estimation of snow water equivalent (SWE), fractional snow covered area, and snow depth is improving. Here we show that GPS observations of vertical land surface loading reveal seasonal responses of the land surface to the total weight of snow, providing information about the stored SWE. We demonstrate that the seasonal signal in Scripps Orbit and Permanent Array Center (SOPAC) GPS vertical land surface position time series at six locations in the western United States is driven by elastic loading of the crust by the snowpack. GPS observations of land surface deformation are then used to predict the water load as a function of time at each location of interest and compared for validation to nearby Snowpack Telemetry observations of SWE. Estimates of soil moisture are included in the analysis and result in considerable improvement in the prediction of SWE. Citation: Ouellette, K. J., C. de Linage, and J. S. Famiglietti (2013), Estimating snow water equivalent from GPS vertical site-position observations in the western United States, Water Resour. Res., 49, 2508–2518, doi:10.1002/wrcr.20173. PMID:24223442

Ozone Profiles in the Baltimore-Washington Region (2006-2011): Satellite Comparisons and DISCOVER-AQ Observations

NASA Technical Reports Server (NTRS)

Thompson, Anne M.; Stauffer, Ryan M.; Miller, Sonya K.; Martins, Douglas K.; Joseph, Everette; Weinheimer, Andrew J.; Diskin, Glenn S.

2014-01-01

Much progress has been made in creating satellite products for tracking the pollutants ozone and NO2 in the troposphere. Yet, in mid-latitude regions where meteorological interactions with pollutants are complex, accuracy can be difficult to achieve, largely due to persistent layering of some constituents. We characterize the layering of ozone soundings and related species measured from aircraft over two ground sites in suburban Washington, DC (Beltsville, MD, 39.05N; 76.9W) and Baltimore (Edgewood, MD, 39.4N; 76.3W) during the July 2011 DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) experiment. First, we compare column-ozone amounts from the Beltsville and Edgewood sondes with data from overpassing satellites. Second, processes influencing ozone profile structure are analyzed using Laminar Identification and tracers: sonde water vapor, aircraft CO and NOy. Third, Beltsville ozone profiles and meteorological influences in July 2011 are compared to those from the summers of 2006-2010. Sonde-satellite offsets in total ozone during July 2011 at Edgewood and Beltsville, compared to the Ozone Monitoring Instrument (OMI), were 3 percent mean absolute error, not statistically significant. The disagreement between an OMIMicrowave Limb Sounder-based tropospheric ozone column and the sonde averaged 10 percent at both sites, with the sonde usually greater than the satellite. Laminar Identification (LID), that distinguishes ozone segments influenced by convective and advective transport, reveals that on days when both stations launched ozonesondes, vertical mixing was stronger at Edgewood. Approximately half the lower free troposphere sonde profiles have very dry laminae, with coincident aircraft spirals displaying low CO (80-110 ppbv), suggesting stratospheric influence. Ozone budgets at Beltsville in July 2011, determined with LID, as well as standard meteorological indicators, resemble those

Cloud vertical profiles derived from CALIPSO and CloudSat and a comparison with MODIS derived clouds

NASA Astrophysics Data System (ADS)

Kato, S.; Sun-Mack, S.; Miller, W. F.; Rose, F. G.; Minnis, P.; Wielicki, B. A.; Winker, D. M.; Stephens, G. L.; Charlock, T. P.; Collins, W. D.; Loeb, N. G.; Stackhouse, P. W.; Xu, K.

2008-05-01

CALIPSO and CloudSat from the a-train provide detailed information of vertical distribution of clouds and aerosols. The vertical distribution of cloud occurrence is derived from one month of CALIPSO and CloudSat data as a part of the effort of merging CALIPSO, CloudSat and MODIS with CERES data. This newly derived cloud profile is compared with the distribution of cloud top height derived from MODIS on Aqua from cloud algorithms used in the CERES project. The cloud base from MODIS is also estimated using an empirical formula based on the cloud top height and optical thickness, which is used in CERES processes. While MODIS detects mid and low level clouds over the Arctic in April fairly well when they are the topmost cloud layer, it underestimates high- level clouds. In addition, because the CERES-MODIS cloud algorithm is not able to detect multi-layer clouds and the empirical formula significantly underestimates the depth of high clouds, the occurrence of mid and low-level clouds is underestimated. This comparison does not consider sensitivity difference to thin clouds but we will impose an optical thickness threshold to CALIPSO derived clouds for a further comparison. The effect of such differences in the cloud profile to flux computations will also be discussed. In addition, the effect of cloud cover to the top-of-atmosphere flux over the Arctic using CERES SSF and FLASHFLUX products will be discussed.

The Effect of Wind-Turbine Wakes on Summertime US Midwest Atmospheric Wind Profiles as Observed with Ground-Based Doppler Lidar

NASA Astrophysics Data System (ADS)

Rhodes, Michael E.; Lundquist, Julie K.

2013-07-01

We examine the influence of a modern multi-megawatt wind turbine on wind and turbulence profiles three rotor diameters (D) downwind of the turbine. Light detection and ranging (lidar) wind-profile observations were collected during summer 2011 in an operating wind farm in central Iowa at 20-m vertical intervals from 40 to 220 m above the surface. After a calibration period during which two lidars were operated next to each other, one lidar was located approximately 2D directly south of a wind turbine; the other lidar was moved approximately 3D north of the same wind turbine. Data from the two lidars during southerly flow conditions enabled the simultaneous capture of inflow and wake conditions. The inflow wind and turbulence profiles exhibit strong variability with atmospheric stability: daytime profiles are well-mixed with little shear and strong turbulence, while nighttime profiles exhibit minimal turbulence and considerable shear across the rotor disk region and above. Consistent with the observations available from other studies and with wind-tunnel and large-eddy simulation studies, measurable reductions in wake wind-speeds occur at heights spanning the wind turbine rotor (43-117 m), and turbulent quantities increase in the wake. In generalizing these results as a function of inflow wind speed, we find the wind-speed deficit in the wake is largest at hub height or just above, and the maximum deficit occurs when wind speeds are below the rated speed for the turbine. Similarly, the maximum enhancement of turbulence kinetic energy and turbulence intensity occurs at hub height, although observations at the top of the rotor disk do not allow assessment of turbulence in that region. The wind shear below turbine hub height (quantified here with the power-law coefficient) is found to be a useful parameter to identify whether a downwind lidar observes turbine wake or free-flow conditions. These field observations provide data for validating turbine-wake models and wind

Long-Term Observations of Ocean Biogeochemistry with Nitrate and Oxygen Sensors in Apex Profiling Floats

NASA Astrophysics Data System (ADS)

Johnson, K. S.; Coletti, L.; Jannasch, H.; Martz, T.; Swift, D.; Riser, S.

2008-12-01

Long-term, autonomous observations of ocean biogeochemical cycles are now feasible with chemical sensors in profiling floats. These sensors will enable decadal-scale observations of trends in global ocean biogeochemical cycles. Here, we focus on measurements on nitrate and dissolved oxygen. The ISUS (In Situ Ultraviolet Spectrophotometer) optical nitrate sensor has been adapted to operate in a Webb Research, Apex profiling float. The Apex float is of the type used in the Argo array and is designed for multi-year, expendable deployments in the ocean. Floats park at 1000 m depth and make 60 nitrate and oxygen measurements at depth intervals ranging from 50 m below 400 m to 5 m in the upper 100 m as they profile to the surface. All data are transmitted to shore using the Iridium telemetry system and they are available on the Internet in near-real time. Floats equipped with ISUS and an Aanderaa oxygen sensor are capable of making 280 vertical profiles from 1000 m. At a 5 day cycle time, the floats should have nearly a four year endurance. Three floats have now been deployed at the Hawaii Ocean Time series station (HOT), Ocean Station Papa (OSP) in the Gulf of Alaska and at 50 South, 30 East in the Southern Ocean. Two additional floats are designated for deployment at the Bermuda Atlantic Time Series station (BATS) and in the Drake Passage. The HOT float has made 56 profiles over 260 days and should continue operating for 3 more years. Nitrate concentrations are in excellent agreement with the long-term mean observed at HOT. No significant long-term drift in sensor response has occurred. A variety of features have been observed in the HOT nitrate data that are linked to contemporaneous changes in oxygen production and mesoscale dynamics. The impacts of these features will be briefly described. The Southern Ocean float has operated for 200 days and is now observing reinjection of nitrate into surface waters as winter mixing occurs(surface nitrate > 24 micromolar). We

Vertical Distribution of PH(sub 3) in Saturn from Observations of the 1-0 and 3-2 Rotational Lines

NASA Technical Reports Server (NTRS)

Orton, G.; Serabyn, E.; Lee, Y.

1999-01-01

Far-infrared Fourier-transform spectrometer measurements of the 1-0 and 3-2 PH(sub 3) transitions in Saturn's disk near 267 and 800 GHz (8.9 and 26.7 cm(sup -1)), respectively, were analyzed simultaneously to derive a global mean profile for the PH(sub 3) vertical mixing ratio between 100 and 800 mbar total pressure.

Vertical rise velocity of equatorial plasma bubbles estimated from Equatorial Atmosphere Radar (EAR) observations and HIRB model simulations

NASA Astrophysics Data System (ADS)

Tulasi Ram, S.; Ajith, K. K.; Yokoyama, T.; Yamamoto, M.; Niranjan, K.

2017-06-01

The vertical rise velocity (Vr) and maximum altitude (Hm) of equatorial plasma bubbles (EPBs) were estimated using the two-dimensional fan sector maps of 47 MHz Equatorial Atmosphere Radar (EAR), Kototabang, during May 2010 to April 2013. A total of 86 EPBs were observed out of which 68 were postsunset EPBs and remaining 18 EPBs were observed around midnight hours. The vertical rise velocities of the EPBs observed around the midnight hours are significantly smaller ( 26-128 m/s) compared to those observed in postsunset hours ( 45-265 m/s). Further, the vertical growth of the EPBs around midnight hours ceases at relatively lower altitudes, whereas the majority of EPBs at postsunset hours found to have grown beyond the maximum detectable altitude of the EAR. The three-dimensional numerical high-resolution bubble (HIRB) model with varying background conditions are employed to investigate the possible factors that control the vertical rise velocity and maximum attainable altitudes of EPBs. The estimated rise velocities from EAR observations at both postsunset and midnight hours are, in general, consistent with the nonlinear evolution of EPBs from the HIRB model. The smaller vertical rise velocities (Vr) and lower maximum altitudes (Hm) of EPBs during midnight hours are discussed in terms of weak polarization electric fields within the bubble due to weaker background electric fields and reduced background ion density levels.