Science.gov

Sample records for advanced atmospheric water

  1. Advanced Atmospheric Water Vapor DIAL Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

    2000-01-01

    Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

  2. Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar (DIAL) Detection System

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1999-01-01

    The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing experiment (LASE) is an instrument designed and operated by the Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing circuit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 x 15 sq cm). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.

  3. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  4. Advanced aircraft for atmospheric research

    NASA Technical Reports Server (NTRS)

    Russell, P.; Wegener, S.; Langford, J.; Anderson, J.; Lux, D.; Hall, D. W.

    1991-01-01

    The development of aircraft for high-altitude research is described in terms of program objectives and environmental, technological limitations, and the work on the Perseus A aircraft. The need for these advanced aircraft is proposed in relation to atmospheric science issues such as greenhouse trapping, the dynamics of tropical cyclones, and stratospheric ozone. The implications of the study on aircraft design requirements is addressed with attention given to the basic categories of high-altitude, long-range, long-duration, and nap-of-the-earth aircraft. A strategy is delineated for a platform that permits unique stratospheric measurements and is a step toward a more advanced aircraft. The goal of Perseus A is to carry scientific air sampling payloads weighing at least 50 kg to altitudes of more than 25 km. The airfoils are designed for low Reynolds numbers, the structural weight is very low, and the closed-cycle power plant runs on liquid oxygen.

  5. PNNL's 'PEGASUS' Advances Atmospheric Chemistry

    SciTech Connect

    Berkowitz, Carl M.; Eades, Robert A.

    2001-04-16

    Presented an overview of software design to maximize computational efficiency on a massively parallel computing system. Also gave highlights of scientific results from this code, focusing primarily on how we can distinguish between stratospheric ozone in remote atmospheres and ozone generated from NOx/VOC chemical mechanisms.

  6. Effects of Atmospheric Water Vapor and Clouds on NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) Satellite Data.

    DTIC Science & Technology

    1984-07-01

    smoke , smog, dust and water ;erosols usually falls within the Mie Regime. The combination of Rayleigh and Mie scattering causes the selective...T. L., 1984. Department of Commerce, NOAA, NESDIS, Assesment Services Center, Columbia, MO, Personal Communications. Barnett, T. L. and Thompson, D...Washington, D.C., NOAA Technical Memorandum, NESS 107, 73 pp. LeDuc, S. K., 1984. U.S. Department of Commerce, NOAA, NESDIS, Assesment Information Services

  7. Advanced Atmospheric Sounder and Imaging Radiometer (AASIR)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Design information for the Advanced Atmospheric Sounder and Imaging Radiometer is reported, which was developed to determine the configuration of a sensor for IR and visible imaging. The areas of technology reported include: systems design, optics, mechanics, electronics, detectors, radiative cooler, and radiometric calibration.

  8. Advanced alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Wakabayashi, N.; Torikai, E.; Kawami, Y.; Takenaka, H.

    Results are presented of experimental studies of possible separators and electrodes for use in advanced, high-temperature, high-pressure alkaline water electrolyzers. Material evaluations in alkaline water electrolyzers at temperatures from 100 to 120 C have shown a new type polytetrafluoroethylene membrane impregnated with potassium titanate to be the most promising when the separator is prepared by the hydrothermal treatment of a porous PFTE membrane impregnated with hydrated titanium oxide. Measurements of cell voltages in 30% KOH at current densities from 5 to 100 A/sq dm at temperatures up to 120 C with nickel electrodes of various structures have shown the foamed nickel electrode, with an average pore size of 1-1.5 mm, to have the best performance. When the foamed nickel is coated by fine powdered nickel, carbonyl nickel or Raney nickel to increase electrode surface areas, even lower cell voltages were found, indicating better performance.

  9. Advanced Raman water vapor lidar

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Melfi, S. Harvey; Ferrare, Richard A.; Evans, Keith A.; Ramos-Izquierdo, Luis; Staley, O. Glenn; Disilvestre, Raymond W.; Gorin, Inna; Kirks, Kenneth R.; Mamakos, William A.

    1992-01-01

    Water vapor and aerosols are important atmospheric constituents. Knowledge of the structure of water vapor is important in understanding convective development, atmospheric stability, the interaction of the atmosphere with the surface, and energy feedback mechanisms and how they relate to global warming calculations. The Raman Lidar group at the NASA Goddard Space Flight Center (GSFC) developed an advanced Raman Lidar for use in measuring water vapor and aerosols in the earth's atmosphere. Drawing on the experience gained through the development and use of our previous Nd:YAG based system, we have developed a completely new lidar system which uses a XeF excimer laser and a large scanning mirror. The additional power of the excimer and the considerably improved optical throughput of the system have resulted in approximately a factor of 25 improvement in system performance for nighttime measurements. Every component of the current system has new design concepts incorporated. The lidar system consists of two mobile trailers; the first (13m x 2.4m) houses the lidar instrument, the other (9.75m x 2.4m) is for system control, realtime data display, and analysis. The laser transmitter is a Lambda Physik LPX 240 iCC operating at 400 Hz with a XeF gas mixture (351 nm). The telescope is a .75m horizontally mounted Dall-Kirkham system which is bore sited with a .8m x 1.1m elliptical flat which has a full 180 degree scan capability - horizon to horizon within a plane perpendicular to the long axis of the trailer. The telescope and scan mirror assembly are mounted on a 3.65m x .9m optical table which deploys out the rear of the trailer through the use of a motor driven slide rail system. The Raman returns from water vapor (403 nm), nitrogen (383 nm) and oxygen (372 nm) are measured in addition to the direct Rayleigh/Mie backscatter (351). The signal from each of these is split at about a 5/95 ratio between two photomultiplier detectors. The 5 percent detector is used for

  10. Modeling of Revitalization of Atmospheric Water

    NASA Technical Reports Server (NTRS)

    Coker, Robert; Knox, Jim

    2014-01-01

    The Atmosphere Revitalization Recovery and Environmental Monitoring (ARREM) project was initiated in September of 2011 as part of the Advanced Exploration Systems (AES) program. Under the ARREM project, testing of sub-scale and full-scale systems has been combined with multiphysics computer simulations for evaluation and optimization of subsystem approaches. In particular, this paper describes the testing and modeling of the water desiccant subsystem of the carbon dioxide removal assembly (CDRA). The goal is a full system predictive model of CDRA to guide system optimization and development.

  11. Advanced Global Atmospheric Gases Experiment (AGAGE)

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.; Kurylo, Michael (Technical Monitor)

    2004-01-01

    We seek funding from NASA for the third year (2005) of the four-year period January 1, 2003 - December 31, 2006 for continued support of the MIT contributions to the multi-national global atmospheric trace species measurement program entitled Advanced Global Atmospheric Gases Experiment (AGAGE). The case for real-time high-frequency measurement networks like AGAGE is very strong and the observations and their interpretation are widely recognized for their importance to ozone depletion and climate change studies and to verification issues arising from the Montreal Protocol (ozone) and Kyoto Protocol (climate). The proposed AGAGE program is distinguished by its capability to measure over the globe at high frequency almost all of the important species in the Montreal Protocol and almost all of the significant non-CO2 gases in the Kyoto Protocol.

  12. The atmospheric water vapor line.

    NASA Astrophysics Data System (ADS)

    Strong, M.; Sharp, Z. D.; Gutzler, D. S.

    2008-12-01

    We have measured the hydrogen and oxygen isotope composition of atmospheric water vapor periodically across the American Southwest through most of 2007. Samples were primarily collected over Albuquerque, NM on the roof of the 3-story UNM geology building on a near-daily basis with occasional sampling in southern Arizona and southern Texas. Water vapor was captured by pumping ~60 to ~600 liters of air (amount depending on dew point) through a cold trap, producing ~1mL of water. Precipitation samples were also collected in Albuquerque throughout the year and analyzed for hydrogen and oxygen isotopic composition. Isotopic compositions of both vapor and precipitation were determined by CO2 equilibration for oxygen and chromium reduction for hydrogen, with resulting gasses analyzed on a mass spectrometer. Nearly all water vapor samples lie parallel to the Global Meteoric Water Line (GMWL) but with a deuterium excess of ~17 (δD = 8δO + 17). This is true regardless of relative humidity, dew point, location, time of day, or season. Precipitation samples fall to the right of the GMWL with a slope of ~5. Within our dataset we have identified 10 pairs of vapor and precipitation samples that were collected within 24 hours. Half of these sample pairs have values consistent with equilibrium conditions at ground temperature, while the other half are not in equilibrium at any temperature. Simple modeling of nonequilibrium fractionation processes suggests that the array of precipitation samples can be derived from the array of vapor samples by equilibrium condensation followed by partial evaporation of falling raindrops. Our data suggests that atmospheric water vapor has a relatively constant deuterium excess value regardless of moisture source, degree of rainout, and/or evapotranspiration contributions.

  13. Advances in water resources technology

    NASA Astrophysics Data System (ADS)

    The presentation of technological advances in the field of water resources will be the focus of Advances in Water Resources Technology, a conference to be held in Athens, Greece, March 20-23, 1991. Organized by the European Committee for Water Resources Management, in cooperation with the National Technical University of Athens, the conference will feature state-of-the art papers, contributed original research papers, and poster papers. Session subjects will include surface water, groundwater, water resources conservation, water quality and reuse, computer modeling and simulation, real-time control of water resources systems, and institutions and methods for technology.The official language of the conference will be English. Special meetings and discussions will be held for investigating methods of effective technology transfer among European countries. For this purpose, a wide representation of research institutions, universities and companies involved in water resources technology will be attempted.

  14. Advances in spacecraft atmospheric entry guidance

    NASA Astrophysics Data System (ADS)

    Benito Manrique, Joel

    In order to advance entry guidance technology two different research areas have been explored with the objective of increasing the reachable landing area and the landing accuracy for future Mars missions. Currently only the northern hemisphere of Mars is available for landing due to its low elevation. Only low elevation landing sites have the necessary atmospheric density to allow landing using current Entry, Descent and Landing (EDL) technology. In order to reach most of the Ancient Highlands, the majority of the southern hemisphere, advanced EDL technology is needed in multiple fields, including entry guidance. The first research area is the definition and applications of reachable and controllable sets for entry. The definition of the reachable and controllable sets provides a framework for the study of the capabilities of an entry vehicle in a given planet. Reachable and controllable sets can be used to comprehensively characterize the envelope of trajectories that a vehicle can fly, the sites it can reach and the entry states that can be accommodated. The sets can also be used for the evaluation of trajectory planning algorithms and to assist in the selection of the entry or landing sites. In essence, the reachable and controllable sets offer a powerful vehicle and trajectory analysis and design framework that allows for better mission design choices. In order to illustrate the use of the sets, they are computed for a representative Mars mission using two different vehicle configurations. The sets characterize the impact of the vehicle configuration on the entry capability. Furthermore, the sets are used to find the best skip-entry trajectory for a return from the Moon mission, highlighting the utility of the sets in atmospheric maneuvers other than entry. The second research area is the development of the components of an entry guidance algorithm that allow high elevation landing and provide as well high landing accuracy. The approach taken follows the

  15. Profiling atmospheric water vapor by microwave radiometry

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Wilheit, T. T.; Szejwach, G.; Gesell, L. H.; Nieman, R. A.; Niver, D. S.; Krupp, B. M.; Gagliano, J. A.; King, J. L.

    1983-01-01

    High-altitude microwave radiometric observations at frequencies near 92 and 183.3 GHz were used to study the potential of retrieving atmospheric water vapor profiles over both land and water. An algorithm based on an extended kalman-Bucy filter was implemented and applied for the water vapor retrieval. The results show great promise in atmospheric water vapor profiling by microwave radiometry heretofore not attainable at lower frequencies.

  16. Atmosphere composition monitor for space station and advanced missions application

    SciTech Connect

    Wynveen, R.A.; Powell, F.T.

    1987-01-01

    Long-term human occupation of extraterrestrial locations may soon become a reality. The National Aeronautics and Space Administration (NASA) has recently completed the definition and preliminary design of the low earth orbit (LEO) space station. They are now currently moving into the detailed design and fabrication phase of this space station and are also beginning to analyze the requirements of several future missions that have been identified. These missions include, for example, Lunar and Mars sorties, outposts, bases, and settlements. A requirement of both the LEO space station and future missions are environmental control and life support systems (ECLSS), which provide a comfortable environment for humans to live and work. The ECLSS consists of several major systems, including atmosphere revitalization system (ARS), atmosphere pressure and composition control system, temperature and humidity control system, water reclamation system, and waste management system. Each of these major systems is broken down into subsystems, assemblies, units, and instruments. Many requirements and design drivers are different for the ECLSS of the LEO space station and the identified advanced missions (e.g., longer mission duration). This paper discusses one of the ARS assemblies, the atmosphere composition monitor assembly (ACMA), being developed for the LEO space station and addresses differences that will exist for the ACMA of future missions.

  17. Profiling atmospheric water vapor using a fiber laser lidar system.

    PubMed

    De Young, Russell J; Barnes, Norman P

    2010-02-01

    A compact, lightweight, and efficient fiber laser lidar system has been developed to measure water vapor profiles in the lower atmosphere of Earth or Mars. The line narrowed laser consist of a Tm:germanate fiber pumped by two 792 nm diode arrays. The fiber laser transmits approximately 0.5 mJ Q- switched pulses at 5 Hz and can be tuned to water vapor lines near 1.94 microm with linewidth of approximately 20 pm. A lightweight lidar receiver telescope was constructed of carbon epoxy fiber with a 30 cm Fresnel lens and an advanced HgCdTe APD detector. This system has made preliminary atmospheric measurements.

  18. Assessing Atmospheric Water Injection from Oceanic Impacts

    NASA Technical Reports Server (NTRS)

    Pierazzo, E.

    2005-01-01

    Collisions of asteroids and comets with the Earth s surface are rare events that punctuate the geologic record. Due to the vastness of Earth s oceans, oceanic impacts of asteroids or comets are expected to be about 4 times more frequent than land impacts. The resulting injections of oceanic water into the upper atmosphere can have important repercussions on Earth s climate and atmospheric circulation. However, the duration and overall effect of these large injections are still unconstrained. This work addresses atmospheric injections of large amounts of water in oceanic impacts.

  19. Atmospheric radiation model for water surfaces

    NASA Technical Reports Server (NTRS)

    Turner, R. E.; Gaskill, D. W.; Lierzer, J. R.

    1982-01-01

    An atmospheric correction model was extended to account for various atmospheric radiation components in remotely sensed data. Components such as the atmospheric path radiance which results from singly scattered sky radiation specularly reflected by the water surface are considered. A component which is referred to as the virtual Sun path radiance, i.e. the singly scattered path radiance which results from the solar radiation which is specularly reflected by the water surface is also considered. These atmospheric radiation components are coded into a computer program for the analysis of multispectral remote sensor data over the Great Lakes of the United States. The user must know certain parameters, such as the visibility or spectral optical thickness of the atmosphere and the geometry of the sensor with respect to the Sun and the target elements under investigation.

  20. Perspective: Water cluster mediated atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Vaida, Veronica

    2011-07-01

    The importance of water in atmospheric and environmental chemistry initiated recent studies with results documenting catalysis, suppression and anti-catalysis of thermal and photochemical reactions due to hydrogen bonding of reagents with water. Water, even one water molecule in binary complexes, has been shown by quantum chemistry to stabilize the transition state and lower its energy. However, new results underscore the need to evaluate the relative competing rates between reaction and dissipation to elucidate the role of water in chemistry. Water clusters have been used successfully as models for reactions in gas-phase, in aqueous condensed phases and at aqueous surfaces. Opportunities for experimental and theoretical chemical physics to make fundamental new discoveries abound. Work in this field is timely given the importance of water in atmospheric and environmental chemistry.

  1. Perspective: Water cluster mediated atmospheric chemistry

    SciTech Connect

    Vaida, Veronica

    2011-07-14

    The importance of water in atmospheric and environmental chemistry initiated recent studies with results documenting catalysis, suppression and anti-catalysis of thermal and photochemical reactions due to hydrogen bonding of reagents with water. Water, even one water molecule in binary complexes, has been shown by quantum chemistry to stabilize the transition state and lower its energy. However, new results underscore the need to evaluate the relative competing rates between reaction and dissipation to elucidate the role of water in chemistry. Water clusters have been used successfully as models for reactions in gas-phase, in aqueous condensed phases and at aqueous surfaces. Opportunities for experimental and theoretical chemical physics to make fundamental new discoveries abound. Work in this field is timely given the importance of water in atmospheric and environmental chemistry.

  2. Advanced microwave sounding unit study for atmospheric infrared sounder

    NASA Technical Reports Server (NTRS)

    Rosenkranz, Philip W.; Staelin, David H.

    1992-01-01

    The Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU-A), and the Microwave Humidity Sounder (MHS, formerly AMSU-B) together constitute the advanced sounding system facility for the Earth Observing System (EOS). A summary of the EOS phase B activities are presented.

  3. Water vapor in Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Bjoraker, G. L.; Larson, H. P.; Kunde, V. G.

    1986-01-01

    High spectral resolution observations of Jupiter at 2.7 and 5 microns acquired from the Kuiper Airborne Observatory were used to infer the vertical distribution of H2O between 0.7 and 6 bars. The H2O mole fraction, qH2O, is saturated for P<2 bars, qH2O = 4x.000001 in the 2 to 4 bar range and it increases to 3x.00001 at 6 bars where T = 288 K. The base of the 5 micron line formation region is determined by pressure-induced H2 opacity. At this deepest accessible level, the O/H ratio in Jupiter is depleted by a factor of 50 with respect to the solar atmosphere. High spatial resolution Voyager IRIS spectra of Jupiter's North Tropical Zone, Equatorial Zone, and Hot Spots in the North and South Equatorial Belt were analyzed to determine the spatial variation of H2O across the planet. The column abundance of H2O above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amgt. A cloud model for Jupiter's belts and zones was developed in order to fit the IRIS 5 micron spectra. An absorbing cloud located at 2 bars whose 5 micron optical thickness varies between 1 in the Hot Spots and 4 in the coldest zones satisfactorily matches the IRIS data.

  4. Atmospheric correction of AVIRIS data in ocean waters

    NASA Technical Reports Server (NTRS)

    Terrie, Gregory; Arnone, Robert

    1992-01-01

    Hyperspectral data offers unique capabilities for characterizing the ocean environment. The spectral characterization of the composition of ocean waters can be organized into biological and terrigenous components. Biological photosynthetic pigments in ocean waters have unique spectral ocean color signatures which can be associated with different biological species. Additionally, suspended sediment has different scattering coefficients which result in ocean color signatures. Measuring the spatial distributions of these components in the maritime environments provides important tools for understanding and monitoring the ocean environment. These tools have significant applications in pollution, carbon cycle, current and water mass detection, location of fronts and eddies, sewage discharge and fate etc. Ocean color was used from satellite for describing the spatial variability of chlorophyll, water clarity (K(sub 490)), suspended sediment concentration, currents etc. Additionally, with improved atmospheric correction methods, ocean color results produced global products of spectral water leaving radiance (L(sub W)). Ocean color results clearly indicated strong applications for characterizing the spatial and temporal variability of bio-optical oceanography. These studies were largely the results of advanced atmospheric correction techniques applied to multispectral imagery. The atmosphere contributes approximately 80 percent - 90 percent of the satellite received radiance in the blue-green portion of the spectrum. In deep ocean waters, maximum transmission of visible radiance is achieved at 490nm. Conversely, nearly all of the light is absorbed by the water at wavelengths greater than about 650nm and thus appears black. These spectral ocean properties are exploited by algorithms developed for the atmospheric correction used in satellite ocean color processing. The objective was to apply atmospheric correction techniques that were used for procesing satellite Coastal

  5. Mars Atmospheric Characterization Using Advanced 2-Micron Orbiting Lidar

    NASA Technical Reports Server (NTRS)

    Singh, U.; Engelund, W.; Refaat, T.; Kavaya, M.; Yu, J.; Petros, M.

    2015-01-01

    Mars atmospheric characterization is critical for exploring the planet. Future Mars missions require landing massive payloads to the surface with high accuracy. The accuracy of entry, descent and landing (EDL) of a payload is a major technical challenge for future Mars missions. Mars EDL depends on atmospheric conditions such as density, wind and dust as well as surface topography. A Mars orbiting 2-micron lidar system is presented in this paper. This advanced lidar is capable of measuring atmospheric pressure and temperature profiles using the most abundant atmospheric carbon dioxide (CO2) on Mars. In addition Martian winds and surface altimetry can be mapped, independent of background radiation or geographical location. This orbiting lidar is a valuable tool for developing EDL models for future Mars missions.

  6. EDITORIAL: The global atmospheric water cycle

    NASA Astrophysics Data System (ADS)

    Bengtsson, Lennart

    2010-06-01

    Water vapour plays a key role in the Earth's energy balance. Almost 50% of the absorbed solar radiation at the surface is used to cool the surface, through evaporation, and warm the atmosphere, through release of latent heat. Latent heat is the single largest factor in warming the atmosphere and in transporting heat from low to high latitudes. Water vapour is also the dominant greenhouse gas and contributes to a warming of the climate system by some 24°C (Kondratev 1972). However, water vapour is a passive component in the troposphere as it is uniquely determined by temperature and should therefore be seen as a part of the climate feedback system. In this short overview, we will first describe the water on planet Earth and the role of the hydrological cycle: the way water vapour is transported between oceans and continents and the return of water via rivers to the oceans. Generally water vapour is well observed and analysed; however, there are considerable obstacles to observing precipitation, in particular over the oceans. The response of the hydrological cycle to global warming is far reaching. Because different physical processes control the change in water vapour and evaporation/precipitation, this leads to a more extreme distribution of precipitation making, in general, wet areas wetter and dry areas dryer. Another consequence is a transition towards more intense precipitation. It is to be expected that the changes in the hydrological cycle as a consequence of climate warming may be more severe that the temperature changes. Water on planet Earth The total amount of available water on the Earth amounts to some 1.5 x 109 km3. The dominant part of this, 1.4 x 109 km3, resides in the oceans. About 29 x 106 km3 are locked up in land ice and glaciers and some 15 x 106 km3 are estimated to exist as groundwater. If all land ice and glaciers were to melt the sea level would rise some 80 m (Baumgartner and Reichel 1975). 13 x 103 km3 of water vapour are found in the

  7. Escape of atmospheres and loss of water

    NASA Technical Reports Server (NTRS)

    Hunten, D. M.; Donahue, T. M.; Walker, J. C. G.; Kasting, J. F.

    1989-01-01

    The properties and limitations of several loss processes for atmospheric gases are presented and discussed. They include thermal loss (Jeans and hydrodynamic); nonthermal loss (all processes involve charged particles); and impact erosion, including thermal escape from a molten body heated by rapid accretion. Hydrodynamic escape, or 'blowoff', is of particular interest because it offers the prospect of processing large quantities of gas and enriching the remainder in heavy elements and isotopes. In a second part, the water budgets and likely evolutionary histories of Venus, Earth and Mars are assessed. Although it is tempting to associate the great D/H enrichment on Venus with loss of a large initial endowment, a steady state with juvenile water (perhaps from comets) is equally probable.

  8. Advanced water iodinating system. [for potable water aboard manned spacecraft

    NASA Technical Reports Server (NTRS)

    Davenport, R. J.; Schubert, F. H.; Wynveen, R. A.

    1975-01-01

    Potable water stores aboard manned spacecraft must remain sterile. Suitable sterilization techniques are needed to prevent microbial growth. The development of an advanced water iodinating system for possible application to the shuttle orbiter and other advanced spacecraft, is considered. The AWIS provides a means of automatically dispensing iodine and controlling iodination levels in potable water stores. In a recirculation mode test, simulating application of the AWIS to a water management system of a long term six man capacity space mission, noniodinated feed water flowing at 32.2 cu cm min was iodinated to 5 + or - ppm concentrations after it was mixed with previously iodinated water recirculating through a potable water storage tank. Also, the AWIS was used to successfully demonstrate its capability to maintain potable water at a desired I2 concentration level while circulating through the water storage tank, but without the addition of noniodinated water.

  9. Constructing an advanced software tool for planetary atmospheric modeling

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.; Sims, Michael; Podolak, Ester; Mckay, Christopher

    1990-01-01

    Scientific model building can be an intensive and painstaking process, often involving the development of large and complex computer programs. Despite the effort involved, scientific models cannot be easily distributed and shared with other scientists. In general, implemented scientific models are complex, idiosyncratic, and difficult for anyone but the original scientist/programmer to understand. We believe that advanced software techniques can facilitate both the model building and model sharing process. In this paper, we describe a prototype for a scientific modeling software tool that serves as an aid to the scientist in developing and using models. This tool includes an interactive intelligent graphical interface, a high level domain specific modeling language, a library of physics equations and experimental datasets, and a suite of data display facilities. Our prototype has been developed in the domain of planetary atmospheric modeling, and is being used to construct models of Titan's atmosphere.

  10. Isotopes in the Arctic atmospheric water cycle

    NASA Astrophysics Data System (ADS)

    Bonne, Jean-Louis; Werner, Martin; Meyer, Hanno; Kipfstuhl, Sepp; Rabe, Benjamin; Behrens, Melanie; Schönicke, Lutz; Steen Larsen, Hans Christian; Masson-Delmotte, Valérie

    2016-04-01

    The ISO-ARC project aims at documenting the Arctic atmospheric hydrological cycle, by assessing the imprint of the marine boundary conditions (e.g. temperature variations, circulation changes, or meltwater input) to the isotopic composition of the atmospheric water cycle (H218O and HDO) with a focus on North Atlantic and Arctic oceans. For this purpose, two continuous monitoring water vapour stable isotopes cavity ring-down spectrometers have been installed in July 2015: on-board the Polarstern research vessel and in the Siberian Lena delta Samoylov research station (N 72° 22', E 126° 29'). The Polarstern measurements cover the summer 2015 Arctic campaign from July to mid-October, including six weeks in the Fram Strait region in July- August, followed by a campaign reaching the North Pole and a transect from the Norwegian Sea to the North Sea. These vapour observations are completed by water isotopic measurements in samples from the surface ocean water for Polarstern and from precipitation in Samoylov and Tiksi (120 km south-east of the station). A custom-made designed automatic calibration system has been implemented in a comparable manner for both vapour instruments, based on the injection of different liquid water standards, which are completely vaporised in dry air at high temperature. Subsequent humidity level can be adjusted from 2000 to at least 30000 ppm. For a better resilience, an independent calibration system has been added on the Samoylov instrument, allowing measurements of one standard at humidity levels ranging from 2000 to 15000 ppm: dry air is introduced in a tank containing a large amount of liquid water standard, undergoing evaporation under a controlled environment. The measurement protocol includes an automatic calibration every 25 hours. First instrument characterisation experiments depict a significant isotope-humidity effect at low humidity, dependant on the isotopic composition of the standard. For ambient air, our first isotope

  11. EPA Water Strategy: Advancing Technologies

    EPA Science Inventory

    National Risk Management Research Laboratory conducts innovative research to manage contaminants in water supplies that pose a threat to human health and the environment, and to develop approaches and tools to monitor, treat, characterize, protect, and restore impaired waterways,...

  12. Next Steps: Water Technology Advances (Research)

    EPA Science Inventory

    This project will focus on contaminants and their impact on health, adequate removal of contaminants from various water systems, and water and resource recovery within treatment systems. It will develop the next generation of technological advances to provide guidance in support ...

  13. Atmospheric water on Mars, energy estimates for extraction

    NASA Technical Reports Server (NTRS)

    Meyer, Tom

    1991-01-01

    The Mars atmosphere is considered as a resource for water to support a human expedition. Information obtained from the Viking mission is used to estimate the near-surface water vapor level. The variability over the diurnal cycle is examined and periods of greatest water abundance are identified. Various methods for extracting atmospheric water are discussed including energy costs and the means for optimizing water extraction techniques.

  14. Advanced piggyback water power generator

    SciTech Connect

    Wiggs, B.R.

    1988-02-16

    A power generating system is described including: a central boat containing gearing and electric and/or power generation equipment, with a forward angled-back deflection screen and a rear non-angled deflection screen, with a smaller outrigger pontoon on each respective side of the central boat, with closed cell, waterproof, plastic foam filling in the central boat and pontoons, and with the bow of the respective outrigger pontoons angled so as to completely turn water away from, and to the outside of, the space and/or incoming water area between each such respective pontooon and the central boat. There are legs with cone shaped bottoms and with wheels attached, with the wheels extending slightly below the cone shaped bottoms; paddle wheels on each side of the central boat, between the central boat, and respective outrigger pontoons, with 90 degree spaced, flat, paddle blades, and with a solid, disk division vertically dividing each respective side paddle wheel in half and extending at right angles to, and from, the central axle, to the outside extreme end of the paddle blades, with each such half of the equally divided paddle wheel being constructed so that the 90 degree spaced paddle blades in one half are offset by 45 degrees from the 90 degree space paddle blades in the other half, and with the extreme ends of each such set of divided paddle wheels being enclosed via a similar solid.

  15. Determining Atmospheric Pressure Using a Water Barometer

    ERIC Educational Resources Information Center

    Lohrengel, C. Frederick, II; Larson, Paul R.

    2012-01-01

    The atmosphere is an envelope of compressible gases that surrounds Earth. Because of its compressibility and nonuniform heating by the Sun, it is in constant motion. The atmosphere exerts pressure on Earth's surface, but that pressure is in constant flux. This experiment allows students to directly measure atmospheric pressure by measuring the…

  16. INTRODUCTION: Anticipated changes in the global atmospheric water cycle

    NASA Astrophysics Data System (ADS)

    Allan, Richard P.; Liepert, Beate G.

    2010-06-01

    The atmospheric branch of the water cycle, although containing just a tiny fraction of the Earth's total water reserves, presents a crucial interface between the physical climate (such as large-scale rainfall patterns) and the ecosystems upon which human societies ultimately depend. Because of the central importance of water in the Earth system, the question of how the water cycle is changing, and how it may alter in future as a result of anthropogenic changes, present one of the greatest challenges of this century. The recent Intergovernmental Panel on Climate Change report on Climate Change and Water (Bates et al 2008) highlighted the increasingly strong evidence of change in the global water cycle and associated environmental consequences. It is of critical importance to climate prediction and adaptation strategies that key processes in the atmospheric water cycle are precisely understood and determined, from evaporation at the surface of the ocean, transport by the atmosphere, condensation as cloud and eventual precipitation, and run-off through rivers following interaction with the land surface, sub-surface, ice, snow and vegetation. The purpose of this special focus issue of Environmental Research Letters on anticipated changes in the global atmospheric water cycle is to consolidate the recent substantial advances in understanding past, present and future changes in the global water cycle through evidence built upon theoretical understanding, backed up by observations and borne out by climate model simulations. Thermodynamic rises in water vapour provide a central constraint, as discussed in a guest editorial by Bengtsson (2010). Theoretical implications of the Clausius-Clapeyron equation are presented by O'Gorman and Muller (2010) and with reference to a simple model (Sherwood 2010) while observed humidity changes confirm these anticipated responses at the land and ocean surface (Willett et al 2008). Rises in low-level moisture are thought to fuel an

  17. Characterization of Advanced Avalanche Photodiodes for Water Vapor Lidar Receivers

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Halama, Gary E.; DeYoung, Russell J.

    2000-01-01

    Development of advanced differential absorption lidar (DIAL) receivers is very important to increase the accuracy of atmospheric water vapor measurements. A major component of such receivers is the optical detector. In the near-infrared wavelength range avalanche photodiodes (APD's) are the best choice for higher signal-to-noise ratio, where there are many water vapor absorption lines. In this study, characterization experiments were performed to evaluate a group of silicon-based APD's. The APD's have different structures representative of different manufacturers. The experiments include setups to calibrate these devices, as well as characterization of the effects of voltage bias and temperature on the responsivity, surface scans, noise measurements, and frequency response measurements. For each experiment, the setup, procedure, data analysis, and results are given and discussed. This research was done to choose a suitable APD detector for the development of an advanced atmospheric water vapor differential absorption lidar detection system operating either at 720, 820, or 940 nm. The results point out the benefits of using the super low ionization ratio (SLIK) structure APD for its lower noise-equivalent power, which was found to be on the order of 2 to 4 fW/Hz(sup (1/2)), with an appropriate optical system and electronics. The water vapor detection systems signal-to-noise ratio will increase by a factor of 10.

  18. Advancing Water Science through Data Visualization

    NASA Astrophysics Data System (ADS)

    Li, X.; Troy, T.

    2014-12-01

    As water scientists, we are increasingly handling larger and larger datasets with many variables, making it easy to lose ourselves in the details. Advanced data visualization will play an increasingly significant role in propelling the development of water science in research, economy, policy and education. It can enable analysis within research and further data scientists' understanding of behavior and processes and can potentially affect how the public, whom we often want to inform, understands our work. Unfortunately for water scientists, data visualization is approached in an ad hoc manner when a more formal methodology or understanding could potentially significantly improve both research within the academy and outreach to the public. Firstly to broaden and deepen scientific understanding, data visualization can allow for more analyzed targets to be processed simultaneously and can represent the variables effectively, finding patterns, trends and relationships; thus it can even explores the new research direction or branch of water science. Depending on visualization, we can detect and separate the pivotal and trivial influential factors more clearly to assume and abstract the original complex target system. Providing direct visual perception of the differences between observation data and prediction results of models, data visualization allows researchers to quickly examine the quality of models in water science. Secondly data visualization can also improve public awareness and perhaps influence behavior. Offering decision makers clearer perspectives of potential profits of water, data visualization can amplify the economic value of water science and also increase relevant employment rates. Providing policymakers compelling visuals of the role of water for social and natural systems, data visualization can advance the water management and legislation of water conservation. By building the publics' own data visualization through apps and games about water

  19. Advance prototype silver ion water bactericide system

    NASA Technical Reports Server (NTRS)

    Jasionowski, W. J.; Allen, E. T.

    1974-01-01

    An advance prototype unit was designed and fabricated to treat anticipated fuel cell water. The unit is a single canister that contains a membrane-type prefilter and a silver bromide contacting bed. A seven day baseline simulated mission test was performed; the performance was satisfactory and the effluent water was within all specifications for potability. After random vibrations another seven day simulated mission test was performed, and results indicate that simulated launch vibrations have no effects on the design and performance of the advanced prototype. Bench tests and accelerated breadboard tests were conducted to define the characteristics of an upgraded model of the advance prototype unit which would have 30 days of operating capability. A preliminary design of a silver ion generator for the shuttle orbiter was also prepared.

  20. NTTC Course 315: Advanced Water Examination.

    ERIC Educational Resources Information Center

    Department of the Navy, Washington, DC.

    This publication is the examination booklet used for a home study course in water treatment. This course is the advanced part of a series produced by the Department of the Navy. This publication is designed to be used in conjunction with a course textbook. Each of the four examinations contained in this document are referenced to a specific…

  1. The Advanced Mars Climate Sounder (AMCS) - A Proven Atmospheric Profiler for Future Mars Orbiters

    NASA Astrophysics Data System (ADS)

    Kleinboehl, A.; Schofield, J. T.; Kass, D. M.; McCleese, D. J.

    2016-10-01

    We describe a mature, low-cost, and low-risk infrared atmospheric profiler based on MRO/MCS heritage for measuring atmospheric temperature, dust, water ice, carbon dioxide ice, and water vapor on a future Mars orbiter mission.

  2. Advances in water resources monitoring from space

    NASA Technical Reports Server (NTRS)

    Salomonson, V. V.

    1974-01-01

    Nimbus-5 observations indicate that over the oceans the total precipitable water in a column of atmosphere can be estimated to within + or - 10%, the liquid water content of clouds can be estimated to within + or - 25%, areas of precipitation can be delineated, and broad estimates of the precipitation rate obtained. ERTS-1 observations permit the measurement of snow covered area to within a few percent of drainage basin area and snowline altitudes can be estimated to within 60 meters. Surface water areas as small as 1 hectare can be inventoried over large regions such as playa lakes region of West Texas and Eastern New Mexico. In addition, changes in land use on water-sheds occurring as a result of forest fires, urban development, clear cutting, or strip mining can be rapidly obtained.

  3. The residence time of water in the atmosphere revisited

    NASA Astrophysics Data System (ADS)

    van der Ent, Ruud J.; Tuinenburg, Obbe A.

    2017-02-01

    This paper revisits the knowledge on the residence time of water in the atmosphere. Based on state-of-the-art data of the hydrological cycle we derive a global average residence time of 8.9 ± 0.4 days (uncertainty given as 1 standard deviation). We use two different atmospheric moisture tracking models (WAM-2layers and 3D-T) to obtain atmospheric residence time characteristics in time and space. The tracking models estimate the global average residence time to be around 8.5 days based on ERA-Interim data. We conclude that the statement of a recent study that the global average residence time of water in the atmosphere is 4-5 days, is not correct. We derive spatial maps of residence time, attributed to evaporation and precipitation, and age of atmospheric water, showing that there are different ways of looking at temporal characteristics of atmospheric water. Longer evaporation residence times often indicate larger distances towards areas of high precipitation. From our analysis we find that the residence time over the ocean is about 2 days less than over land. It can be seen that in winter, the age of atmospheric moisture tends to be much lower than in summer. In the Northern Hemisphere, due to the contrast in ocean-to-land temperature and associated evaporation rates, the age of atmospheric moisture increases following atmospheric moisture flow inland in winter, and decreases in summer. Looking at the probability density functions of atmospheric residence time for precipitation and evaporation, we find long-tailed distributions with the median around 5 days. Overall, our research confirms the 8-10-day traditional estimate for the global mean residence time of atmospheric water, and our research contributes to a more complete view of the characteristics of the turnover of water in the atmosphere in time and space.

  4. Anomalous atmospheric absorption spectra due to water dimer

    NASA Astrophysics Data System (ADS)

    Cai, Peipei; Zhang, Hansheng; Shen, Shanxiong; Cheng, I.-Shan

    1986-11-01

    The anomalous atmospheric absorption spectra in the window wavelength region of 8-14 microns have been suggested due to the water dimer. Based on laboratory measurements, water continuum CO2 laser absorption spectra and a resonance absorption line due to the weak local wave vapor pure rotational transition have been reported. The equilibrium concentration of water dimers in the atmosphere, the electronic binding energy and the theoretical calculations for absorption attenuation have been obtained in agreement with published data.

  5. Advancing Water Science through Improved Cyberinfrastructure

    NASA Astrophysics Data System (ADS)

    Koch, B. J.; Miles, B.; Rai, A.; Ahalt, S.; Band, L. E.; Minsker, B.; Palmer, M.; Williams, M. R.; Idaszak, R.; Whitton, M. C.

    2012-12-01

    Major scientific advances are needed to help address impacts of climate change and increasing human-mediated environmental modification on the water cycle at global and local scales. However, such advances within the water sciences are limited in part by inadequate information infrastructures. For example, cyberinfrastructure (CI) includes the integrated computer hardware, software, networks, sensors, data, and human capital that enable scientific workflows to be carried out within and among individual research efforts and across varied disciplines. A coordinated transformation of existing CI and development of new CI could accelerate the productivity of water science by enabling greater discovery, access, and interoperability of data and models, and by freeing scientists to do science rather than create and manage technological tools. To elucidate specific ways in which improved CI could advance water science, three challenges confronting the water science community were evaluated: 1) How does ecohydrologic patch structure affect nitrogen transport and fate in watersheds?, 2) How can human-modified environments emulate natural water and nutrient cycling to enhance both human and ecosystem well-being?, 3) How do changes in climate affect water availability to support biodiversity and human needs? We assessed the approaches used by researchers to address components of these challenges, identified barriers imposed by limitations of current CI, and interviewed leaders in various water science subdisciplines to determine the most recent CI tools employed. Our preliminary findings revealed four areas where CI improvements are likely to stimulate scientific advances: 1) sensor networks, 2) data quality assurance/quality control, 3) data and modeling standards, 4) high performance computing. In addition, the full potential of a re-envisioned water science CI cannot be realized without a substantial training component. In light of these findings, we suggest that CI

  6. Regolith-atmosphere exchange of water in Mars' recent past

    NASA Astrophysics Data System (ADS)

    Steele, Liam J.; Balme, Matthew R.; Lewis, Stephen R.

    2017-03-01

    We investigate the exchange of water vapour between the regolith and atmosphere of Mars, and how it varies with different orbital parameters, atmospheric dust contents and surface water ice reservoirs. This is achieved through the coupling of a global circulation model (GCM) and a regolith diffusion model. GCM simulations are performed for hundreds of Mars years, with additional one-dimensional simulations performed for 50 kyr. At obliquities ɛ =15∘ and 30°, the thermal inertia and albedo of the regolith have more control on the subsurface water distribution than changes to the eccentricity or solar longitude of perihelion. At ɛ =45∘ , atmospheric water vapour abundances become much larger, allowing stable subsurface ice to form in the tropics and mid-latitudes. The circulation of the atmosphere is important in producing the subsurface water distribution, with increased water content in various locations due to vapour transport by topographically-steered flows and stationary waves. As these circulation patterns are due to topographic features, it is likely the same regions will also experience locally large amounts of subsurface water at different epochs. The dustiness of the atmosphere plays an important role in the distribution of subsurface water, with a dusty atmosphere resulting in a wetter water cycle and increased stability of subsurface ice deposits.

  7. Prototype Operational Advances for Atmospheric Radiation Dose Rate Specification

    NASA Astrophysics Data System (ADS)

    Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Garrett, H. B.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, D.; Mertens, C. J.; Xu, X.; Crowley, G.; Reynolds, A.; Azeem, I.; Wiltberger, M. J.; Wiley, S.; Bacon, S.; Teets, E.; Sim, A.; Dominik, L.

    2014-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has developed innovative, new space weather observations that will become part of the toolset that is transitioned into operational use. One prototype operational system for providing timely information about the effects of space weather is SET's Automated Radiation Measurements for Aerospace Safety (ARMAS) system. ARMAS will provide the "weather" of the radiation environment to improve aircraft crew and passenger safety. Through several dozen flights the ARMAS project has successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time via Iridium satellites, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. We are extending the dose measurement domain above commercial aviation altitudes into the stratosphere with a collaborative project organized by NASA's Armstrong Flight Research Center (AFRC) called Upper-atmospheric Space and Earth Weather eXperiment (USEWX). In USEWX we will be flying on the ER-2 high altitude aircraft a micro dosimeter for

  8. How Water Advances on Superhydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Schellenberger, Frank; Encinas, Noemí; Vollmer, Doris; Butt, Hans-Jürgen

    2016-03-01

    Superliquid repellency can be achieved by nano- and microstructuring surfaces in such a way that protrusions entrap air underneath the liquid. It is still not known how the three-phase contact line advances on such structured surfaces. In contrast to a smooth surface, where the contact line can advance continuously, on a superliquid-repellent surface, the contact line has to overcome an air gap between protrusions. Here, we apply laser scanning confocal microscopy to get the first microscopic videos of water drops advancing on a superhydrophobic array of micropillars. In contrast to common belief, the liquid surface gradually bends down until it touches the top face of the next micropillars. The apparent advancing contact angle is 180°. On the receding side, pinning to the top faces of the micropillars determines the apparent receding contact angle. Based on these observations, we propose that the apparent receding contact angle should be used for characterizing superliquid-repellent surfaces rather than the apparent advancing contact angle and hysteresis.

  9. Atmospheric water budget over the South Asian summer monsoon region

    NASA Astrophysics Data System (ADS)

    Unnikrishnan, C. K.; Rajeevan, M.

    2017-02-01

    High resolution hybrid atmospheric water budget over the South Asian monsoon region is examined. The regional characteristics, variability, regional controlling factors and the interrelations of the atmospheric water budget components are investigated. The surface evapotranspiration was created using the High Resolution Land Data Assimilation System (HRLDAS) with the satellite-observed rainfall and vegetation fraction. HRLDAS evapotranspiration shows significant similarity with in situ observations and MODIS satellite-observed evapotranspiration. Result highlights the fundamental importance of evapotranspiration over northwest and southeast India on atmospheric water balance. The investigation shows that the surface net radiation controls the annual evapotranspiration over those regions, where the surface evapotranspiration is lower than 550 mm. The rainfall and evapotranspiration show a linear relation over the low-rainfall regions (<500 mm/year). Similar result is observed in in NASA GLDAS data (1980-2014). The atmospheric water budget shows annual, seasonal, and intra-seasonal variations. Evapotranspiration does not show a high intra-seasonal variability as compared to other water budget components. The coupling among the water budget anomalies is investigated. The results show that regional inter-annual evapotranspiration anomalies are not exactly in phase with rainfall anomalies; it is strongly influenced by the surface conditions and other atmospheric forcing (like surface net radiation). The lead and lag correlation of water budget components show that the water budget anomalies are interrelated in the monsoon season even up to 4 months lead. These results show the important regional interrelation of water budget anomalies on south Asian monsoon.

  10. Measurement of atmospheric precipitable water using a solar radiometer. [water vapor absorption effects

    NASA Technical Reports Server (NTRS)

    Pitts, D. E.; Dillinger, A. E.; Mcallum, W. E.

    1974-01-01

    A technique is described and tested that allows the determination of atmospheric precipitable water from two measurements of solar intensity: one in a water-vapor absorption band and another in a nearby spectral region unaffected by water vapor.

  11. WATER FORMATION IN THE UPPER ATMOSPHERE OF THE EARLY EARTH

    SciTech Connect

    Fleury, Benjamin; Carrasco, Nathalie; Marcq, Emmanuel; Vettier, Ludovic; Määttänen, Anni

    2015-07-10

    The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N{sub 2}, CO{sub 2}, and H{sub 2}. The formation of gaseous products was monitored using infrared spectroscopy. Water was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.

  12. FORMATION OF WATER IN THE WARM ATMOSPHERES OF PROTOPLANETARY DISKS

    SciTech Connect

    Glassgold, A. E.; Meijerink, R.; Najita, J. R. E-mail: rowin@gps.caltech.edu

    2009-08-10

    The gas-phase chemistry of water in protoplanetary disks is analyzed with a model based on X-ray heating and ionization of the disk atmosphere. Several uncertain processes appear to play critical roles in generating the column densities of warm water that are detected from disks at infrared wavelengths. The dominant factors are the reactions that form molecular hydrogen, including formation on warm grains, and the ionization and heating of the atmosphere. All of these can work together to produce a region of high water abundances in the molecular transition layer of the inner disk atmosphere, where atoms are transformed into molecules, the temperature drops from thousands to hundreds of Kelvins, and the ionization begins to be dominated by the heavy elements. Grain formation of molecular hydrogen and mechanical heating of the atmosphere can play important roles in this region and directly affect the amount of warm water in protoplanetary disk atmospheres. Thus, it may be possible to account for the existing measurements of water emission from T Tauri disks without invoking transport of water from cooler to warmer regions. The hydroxyl radical OH is underabundant in this model of disk atmospheres and requires consideration of additional production and excitation processes.

  13. Atmospheric drivers of storage water use in Scots pine

    NASA Astrophysics Data System (ADS)

    Verbeeck, H.; Steppe, K.; Nadezhdina, N.; de Beeck, M. Op; Deckmyn, G.; Meiresonne, L.; Lemeur, R.; Čermák, J.; Ceulemans, R.; Janssens, I. A.

    2007-02-01

    In this study we determined the microclimatic drivers of storage water use in Scots pine (Pinus sylvestris L.) growing in a temperate climate. The storage water use was modeled using the ANAFORE model, integrating a dynamic water flow and - storage model with a process-based transpiration model. The model was calibrated and validated with sap flow measurements for the growing season of 2000 (26 May-18 October). Because there was no severe soil drought during the study period, we were able to study atmospheric effects. Incoming radiation was the main driver of storage water use. The general trends of sap flow and storage water use are similar, and follow more or less the pattern of incoming radiation. Nevertheless, considerable differences in the day-to-day pattern of sap flow and storage water use were observed, mainly driven by vapour pressure deficit (VPD). During dry atmospheric conditions (high VPD) storage water use was reduced. This reduction was disproportionally higher than the reduction in measured sap flow. Our results suggest that the trees did not rely more on storage water during periods of atmospheric drought, without severe soil drought. A third important factor was the tree water deficit. When storage compartments were depleted beyond a threshold, storage water use was limited due to the low water potential in the storage compartments. The maximum relative contribution of storage water to daily transpiration was also constrained by an increasing tree water deficit.

  14. Atmospheric corrections for satellite water quality studies

    NASA Technical Reports Server (NTRS)

    Piech, K. R.; Schott, J. R.

    1975-01-01

    Variations in the relative value of the blue and green reflectances of a lake can be correlated with important optical and biological parameters measured from surface vessels. Measurement of the relative reflectance values from color film imagery requires removal of atmospheric effects. Data processing is particularly crucial because: (1) lakes are the darkest objects in a scene; (2) minor reflectance changes can correspond to important physical changes; (3) lake systems extend over broad areas in which atmospheric conditions may fluctuate; (4) seasonal changes are of importance; and, (5) effects of weather are important, precluding flights under only ideal weather conditions. Data processing can be accomplished through microdensitometry of scene shadow areas. Measurements of reflectance ratios can be made to an accuracy of plus or minus 12%, sufficient to permit monitoring of important eutrophication indices.

  15. An advanced technique for speciation of organic nitrogen in atmospheric aerosols

    NASA Astrophysics Data System (ADS)

    Samy, S.; Robinson, J.; Hays, M. D.

    2011-12-01

    threshold as water-soluble free AA, with an average concentration of 22 ± 9 ng m-3 (N=13). Following microwave-assisted gas phase hydrolysis, the total AA concentration in the forest environment increased significantly (70 ± 35 ng m-3) and additional compounds (methionine, isoleucine) were detected above the reporting threshold. The ability to quantify AA in aerosol samples without derivatization reduces time consuming preparation procedures while providing the advancement of selective mass determination that eliminates potential interferences associated with traditional fluorescence detection. This step forward in precise mass determination with the use of internal standardization, improves the confidence of compound identification. With the increasing focus on WSOC (including ON) characterization in the atmospheric science community, native detection by LC-MS (Q-TOF) will play a central role in determining the most direct approach to quantify an increasing fraction of the co-extracted polar organic compounds. Method application for further characterization of atmospheric ON will be discussed. Reference: Samy, S., Robinson, J., and M.D. Hays. "An Advanced LC-MS (Q-TOF) Technique for the Detection of Amino Acids in Atmospheric Aerosols", Analytical Bioanalytical Chemistry, 2011, DOI: 10.1007/s00216-011-5238-2

  16. Factors governing water condensation in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Colburn, David S.; Pollack, J. B.; Haberle, Robert M.

    1988-01-01

    Modeling results are presented suggesting a diurnal condensation cycle at high altitudes at some seasons and latitudes. In a previous paper, the use of atmospheric optical depth measurements at the Viking lander site to show diurnal variability of water condensation at different seasons of the Mars year was described. Factors influencing the amount of condensation include latitude, season, atmospheric dust content and water vapor content at the observation site. A one-dimensional radiative-convective model is used herein based on the diabatic heating routines under development for the Mars General Circulation Model. The model predicts atmospheric temperature profiles at any latitude, season, time of day and dust load. From these profiles and an estimate of the water vapor, one can estimate the maximum occurring at an early morning hour (AM) and the minimum in the late afternoon (PM). Measured variations in the atmospheric optical density between AM and PM measurements were interpreted as differences in AM and PM condensation.

  17. Water vapor absorption in the atmospheric window at 239 GHz

    NASA Technical Reports Server (NTRS)

    Bauer, A.; Godon, M.; Carlier, J.; Ma, Q.

    1995-01-01

    Absolute absorption rates of pure water vapor and mixtures of water vapor and nitrogen have been measured in the atmospheric window at 239 GHz. The dependence on pressure as well as temperature has been obtained. The experimental data are compared with several theoretical or empirical models, and satisfactory agreement is obtained with the models involving a continuum; in the case of pure water vapor, the continuum contribution based upon recent theoretical developments gives good results. The temperature dependence is stronger than that proposed in a commonly used atmospheric transmission model.

  18. Isotopic composition of atmospheric moisture from pan water evaporation measurements.

    PubMed

    Devi, Pooja; Jain, Ashok Kumar; Rao, M Someshwer; Kumar, Bhishm

    2015-01-01

    A continuous and reliable time series data of the stable isotopic composition of atmospheric moisture is an important requirement for the wider applicability of isotope mass balance methods in atmospheric and water balance studies. This requires routine sampling of atmospheric moisture by an appropriate technique and analysis of moisture for its isotopic composition. We have, therefore, used a much simpler method based on an isotope mass balance approach to derive the isotopic composition of atmospheric moisture using a class-A drying evaporation pan. We have carried out the study by collecting water samples from a class-A drying evaporation pan and also by collecting atmospheric moisture using the cryogenic trap method at the National Institute of Hydrology, Roorkee, India, during a pre-monsoon period. We compared the isotopic composition of atmospheric moisture obtained by using the class-A drying evaporation pan method with the cryogenic trap method. The results obtained from the evaporation pan water compare well with the cryogenic based method. Thus, the study establishes a cost-effective means of maintaining time series data of the isotopic composition of atmospheric moisture at meteorological observatories. The conclusions drawn in the present study are based on experiments conducted at Roorkee, India, and may be examined at other regions for its general applicability.

  19. Determinations by Seasat of atmospheric water and synoptic fronts

    NASA Technical Reports Server (NTRS)

    Taylor, P. K.; Katsaros, K. B.; Lipes, R. G.

    1981-01-01

    It is shown by means of radiosonde data from the Joint Air-Sea Interaction (JASIN) experiment that the Seasat Scanning Multichannel Microwave Radiometer (SMMR) atmospheric water vapor distributions, taken over 600-km wide swaths with a resolution of 54 km, can be used to detect the position of atmospheric fronts in the lower troposphere. In addition to the fact that, unlike visible and IR radiometry, the SMMR determinations are not hampered by extensive cirrus or by a lack of frontal clouds, they use more channels, allowing better discrimination between the effects of liquid water, water vapor and sea state, and show improved spatial resolution. Data analysis results show that the SMMR atmospheric water vapor distributions have an accuracy comparable to that of in situ radiosonde measurements.

  20. Column atmospheric water vapor retrievals from airborne imaging spectrometer data

    NASA Technical Reports Server (NTRS)

    Gao, Bo-Cai; Goetz, Alexander F. H.

    1989-01-01

    High-spatial-resolution column atmospheric water vapor amounts were derived from spectral data collected by the Airborne Visible Infrared Imaging Spectrometer (AVIRIS). The quantitative derivation is made by curve fitting observed spectra with calculated spectra in the 1.14- and 0.94-micron water-vapor band absorption regions with a nonlinear least-squares technique. The precision of the retrieved column water vapor is approximately 5 percent. The derived column water vapor amounts are independent of the absolute surface reflectance. Curve fitting of spectra near 1 micron from areas covered with vegetation indicates that both the amount of atmospheric water vapor and the moisture content of vegetation can be retrieved simultaneously. It should be possible to measure column water vapor over land areas from satellite altitude with the proposed high-resolution imaging spectrometer or even the moderate-resolution imaging spectrometer.

  1. Water Cycle in the Atmosphere and Shallow Subsurface

    NASA Astrophysics Data System (ADS)

    Tokano, Tetsuya

    The global water cycle on Earth constitutes one of the most relevant components of the terrestrial ecosystem. While the vast majority of terrestrial water is stored in the world oceans, the perpetual cycle of water between ocean, atmosphere and land in all three phases is recognised as one basic feature that characterises the Earth, and is contrasted to the rest of the Solar System. On the other hand, Mars is devoid of a liquid hydrological cycle in the atmosphere and on the surface in the form of rainfall, rivers or oceans, which favour life on Earth's surface. However, a subtle water cycle does exist on present Mars and elucidating the details of the water cycle is crucial in understanding the global water inventory.

  2. Water Loss from Terrestrial Planets with CO2-rich Atmospheres

    NASA Astrophysics Data System (ADS)

    Wordsworth, R. D.; Pierrehumbert, R. T.

    2013-12-01

    Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study the dependence of water loss rates from terrestrial planets on a range of atmospheric and external parameters. We show that CO2 can only cause significant water loss by increasing surface temperatures over a narrow range of conditions, with cooling of the middle and upper atmosphere acting as a bottleneck on escape in other circumstances. Around G-stars, efficient loss only occurs on planets with intermediate CO2 atmospheric partial pressures (0.1-1 bar) that receive a net flux close to the critical runaway greenhouse limit. Because G-star total luminosity increases with time but X-ray and ultraviolet/ultravoilet luminosity decreases, this places strong limits on water loss for planets like Earth. In contrast, for a CO2-rich early Venus, diffusion limits on water loss are only important if clouds caused strong cooling, implying that scenarios where the planet never had surface liquid water are indeed plausible. Around M-stars, water loss is primarily a function of orbital distance, with planets that absorb less flux than ~270 W m-2 (global mean) unlikely to lose more than one Earth ocean of H2O over their lifetimes unless they lose all their atmospheric N2/CO2 early on. Because of the variability of H2O delivery during accretion, our results suggest that many "Earth-like" exoplanets in the habitable zone may have ocean-covered surfaces, stable CO2/H2O-rich atmospheres, and high mean surface temperatures.

  3. Advances in Diode-Laser-Based Water Vapor Differential Absorption Lidar

    NASA Astrophysics Data System (ADS)

    Spuler, Scott; Repasky, Kevin; Morley, Bruce; Moen, Drew; Weckwerth, Tammy; Hayman, Matt; Nehrir, Amin

    2016-06-01

    An advanced diode-laser-based water vapor differential absorption lidar (WV-DIAL) has been developed. The next generation design was built on the success of previous diode-laser-based prototypes and enables accurate measurement of water vapor closer to the ground surface, in rapidly changing atmospheric conditions, and in daytime cloudy conditions up to cloud base. The lidar provides up to 1 min resolution, 150 m range resolved measurements of water vapor in a broad range of atmospheric conditions. A description of the instrument and results from its initial field test in 2014 are discussed.

  4. OPERA: An Atmospheric Correction for Land and Water

    NASA Astrophysics Data System (ADS)

    Sterckx, Sindy; Knaeps, Els; Adriaensen, Stefan; Reusen, Ils; De Keukelaere, Liesbeth; Hunter, Peter; Giardino, Claudia; Odermatt, Daniel

    2015-12-01

    Atmospheric correction is one of the most important part of the pre-processing of satellite remotely sensed data used to retrieve bio-geophysical paramters. In this paper we present the scene and sensor generic atmospheric correction scheme ‘OPERA’ allowing to correct both land and water areas in the remote sensing image. OPERA can now be used to correct for atmospheric effects in scenes acquired by MERIS, Landsat-8, hyperspectral sensors and will be applicable to Sentinel-3 and Sentinel-2.

  5. Detection of carbon monoxide and water absorption lines in an exoplanet atmosphere.

    PubMed

    Konopacky, Quinn M; Barman, Travis S; Macintosh, Bruce A; Marois, Christian

    2013-03-22

    Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging--spatially resolving the planet from its parent star--which enables high-resolution spectroscopy of self-luminous planets in jovian-like orbits. Here, we present a spectrum with numerous, well-resolved molecular lines from both water and carbon monoxide from a massive planet orbiting less than 40 astronomical units from the star HR 8799. These data reveal the planet's chemical composition, atmospheric structure, and surface gravity, confirming that it is indeed a young planet. The spectral lines suggest an atmospheric carbon-to-oxygen ratio that is greater than that of the host star, providing hints about the planet's formation.

  6. Profiling of Atmospheric Water Vapor with MIR and LASE

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Racette, P.; Triesly, M. E.; Browell, E. V.; Ismail, S.; Chang, L. A.; Hildebrand, Peter H. (Technical Monitor)

    2001-01-01

    This paper presents the first and the only simultaneous measurements of water vapor by MIR (Millimeter-wave Imaging Radiometer) and LASE (Lidar Atmospheric Sounding Experiment) on board the same ER-2 aircraft. Water vapor is one of the most important constituents in the Earth's atmosphere, as its spatial and temporal variations affect a wide spectrum of meteorological phenomena ranging from the formation of clouds to the development of severe storms. Its concentration, as measured in terms of relative humidity, determines the extinction coefficient of atmospheric aerosol particles and therefore visibility. These considerations point to the need for effective and frequent measurements of the atmospheric water vapor. The MIR and LASE instruments provide measurements of water vapor profiles with two markedly different techniques. LASE can give water vapor profiles with excellent vertical resolution under clear condition, while MIR can retrieve water vapor profiles with a crude vertical resolution even under a moderate cloud cover. Additionally, millimeter-wave measurements are relatively simple and provide better spatial coverage.

  7. Advanced ceramic cladding for water reactor fuel

    SciTech Connect

    Feinroth, H.

    2000-07-01

    Under the US Department of Energy's Nuclear Energy Research Initiatives (NERI) program, continuous fiber ceramic composites (CFCCs) are being developed as cladding for water reactor fuel elements. The purpose is to substantially increase the passive safety of water reactors. A development effort was initiated in 1991 to fabricate CFCC-clad tubes using commercially available fibers and a sol-gel process developed by McDermott Technologies. Two small-diameter CFCC tubes were fabricated using pure alumina and alumina-zirconia fibers in an alumina matrix. Densities of {approximately}60% of theoretical were achieved. Higher densities are required to guarantee fission gas containment. This NERI work has just begun, and only preliminary results are presented herein. Should the work prove successful, further development is required to evaluate CFCC cladding and performance, including in-pile tests containing fuel and exploring a marriage of CFCC cladding materials with suitable advanced fuel and core designs. The possibility of much higher temperature core designs, possibly cooled with supercritical water, and achievement of plant efficiencies {ge}50% would be examined.

  8. Biogenic metals in advanced water treatment.

    PubMed

    Hennebel, Tom; De Gusseme, Bart; Boon, Nico; Verstraete, Willy

    2009-02-01

    Microorganisms can change the oxidation state of metals and concomitantly deposit metal oxides and zerovalent metals on or into their cells. The microbial mechanisms involved in these processes have been extensively studied in natural environments, and researchers have recently gained interest in the applications of microbe-metal interactions in biotechnology. Because of their specific characteristics, such as high specific surface areas and high catalytic reactivity, biogenic metals offer promising perspectives for the sorption and (bio)degradation of contaminants. In this review, the precipitation of biogenic manganese and iron species and the microbial reduction of precious metals, such as palladium, platinum, silver and gold, are discussed with specific attention to the application of these biogenic metals in innovative remediation technologies in advanced water treatment.

  9. Spectroscopy underlying microwave remote sensing of atmospheric water vapor

    NASA Astrophysics Data System (ADS)

    Tretyakov, M. Yu.

    2016-10-01

    The paper presents a spectroscopist's view on the problem of recovery of the atmosphere humidity profile using modern microwave radiometers. Fundamental equations, including the description of their limitations, related to modeling of atmospheric water vapor absorption are given. A review of all reported to date experimental studies aimed at obtaining corresponding numerical parameters is presented. Best estimates of these parameters related to the Voigt (Lorentz, Gross, Van Vleck - Weisskopf and other equivalent) profile based modeling of the 22- and 183-GHz water vapor diagnostic lines and to non-resonance absorption as well as corresponding uncertainties are made on the basis of their comparative analysis.

  10. Water loss from Venus: Implications for the Earth's early atmosphere

    NASA Technical Reports Server (NTRS)

    Richardson, S. M.; Pollack, J. B.; Reynolds, R. T.

    1985-01-01

    The atmosphere of Venus outgassed rapidly as a result of planetary heating during accretion, resulting in massive water loss. The processes affecting atmospheric chemistry following accretion have consisted largely of hydrogen escape and internal re-equilibrium. The initial bulk composition of Venus and Earth are assumed to have been roughly similar. Chemical speciation on Venus was controlled by the temperature and oxygen buffering capacity of the surface magma. It is also assumed that the surfaces of planetary bodies of the inner solar system were partly or wholly molten during accretion with a temperature estimated at 1273 to 1573 K. To investigate the range of reasonable initial atmospheric compositions on Venus, limits have to be set for the proportion of total hydrogen and the buffered fugacity of oxygen. Using the C/H ratio of 0.033 set for Earth, virtually all of the water generated during outgassing must later have been lost in order to bring the current CO2/H2O ratio for Venus up to its observed value of 10 sup 4 to 10 sup 5. The proportion of H2O decreases in model atmospheres with successfully higher C/H values, ultimately approaching the depleted values currently observed on Venus. Increasing C/H also results in a rapid increase in CO/H2O and provides an efficient mechanism for water loss by the reaction CO+H2O = CO2 + H2. This reaction, plus water loss mechanisms involving crustal iron, could have removed a very large volume of water from the Venusian atmosphere, even at a low C/H value.

  11. Water Planetary and Cometary Atmospheres: H2O/HDO Transmittance and Fluorescence Models

    NASA Technical Reports Server (NTRS)

    Villanueva, G. L.; Mumma, M. J.; Bonev, B. P.; Novak, R. E.; Barber, R. J.; DiSanti, M. A.

    2012-01-01

    We developed a modern methodology to retrieve water (H2O) and deuterated water (HDO) in planetary and cometary atmospheres, and constructed an accurate spectral database that combines theoretical and empirical results. Based on a greatly expanded set of spectroscopic parameters, we built a full non-resonance cascade fluorescence model and computed fluorescence efficiencies for H2O (500 million lines) and HDO (700 million lines). The new line list was also integrated into an advanced terrestrial radiative transfer code (LBLRTM) and adapted to the CO2 rich atmosphere of Mars, for which we adopted the complex Robert-Bonamy formalism for line shapes. We then retrieved water and D/H in the atmospheres of Mars, comet C/2007 WI, and Earth by applying the new formalism to spectra obtained with the high-resolution spectrograph NIRSPEC/Keck II atop Mauna Kea (Hawaii). The new model accurately describes the complex morphology of the water bands and greatly increases the accuracy of the retrieved abundances (and the D/H ratio in water) with respect to previously available models. The new model provides improved agreement of predicted and measured intensities for many H2O lines already identified in comets, and it identifies several unassigned cometary emission lines as new emission lines of H2O. The improved spectral accuracy permits retrieval of more accurate rotational temperatures and production rates for cometary water.

  12. Advanced Water Vapor Lidar Detection System

    NASA Technical Reports Server (NTRS)

    Elsayed-Ali, Hani

    1998-01-01

    In the present water vapor lidar system, the detected signal is sent over long cables to a waveform digitizer in a CAMAC crate. This has the disadvantage of transmitting analog signals for a relatively long distance, which is subjected to pickup noise, leading to a decrease in the signal to noise ratio. Generally, errors in the measurement of water vapor with the DIAL method arise from both random and systematic sources. Systematic errors in DIAL measurements are caused by both atmospheric and instrumentation effects. The selection of the on-line alexandrite laser with a narrow linewidth, suitable intensity and high spectral purity, and its operation at the center of the water vapor lines, ensures minimum influence in the DIAL measurement that are caused by the laser spectral distribution and avoid system overloads. Random errors are caused by noise in the detected signal. Variability of the photon statistics in the lidar return signal, noise resulting from detector dark current, and noise in the background signal are the main sources of random error. This type of error can be minimized by maximizing the signal to noise ratio. The increase in the signal to noise ratio can be achieved by several ways. One way is to increase the laser pulse energy, by increasing its amplitude or the pulse repetition rate. Another way, is to use a detector system with higher quantum efficiency and lower noise, on the other hand, the selection of a narrow band optical filter that rejects most of the day background light and retains high optical efficiency is an important issue. Following acquisition of the lidar data, we minimize random errors in the DIAL measurement by averaging the data, but this will result in the reduction of the vertical and horizontal resolutions. Thus, a trade off is necessary to achieve a balance between the spatial resolution and the measurement precision. Therefore, the main goal of this research effort is to increase the signal to noise ratio by a factor of

  13. Chlorinated hydrocarbons in the Sargasso sea atmosphere and surface water.

    PubMed

    Bidleman, T F; Olney, C E

    1974-02-08

    Polychlorinated biphenyls (PCB), DDT, and chlordane concentrations were measured in air sampled from a tower on the south shore of Bermuda and in Sargasso Sea surface water approximately 80 to 320 kilometers south of Bermuda. The atmospheric chlorinated hydrocarbons appeared to be gaseous, and the DDT concentration was two orders of magnitude higher than previously reported particulate values. The PCB and DDT were enriched in the surface microlayer (150 micrometers) relative to their concentrations in water at a depth of 30 centimeters. Atmospheric residence times for PCB and DDT of 40 to 50 days, calculated from the concentrations in the air and water, are 20 times shorter than values previously estimated for DDT from rainfall and DDT production data.

  14. Electron deposition in water vapor, with atmospheric applications.

    NASA Technical Reports Server (NTRS)

    Olivero, J. J.; Stagat, R. W.; Green, A. E. S.

    1972-01-01

    Examination of the consequences of electron impact on water vapor in terms of the microscopic details of excitation, dissociation, ionization, and combinations of these processes. Basic electron-impact cross-section data are assembled in many forms and are incorporated into semianalytic functions suitable for analysis with digital computers. Energy deposition in water vapor is discussed, and the energy loss function is presented, along with the 'electron volts per ion pair' and the efficiencies of energy loss in various processes. Several applications of electron and water-vapor interactions in the atmospheric sciences are considered, in particular, H2O comets, aurora and airglow, and lightning.

  15. ANALYTICAL MODELS OF EXOPLANETARY ATMOSPHERES. I. ATMOSPHERIC DYNAMICS VIA THE SHALLOW WATER SYSTEM

    SciTech Connect

    Heng, Kevin; Workman, Jared E-mail: jworkman@coloradomesa.edu

    2014-08-01

    Within the context of exoplanetary atmospheres, we present a comprehensive linear analysis of forced, damped, magnetized shallow water systems, exploring the effects of dimensionality, geometry (Cartesian, pseudo-spherical, and spherical), rotation, magnetic tension, and hydrodynamic and magnetic sources of friction. Across a broad range of conditions, we find that the key governing equation for atmospheres and quantum harmonic oscillators are identical, even when forcing (stellar irradiation), sources of friction (molecular viscosity, Rayleigh drag, and magnetic drag), and magnetic tension are included. The global atmospheric structure is largely controlled by a single key parameter that involves the Rossby and Prandtl numbers. This near-universality breaks down when either molecular viscosity or magnetic drag acts non-uniformly across latitude or a poloidal magnetic field is present, suggesting that these effects will introduce qualitative changes to the familiar chevron-shaped feature witnessed in simulations of atmospheric circulation. We also find that hydrodynamic and magnetic sources of friction have dissimilar phase signatures and affect the flow in fundamentally different ways, implying that using Rayleigh drag to mimic magnetic drag is inaccurate. We exhaustively lay down the theoretical formalism (dispersion relations, governing equations, and time-dependent wave solutions) for a broad suite of models. In all situations, we derive the steady state of an atmosphere, which is relevant to interpreting infrared phase and eclipse maps of exoplanetary atmospheres. We elucidate a pinching effect that confines the atmospheric structure to be near the equator. Our suite of analytical models may be used to develop decisively physical intuition and as a reference point for three-dimensional magnetohydrodynamic simulations of atmospheric circulation.

  16. Follow The Water: The Ultimate WFC3 Exoplanet Atmosphere Survey

    NASA Astrophysics Data System (ADS)

    Bean, Jacob

    2013-10-01

    Recent surveys have revealed an amazing, and yet unexplained, diversity of planets orbiting other stars. Studying the atmospheres of representative exoplanets is the key next step in leveraging these detections to further transform our understanding of planet formation and planetary physics. This is because a planet's atmosphere is a fossil record of its primordial origins and controls its size and appearance.We propose an intensive and comprehensive exoplanet atmosphere Large Treasury survey using the unrivaled capabilities of the WFC3 IR instrument to measure high-precision transmission, dayside emission, and phase-resolved emission spectra over a broad wavelength range for eight planetary Rosetta Stones. These data will yield unprecedented constraints on the abundances of water, elemental abundance ratios, thermal profiles, chemistries, presence of clouds and hazes, and dynamics of exoplanet atmospheres. Just detecting the atmospheres of these planets is not enough anymore. Revealing the fundamental properties of exoplanet atmospheres to investigate their nature and origins requires high-precision spectroscopy that is sensitive to spectral features from multiple chemical species and altitudes, and such data can only be obtained with an intensive HST program. A survey is mandatory to put the individual objects in a broader context, and to get at the underlying physics that results in a diverse array of emergent properties. This Treasury program will have no proprietary period in order to accelerate the progress of the field. This program is urgently needed to prepare for the future characterization of habitable exoplanets using JWST.

  17. An advanced open-path atmospheric monitor design

    SciTech Connect

    Taylor, L.; Suhre, D.; Mech, S.

    1996-05-01

    The conceptual design of an open-path atmospheric monitor combines an acousto-optic tunable filter for emission spectroscopy (3-14 {mu}m) with a mid-IR (4.6-5.4 {mu}m) for absorption spectroscopy. It utilizes mostly commercially available components, covers a large area ({approximately}4 km radius), measures the distance to any reflecting object, can take measurements along any line-of-sight, and is eye safe. Of twenty test pollutants it is to detect, the concentrations of all twenty will be measurable via emission spectroscopy and ten by the more sensitive absorption spectroscopy.

  18. Atmospheric Water Balance and Variability in the MERRA-2 Reanalysis

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Robertson, Franklin R.; Takacs, Lawrence; Molod, Andrea; Mocko, David

    2017-01-01

    Closing and balancing Earths global water cycle remains a challenge for the climate community. Observations are limited in duration, global coverage, and frequency, and not all water cycle terms are adequately observed. Reanalyses aim to fill the gaps through the assimilation of as many atmospheric water vapor observations as possible. Former generations of reanalyses have demonstrated a number of systematic problems that have limited their use in climate studies, especially regarding low-frequency trends. This study characterizes the NASA Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) water cycle relative to contemporary reanalyses and observations. MERRA-2 includes measures intended to minimize the spurious global variations related to in homogeneity in the observational record. The global balance and cycling of water from ocean to land is presented, with special attention given to the water vapor analysis increment and the effects of the changing observing system. While some systematic regional biases can be identified,MERRA-2 produces temporally consistent time series of total column water and transport of water from ocean to land. However, the interannual variability of ocean evaporation is affected by the changing surface-wind-observing system, and precipitation variability is closely related to the evaporation. The surface energy budget is also strongly influenced by the interannual variability of the ocean evaporation. Furthermore, evaluating the relationship of temperature and water vapor indicates that the variations of water vapor with temperature are weaker in satellite data reanalyses, not just MERRA-2, than determined by observations, atmospheric models, or reanalyses without water vapor assimilation.

  19. Advanced Global Atmospheric Gases Experiment (AGAGE): MIT Contribution

    NASA Technical Reports Server (NTRS)

    Kurylo, Michael

    2003-01-01

    We describe in detail the instrumentation and calibrations used in the ALE, GAGE and AGAGE experiments and present a history of the majority of the anthropogenic ozone- depleting and climate-forcing gases in air based on these experiments. Beginning in 1978, these three successive automated high frequency in-situ experiments have documented the long-term behavior of the measured concentrations of these gases over the past twenty years, and show both the evolution of latitudinal gradients and the high frequency variability due to sources and circulation. We provide estimates of the long-term trends in total chlorine contained in long- lived halocarbons involved in ozone depletion. We summarize interpretations of these measurements using inverse methods to determine trace gas lifetimes and emissions. Finally, we provide a combined observational and modeled reconstruction of the evolution of chlorocarbons by latitude in the atmosphere over the past sixty years which can be used as boundary conditions for interpreting trapped air in glaciers and oceanic measurements of chlorocarbon tracers of the deep oceanic circulation. Some specific conclusions are: (a) International compliance with the Montreal Protocol is so far resulting in chlorofluorocarbon and chlorocarbon mole fractions comparable to target levels, (b) Mole fractions of total chlorine contained in long-lived halocarbons (CCl2F2, CCl3F, CH3CCl3, CCl4, CHClF2, CCl2FCClF2, CH3Cl, CH2Cl2, CHCl3, CCl2=CCl2) in the lower troposphere reached maximum values of about 3.6 ppb in 1993 and are beginning to slowly decrease in the global lower atmosphere, (c) The chlorofluorocarbons have atmospheric lifetimes consistent with destruction in the stratosphere being their principal removal mechanism, (d) Multi-annual variations in chlorofluorocarbon and chlorocarbon emissions deduced from ALUGAGWAGAGE data are consistent approximately with variations estimated independently from industrial production and sales data where

  20. Thermochemistry of substellar atmospheres: Water, oxygen, sulfur, and phosphorus

    NASA Astrophysics Data System (ADS)

    Visscher, Channon Wayne

    2006-09-01

    Thermochemical equilibrium and kinetic calculations are used to investigate atmospheric chemistry in substellar objects: giant planets, extrasolar giant planets (EGPs), and brown dwarfs. These studies include an assessment of the water and total oxygen inventories in the interiors of Jupiter and Saturn, and detailed modeling of sulfur and phosphorus chemistry in the atmospheres of substellar objects. In the first part of the dissertation, the water and total oxygen abundances in the deep atmospheres of Jupiter and Saturn are determined by considering the effects of H 2 O and O on the chemistry of CO, PH 3 , and SiH 4 . On Jupiter, the observed CO abundance indicates a water abundance of 0.4--1.4 times the protosolar H 2 O/H 2 ratio (8.96 × 10 -4 ). On Saturn, a combination of CO and PH 3 chemical constraints requires a water abundance of 1.9--6.1 times the protosolar abundance. Combining these results with Si mass balance considerations gives a total oxygen abundance of 0.7--1.7 and 3.2--6.4 times the protosolar O/H 2 ratio (1.16 × 10 -3 ) on Jupiter and Saturn, respectively. In both planets, oxygen is less enriched than other heavy elements (such as carbon) relative to hydrogen and the solar system composition. These results provide important constraints for giant planet formation mechanisms and models of tropospheric chemistry. The second part of the dissertation is a detailed study of sulfur and phosphorus chemistry in substellar atmospheres. The chemical behavior of individual S- and P-bearing gases and condensates is determined as a function of temperature, total pressure, and metallicity. Aside from minor amounts of sulfur removed by metal sulfide cloud formation, H 2 S is approximately representative of the sulfur inventory throughout substellar atmospheres. Silicon sulfide (SiS) is a potential tracer of weather in EGPs and L dwarfs. Phosphorus chemistry is considerably more complex than that of sulfur. Disequilibrium abundances of PH 3 approximately

  1. Constructing an advanced software tool for planetary atmospheric modeling

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.; Sims, Michael H.; Podolak, Esther; Mckay, Christopher P.

    1990-01-01

    A prototype is described that can serve as a scientific-modeling software tool to facilitate the development of useful scientific models. The prototype is developed for applications to planetary modeling, and specific examples are given that relate to the atmosphere of Titan. The scientific modeling tool employs a high-level domain-specific modeling language, several data-display facilities, and a library of experimental datasets and scientific equations. The planetary modeling prototype links uncomputed physical variables to computed variables with computational transformations based on a backchaining procedure. The system - implemented in LISP with an object-oriented knowledge-representation tool - is run on a workstation that provides interface with several models. The prototype is expected to form the basis for a sophisticated modeling tool that can permit active experimentation.

  2. Construction of an advanced software tool for planetary atmospheric modeling

    NASA Technical Reports Server (NTRS)

    Friedland, Peter; Keller, Richard M.; Mckay, Christopher P.; Sims, Michael H.; Thompson, David E.

    1992-01-01

    Scientific model-building can be a time intensive and painstaking process, often involving the development of large complex computer programs. Despite the effort involved, scientific models cannot be distributed easily and shared with other scientists. In general, implemented scientific models are complicated, idiosyncratic, and difficult for anyone but the original scientist/programmer to understand. We propose to construct a scientific modeling software tool that serves as an aid to the scientist in developing, using and sharing models. The proposed tool will include an interactive intelligent graphical interface and a high-level domain-specific modeling language. As a test bed for this research, we propose to develop a software prototype in the domain of planetary atmospheric modeling.

  3. Construction of an advanced software tool for planetary atmospheric modeling

    NASA Technical Reports Server (NTRS)

    Friedland, Peter; Keller, Richard M.; Mckay, Christopher P.; Sims, Michael H.; Thompson, David E.

    1993-01-01

    Scientific model-building can be a time intensive and painstaking process, often involving the development of large complex computer programs. Despite the effort involved, scientific models cannot be distributed easily and shared with other scientists. In general, implemented scientific models are complicated, idiosyncratic, and difficult for anyone but the original scientist/programmer to understand. We propose to construct a scientific modeling software tool that serves as an aid to the scientist in developing, using and sharing models. The proposed tool will include an interactive intelligent graphical interface and a high-level domain-specific modeling language. As a testbed for this research, we propose to develop a software prototype in the domain of planetary atmospheric modeling.

  4. Advanced development of atmospheric models. [SEASAT Program support

    NASA Technical Reports Server (NTRS)

    Kesel, P. G.; Langland, R. A.; Stephens, P. L.; Welleck, R. E.; Wolff, P. M.

    1979-01-01

    A set of atmospheric analysis and prediction models was developed in support of the SEASAT Program existing objective analysis models which utilize a 125x125 polar stereographic grid of the Northern Hemisphere, which were modified in order to incorporate and assess the impact of (real or simulated) satellite data in the analysis of a two-day meteorological scenario in January 1979. Program/procedural changes included: (1) a provision to utilize winds in the sea level pressure and multi-level height analyses (1000-100 MBS); (2) The capability to perform a pre-analysis at two control levels (1000 MBS and 250 MBS); (3) a greater degree of wind- and mass-field coupling, especially at these controls levels; (4) an improved facility to bogus the analyses based on results of the preanalysis; and (5) a provision to utilize (SIRS) satellite thickness values and cloud motion vectors in the multi-level height analysis.

  5. Advanced Doubling Adding Method for Radiative Transfer in Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Liu, Quanhua; Weng, Fuzhong

    2006-12-01

    The doubling adding method (DA) is one of the most accurate tools for detailed multiple-scattering calculations. The principle of the method goes back to the nineteenth century in a problem dealing with reflection and transmission by glass plates. Since then the doubling adding method has been widely used as a reference tool for other radiative transfer models. The method has never been used in operational applications owing to tremendous demand on computational resources from the model. This study derives an analytical expression replacing the most complicated thermal source terms in the doubling adding method. The new development is called the advanced doubling adding (ADA) method. Thanks also to the efficiency of matrix and vector manipulations in FORTRAN 90/95, the advanced doubling adding method is about 60 times faster than the doubling adding method. The radiance (i.e., forward) computation code of ADA is easily translated into tangent linear and adjoint codes for radiance gradient calculations. The simplicity in forward and Jacobian computation codes is very useful for operational applications and for the consistency between the forward and adjoint calculations in satellite data assimilation.

  6. Hurricane Isabel, Amount of Atmospheric Water Vapor Observed By AIRS

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site] Figure 1

    These false-color images show the amount of atmospheric water vapor observed by AIRS two weeks prior to the passage of Hurricane Isabel, and then when it was a Category 5 storm. The region shown includes parts of South America and the West Indies. Puerto Rico is the large island below the upper left corner.

    Total water vapor represents the depth of a layer if all the water vapor in the atmosphere were to condense and fall to the surface. The color bar on the right sides of the plots give the thickness of this layer in millimeters (mm). The first image, from August 28, shows typical tropical water vapor amounts over the ocean: between roughly 25 and 50 mm, or 1 to 2 inches. The highest values of roughly 80 mm, seen as a red blob over South America, corresponds to intense thunderstorms. Thunderstorms pull in water vapor from surrounding regions and concentrate it, with much of it then falling as rain.

    Figure 1 shows total water during the passage of Hurricane Isabel on September 13. The storm is apparent: the ring of moderate values surrounding a very strong maximum of 100 mm. Total water of more than 80 mm is unusual, and these values correspond to the intense thunderstorms contained within Isabel. The thunderstorms--and the large values of total water--are fed by evaporation from the ocean in the hurricane's high winds. The water vapor near the center of the storm does not remain there long, since hurricane rain rates as high 50 mm (2 inches) per hour imply rapid cycling of the water we observe. Away from the storm the amount of total water vapor is rather low, associated with fair weather where air that ascended near the storm's eye returns to earth, having dropped its moisture as rain. Also seen in the second images are two small regions of about 70 mm of total water over south America. These are yet more thunderstorms, though likely much more benign than those in Isabel.

    The

  7. Stable isotopes in atmospheric water vapor and applications to the hydrologic cycle

    NASA Astrophysics Data System (ADS)

    Galewsky, Joseph; Steen-Larsen, Hans Christian; Field, Robert D.; Worden, John; Risi, Camille; Schneider, Matthias

    2016-12-01

    The measurement and simulation of water vapor isotopic composition has matured rapidly over the last decade, with long-term data sets and comprehensive modeling capabilities now available. Theories for water vapor isotopic composition have been developed by extending the theories that have been used for the isotopic composition of precipitation to include a more nuanced understanding of evaporation, large-scale mixing, deep convection, and kinetic fractionation. The technologies for in situ and remote sensing measurements of water vapor isotopic composition have developed especially rapidly over the last decade, with discrete water vapor sampling methods, based on mass spectroscopy, giving way to laser spectroscopic methods and satellite- and ground-based infrared absorption techniques. The simulation of water vapor isotopic composition has evolved from General Circulation Model (GCM) methods for simulating precipitation isotopic composition to sophisticated isotope-enabled microphysics schemes using higher-order moments for water and ice size distributions. The incorporation of isotopes into GCMs has enabled more detailed diagnostics of the water cycle and has led to improvements in its simulation. The combination of improved measurement and modeling of water vapor isotopic composition opens the door to new advances in our understanding of the atmospheric water cycle, in processes ranging from the marine boundary layer, through deep convection and tropospheric mixing, and into the water cycle of the stratosphere. Finally, studies of the processes governing modern water vapor isotopic composition provide an improved framework for the interpretation of paleoclimate proxy records of the hydrological cycle.

  8. Advanced methods and means to improve atmospheric lidar stability against sky background clutter

    NASA Astrophysics Data System (ADS)

    Agishev, Ravil R.

    2011-11-01

    An impact of intensive background clutter on lidar photodetectors leads to changes of their sensitivity and can even overload them. As a result, information on atmospheric optical parameters is distorted and sometimes can be completely lost. Since a problem of lidar system structure and parameters adaptation to background radiation remains actual one, some advanced methods and means to improve atmospheric lidar stability against sky background clutter are discussed.

  9. Water inventories on Earth and Mars: Clues to atmosphere formation

    NASA Technical Reports Server (NTRS)

    Carr, M. H.

    1992-01-01

    Water is distributed differently on Earth and on Mars and the differences may have implications for the accretion of the two planets and the formation of their atmospheres. The Earth's mantle appears to contain at least several times the water content of the Martian mantle even accounting for differences in plate tectonics. One explanation is that the Earth's surface melted during accretion, as a result of development of a steam atmosphere, thereby allowing impact-devolitalized water at the surface to dissolve into the Earth's interior. In contrast, because of Mars' smaller size and greater distance from the Sun, the Martian surface may not have melted, so that the devolatilized water could not dissolve into the surface. A second possibility is suggested by the siderophile elements in the Earth's mantle, which indicates the Earth acquired a volatile-rich veneer after the core formed. Mars may have acquired a late volatile-rich veneer, but it did not get folded into the interior as with the Earth, but instead remained as a water rich veneer. This perception of Mars with a wet surface but dry interior is consistent with our knowledge of Mars' geologic history.

  10. Proposed reference model for middle atmosphere water vapor

    NASA Astrophysics Data System (ADS)

    Chiou, E. W.; Remsberg, E. E.; Rodgers, C. D.; Munro, R.; Bevilacqua, R. M.; McCormick, M. P.; Russell, J. M.

    Several new and significant satellite data sets on middle atmosphere water vapor have been produced recently. They include data from the Stratospheric Aerosol and Gas Experiment II (SAGE II) and the Nimbus-7 Stratospheric and Mesospheric Sounder (SAMS) experiment. The SAGE II data provide an estimate of interannual variability of water vapor in the stratosphere. The SAMS data are appropriate for the upper stratosphere and lower mesosphere. We combine these two data sets with those from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) experiment to update the COSPAR interim reference model for water vapor. Water vapor profiles from the Spacelab 3 Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment, ground-based microwave, and in situ balloon and aircraft measurements have been used to check the quality of the satellite data sets. The updated reference model is given as a function of latitude and pressure altitude and now covers all four seasons. Tabulations are included for these seasonal water vapor mixing ratios (in ppmv) and their estimated errors (in percent).

  11. Water and acid soluble trace metals in atmospheric particles

    NASA Technical Reports Server (NTRS)

    Lindberg, S. E.; Harriss, R. C.

    1983-01-01

    Continental aerosols are collected above a deciduous forest in eastern Tennessee and subjected to selective extractions to determine the water-soluble and acid-leachable concentrations of Cd, Mn, Pb, and Zn. The combined contributions of these metals to the total aerosol mass is 0.5 percent, with approximately 70 percent of this attributable to Pb alone. A substantial fraction (approximately 50 percent or more) of the acid-leachable metals is soluble in distilled water. In general, this water-soluble fraction increases with decreasing particle size and with increasing frequency of atmospheric water vapor saturation during the sampling period. The pattern of relative solubilities (Zn being greater than Mn, which is approximately equal to Cd, which is greater than Pb) is found to be similar to the general order of the thermodynamic solubilities of the most probable salts of these elements in continental aerosols with mixed fossil fuel and soil sources.

  12. Atmospheric cloud water contains a diverse bacterial community

    SciTech Connect

    Kourtev, P. S.; Hill, Kimberly A.; Shepson, Paul B.; Konopka, Allan

    2011-06-15

    Atmospheric cloud water contains an active microbial community which can impact climate, human health and ecosystem processes in terrestrial and aquatic systems. Most studies on the composition of microbial communities in clouds have been performed with orographic clouds that are typically in direct contact with the ground. We collected water samples from cumulus clouds above the upper U.S. Midwest. The cloud water was analyzed for the diversity of bacterial phylotypes by denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rRNA gene amplicons. DGGE analyses of bacterial communities detected 17e21 bands per sample. Sequencing confirmed the presence of a diverse bacterial community; sequences from seven bacterial phyla were retrieved. Cloud water bacterial communities appeared to be dominated by members of the cyanobacteria, proteobacteria, actinobacteria and firmicutes.

  13. Unusual ultra-hydrophilic, porous carbon cuboids for atmospheric-water capture.

    PubMed

    Hao, Guang-Ping; Mondin, Giovanni; Zheng, Zhikun; Biemelt, Tim; Klosz, Stefan; Schubel, René; Eychmüller, Alexander; Kaskel, Stefan

    2015-02-02

    There is significant interest in high-performance materials that can directly and efficiently capture water vapor, particularly from air. Herein, we report a class of novel porous carbon cuboids with unusual ultra-hydrophilic properties, over which the synergistic effects between surface heterogeneity and micropore architecture is maximized, leading to the best atmospheric water-capture performance among porous carbons to date, with a water capacity of up to 9.82 mmol g(-1) at P/P0 =0.2 and 25 °C (20% relative humidity or 6000 ppm). Benefiting from properties, such as defined morphology, narrow pore size distribution, and high heterogeneity, this series of functional carbons may serve as model materials for fundamental research on carbon chemistry and the advance of new types of materials for water-vapor capture as well as other applications requiring combined highly hydrophilic surface chemistry, developed hierarchical porosity, and excellent stability.

  14. An advanced open path atmospheric pollution monitor for large areas

    SciTech Connect

    Taylor, L.; Suhre, D.; Mani, S.

    1996-12-31

    Over 100 million gallons of radioactive and toxic waste materials generated in weapon materials production are stored in 322 tanks buried within large areas at DOE sites. Toxic vapors occur in the tank headspace due to the solvents used and chemical reactions within the tanks. To prevent flammable or explosive concentration of volatile vapors, the headspace are vented, either manually or automatically, to the atmosphere when the headspace pressure exceeds preset values. Furthermore, 67 of the 177 tanks at the DOE Hanford Site are suspected or are known to be leaking into the ground. These underground storage tanks are grouped into tank farms which contain closely spaced tanks in areas as large as 1 km{sup 2}. The objective of this program is to protect DOE personnel and the public by monitoring the air above these tank farms for toxic air pollutants without the monitor entering the tanks farms, which can be radioactive. A secondary objective is to protect personnel by monitoring the air above buried 50 gallon drums containing moderately low radioactive materials but which could also emit toxic air pollutants.

  15. Water Vapour Abundance and Distribution in the Lower Venusian Atmosphere

    NASA Astrophysics Data System (ADS)

    Chamberlain, S.; Bailey, J.

    2012-04-01

    We present ground-based observations and modelling studies of water vapour abundance and distribution in the Venusian lower atmosphere through analysis of absorption band depths within the 1.18 μm window. The lower atmosphere of Venus is difficult to study by both in situ and remote instruments. This is due to the planet wide cloud cover that obscures visual wavelengths and surface pressures approaching 100 times that of the Earth. In 1984 ground based observations resulted in the discovery of atmospheric windows on the Venusian nightside (Allen and Crawford, 1984). Here, near infrared radiation originating at the surface and lower atmosphere, pass relatively unimpeded through the Venus clouds. This discovery enabled remote studies of the Venusian subcloud region. Determining the abundance and distribution of water vapour is key to understanding the development, maintenance and links between major radiative and dynamical features of the Venus atmosphere. Water vapour in the lower atmosphere plays an important role in heat transfer and is pertinent to the runaway greenhouse effect and dynamical superrotation observed on Venus. Detailed studies of water vapour abundance and distribution throughout the lower atmosphere of Venus are therefore needed in order to develop accurate chemical, radiative and dynamical models. Ground-based spatially resolved near infrared spectroscopic observations of the Venusian nightside have been obtained from Siding Spring Observatory at each inferior conjunction since 2002. Observations have been made using the IRIS2 instrument on the Anglo-Australian Telescope and CASPIR on the 2.3m ANU telescope. The model VSTAR (Bailey and Kedziora-Chudczer 2012) is used to simulate the observed Venus spectra as seen through the Earth's atmosphere and best fit water vapour abundances are found for approximately 300 locations across the Venus nightside disk. Recent improvements in ground-based near-infrared instruments allow a substantial improvement

  16. Lake-Atmosphere Greenhouse Gas Exchange in Relation to Atmospheric Forcing and Water Clarity

    NASA Astrophysics Data System (ADS)

    Heiskanen, J. J.; Ojala, A.; Mammarella, I.; Vesala, T.

    2015-12-01

    Even though lakes cover only 2 % of the world's land surface, it has been estimated that lakes release about 10 % of the carbon fixed annually by the terrestrial ecosystems back to the atmosphere. A critical parameter in the gas exchange estimates is the gas transfer velocity (k), which is governed by turbulence. The aim of our study was to assess the current global CO2 evasion estimates from lakes to the atmosphere by comparing parameterizations for kand the significance of wind and heat flux to the gas transfer in small lakes. To improve future predictions of gas evasion from lakes, we focused on the changes in water clarity and how they affect water column physics and processes in the air-water interface. We studied a small boreal lake and used the eddy covariance (EC) method for the high precision data needed, and therefore also aimed to improve the EC methodology on lakes. The air-water gas transfer was related to both wind and heat loss during times of seasonal stratification, but only to wind during autumn overturn. When wind-induced thermocline tilting and resulting spatial variability in surface water CO2 concentrations was accounted for, average k derived from the measurements dropped from 6.0 cm h-1 to 5.2 cm h-1. This was still over twice the estimate (2.2 cm h-1) calculated with a widely used model for kin lakes suggesting that the global estimates of gas evasion from lakes might be underestimations. Water clarity was a significant parameter defining the thermal stratification of the lake: a change from clear to dark water would lead to shorter stratification period and lower water column temperatures in small lakes and therefore have significant impact on the lake-atmosphere exchange processes. Figure 1. The isotherms of Lake Kuivajärvi throughout the open-water period 2013. The top left are the measured temperatures and the others are modeled with LAKE model using fixed light extinction coefficient, Kd. The horizontal dashed black line represents

  17. Thermal shallow water models of geostrophic turbulence in Jovian atmospheres

    SciTech Connect

    Warneford, Emma S. Dellar, Paul J.

    2014-01-15

    Conventional shallow water theory successfully reproduces many key features of the Jovian atmosphere: a mixture of coherent vortices and stable, large-scale, zonal jets whose amplitude decreases with distance from the equator. However, both freely decaying and forced-dissipative simulations of the shallow water equations in Jovian parameter regimes invariably yield retrograde equatorial jets, while Jupiter itself has a strong prograde equatorial jet. Simulations by Scott and Polvani [“Equatorial superrotation in shallow atmospheres,” Geophys. Res. Lett. 35, L24202 (2008)] have produced prograde equatorial jets through the addition of a model for radiative relaxation in the shallow water height equation. However, their model does not conserve mass or momentum in the active layer, and produces mid-latitude jets much weaker than the equatorial jet. We present the thermal shallow water equations as an alternative model for Jovian atmospheres. These equations permit horizontal variations in the thermodynamic properties of the fluid within the active layer. We incorporate a radiative relaxation term in the separate temperature equation, leaving the mass and momentum conservation equations untouched. Simulations of this model in the Jovian regime yield a strong prograde equatorial jet, and larger amplitude mid-latitude jets than the Scott and Polvani model. For both models, the slope of the non-zonal energy spectra is consistent with the classic Kolmogorov scaling, and the slope of the zonal energy spectra is consistent with the much steeper spectrum observed for Jupiter. We also perform simulations of the thermal shallow water equations for Neptunian parameter values, with a radiative relaxation time scale calculated for the same 25 mbar pressure level we used for Jupiter. These Neptunian simulations reproduce the broad, retrograde equatorial jet and prograde mid-latitude jets seen in observations. The much longer radiative time scale for the colder planet Neptune

  18. Natural chlorine and fluorine in the atmosphere, water and precipitation

    NASA Technical Reports Server (NTRS)

    Friend, James P.

    1990-01-01

    The geochemical cycles of chlorine and fluorine are surveyed and summarized as framework for the understanding of the global natural abundances of these species in the atmosphere, water, and precipitation. In the cycles the fluxes into and out of the atmosphere can be balanced within the limits of our knowledge of the natural sources and sinks. Sea salt from the ocean surfaces represent the predominant portion of the source of chlorine. It is also an important source of atmospheric fluorine, but volcanoes are likely to be more important fluorine sources. Dry deposition of sea salt returns about 85 percent of the salt released there. Precipitation removes the remainder. Most of the sea salt materials are considered to be cyclic, moving through sea spray over the oceans and either directly back to the oceans or deposited dry and in precipitation on land, whence it runs off into rivers and streams and returns to the oceans. Most of the natural chlorine in the atmosphere is in the form of particulate chloride ion with lesser amounts as gaseous inorganic chloride and methyl chloride vapor. Fluorine is emitted from volcanoes primarily as HF. It is possible that HF may be released directly form the ocean surface but this has not been confirmed by observation. HCl and most likely HF gases are released into the atmosphere by sea salt aerosols. The mechanism for the release is likely to be the provision of protons from the so-called excess sulfate and HNO3. Sea salt aerosol contains fluorine as F(-), MgF(+), CaF(+), and NaF. The concentrations of the various species of chlorine and fluorine that characterize primarily natural, unpolluted atmospheres are summarized in tables and are discussed in relation to their fluxes through the geochemical cycle.

  19. ADVANCES IN GROUND WATER SAMPLING PROCEDURES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  20. The seasonal and global behavior of water vapor in the Mars atmosphere - Complete global results of the Viking atmospheric water detector experiment

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Farmer, C. B.

    1982-01-01

    A key question regarding the evolution of Mars is related to the behavior of its volatiles. The present investigation is concerned with the global and seasonal abundances of water vapor in the Mars atmosphere as mapped by the Viking Mars Atmospheric Water Detector (MAWD) instrument for almost 1-1/2 Martian years from June 1976 to April 1979. Attention is given to the implications of the observed variations for determining the relative importance of those processes which may be controlling the vapor cycle on a seasonal basis. The processes considered include buffering of the atmosphere water by a surface or subsurface reservior of ground ice, physically adsorbed water, or chemically bound water. Other processes are related to the supply of water from the residual or seasonal north polar ice cap, the redistribution of the vapor resulting from atmospheric circulation, and control of the vapor holding capacity of the atmosphere by the local atmospheric temperatures.

  1. Water vapour in the atmosphere of a transiting extrasolar planet

    NASA Astrophysics Data System (ADS)

    Tinetti, Giovanna; Vidal-Madjar, Alfred; Liang, Mao-Chang; Beaulieu, Jean-Philippe; Yung, Yuk; Carey, Sean; Barber, Robert J.; Tennyson, Jonathan; Ribas, Ignasi; Allard, Nicole; Ballester, Gilda E.; Sing, David K.; Selsis, Franck

    2007-07-01

    Water is predicted to be among the most abundant (if not the most abundant) molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets (`hot Jupiters'). Several attempts have been made to detect water on such planets, but have either failed to find compelling evidence for it or led to claims that should be taken with caution. Here we report an analysis of recent observations of the hot Jupiter HD 189733b (ref. 6) taken during the transit, when the planet passed in front of its parent star. We find that absorption by water vapour is the most likely cause of the wavelength-dependent variations in the effective radius of the planet at the infrared wavelengths 3.6μm, 5.8μm (both ref. 7) and 8μm (ref. 8). The larger effective radius observed at visible wavelengths may arise from either stellar variability or the presence of clouds/hazes. We explain the report of a non-detection of water on HD 189733b (ref. 4) as being a consequence of the nearly isothermal vertical profile of the planet's atmosphere.

  2. Water vapour in the atmosphere of a transiting extrasolar planet.

    PubMed

    Tinetti, Giovanna; Vidal-Madjar, Alfred; Liang, Mao-Chang; Beaulieu, Jean-Philippe; Yung, Yuk; Carey, Sean; Barber, Robert J; Tennyson, Jonathan; Ribas, Ignasi; Allard, Nicole; Ballester, Gilda E; Sing, David K; Selsis, Franck

    2007-07-12

    Water is predicted to be among the most abundant (if not the most abundant) molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets ('hot Jupiters'). Several attempts have been made to detect water on such planets, but have either failed to find compelling evidence for it or led to claims that should be taken with caution. Here we report an analysis of recent observations of the hot Jupiter HD 189733b (ref. 6) taken during the transit, when the planet passed in front of its parent star. We find that absorption by water vapour is the most likely cause of the wavelength-dependent variations in the effective radius of the planet at the infrared wavelengths 3.6 mum, 5.8 mum (both ref. 7) and 8 mum (ref. 8). The larger effective radius observed at visible wavelengths may arise from either stellar variability or the presence of clouds/hazes. We explain the report of a non-detection of water on HD 189733b (ref. 4) as being a consequence of the nearly isothermal vertical profile of the planet's atmosphere.

  3. The evolution of water vapor in the atmosphere of Venus.

    NASA Technical Reports Server (NTRS)

    Smith, L. L.; Gross, S. H.

    1972-01-01

    Examination of the feasibility of loss of water vapor from the Venus atmosphere, assuming H2O as the sole initial constituent. A steady-state model is constructed, and the photochemistry establishes the distribution of important products in the upper atmosphere. Calculations of exospheric temperatures yield values as high as 100,000 K. Such large temperatures result from the large abundance of atomic hydrogen in the exosphere, and imply a dynamic outflow of all constituents from the upper region of the atmosphere. Such an outflow would cause the escape of all hydrogen and some of the oxygen resulting from dissociation of H2O. Little loss of CO2 would result, due to its low abundance in the upper region, permitting its accumulation to the present observed value. It is concluded that if Venus formed from the same mix of materials as the earth, much tectonic activity and fairly rapid outgassing must have occurred during the early phase of its history to account for the loss of water vapor.

  4. Interpolating atmospheric water vapor delay by incorporating terrain elevation information

    NASA Astrophysics Data System (ADS)

    Xu, W. B.; Li, Z. W.; Ding, X. L.; Zhu, J. J.

    2011-09-01

    In radio signal-based observing systems, such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR), the water vapor in the atmosphere will cause delays during the signal transmission. Such delays vary significantly with terrain elevation. In the case when atmospheric delays are to be eliminated from the measured raw signals, spatial interpolators may be needed. By taking advantage of available terrain elevation information during spatial interpolation process, the accuracy of the atmospheric delay mapping can be considerably improved. This paper first reviews three elevation-dependent water vapor interpolation models, i.e., the Best Linear Unbiased Estimator in combination with the water vapor Height Scaling Model (BLUE + HSM), the Best Linear Unbiased Estimator coupled with the Elevation-dependent Covariance Model (BLUE + ECM), and the Simple Kriging with varying local means based on the Baby semi-empirical model (SKlm + Baby for short). A revision to the SKlm + Baby model is then presented, where the Onn water vapor delay model is adopted to substitute the inaccurate Baby semi-empirical model (SKlm + Onn for short). Experiments with the zenith wet delays obtained through the GPS observations from the Southern California Integrated GPS Network (SCIGN) demonstrate that the SKlm + Onn model outperforms the other three. The RMS of SKlm + Onn is only 0.55 cm, while those of BLUE + HSM, BLUE + ECM and SKlm + Baby amount to 1.11, 1.49 and 0.77 cm, respectively. The proposed SKlm + Onn model therefore represents an improvement of 29-63% over the other known models.

  5. Decomposition of Glycerine by Water Plasmas at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Takayuki, Watanabe; Narengerile

    2013-04-01

    High concentration of aqueous glycerine was decomposed using a direct current (DC) plasma torch at atmospheric pressure. The torch can generate the plasma with water as the plasma-supporting gas in the absence of any additional gas supply system and cooling devices. The results indicated that 5 mol% glycerine was completely decomposed by water plasmas at arc powers of 0.55~1.05 kW. The major products in the effluent gas were H2 (68.9%~71.1%), CO2 (18.9%~23.0%), and CO (0.2%~0.6%). However, trace levels of formic acid (HCOOH) and formaldehyde (HCHO) were observed in the liquid effluent. The results indicated that the water plasma waste treatment process is capable of being an alternative green technology for organic waste decomposition.

  6. Water Vapour In The Atmosphere Of An Extrasolar Planet

    NASA Astrophysics Data System (ADS)

    Tinetti, Giovanna; Liang, M.; Beaulieu, J.; Yung, Y. L.; Carey, S.; Ribas, I.; Tennyson, J.; Barber, B.; Allard, N.; Ballester, G.; Sing, D.; Selsis, F.

    2007-10-01

    Water is predicted to be among the most abundant (if not the most abundant) molecular species after hydrogen in the atmospheres of close-in extrasolar giant planets (`hot Jupiters'). Several attempts have been made to detect water on such planets, but have either failed to find compelling evidence for it or led to claims that should be taken with caution. Here we report an analysis of recent observations of the hot Jupiter HD 189733b taken during the transit, when the planet passed in front of its parent star. We find that absorption by water vapour is the most likely cause of the wavelength-dependent variations in the effective radius of the planet at the infrared wavelengths 3.6, 5.8 and 8 microns. The larger effective radius observed at visible wavelengths may arise from either stellar variability or the presence of clouds/hazes.

  7. Atmosphere and water quality monitoring on Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Niu, William

    1990-01-01

    In Space Station Freedom air and water will be supplied in closed loop systems. The monitoring of air and water qualities will ensure the crew health for the long mission duration. The Atmosphere Composition Monitor consists of the following major instruments: (1) a single focusing mass spectrometer to monitor major air constituents and control the oxygen/nitrogen addition for the Space Station; (2) a gas chromatograph/mass spectrometer to detect trace contaminants; (3) a non-dispersive infrared spectrometer to determine carbon monoxide concentration; and (4) a laser particle counter for measuring particulates in the air. An overview of the design and development concepts for the air and water quality monitors is presented.

  8. Martian atmospheric chemistry during the time of low water abundance

    NASA Technical Reports Server (NTRS)

    Nair, Hari; Allen, Mark; Yung, Yuk L.; Clancy, R. Todd

    1992-01-01

    The importance of odd hydrogen (or HO(x)) radicals in the catalytic recombination of carbon monoxide and oxygen in the Martian atmosphere is a well known fact. The inclusion of recent chemical kinetics data, specifically temperature-dependent CO2 absorption cross sections, into our one dimensional photochemical model shows that HO(x) is too efficient in this regard. The absorption cross sections of CO2 are smaller than previously assumed; this leads to a reduction in the photolysis rate of CO2 while the photolysis rate of H2O has increased. As a consequence the predicted mixing ratio of CO in our models is substantially less than the observed value of 6.5(10)(exp -4). Simultaneous measurements of water, ozone, and carbon monoxide were obtained in the Martian atmosphere in early Dec. 1990 (L(sub s) for Mars was 344 deg.).

  9. Solar geoengineering, atmospheric water vapor transport, and land plants

    NASA Astrophysics Data System (ADS)

    Caldeira, Ken; Cao, Long

    2015-04-01

    This work, using the GeoMIP database supplemented by additional simulations, discusses how solar geoengineering, as projected by the climate models, affects temperature and the hydrological cycle, and how this in turn is related to projected changes in net primary productivity (NPP). Solar geoengineering simulations typically exhibit reduced precipitation. Solar geoengineering reduces precipitation because solar geoengineering reduces evaporation. Evaporation precedes precipitation, and, globally, evaporation equals precipitation. CO2 tends to reduce evaporation through two main mechanisms: (1) CO2 tends to stabilize the atmosphere especially over the ocean, leading to a moister atmospheric boundary layer over the ocean. This moistening of the boundary layer suppresses evaporation. (2) CO2 tends to diminish evapotranspiration, at least in most land-surface models, because higher atmospheric CO2 concentrations allow leaves to close their stomata and avoid water loss. In most high-CO2 simulations, these effects of CO2 which tend to suppress evaporation are masked by the tendency of CO2-warming effect to increase evaporation. In a geoengineering simulation, with the warming effect of CO2 largely offset by the solar geoengineering, the evaporation suppressing characteristics of CO2 are no longer masked and are clearly exhibited. Decreased precipitation in solar geoengineering simulations is a bit like ocean acidification - an effect of high CO2 concentrations that is not offset by solar geoengineering. Locally, precipitation ultimately either evaporates (much of that through the leaves of plants) or runs off through groundwater to streams and rivers. On long time scales, runoff equals precipitation minus evaporation, and thus, water runoff generated at a location is equal to the net atmospheric transport of water to that location. Runoff typically occurs where there is substantial soil moisture, at least seasonally. Locations where there is enough water to maintain

  10. Arctic warming induced by atmospheric transport of water vapour

    NASA Astrophysics Data System (ADS)

    Grand Graversen, Rune

    2015-04-01

    The atmospheric northward energy transport plays a crucial role for the Arctic climate; the transport brings to the Arctic an amount of energy comparable to that provided directly by the sun. During recent decades warming of the Arctic surface air has been more than twice as large as the warming averaged over the Northern Hemisphere. This is known as Arctic amplification. Climate models predict that Arctic amplification will continue during the 21st century. The models also show that the atmospheric energy transport to the Arctic will remain almost unchanged or will even decrease in the future. This has led to the conclusion that atmospheric energy transport does not contribute but rather opposes Arctic amplification. Here we show that the atmospheric energy transport will indeed contribute to Arctic amplification even while decreasing. A split of the transport into latent and dry-static components reveals that a change of the latent transport compared to a change of the dry-static has a much larger effect on the Arctic climate. This is because the latent transport brings not only energy, but also water vapour into the Arctic. This water vapour enhances the local greenhouse effect, both in itself and through the formation of clouds. An increase of the latent transport at the Arctic boundary therefore causes Arctic warming, both directly due to latent heat release, and indirectly due to an enhancement of the local greenhouse effect. Climate models tend to agree that the latent energy transport will increase on the expense of the dry-static transport in future simulations. Our results imply that the Arctic cooling caused by the reduction of the dry-static transport is more than compensated for by the warming induced by the latent transport.

  11. Advances in atmospheric light scattering theory and remote-sensing techniques

    NASA Astrophysics Data System (ADS)

    Videen, Gorden; Sun, Wenbo; Gong, Wei

    2017-02-01

    This issue focuses especially on characterizing particles in the Earth-atmosphere system. The significant role of aerosol particles in this system was recognized in the mid-1970s [1]. Since that time, our appreciation for the role they play has only increased. It has been and continues to be one of the greatest unknown factors in the Earth-atmosphere system as evidenced by the most recent Intergovernmental Panel on Climate Change (IPCC) assessments [2]. With increased computational capabilities, in terms of both advanced algorithms and in brute-force computational power, more researchers have the tools available to address different aspects of the role of aerosols in the atmosphere. In this issue, we focus on recent advances in this topical area, especially the role of light scattering and remote sensing. This issue follows on the heels of four previous topical issues on this subject matter that have graced the pages of this journal [3-6].

  12. Calibration of Atmospherically Induced Delay Fluctuations Due to Water Vapor

    NASA Technical Reports Server (NTRS)

    Resch, George; Jacobs, Christopher; Keihm, Steve; Lanyi, Gabor; Naudet, Charles; Riley, Abraham; Rosenberger, Hans; Tanner, Alan

    2000-01-01

    We have completed a new generation of water vapor radiometers (WVR), the A- series, in order to support radio science experiments with the Cassini spacecraft. These new instruments sense three frequencies in the vicinity of the 22 GHz emission line of atmospheric water vapor within a 1 degree beamwidth from a clear aperture antenna that is co-pointed with the radio telescope down to 10 degree elevation. The radiometer electronics features almost an order of magnitude improvement in temperature stability compared with earlier WVR designs. For many radio science experiments, the error budget is likely to be dominated by path delay fluctuations due to variable atmospheric water vapor along the line-of-sight to the spacecraft. In order to demonstrate the performance of these new WVRs we are attempting to calibrate the delay fluctuations as seen by a radio interferometer operating over a 21 km baseline with a WVR near each antenna. The characteristics of these new WVRs will be described and the results of our preliminary analysis will be presented indicating an accuracy of 0.2 to 0.5 mm in tracking path delay fluctuations over time scales of 10 to 10,000 seconds.

  13. Water vapor measurement system in global atmospheric sampling program, appendix

    NASA Technical Reports Server (NTRS)

    Englund, D. R.; Dudzinski, T. J.

    1982-01-01

    The water vapor measurement system used in the NASA Global Atmospheric Sampling Program (GASP) is described. The system used a modified version of a commercially available dew/frostpoint hygrometer with a thermoelectrically cooled mirror sensor. The modifications extended the range of the hygrometer to enable air sample measurements with frostpoint temperatures down to -80 C at altitudes of 6 to 13 km. Other modifications were made to permit automatic, unattended operation in an aircraft environment. This report described the hygrometer, its integration with the GASP system, its calibration, and operational aspects including measurement errors. The estimated uncertainty of the dew/frostpoint measurements was + or - 1.7 Celsius.

  14. Column atmospheric water vapor and vegetation liquid water retrievals from Airborne Imaging Spectrometer data

    NASA Astrophysics Data System (ADS)

    Gao, Bo-Cai; Goetz, Alexander F. H.

    1990-03-01

    High spatial resolution column atmospheric water vapor amounts were derived from spectral data collected by the airborne visible-infrared imaging spectrometer (AVIRIS), which covers the spectral region from 0.4 to 2.5 μm in 10-nm bands and has a ground instantaneous field of view of 20×20 m from an altitude of 20 km. The quantitative derivation is made by curve fitting observed spectra with calculated spectra in the 1.14-μm and 0.94-μm water vapor band absorption regions using an atmospheric model, a narrowband spectral model, and a nonlinear least squares fitting technique. The derivation makes use of the facts that (1) the reflectances of many ground targets vary approximately linearly with wavelength in the 0.94- and 1.14-μm water vapor band absorption regions, (2) the scattered radiation near 1 μm is small compared with the directly reflected radiation when the atmospheric aerosol concentrations are low, and (3) the scattered radiation in the lower part of the atmosphere is subjected to the water vapor absorption. The technique is directly applicable for retrieving column water vapor amounts from AVIRIS spectra measured on clear days with visibilities 20 km or greater. The precision of the retrieved column water vapor amounts from several data sets is 5% or better. Based on the analyses of an AVIRIS data set that was acquired within an hour of radiosonde launch, it appears that the accuracy approaches the precision. The derived column water vapor amounts are independent of the absolute surface reflectances. It now appears feasible to derive high spatial resolution column water vapor amounts over land areas from satellite altitude with the proposed high resolution imaging spectrometer (HIRIS). Curve fitting of spectra near 1 μm from areas covered with vegetation, using an atmospheric model and a simplified vegetation reflectance model, indicates that both the amount of atmospheric water vapor and the moisture content of vegetation can be retrieved

  15. Modeling the water decarbonization processes in atmospheric deaerators

    NASA Astrophysics Data System (ADS)

    Leduhovsky, G. V.

    2017-02-01

    A mathematical model of the water decarbonization processes in atmospheric deaerators is proposed to calculate the thermal decomposition degree of hydrocarbonates in a deaerator, pH of a deaerated water sample, and the mass concentration of free carbonic acid in it on a carbon dioxide basis. The mathematical description of these processes is based on the deaeration tank water flow model implemented in the specialized software suite for the calculation of three-dimensional liquid flows, where a real water flow is a set of parallel small plug-flow reactors, and the rate constant of the reaction representing a generalized model of the thermal decomposition of hydrocarbonates with consideration for its chemical and diffusion stages is identified by experimental data. Based on the results of experimental studies performed on deaerators of different designs with and without steam bubbling in their tanks, an empirical support of this model has been developed in the form of recommended reaction order and rate constant values selected depending on the overall alkalinity of water fed into a deaerator. A self-contained mathematical description of the water decarbonization processes in deaerators has been obtained. The proposed model precision has been proven to agree with the specified metrological characteristics of the potentiometric and alkalimetric methods for measuring pH and the free carbonic acid concentration in water. This allows us to recommend the obtained model for the solution of practical problems of forming a specified amount of deaerated water via the selection of the structural and regime parameters of deaerators during their design and regime adjustment.

  16. Habitability of Waterworlds: Runaway Greenhouses, Atmospheric Expansion, and Multiple Climate States of Pure Water Atmospheres

    PubMed Central

    2015-01-01

    Abstract There are four different stable climate states for pure water atmospheres, as might exist on so-called “waterworlds.” I map these as a function of solar constant for planets ranging in size from Mars-sized to 10 Earth-mass. The states are as follows: globally ice covered (Ts⪅245 K), cold and damp (270⪅Ts⪅290 K), hot and moist (350⪅Ts⪅550 K), and very hot and dry (Tsx2A86;900 K). No stable climate exists for 290⪅Ts ⪅350 K or 550⪅Ts⪅900 K. The union of hot moist and cold damp climates describes the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong nonlinearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity; the effective runaway greenhouse threshold is about 35 W m−2 higher for Mars, 10 W m−2 higher for Earth or Venus, but only a few W m−2 higher for a 10 Earth-mass planet. There is an underlying (expansion-neglected) trend of increasing runaway greenhouse threshold with planetary size (40 W m−2 higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-sized (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas: N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance. Key Words

  17. Habitability of waterworlds: runaway greenhouses, atmospheric expansion, and multiple climate states of pure water atmospheres.

    PubMed

    Goldblatt, Colin

    2015-05-01

    There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds." I map these as a function of solar constant for planets ranging in size from Mars-sized to 10 Earth-mass. The states are as follows: globally ice covered (Ts ⪅ 245 K), cold and damp (270 ⪅ Ts ⪅ 290 K), hot and moist (350 ⪅ Ts ⪅ 550 K), and very hot and dry (Tsx2A86;900 K). No stable climate exists for 290 ⪅ T s ⪅ 350 K or 550 ⪅ Ts ⪅ 900 K. The union of hot moist and cold damp climates describes the liquid water habitable zone, the width and location of which depends on planet mass. At each solar constant, two or three different climate states are stable. This is a consequence of strong nonlinearities in both thermal emission and the net absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surface, so more thermal radiation is emitted and more sunlight absorbed (the former dominates). The atmospheres of small planets expand more due to weaker gravity; the effective runaway greenhouse threshold is about 35 W m(-2) higher for Mars, 10 W m(-2) higher for Earth or Venus, but only a few W m(-2) higher for a 10 Earth-mass planet. There is an underlying (expansion-neglected) trend of increasing runaway greenhouse threshold with planetary size (40 W m(-2) higher for a 10 Earth-mass planet than for Mars). Summing these opposing trends means that Venus-sized (or slightly smaller) planets are most susceptible to a runaway greenhouse. The habitable zone for pure water atmospheres is very narrow, with an insolation range of 0.07 times the solar constant. A wider habitable zone requires background gas and greenhouse gas: N2 and CO2 on Earth, which are biologically controlled. Thus, habitability depends on inhabitance.

  18. A new passive sampler for collecting atmospheric tritiated water vapor

    NASA Astrophysics Data System (ADS)

    Feng, Bin; Chen, Bo; Zhuo, Weihai; Zhang, Weiyuan

    2017-04-01

    A new passive sampler was developed for collecting environmental tritiated water vapor. The construction of the sampler was improved according to computational fluid dynamics (CFD) simulations in which the influence on vapor collection by the turbulence inside the sampler was considered. Through changes in temperature from 5 °C to 35 °C and relative humidity from 45% to 90%, the new sampler revealed stable performance of the sampling rate. Compared with the previous samplers, the new sampler significantly lowered the effect of wind speed. Using the adsorption kinetic curve of the sampler provided in the co-comparison experiments, the quantitative relationship between the mass of adsorbed water and the cumulative absolute humidity exposure was established. Field applications in the vicinity of a nuclear power plant show that the data obtained by the new samplers is consistent with the active measurement. The sampler was preliminarily proven to be reliable and flexible for field investigation of HTO in the atmosphere.

  19. Effect of Upper Atmospheric Water on Martian Photochemistry and Water Loss

    NASA Astrophysics Data System (ADS)

    Chaffin, M.; Deighan, J.; Stewart, I. F.; Schneider, N. M.

    2014-12-01

    Volatile loss to space may have dominated the history of the Martian climate, removing a substantial fraction of the water initially present on the planet over the last four billion years. Until recently, the atomic H component of this loss was thought to be relatively constant in time, based on arguments from Mariner data that the source of the escaping H was molecular hydrogen, with an atmospheric lifetime of decades. New data gathered by the SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) instrument on the European Space Agency's Mars Express mission has shown that H escape varies by more than an order of magnitude in Fall 2007 alone, requiring a different parent molecule for the escaping atomic H. Using a completely new 1D time-dependent photochemical model of the Martian atmosphere, we investigate the effect of transient upper atmospheric water vapor on H and O escape to space and the abundance of minor species throughout the atmosphere. We demonstrate that detached water layers between 40-100 km, recently discovered by the infrared channel of SPICAM, produce an order of magnitude increase in the escape rate of H from the Martian atmosphere to space on a timescale of months. This provides an explanation for the observed H escape variation, adding to evidence that the upper, middle, and lower atmosphere of Mars are more tightly coupled in time than was previously expected. Implications for MAVEN measurements and for reconstructing the history of Martian water loss and the oxidation state of the crust will be discussed. Support for this work was provided by the NASA Earth and Space Science Fellowship Program, Award Number NNX11AP49H.

  20. Case history advanced coatings for water treatment plant components

    SciTech Connect

    Stephenson, L.D.; Kumar, A.

    2008-12-15

    Components of water treatment plants (WTPs) are susceptible to corrosion from constant immersion in water. A case history of corrosion and proximity to chlorine problems and their treatment at an Army WTP is presented. Solutions included using high micro-silica restoration mortar and advanced coal tar epoxy coatings.

  1. Atmospheric CO2 Enrichment of Water Hyacinths: Effects on Transpiration and Water Use Efficiency

    NASA Astrophysics Data System (ADS)

    Idso, Sherwood B.; Kimball, Bruce A.; Anderson, Michael G.

    1985-11-01

    Open-top clear plastic wall chambers enclosing pairs of sunken metal stock tanks, one of each pair of which contained a full cover of water hyacinths, were maintained out-of-doors at Phoenix, Arizona for several weeks during the summer of 1984. One of these chambers represented ambient conditions, while the other three were continuously enriched with carbon dioxide to approximate target concentrations of 500, 650, and 900 ppm. During a 4-week period when plant growth was at its maximum, water hyacinth biomass production increased by 36% for a 300-600 ppm doubling of the atmospheric CO2 content, while water use efficiency, or the biomass produced per unit of water transpired, actually doubled. These results are similar to what has been observed in several terrestrial plants and they indicate the general trend which may be expected to occur as atmospheric CO2 continues to rise in the years ahead.

  2. Advanced Water Removal via Membrane Solvent Extraction

    SciTech Connect

    2009-02-01

    This factsheet describes a research project that will focus on further concept and technology development and verification at the pilot scale of an MSE technology developed by 3M. The technology shows great promise to substantially decrease energy and water consumption in bioethanol production.

  3. Advances in nitrogen management for water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The creation of this book was inspired by collaborative discussions with some of the individuals who presented at the 7th annual symposium that was jointly held by the Soil and Water Conservation Society (SWCS) and Soil Science Society of America (SSSA) in 2006. These individuals were asked to work ...

  4. Editorial changes - Advances in Water Resources

    NASA Astrophysics Data System (ADS)

    Barry, D. A.; D'Odorico, P.; Rinaldo, A.

    2015-10-01

    Prof. Miller's longevity of service as Editor is remarkable - he started this role in August 1997. During his nearly 18 years as Editor, he provided unstinting energy, attention to detail, and commitment to the water resources community. A hallmark of his stewardship of the journal is that he "led from the front". He undertook not only to sustain a suitable venue for high quality research, but also to foster special issues, especially in emerging research topics. Prof. Miller ensured that at all times the journal's core focus of fundamental water resources science was not diluted. Indeed, a major legacy of Prof. Miller's vision is that the journal is a destination of choice for such contributions.

  5. Mars atmospheric water vapor abundance: 1996-1997

    NASA Astrophysics Data System (ADS)

    Sprague, A. L.; Hunten, D. M.; Doose, L. R.; Hill, R. E.

    2003-05-01

    Measurements of martian atmospheric water vapor made throughout Ls = 18.0°-146.4° (October 3, 1996-July 12, 1997) show changes in Mars humidity on hourly, daily, and seasonal time scales. Because our observing program during the 1996-1997 Mars apparition did not include concomitant measurement of nearby CO 2 bands, high northern latitude data were corrected for dust and aerosol extinction assuming an optical depth of 0.8, consistent with ground-based and HST imaging of northern dust storms. All other measurements with airmass greater than 3.5 were corrected using a total optical depth of 0.5. Three dominant results from this data set are as follows: (1) pre- and post-opposition measurements made with the slit crossing many hours of local time on Mars' Earth-facing disk show a distinct diurnal pattern with highest abundances around and slightly after noon with low abundances in the late afternoon, (2) measurements of water vapor over the Mars Pathfinder landing site (Carl Sagan Memorial Station) on July 12, 1997, found 21 ppt μm in the spatial sector centered near 19° latitude, 36° longitude while abundances around the site varied from as low as 6 to as high as 28 ppt μm, and (3) water vapor abundance is patchy on hourly and daily time scales but follows the usual seasonal trends.

  6. The slant path atmospheric refraction calibrator - An instrument to measure the microwave propagation delays induced by atmospheric water vapor

    NASA Technical Reports Server (NTRS)

    Walter, Steven J.; Bender, Peter L.

    1992-01-01

    The water vapor-induced propagation delay experienced by a radio signal traversing the atmosphere is characterized by the Slant Path Atmospheric Refraction Calibrator (SPARC), which measures the difference in the travel times between an optical and a microwave signal propagating along the same atmospheric path with an accuracy of 15 picosec or better. Attention is given to the theoretical and experimental issues involved in measuring the delay induced by water vapor; SPARC measurements conducted along a 13.35-km ground-based path are presented, illustrating the instrument's stability, precision, and accuracy.

  7. [Relationship between atmospheric particles and rain water chemistry character].

    PubMed

    Huo, Ming-Qun; Sun, Qian; Xie, Peng; Bai, Yu-Hua; Liu, Zhao-Rong; Li, Ji-Long; Lu, Si-Hua

    2009-11-01

    Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 microeq x L(-1). The mass concentration of PM10 in Taian was 131.76 microg/m3 and that of PM2.5 was 103.84 microg/m3. The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 microeq x L(-1). The mass concentration of PM10 in Shenzhen was 56.66 microg/m3 and that of PM2.5 was 41.52 microg/m3. During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na+ and Ca2+ by rain is high and which of NH4+ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

  8. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Wynveen, R. A.

    1977-01-01

    A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

  9. High-resolution atmospheric water vapor measurements with a scanning differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Späth, F.; Behrendt, A.; Muppa, S. K.; Metzendorf, S.; Riede, A.; Wulfmeyer, V.

    2014-11-01

    The scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) is presented. The UHOH DIAL is equipped with an injection-seeded frequency-stabilized high-power Ti:sapphire laser operated at 818 nm with a repetition rate of 250 Hz. A scanning transceiver unit with a 80 cm primary mirror receives the atmospheric backscatter signals. The system is capable of water vapor measurements with temporal resolutions of a few seconds and a range resolution between 30 and 300 m at daytime. It allows to investigate surface-vegetation-atmosphere exchange processes with high resolution. In this paper, we present the design of the instrument and illustrate its performance with recent water vapor measurements taken in Stuttgart-Hohenheim and in the frame of the HD(CP)2 Observational Prototype Experiment (HOPE). HOPE was located near research center Jülich, in western Germany, in spring 2013 as part of the project "High Definition of Clouds and Precipitation for advancing Climate Prediction" (HD(CP)2). Scanning measurements reveal the 3-dimensional structures of the water vapor field. The influence of uncertainties within the calculation of the absorption cross-section at wavelengths around 818 nm for the WV retrieval is discussed. Radiosonde intercomparisons show a very small bias between the instruments of only (-0.04 ± 0.11) g m-3 or (-1.0 ± 2.3) % in the height range of 0.5 to 3 km.

  10. Advanced Water-Gas Shift Membrane Reactor

    SciTech Connect

    Sean Emerson; Thomas Vanderspurt; Susanne Opalka; Rakesh Radhakrishnan; Rhonda Willigan

    2009-01-07

    The overall objectives for this project were: (1) to identify a suitable PdCu tri-metallic alloy membrane with high stability and commercially relevant hydrogen permeation in the presence of trace amounts of carbon monoxide and sulfur; and (2) to identify and synthesize a water gas shift catalyst with a high operating life that is sulfur and chlorine tolerant at low concentrations of these impurities. This work successfully achieved the first project objective to identify a suitable PdCu tri-metallic alloy membrane composition, Pd{sub 0.47}Cu{sub 0.52}G5{sub 0.01}, that was selected based on atomistic and thermodynamic modeling alone. The second objective was partially successful in that catalysts were identified and evaluated that can withstand sulfur in high concentrations and at high pressures, but a long operating life was not achieved at the end of the project. From the limited durability testing it appears that the best catalyst, Pt-Re/Ce{sub 0.333}Zr{sub 0.333}E4{sub 0.333}O{sub 2}, is unable to maintain a long operating life at space velocities of 200,000 h{sup -1}. The reasons for the low durability do not appear to be related to the high concentrations of H{sub 2}S, but rather due to the high operating pressure and the influence the pressure has on the WGS reaction at this space velocity.

  11. The role of carbon dioxide and water vapor in biosphere- atmosphere exchange

    NASA Astrophysics Data System (ADS)

    Lai, Chun-Ta Derek

    2001-12-01

    The exchange of mass, energy, and momentum between the biosphere and the atmosphere continues to be a fundamental and practical research problem in hydrology, meteorology, and ecology. Recent interest in the role of the biosphere to function as a carbon sink has moved the question of biosphere-atmosphere exchange into a central research topic in the climate community. My dissertation work focuses on understanding and depicting much of the primary hydrologic, eco-physiological, radiative, and turbulent transport processes regulating biosphere- atmosphere exchange. In particular, my focus is linking hydrologic and ecological processes to arrive at a mathematical framework for describing sources and sinks of carbon in ecosystems. My first paper, which appeared in Advances in Water Resources, considered the movement of water from soil to the rooting system. This subsurface zone is the water reservoir for much of the biosphere's function. Here, we seek ``low-dimensional'' descriptors of the root-water uptake along with Richards' equation for soil water redistribution. After describing the root-water- soil system, the next logical progression is above-ground processes. In a sequence of two papers, published in Boundary Layer Meteorology and Journal of Geophysical Research, I developed a multilevel canopy model that couples turbulent transport with radiative transfer schemes, eco-physiological principles to arrive at a mathematical description of the biosphere-atmosphere exchange. Particularly, these models seek to address the following problem: How can one deconvolve the effects of biophysical controls on biosphere-atmosphere fluxes? While addressing this problem, I found that night-time carbon fluxes are both difficult to measure and model. This uncertainty possessed a fundamental challenge when considering the carbon balance at annual time scales. This challenge motivated my fourth paper, which considered the use of ``inverse methods'' to estimate night-time CO2

  12. Correcting infrared satellite estimates of sea surface temperature for atmospheric water vapor attenuation

    NASA Technical Reports Server (NTRS)

    Emery, William J.; Yu, Yunyue; Wick, Gary A.; Schluessel, Peter; Reynolds, Richard W.

    1994-01-01

    A new satellite sea surface temperature (SST) algorithm is developed that uses nearly coincident measurements from the microwave special sensor microwave imager (SSM/I) to correct for atmospheric moisture attenuation of the infrared signal from the advanced very high resolution radiometer (AVHRR). This new SST algorithm is applied to AVHRR imagery from the South Pacific and Norwegian seas, which are then compared with simultaneous in situ (ship based) measurements of both skin and bulk SST. In addition, an SST algorithm using a quadratic product of the difference between the two AVHRR thermal infrared channels is compared with the in situ measurements. While the quadratic formulation provides a considerable improvement over the older cross product (CPSST) and multichannel (MCSST) algorithms, the SSM/I corrected SST (called the water vapor or WVSST) shows overall smaller errors when compared to both the skin and bulk in situ SST observations. Applied to individual AVHRR images, the WVSST reveals an SST difference pattern (CPSST-WVSST) similar in shape to the water vapor structure while the CPSST-quadratic SST difference appears unrelated in pattern to the nearly coincident water vapor pattern. An application of the WVSST to week-long composites of global area coverage (GAC) AVHRR data demonstrates again the manner in which the WVSST corrects the AVHRR for atmospheric moisture attenuation. By comparison the quadratic SST method underestimates the SST corrections in the lower latitudes and overestimates the SST in th e higher latitudes. Correlations between the AVHRR thermal channel differences and the SSM/I water vapor demonstrate the inability of the channel difference to represent water vapor in the midlatitude and high latitudes during summer. Compared against drifting buoy data the WVSST and the quadratic SST both exhibit the same general behavior with the relatively small differences with the buoy temperatures.

  13. Advanced Detector and Waveform Digitizer for Water Vapor DIAL Systems

    NASA Technical Reports Server (NTRS)

    Refaat, Tamer F.; Luck, William S., Jr.; DeYoung, Russell J.

    1998-01-01

    Measurement of atmospheric water vapor has become a major requirement for understanding moist-air processes. Differential absorption lidar (DIAL) is a technique best suited for the measurement of atmospheric water vapor. NASA Langley Research Center is continually developing improved DIAL systems. One aspect of current development is focused on the enhancement of a DIAL receiver by applying state-of-the-art technology in building a new compact detection system that will be placed directly on the DIAL receiver telescope. The newly developed detection system has the capability of being digitally interfaced with a simple personal computer, using a discrete input/output interface. This has the potential of transmitting digital data over relatively long distances instead of analog signals, which greatly reduces measurement noise. In this paper, we discuss some results from the new compact water vapor DIAL detection system which includes a silicon based avalanche photodiode (APD) detector, a 14-bit, 10-MHz waveform digitizer, a microcontroller and other auxiliary electronics. All of which are contained on a small printed-circuit-board. This will significantly reduce the weight and volume over the current CAMAC system and eventually will be used in a water vapor DIAL system on an unpiloted atmospheric vehicle (UAV) aircraft, or alternatively on an orbiting spacecraft.

  14. A SEARCH FOR WATER IN THE ATMOSPHERE OF HAT-P-26b USING LDSS-3C

    SciTech Connect

    Stevenson, Kevin B.; Bean, Jacob L.; Seifahrt, Andreas; Gilbert, Gregory J.; Line, Michael R.; Désert, Jean-Michel; Fortney, Jonathan J.

    2016-02-01

    The characterization of a physically diverse set of transiting exoplanets is an important and necessary step toward establishing the physical properties linked to the production of obscuring clouds or hazes. It is those planets with identifiable spectroscopic features that can most effectively enhance our understanding of atmospheric chemistry and metallicity. The newly commissioned LDSS-3C instrument on Magellan provides enhanced sensitivity and suppressed fringing in the red optical, thus advancing the search for the spectroscopic signature of water in exoplanetary atmospheres from the ground. Using data acquired by LDSS-3C and the Spitzer Space Telescope, we search for evidence of water vapor in the transmission spectrum of the Neptune-mass planet HAT-P-26b. Our measured spectrum is best explained by the presence of water vapor, a lack of potassium, and either a high-metallicity, cloud-free atmosphere or a solar-metallicity atmosphere with a cloud deck at ∼10 mbar. The emergence of multi-scale-height spectral features in our data suggests that future observations at higher precision could break this degeneracy and reveal the planet’s atmospheric chemical abundances. We also update HAT-P-26b’s transit ephemeris, t{sub 0} = 2455304.65218(25) BJD{sub TDB}, and orbital period, p = 4.2345023(7) days.

  15. International Space Station Atmosphere Control and Supply, Atmosphere Revitalization, and Water Recovery and Management Subsystem - Verification for Node 1

    NASA Technical Reports Server (NTRS)

    Williams, David E.

    2007-01-01

    The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the nominal operation of the Node 1 ACS, AR, and WRM design and detailed Element Verification methodologies utilized during the Qualification phase for Node 1.

  16. Iron analysis in atmospheric water samples by atomic absorption spectroscopy (AAS) in water-methanol.

    PubMed

    Sofikitis, A M; Colin, J L; Desboeufs, K V; Losno, R

    2004-01-01

    To distinguish between Fe(II) and Fe(III) species in atmospheric water samples, we have adapted an analytical procedure based on the formation of a specific complex between Fe(II) and ferrozine (FZ) on a chromatographic column. After elution of Fe(III), the Fe(II) complex is recovered with water-methanol (4:1). The possibility of trace iron measurements in this complex medium by graphite-furnace atomic-absorption spectrometry has been investigated. A simplex optimization routine was required to complete the development of the analytical method.

  17. Advanced Modeling Techniques to Study Anthropogenic Influences on Atmospheric Chemical Budgets

    NASA Technical Reports Server (NTRS)

    Mathur, Rohit

    1997-01-01

    This research work is a collaborative effort between research groups at MCNC and the University of North Carolina at Chapel Hill. The overall objective of this research is to improve the level of understanding of the processes that determine the budgets of chemically and radiatively active compounds in the atmosphere through development and application of advanced methods for calculating the chemical change in atmospheric models. The research performed during the second year of this project focused on four major aspects: (1) The continued development and refinement of multiscale modeling techniques to address the issue of the disparate scales of the physico-chemical processes that govern the fate of atmospheric pollutants; (2) Development and application of analysis methods utilizing process and mass balance techniques to increase the interpretive powers of atmospheric models and to aid in complementary analysis of model predictions and observations; (3) Development of meteorological and emission inputs for initial application of the chemistry/transport model over the north Atlantic region; and, (4) The continued development and implementation of a totally new adaptive chemistry representation that changes the details of what is represented as the underlying conditions change.

  18. Tm:germanate Fiber Laser for Planetary Water Vapor Atmospheric Profiling

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; De Young, Russell

    2009-01-01

    The atmospheric profiling of water vapor is necessary for finding life on Mars and weather on Earth. The design and performance of a water vapor lidar based on a Tm:germanate fiber laser is presented.

  19. Isotopic signature of atmospheric xenon released from light water reactors.

    PubMed

    Kalinowski, Martin B; Pistner, Christoph

    2006-01-01

    A global monitoring system for atmospheric xenon radioactivity is being established as part of the International Monitoring System to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The isotopic activity ratios of (135)Xe, (133m)Xe, (133)Xe and (131m)Xe are of interest for distinguishing nuclear explosion sources from civilian releases. Simulations of light water reactor (LWR) fuel burn-up through three operational reactor power cycles are conducted to explore the possible xenon isotopic signature of nuclear reactor releases under different operational conditions. It is studied how ratio changes are related to various parameters including the neutron flux, uranium enrichment and fuel burn-up. Further, the impact of diffusion and mixing on the isotopic activity ratio variability are explored. The simulations are validated with reported reactor emissions. In addition, activity ratios are calculated for xenon isotopes released from nuclear explosions and these are compared to the reactor ratios in order to determine whether the discrimination of explosion releases from reactor effluents is possible based on isotopic activity ratios.

  20. 3-D water vapor field in the atmospheric boundary layer observed with scanning differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Späth, Florian; Behrendt, Andreas; Muppa, Shravan Kumar; Metzendorf, Simon; Riede, Andrea; Wulfmeyer, Volker

    2016-04-01

    High-resolution three-dimensional (3-D) water vapor data of the atmospheric boundary layer (ABL) are required to improve our understanding of land-atmosphere exchange processes. For this purpose, the scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) was developed as well as new analysis tools and visualization methods. The instrument determines 3-D fields of the atmospheric water vapor number density with a temporal resolution of a few seconds and a spatial resolution of up to a few tens of meters. We present three case studies from two field campaigns. In spring 2013, the UHOH DIAL was operated within the scope of the HD(CP)2 Observational Prototype Experiment (HOPE) in western Germany. HD(CP)2 stands for High Definition of Clouds and Precipitation for advancing Climate Prediction and is a German research initiative. Range-height indicator (RHI) scans of the UHOH DIAL show the water vapor heterogeneity within a range of a few kilometers up to an altitude of 2 km and its impact on the formation of clouds at the top of the ABL. The uncertainty of the measured data was assessed for the first time by extending a technique to scanning data, which was formerly applied to vertical time series. Typically, the accuracy of the DIAL measurements is between 0.5 and 0.8 g m-3 (or < 6 %) within the ABL even during daytime. This allows for performing a RHI scan from the surface to an elevation angle of 90° within 10 min. In summer 2014, the UHOH DIAL participated in the Surface Atmosphere Boundary Layer Exchange (SABLE) campaign in southwestern Germany. Conical volume scans were made which reveal multiple water vapor layers in three dimensions. Differences in their heights in different directions can be attributed to different surface elevation. With low-elevation scans in the surface layer, the humidity profiles and gradients can be related to different land cover such as maize, grassland, and forest as well as different surface layer

  1. Latitudinal survey of middle atmospheric water vapor revealed by shipboard microwave spectroscopy. Master's thesis

    SciTech Connect

    Schrader, M.L.

    1994-05-01

    Water vapor is one of the most important greenhouse gases and is an important tracer of atmospheric motions in the middle atmosphere. It also plays an important role in the chemistry of the middle atmosphere and through its photodissociation by solar radiation, it is the major source of hydrogen escaping to space. Ground-based microwave measurements conducted in the 1980s have provided a fair understanding of the seasonal variation of mesospheric water vapor in the northern hemisphere mid-latitudes, but the global distribution of water vapor in the middle atmosphere is only beginning to be revealed by space-based measurements.

  2. The effect of global-scale divergent circulation on the atmospheric water vapor transport and maintenance

    NASA Technical Reports Server (NTRS)

    Chen, Tsing-Chang

    1988-01-01

    The detection, distribution, and dynamics of atmospheric water on Earth was examined. How the high levels of water vapor and precipitation that occur over the tropics during the monsoon season result from the development of a strong divergent atmospheric circulation is discussed.

  3. Advanced Exploration Systems Water Architecture Study Interim Results

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam J.

    2013-01-01

    The mission of the Advanced Exploration System (AES) Water Recovery Project (WRP) is to develop advanced water recovery systems that enable NASA human exploration missions beyond low Earth orbit (LEO). The primary objective of the AES WRP is to develop water recovery technologies critical to near-term missions beyond LEO. The secondary objective is to continue to advance mid-readiness-level technologies to support future NASA missions. An effort is being undertaken to establish the architecture for the AES Water Recovery System (WRS) that meets both near- and long-term objectives. The resultant architecture will be used to guide future technical planning, establish a baseline development roadmap for technology infusion, and establish baseline assumptions for integrated ground and on-orbit Environmental Control and Life Support Systems definition. This study is being performed in three phases. Phase I established the scope of the study through definition of the mission requirements and constraints, as well as identifying all possible WRS configurations that meet the mission requirements. Phase II focused on the near-term space exploration objectives by establishing an International Space Station-derived reference schematic for long-duration (>180 day) in-space habitation. Phase III will focus on the long-term space exploration objectives, trading the viable WRS configurations identified in Phase I to identify the ideal exploration WRS. The results of Phases I and II are discussed in this paper.

  4. Measurements of gaseous mercury exchanges at the sediment-water, water-atmosphere and sediment-atmosphere interfaces of a tidal environment (Arcachon Bay, France).

    PubMed

    Bouchet, Sylvain; Tessier, Emmanuel; Monperrus, Mathilde; Bridou, Romain; Clavier, Jacques; Thouzeau, Gerard; Amouroux, David

    2011-05-01

    The elemental mercury evasion from non-impacted natural areas is of significant importance in the global Hg cycle due to their large spatial coverage. Intertidal areas represent a dynamic environment promoting the transformations of Hg species and their subsequent redistribution. A major challenge remains in providing reliable data on Hg species variability and fluxes under typical transient tidal conditions found in such environment. Field experiments were thus carried out to allow the assessment and comparison of the magnitude of the gaseous Hg fluxes at the three interfaces, sediment-water, sediment-atmosphere and water-atmosphere of a mesotidal temperate lagoon (Arcachon Bay, Aquitaine, France) over three distinct seasonal conditions. The fluxes between the sediment-water and the sediment-atmosphere interfaces were directly evaluated with field flux chambers, respectively static or dynamic. Water-atmosphere fluxes were evaluated from ambient concentrations using a gas exchange model. The fluxes at the sediment-water interface ranged from -5.0 to 5.1 ng m(-2) h(-1) and appeared mainly controlled by diffusion. The occurrence of macrophytic covers (i.e.Zostera noltii sp.) enhanced the fluxes under light radiations. The first direct measurements of sediment-atmosphere fluxes are reported here. The exchanges were more intense and variable than the two other interfaces, ranging between -78 and 40 ng m(-2) h(-1) and were mostly driven by the overlying atmospheric Hg concentrations and superficial sediment temperature. The exchanges between the water column and the atmosphere, computed as a function of wind speed and gaseous mercury saturation ranged from 0.4 to 14.5 ng m(-2) h(-1). The flux intensities recorded over the intertidal sediments periodically exposed to the atmosphere were roughly 2 to 3 times higher than the fluxes of the other interfaces. The evasion of elemental mercury from emerged intertidal sediments is probably a significant pathway for Hg evasion in

  5. The influence of water vapor on atmospheric exchange measurements with an ICOS* based Laser absorption analyzer

    NASA Astrophysics Data System (ADS)

    Bunk, Rüdiger; Quan, Zhi; Wandel, Matthias; Yi, Zhigang; Bozem, Heiko; Kesselmeier, Jürgen

    2014-05-01

    Carbonyl sulfide and carbon monoxide are both atmospheric trace gases of high interest. Recent advances in the field of spectroscopy have enabled instruments that measure the concentration of the above and other trace gases very fast and with good precision. Increasing the effective path length by reflecting the light between two mirrors in a cavity, these instruments reach impressive sensitivities. Often it is possible to measure the concentration of more than one trace gas at the same time. The OCS/CO2 Analyzer by LGR (Los Gatos Research, Inc.) measures the concentration of water vapor [H2O], carbonyl sulfide [COS], carbon dioxide [CO2] and carbon monoxide [CO] simultaneously. For that the cavity is saturated with light, than the attenuation of light is measured as in standard absorption spectroscopy. The instrument proved to be very fast with good precision and to be able to detect even very low concentrations, especially for COS (as low as 30ppt in the case of COS). However, we observed a rather strong cross sensitivity to water vapor. Altering the water vapor content of the sampled air with two different methods led to a change in the perceived concentration of COS, CO and CO2. This proved especially problematic for enclosure (cuvette) measurements, where the concentrations of one of the above species in an empty cuvette are compared to the concentration of another cuvette containing a plant whose exchange of trace gases with the atmosphere is of interest. There, the plants transpiration leads to a large difference in water vapor content between the cuvettes and that in turn produces artifacts in the concentration differences between the cuvettes for the other above mentioned trace gases. For CO, simultaneous measurement with a UV-Emission Analyzer (AL 5002, Aerolaser) and the COS/CO Analyzer showed good agreement of perceived concentrations as long as the sample gas was dry and an increasing difference in perceived concentration when the sample gas was

  6. Water solubility in rhyolitic silicate melts at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Ryan, Amy; Russell, Kelly; Nichols, Alexander; Porritt, Lucy; Friedlander, Elizabeth

    2014-05-01

    High temperature (900-1100 °C) experiments have been conducted to measure the solubility of water in a rhyolitic melt at atmospheric pressure (1 atm) and to quantify the magnitude of retrograde solubility at low pressure. Individual cores (1 cm x 1 cm) of crystal- and bubble-free rhyolitic obsidian from Hrafntinnugryggur, Krafla (Iceland) were held in a furnace at 900-1100 °C for 0.25 to 20 hours. During this time, the uniform bubble-free cores vesiculate to produce variably swollen bubble-rich run products. The volume change in each core reflects the volume of bubbles produced in each experiment and depends on the experimental temperature and the time held at that temperature. The run product volumes for isothermal experiments (e.g., 950 °C) increase non-linearly with increasing time (e.g., 0.18 cm3 at 1.5 h, 0.96 cm3 at 12.5 h) until reaching a maximum value, after which the volume does not change appreciably. We take this plateau in the isothermal volume:time curve as coinciding with the 1 atm. solubility limit for the rhyolite at this temperature. With increasing temperature, the slope and final horizontal plateaus of the volume:time curves increase such that samples from the higher temperature suites vesiculate more, as well as more rapidly (e.g., 0.85 cm3 after 0.5 hours, 1.78 cm3 after 1 hour at 1100 °C). The variations in the maximum volume of bubbles produced for each temperature constrain the retrograde solubility of water in the melt at 1 atm. Fourier transform infrared spectroscopy (FTIR) analyses of the residual water content of the glass in the starting material and in the most vesiculated sample from each temperature suite shows a decrease in the water content of the glass from an initial 0.114 wt% (σ 0.013) to 0.098 wt% (σ 0.010), 0.087 wt% (σ 0.009), 0.093 wt% (σ 0.008), 0.090 wt% (σ 0.006) and 0.108 wt% (σ 0.010) for 900 °C, 950 °C, 1000 °C, 1050 °C and 1100 °C respectively. This change in the solubility of water at different

  7. Comparing Stable Water Isotope Variation in Atmospheric Moisture Observed over Coastal Water and Forests

    NASA Astrophysics Data System (ADS)

    Lai, C. T.; Rambo, J. P.; Welp, L. R.; Bible, K.; Hollinger, D. Y.

    2014-12-01

    Stable oxygen (δ18O) and hydrogen (δD) isotopologues of atmospheric moisture are strongly influenced by large-scale synoptic weather cycles, surface evapotranspiration and boundary layer mixing. Atmospheric water isotope variation has been shown to empirically relate to relative humidity (Rh) of near surface moisture, and to a less degree, air temperature. Continuous δ18O and δD measurements are becoming more available, providing new opportunities to investigate processes that control isotope variability. This study shows the comparison of δ18O and δD measured at a continental location and over coastal waters for 3 seasons (spring to fall, 2014). The surface moisture isotope measurements were made using two LGR spectroscopy water vapor isotope analyzers (Los Gatos Research Inc.), one operated in an old-growth coniferous forest at Wind River field station, WA (45.8205°N, 121.9519°W), and another sampling marine air over seawater at the Scripps Pier in San Diego, CA (32.8654°N, 117.2536°W), USA. Isotope variations were measured at 1Hz and data were reported as hourly averages with an overall accuracy of ±0.1‰ for δ18O, ±0.5‰ for δ2H. Day-to-day variations in δ18O and δD are shown strongly influenced by synoptic weather events at both locations. Boundary layer mixing between surface moisture and the dry air entrained from the free troposphere exerts a midday maximum and a consistent diel pattern in deuterium excess (dx). At the forest site, surface moisture also interacts with leaf water through transpiration during the day and re-equilibration at night. The latter occurs by retro-diffusion of atmospheric H2O molecules into leaf intercellular space, which becomes intensified as Rh increaes after nightfall, and continues until sunrise, to counter-balance the evaporative isotopic enrichment in leaf water on a daily basis. These vegetation effects lead to negative dx values consistently observed at nighttime in this continental location that were not

  8. Chemistry of atmospheric nucleation: on the recent advances on precursor characterization and atmospheric cluster composition in connection with atmospheric new particle formation.

    PubMed

    Kulmala, M; Petäjä, T; Ehn, M; Thornton, J; Sipilä, M; Worsnop, D R; Kerminen, V-M

    2014-01-01

    The recent development in measurement techniques and theoretical understanding has enabled us to study atmospheric vapor, cluster and nanoparticle concentrations, dynamics, and their connection to atmospheric nucleation. Here we present a summary of the chemistry of atmospheric clustering, growing nanoparticles, and their precursors. In this work, we focus particularly on atmospheric gas-to-particle conversion and recent progress in its understanding.

  9. Advanced Water Purification System for In Situ Resource Utilization

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

    2013-01-01

    One of NASA's goals is to enable longterm human presence in space, without the need for continuous replenishment of consumables from Earth. In situ resource utilization (ISRU) is the use of extraterrestrial resources to support activities such as human life-support, material fabrication and repair, and radiation shielding. Potential sources of ISRU resources include lunar and Martian regolith, and Martian atmosphere. Water and byproducts (including hydrochloric and hydrofluoric acids) can be produced from lunar regolith via a high-temperature hydrogen reduction reaction and passing the produced gas through a condenser. center dot Due to the high solubility of HCI and HF in water, these byproducts are expected to be present in the product stream (up to 20,000 ppm) and must be removed (less than 10 ppm) prior to water consumption or electrolysis.

  10. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ≤ 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  11. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    NASA Technical Reports Server (NTRS)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; Ponsardin, Patrick; Hueser, Alene W.

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  12. Airborne lidar for simultaneous measurement of column CO2 and water vapor in the atmosphere

    NASA Astrophysics Data System (ADS)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Antill, Charles W.; Remus, Ruben; Yu, Jirong

    2016-10-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption feathers for the gas at this particular wavelength. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers. This paper will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar. The development of this active optical remote sensing IPDA instrument is targeted for measuring both CO2 and water vapor (H2O) in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver telescope, detection system and data acquisition. Future plans for the IPDA lidar system for ground integration, testing and flight validation will also be presented.

  13. Airborne Lidar for Simultaneous Measurement of Column CO2 and Water Vapor in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Antill, Charles W.; Remus, Ruben; Yu, Jirong

    2016-01-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption feathers for the gas at this particular wavelength. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers. This paper will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar. The development of this active optical remote sensing IPDA instrument is targeted for measuring both CO2 and water vapor (H2O) in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver telescope, detection system and data acquisition. Future plans for the IPDA lidar system for ground integration, testing and flight validation will also be presented.

  14. Advanced Nuclear Technology: Advanced Light Water Reactors Utility Requirements Document Small Modular Reactors Inclusion Summary

    SciTech Connect

    Loflin, Leonard; McRimmon, Beth

    2014-12-18

    This report summarizes a project by EPRI to include requirements for small modular light water reactors (smLWR) into the EPRI Utility Requirements Document (URD) for Advanced Light Water Reactors. The project was jointly funded by EPRI and the U.S. Department of Energy (DOE). The report covers the scope and content of the URD, the process used to revise the URD to include smLWR requirements, a summary of the major changes to the URD to include smLWR, and how to use the URD as revised to achieve value on new plant projects.

  15. 76 FR 61118 - Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the ACRS Subcommittee on Advanced Boiling Water Reactor; Notice of Meeting The ACRS Subcommittee on Advanced Boiling Water Reactor...

  16. Space water electrolysis: Space Station through advance missions

    NASA Technical Reports Server (NTRS)

    Davenport, Ronald J.; Schubert, Franz H.; Grigger, David J.

    1991-01-01

    Static Feed Electrolyzer (SFE) technology can satisfy the need for oxygen (O2) and Hydrogen (H2) in the Space Station Freedom and future advanced missions. The efficiency with which the SFE technology can be used to generate O2 and H2 is one of its major advantages. In fact, the SFE is baselined for the Oxygen Generation Assembly within the Space Station Freedom's Environmental Control and Life Support System (ECLSS). In the conventional SFE process an alkaline electrolyte is contained within the matrix and is sandwiched between two porous electrodes. The electrodes and matrix make up a unitized cell core. The electrolyte provides the necessary path for the transport of water and ions between the electrodes, and forms a barrier to the diffusion of O2 and H2. A hydrophobic, microporous membrane permits water vapor to diffuse from the feed water to the cell core. This membrane separates the liquid feed water from the product H2, and, therefore, avoids direct contact of the electrodes by the feed water. The feed water is also circulated through an external heat exchanger to control the temperature of the cell.

  17. Space water electrolysis: Space Station through advance missions

    NASA Astrophysics Data System (ADS)

    Davenport, Ronald J.; Schubert, Franz H.; Grigger, David J.

    1991-09-01

    Static Feed Electrolyzer (SFE) technology can satisfy the need for oxygen (O2) and Hydrogen (H2) in the Space Station Freedom and future advanced missions. The efficiency with which the SFE technology can be used to generate O2 and H2 is one of its major advantages. In fact, the SFE is baselined for the Oxygen Generation Assembly within the Space Station Freedom's Environmental Control and Life Support System (ECLSS). In the conventional SFE process an alkaline electrolyte is contained within the matrix and is sandwiched between two porous electrodes. The electrodes and matrix make up a unitized cell core. The electrolyte provides the necessary path for the transport of water and ions between the electrodes, and forms a barrier to the diffusion of O2 and H2. A hydrophobic, microporous membrane permits water vapor to diffuse from the feed water to the cell core. This membrane separates the liquid feed water from the product H2, and, therefore, avoids direct contact of the electrodes by the feed water. The feed water is also circulated through an external heat exchanger to control the temperature of the cell.

  18. Proposal for constructing an advanced software tool for planetary atmospheric modeling

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.; Sims, Michael H.; Podolak, Esther; Mckay, Christopher P.; Thompson, David E.

    1990-01-01

    Scientific model building can be a time intensive and painstaking process, often involving the development of large and complex computer programs. Despite the effort involved, scientific models cannot easily be distributed and shared with other scientists. In general, implemented scientific models are complex, idiosyncratic, and difficult for anyone but the original scientist/programmer to understand. We believe that advanced software techniques can facilitate both the model building and model sharing process. We propose to construct a scientific modeling software tool that serves as an aid to the scientist in developing and using models. The proposed tool will include an interactive intelligent graphical interface and a high level, domain specific, modeling language. As a testbed for this research, we propose development of a software prototype in the domain of planetary atmospheric modeling.

  19. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a recirculating control loop which had no water quality maintenance. Results show that periodic water maintenance can improve performance of the SWME. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage of this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing sublimator technology. The driver for the evaluation of water recirculation maintenance components was to enhance the robustness of the SWME through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A patented bed design that was developed for a United Technologies Aerospace System military application provided a low pressure drop means for water maintenance in the SWME recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for the ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  20. The Martian atmospheric water cycle as viewed from a terrestrial perspective

    NASA Technical Reports Server (NTRS)

    Zurek, Richard W.

    1988-01-01

    It is noted that the conditions of temperature and pressure that characterize the atmosphere of Mars are similar to those found in the Earth's stratosphere. Of particular significance is the fact that liquid water is unstable in both environments. Thus, it is expected that terrestrial studies of the dynamical behavior of stratospheric water should benefit the understanding of water transport on Mars as well.

  1. Maintaining Atmospheric Mass and Water Balance Within Reanalysis

    NASA Technical Reports Server (NTRS)

    Takacs, Lawrence L.; Suarez, Max; Todling, Ricardo

    2015-01-01

    This report describes the modifications implemented into the Goddard Earth Observing System Version-5 (GEOS-5) Atmospheric Data Assimilation System (ADAS) to maintain global conservation of dry atmospheric mass as well as to preserve the model balance of globally integrated precipitation and surface evaporation during reanalysis. Section 1 begins with a review of these global quantities from four current reanalysis efforts. Section 2 introduces the modifications necessary to preserve these constraints within the atmospheric general circulation model (AGCM), the Gridpoint Statistical Interpolation (GSI) analysis procedure, and the Incremental Analysis Update (IAU) algorithm. Section 3 presents experiments quantifying the impact of the new procedure. Section 4 shows preliminary results from its use within the GMAO MERRA-2 Reanalysis project. Section 5 concludes with a summary.

  2. CalWater 2 - Precipitation, Aerosols, and Pacific Atmospheric Rivers Experiment

    NASA Astrophysics Data System (ADS)

    Spackman, Ryan; Ralph, Marty; Prather, Kim; Cayan, Dan; DeMott, Paul; Dettinger, Mike; Fairall, Chris; Leung, Ruby; Rosenfeld, Daniel; Rutledge, Steven; Waliser, Duane; White, Allen

    2014-05-01

    Emerging research has identified two phenomena that play key roles in the variability of the water supply and the incidence of extreme precipitation events along the West Coast of the United States. These phenomena include the role of (1) atmospheric rivers (ARs) in delivering much of the precipitation associated with major storms along the U.S. West Coast, and (2) aerosols—from local sources as well as those transported from remote continents—and their modulating effects on western U.S. precipitation. A better understanding of these processes is needed to reduce uncertainties in weather predictions and climate projections of extreme precipitation and its effects, including the provision of beneficial water supply. This presentation summarizes science gaps associated with (1) the evolution and structure of ARs including cloud and precipitation processes and air-sea interaction, and (2) aerosol interaction with ARs and the impact on precipitation, including locally-generated aerosol effects on orographic precipitation along the U.S. West Coast. Observations are proposed for multiple winter seasons as part of a 5-year broad interagency vision referred to as CalWater 2 to address these science gaps (http://esrl.noaa.gov/psd/calwater). In the near term, a science investigation is being planned including a targeted set of aircraft and ship-based measurements and associated evaluation of data in near-shore regions of California and in the eastern Pacific for an intensive observing period between January 2015 and March 2015. DOE's Atmospheric Radiation Measurement (ARM) program and NOAA are coordinating on deployment of airborne and ship-borne facilities for this period in a DOE-sponsored study called ACAPEX (ARM Cloud Aerosol and Precipitation Experiment) to complement CalWater 2. The motivation for this major study is based on findings that have emerged in the last few years from airborne and ground-based studies including CalWater and NOAA's HydroMeterology Testbed

  3. Research for the advancement of green chemistry practice: Studies in atmospheric and educational chemistry

    NASA Astrophysics Data System (ADS)

    Cullipher, Steven Gene

    Green chemistry is a philosophy of chemistry that emphasizes a decreasing dependence on limited non-renewable resources and an increasing focus on preventing pollution byproducts of the chemical industry. In short, it is the discipline of chemistry practiced through the lens of environmental stewardship. In an effort to advance the practice of green chemistry, three studies will be described that have ramifications for the practice. The first study examines the atmospheric oxidation of a hydrofluorinated ether, a third-generation CFC replacement compound with primarily unknown atmospheric degradation products. Determination of these products has the potential to impact decisions on refrigerant usage in the future. The second study examines chemistry students' development of understanding benefits-costs-risks analysis when presented with two real-world scenarios: refrigerant choice and fuel choice. By studying how benefits-costs-risks thinking develops, curricular materials and instructional approaches can be designed to better foster the development of an ability that is both necessary for green chemists and important in daily decision-making for non-chemists. The final study uses eye tracking technology to examine students' abilities to interpret molecular properties from structural information in the context of global warming. Such abilities are fundamental if chemists are to appropriately assess risks and hazards of chemistry practice.

  4. Water cycle dynamic increases resilience of vegetation under higher atmospheric carbon dioxide concentration

    NASA Astrophysics Data System (ADS)

    Lemordant, L. A.; Gentine, P.; Stéfanon, M.; Drobinski, P. J.; Fatichi, S.

    2015-12-01

    Plant stomata couple the energy, water and carbon cycles. Photosynthesis requires stomata to open to take up carbon dioxide. In the process water vapor is released as transpiration. As atmospheric CO2 concentration rises, for the same amount of CO2 uptake, less water vapor is transpired, translating into higher water use efficiency. Reduced water vapor losses will increase soil water storage if the leaf area coverage remains similar. This will in turn alter the surface energy partitioning: more heat will be dissipated as sensible heat flux, resulting in possibly higher surface temperatures. In contrast with this common hypothesis, our study shows that the water saved during the growing season by increased WUE can be mobilized by the vegetation and help reduce the maximum temperature of mid-latitude heat waves. The large scale meteorological conditions of 2003 are the basis of four regional model simulations coupling an atmospheric model to a surface model. We performed two simulations with respectively 2003 (CTL) and 2100 (FUT) atmospheric CO2 applied to both the atmospheric and surface models. A third (RAD) and a fourth (FER) simulations are run with 2100 CO2 concentration applied to respectively the atmospheric model only and the surface model only. RAD investigates the impact of the radiative forcing, and FER the response to vegetation CO2 fertilization. Our results show that the water saved through higher water use efficiency during the growing season enabled by higher atmospheric carbon dioxide concentrations helps the vegetation to cope during severe heat and dryness conditions in the summer of mid-latitude climate. These results demonstrate that consideration of the vegetation carbon cycle is essential to model the seasonal water cycle dynamic and land-atmosphere interactions, and enhance the accuracy of the model outputs especially for extreme events. They also have important implications for the future of agriculture, water resources management, ecosystems

  5. Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions

    USGS Publications Warehouse

    Rojstaczer, S.; Riley, F.S.

    1990-01-01

    The response to Earth tides is strongly governed by a dimensionless aquifer frequency Q???u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q???u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q???u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q???u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. -from Authors

  6. The Consortium for Advanced Simulation of Light Water Reactors

    SciTech Connect

    Ronaldo Szilard; Hongbin Zhang; Doug Kothe; Paul Turinsky

    2011-10-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is a DOE Energy Innovation Hub for modeling and simulation of nuclear reactors. It brings together an exceptionally capable team from national labs, industry and academia that will apply existing modeling and simulation capabilities and develop advanced capabilities to create a usable environment for predictive simulation of light water reactors (LWRs). This environment, designated as the Virtual Environment for Reactor Applications (VERA), will incorporate science-based models, state-of-the-art numerical methods, modern computational science and engineering practices, and uncertainty quantification (UQ) and validation against data from operating pressurized water reactors (PWRs). It will couple state-of-the-art fuel performance, neutronics, thermal-hydraulics (T-H), and structural models with existing tools for systems and safety analysis and will be designed for implementation on both today's leadership-class computers and the advanced architecture platforms now under development by the DOE. CASL focuses on a set of challenge problems such as CRUD induced power shift and localized corrosion, grid-to-rod fretting fuel failures, pellet clad interaction, fuel assembly distortion, etc. that encompass the key phenomena limiting the performance of PWRs. It is expected that much of the capability developed will be applicable to other types of reactors. CASL's mission is to develop and apply modeling and simulation capabilities to address three critical areas of performance for nuclear power plants: (1) reduce capital and operating costs per unit energy by enabling power uprates and plant lifetime extension, (2) reduce nuclear waste volume generated by enabling higher fuel burnup, and (3) enhance nuclear safety by enabling high-fidelity predictive capability for component performance.

  7. Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water

    NASA Astrophysics Data System (ADS)

    Chaffin, M. S.; Deighan, J.; Schneider, N. M.; Stewart, A. I. F.

    2017-01-01

    Atmospheric loss has controlled the history of Martian habitability, removing most of the planet’s initial water through atomic hydrogen and oxygen escape from the upper atmosphere to space. In standard models, H and O escape in a stoichiometric 2:1 ratio because H reaches the upper atmosphere via long-lived molecular hydrogen, whose abundance is regulated by a photochemical feedback sensitive to atmospheric oxygen content. The relatively constant escape rates these models predict are inconsistent with known H escape variations of more than an order of magnitude on seasonal timescales, variation that requires escaping H to have a source other than H2. The best candidate source is high-altitude water, detected by the Mars Express spacecraft in seasonally variable concentrations. Here we use a one-dimensional time-dependent photochemical model to show that the introduction of high-altitude water can produce a large increase in the H escape rate on a timescale of weeks, quantitatively linking these observations. This H escape pathway produces prompt H loss that is not immediately balanced by O escape, influencing the oxidation state of the atmosphere for millions of years. Martian atmospheric water loss may be dominated by escape via this pathway, which may therefore potentially control the planet’s atmospheric chemistry. Our findings highlight the influence that seasonal atmospheric variability can have on planetary evolution.

  8. The Interaction of Spacecraft Cabin Atmospheric Quality and Water Processing System Performance

    NASA Technical Reports Server (NTRS)

    Perry, Jay L.; Croomes, Scott D. (Technical Monitor)

    2002-01-01

    Although designed to remove organic contaminants from a variety of waste water streams, the planned U.S.- and present Russian-provided water processing systems onboard the International Space Station (ISS) have capacity limits for some of the more common volatile cleaning solvents used for housekeeping purposes. Using large quantities of volatile cleaning solvents during the ground processing and in-flight operational phases of a crewed spacecraft such as the ISS can lead to significant challenges to the water processing systems. To understand the challenges facing the management of water processing capacity, the relationship between cabin atmospheric quality and humidity condensate loading is presented. This relationship is developed as a tool to determine the cabin atmospheric loading that may compromise water processing system performance. A comparison of cabin atmospheric loading with volatile cleaning solvents from ISS, Mir, and Shuttle are presented to predict acceptable limits to maintain optimal water processing system performance.

  9. Advanced fuels for plutonium management in pressurized water reactors

    NASA Astrophysics Data System (ADS)

    Vasile, A.; Dufour, Ph; Golfier, H.; Grouiller, J. P.; Guillet, J. L.; Poinot, Ch; Youinou, G.; Zaetta, A.

    2003-06-01

    Several fuel concepts are under investigation at CEA with the aim of manage plutonium inventories in pressurized water reactors. This options range from the use of mature technologies like MOX adapted in the case of MOX-EUS (enriched uranium support) and COmbustible Recyclage A ILot (CORAIL) assemblies to more innovative technologies using IMF like DUPLEX and advanced plutonium assembly (APA). The plutonium burning performances reported to the electrical production go from 7 to 60 kg (TW h) -1. More detailed analysis covering economic, sustainability, reliability and safety aspects and their integration in the whole fuel cycle would allow identifying the best candidate.

  10. A Hydrological Perspective to Advance Understanding of the Water Cycle

    NASA Astrophysics Data System (ADS)

    Berghuijs, W.

    2014-12-01

    In principle hydrologists are scientists that study relationships within the water cycle. Yet, current technology makes it tempting for hydrology students to lose their "hydrological perspective" and become instead full-time computer programmers or statisticians. I assert that students should ensure their hydrological perspective thrives, notwithstanding the importance and possibilities of current technology. This perspective is necessary to advance the science of hydrology. As other hydrologists have pondered similar views before, I make no claims of originality here. I just hope that in presenting my perspective on this issue I may spark the interest of other early career hydrologists.

  11. Performance modeling of ultraviolet Raman lidar systems for daytime profiling of atmospheric water vapor

    NASA Technical Reports Server (NTRS)

    Ferrare, R. A.; Whiteman, D. N.; Melfi, S. H.; Goldsmith, J. E. M.; Bisson, S. E.; Lapp, M.

    1991-01-01

    We describe preliminary results from a comprehensive computer model developed to guide optimization of a Raman lidar system for measuring daytime profiles of atmospheric water vapor, emphasizing an ultraviolet, solar-blind approach.

  12. Stratospheric Temperatures and Water Loss from Moist Greenhouse Atmospheres of Earth-like Planets

    NASA Astrophysics Data System (ADS)

    Kasting, James F.; Chen, Howard; Kopparapu, Ravi K.

    2015-11-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.

  13. Evidence of water vapor in excess of saturation in the atmosphere of Mars.

    PubMed

    Maltagliati, L; Montmessin, F; Fedorova, A; Korablev, O; Forget, F; Bertaux, J-L

    2011-09-30

    The vertical distribution of water vapor is key to the study of Mars' hydrological cycle. To date, it has been explored mainly through global climate models because of a lack of direct measurements. However, these models assume the absence of supersaturation in the atmosphere of Mars. Here, we report observations made using the SPICAM (Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars) instrument onboard Mars Express that provide evidence of the frequent presence of water vapor in excess of saturation, by an amount far surpassing that encountered in Earth's atmosphere. This result contradicts the widespread assumption that atmospheric water on Mars cannot exist in a supersaturated state, directly affecting our long-term representation of water transport, accumulation, escape, and chemistry on a global scale.

  14. STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

    SciTech Connect

    Kasting, James F.; Kopparapu, Ravi K.; Chen, Howard E-mail: hwchen@bu.edu

    2015-11-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.

  15. Galileo Update: The Search for Water in Jupiter's Atmosphere

    NASA Astrophysics Data System (ADS)

    1997-06-01

    This videotape presents a panel discussion press conference about the attempts to discover if there is moisture in the atmosphere of Jupiter. David Seidel, of the Jet Propulsion Laboratory (JPL) moderates the discussion. The panel consists of Andrew Ingersoll, California Institute of Technology, Tobias Owen, of the University of Hawaii, Glenn Orton, Robert Carlson of JPL, and Ashwin Vasavada, a graduate student at Cal Tech. Each of the panelists discusses evidence for moisture in Jupiter's atmosphere. They show video tapes of either animation or shots from the Galileo mission or diagrams of the atmosphere of Jupiter. The videos clips that are shown, include a brief summary of the Galileo mission. A diagram showing the layers of Jupiter's atmosphere is discussed. One panelist discusses and shows shots from the nightside of Jupiter. Another video clip shows evidence for convergence downdrafts around dry spots. Evidence for thunderstorms and updrafts is also reviewed. Shots of the giant red spot on Jupiter are shown, and explanations are given as to what it may be.

  16. Model analysis of the effects of atmospheric drivers on storage water use in Scots pine

    NASA Astrophysics Data System (ADS)

    Verbeeck, H.; Steppe, K.; Nadezhdina, N.; de Beeck, M. Op; Deckmyn, G.; Meiresonne, L.; Lemeur, R.; Čermák, J.; Ceulemans, R.; Janssens, I. A.

    2007-08-01

    Storage water use is an indirect consequence of the interplay between different meteorological drivers through their effect on water flow and water potential in trees. We studied these microclimatic drivers of storage water use in Scots pine (Pinus sylvestris L.) growing in a temperate climate. The storage water use was modeled using the ANAFORE model, integrating a dynamic water flow and - storage model with a process-based transpiration model. The model was calibrated and validated with sap flow measurements for the growing season of 2000 (26 May-18 October). Because there was no severe soil drought during the study period, we were able to study atmospheric effects. Incoming radiation and vapour pressure deficit (VPD) were the main atmospheric drivers of storage water use. The general trends of sap flow and storage water use are similar, and follow more or less the pattern of incoming radiation. Nevertheless, considerable differences in the day-to-day pattern of sap flow and storage water use were observed. VPD was determined to be one of the main drivers of these differences. During dry atmospheric conditions (high VPD) storage water use was reduced. This reduction was higher than the reduction in measured sap flow. Our results suggest that the trees did not rely more on storage water during periods of atmospheric drought, without severe soil drought. The daily minimum tree water content was lower in periods of high VPD, but the reserves were not completely depleted after the first day of high VPD, due to refilling during the night. Nevertheless, the tree water content deficit was a third important factor influencing storage water use. When storage compartments were depleted beyond a threshold, storage water use was limited due to the low water potential in the storage compartments. The maximum relative contribution of storage water to daily transpiration was also constrained by an increasing tree water content deficit.

  17. Assessing the Influence of Human Activities on Global Water Resources Using an Advanced Land Surface Model

    NASA Astrophysics Data System (ADS)

    Pokhrel, Y.; Hanasaki, N.; Koirala, S.; Kanae, S.; Oki, T.

    2010-12-01

    In order to examine the impact of human intervention on the global hydrological cycle, a Land Surface Model was enhanced with schemes to assess the anthropogenic disturbance on the natural water flow at the global scale. Four different schemes namely; reservoir operation, crop growth, environmental flow, and anthropogenic water withdrawal modules from a state-of-the-art global water resources assessment model called H08 were integrated into an offline version of LSM, Minimal Advance Treatment of Surface Interaction and Runoff (MATSIRO). MATSIRO represents majority of the hydrological processes of water and energy exchange between the land surface and the atmosphere on a physical basis and is designed to be coupled with GCM. The integrated model presented here thus has the capability to simulate both natural and anthropogenic flows of water globally at a spatial resolution of 1°x1°, considering dam operation, domestic, industrial and agricultural water withdrawals and environmental flow requirements. The model can also be coupled with climate models to assess the impact of human activities on the climate system. A simple groundwater scheme was also incorporated and the model can be used to assess the change in water table due to groundwater pumping for irrigation. The model was validated by comparing simulated soil moisture, river discharge and Terrestrial Water Storage Anomaly (TWSA) with observations. The model performs well in simulating TWSA as compared to GRACE observation in different river basins ranging from very wet to very dry. Soil moisture cannot be validated globally because of the lack of validation datasets. For Illinois region, where long term soil moisture observations are available, the model captures the seasonal variation quite well. The simulated global potential irrigation demand is about 1100km3/year, which is within the range of previously published estimates based on various water balance models and LSMs. The model has an advanced option

  18. Assessment of temporal variations of water quality in inland water bodies using atmospheric corrected satellite remotely sensed image data.

    PubMed

    Hadjimitsis, Diofantos G; Clayton, Chris

    2009-12-01

    Although there have been many studies conducted on the use of satellite remote sensing for water quality monitoring and assessment in inland water bodies, relatively few studies have considered the problem of atmospheric intervention of the satellite signal. The problem is especially significant when using time series multi-spectral satellite data to monitor water quality surveillance in inland waters such as reservoirs, lakes, and dams because atmospheric effects constitute the majority of the at-satellite reflectance over water. For the assessment of temporal variations of water quality, the use of multi-date satellite images is required so atmospheric corrected image data must be determined. The aim of this study is to provide a simple way of monitoring and assessing temporal variations of water quality in a set of inland water bodies using an earth observation- based approach. The proposed methodology is based on the development of an image-based algorithm which consists of a selection of sampling area on the image (outlet), application of masking and convolution image processing filter, and application of the darkest pixel atmospheric correction. The proposed method has been applied in two different geographical areas, in UK and Cyprus. Mainly, the method has been applied to a series of eight archived Landsat-5 TM images acquired from March 1985 up to November 1985 of the Lower Thames Valley area in the West London (UK) consisting of large water treatment reservoirs. Finally, the method is further tested to the Kourris Dam in Cyprus. It has been found that atmospheric correction is essential in water quality assessment studies using satellite remotely sensed imagery since it improves significantly the water reflectance enabling effective water quality assessment to be made.

  19. The Unmanned Research Airplane Facility at the Cyprus Institute: Advanced Atmospheric Observations

    NASA Astrophysics Data System (ADS)

    Lange, Manfred A.; Argyrides, Marios; Ioannou, Stelios; Keleshis, Christos

    2014-05-01

    Unmanned Aerial Systems (UASs) have been established as versatile tools for different applications, providing data and observations for atmospheric and Earth-Systems research. They provide an urgently needed link between in-situ ground based measurements and satellite remote sensing observations and are distinguished by significant versatility, flexibility and moderate operational costs. Building on an earlier project (Autonomous Flying Platforms for Atmospheric and Earth Surface Observations project; APAESO) of the Energy, Environment and Water Research Center (EEWRC) at the Cyprus Institute (APAESO is co-financed by the European Development Fund and the Republic of Cyprus through the Cyprus Research Promotion Foundation), we have built up an Unmanned Research Aircraft Facility at The Cyprus Institute (CyI-URAF). The basic components of this facility comprise four CRUISERS airplanes (ET-Air, Slovakia) as UAS platforms, a substantial range of scientific instruments to be flown on these platforms, a mobile Ground Control Station and a well-equipped workshop and calibration laboratory. The APAESO platforms are suitable to carrying out atmospheric and earth-surface observations in the (Eastern) Mediterranean (and elsewhere). They enable 3D measurements for determining physical, chemical and radiative atmospheric properties, aerosol and dust concentrations and atmospheric dynamics as well as 2D investigations into land management practices, vegetation and agricultural mapping, contaminant detection and the monitoring and assessment of hydrological parameters and processes of a given region at high spatial resolution. We will report on some of the essential modifications of the platforms and some of the instrumentation that were instrumental in preparing the research airplanes for a variety of collaborative research projects with. The first scientific mission involved the employment of a DOAS-system (Differential Optical Absorption Spectroscopy) in cooperation with

  20. Evaluation of the Advanced-Canopy-Atmosphere-Surface Algorithm (ACASA Model) Using Eddy Covariance Technique Over Sparse Canopy

    NASA Astrophysics Data System (ADS)

    Marras, S.; Spano, D.; Sirca, C.; Duce, P.; Snyder, R.; Pyles, R. D.; Paw U, K. T.

    2008-12-01

    Land surface models are usually used to quantify energy and mass fluxes between terrestrial ecosystems and atmosphere on micro- and regional scales. One of the most elaborate land surface models for flux modelling is the Advanced Canopy-Atmosphere-Soil Algorithm (ACASA) model, which provides micro-scale as well as regional-scale fluxes when imbedded in a meso-scale meteorological model (e.g., MM5 or WRF). The model predicts vegetation conditions and changes with time due to plant responses to environment variables. In particular, fluxes and profiles of heat, water vapor, carbon and momentum within and above canopy are estimated using third-order equations. It also estimates turbulent profiles of velocity, temperature, humidity within and above canopy, and CO2 fluxes are estimated using a combination of Ball-Berry and Farquhar equations. The ACASA model is also able to include the effects of water stress on stomata, transpiration and CO2 assimilation. ACASA model is unique because it separates canopy domain into twenty atmospheric layers (ten layers within the canopy and ten layers above the canopy), and the soil is partitioned into fifteen layers of variable thickness. The model was mainly used over dense canopies in the past, so the aim of this work was to test the ACASA model over a sparse canopy as Mediterranean maquis. Vegetation is composed by sclerophyllous species of shrubs that are always green, with leathery leaves, small height, with a moderately sparse canopy, and that are tolerant at water stress condition. Eddy Covariance (EC) technique was used to collect continuous data for more than 3 years period. Field measurements were taken in a natural maquis site located near Alghero, Sardinia, Italy and they were used to parameterize and validate the model. The input values were selected by running the model several times varying the one parameter per time. A second step in the parameterization process was the simultaneously variation of some parameters

  1. Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres

    NASA Astrophysics Data System (ADS)

    Heng, Kevin; Lyons, James R.

    2016-02-01

    We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres in hot, hydrogen-dominated atmospheres. We construct novel analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios, we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if the metallicity is greatly enhanced, but this property is negated by temperatures above 1000 K. For hydrogen-dominated atmospheres, our generic result has the implication that retrieval studies may wish to set the subdominance of carbon dioxide as a prior of the calculation and not let its abundance completely roam free as a fitting parameter, because it directly affects the inferred value of the carbon-to-oxygen ratio and may produce unphysical conclusions. We discuss the relevance of these implications for the hot Jupiter WASP-12b and suggest that some of the previous results are chemically impossible. The relative abundance of carbon dioxide to acetylene is potentially a sensitive diagnostic of the carbon-to-oxygen ratio.

  2. Atmospheric water mapping with the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Mountain Pass, California

    NASA Technical Reports Server (NTRS)

    Conel, James E.; Green, Robert O.; Carrere, Veronique; Margolis, Jack S.; Alley, Ronald E.; Vane, Gregg; Bruegge, Carol J.; Gary, Bruce L.

    1988-01-01

    Observations are given of the spatial variation of atmospheric precipitable water using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) over a desert area in eastern California, derived using a band ratio method and the 940 nm atmospheric water band and 870 nm continuum radiances. The ratios yield total path water from curves of growth supplied by the LOWTRAN 7 atmospheric model. An independent validation of the AVIRIS-derived column abundance at a point is supplied by a spectral hygrometer calibrated with respect to radiosonde observations. Water values conform to topography and fall off with surface elevation. The edge of the water vapor boundary layer defined by topography is thought to have been recovered. The ratio method yields column abundance estimates of good precision and high spatial resolution.

  3. Development of the Lidar Atmospheric Sensing Experiment (LASE): An Advanced Airborne DIAL Instrument

    NASA Technical Reports Server (NTRS)

    Moore, Alvah S., Jr.; Brown, Kevin E.; Hall, William M.; Barnes, James C.; Edwards, William C.; Petway, Larry B.; Little, Alan D.; Luck, William S., Jr.; Jones, Irby W.; Antill, Charles W., Jr.

    1997-01-01

    The Lidar Atmospheric Sensing Experiment (LASE) Instrument is the first fully-engineered, autonomous Differential Absorption Lidar (DIAL) System for the measurement of water vapor in the troposphere (aerosol and cloud measurements are included). LASE uses a double-pulsed Ti:Sapphire laser for the transmitter with a 30 ns pulse length and 150 mJ/pulse. The laser beam is "seeded" to operate on a selected water vapor absorption line in the 815-nm region using a laser diode and an onboard absorption reference cell. A 40 cm diameter telescope collects the backscattered signals and directs them onto two detectors. LASE collects DIAL data at 5 Hz while onboard a NASA/Ames ER-2 aircraft flying at altitudes from 16-21 km. LASE was designed to operate autonomously within the environment and physical constraints of the ER-2 aircraft and to make water vapor profile measurements across the troposphere to better than 10% accuracy. LASE has flown 19 times during the development of the instrument and the validation of the science data. This paper describes the design, operation, and reliability of the LASE Instrument.

  4. The increasing importance of atmospheric demand for ecosystem water and carbon fluxes

    NASA Astrophysics Data System (ADS)

    Novick, Kimberly A.; Ficklin, Darren L.; Stoy, Paul C.; Williams, Christopher A.; Bohrer, Gil; Oishi, A. Christopher; Papuga, Shirley A.; Blanken, Peter D.; Noormets, Asko; Sulman, Benjamin N.; Scott, Russell L.; Wang, Lixin; Phillips, Richard P.

    2016-11-01

    Soil moisture supply and atmospheric demand for water independently limit--and profoundly affect--vegetation productivity and water use during periods of hydrologic stress. Disentangling the impact of these two drivers on ecosystem carbon and water cycling is difficult because they are often correlated, and experimental tools for manipulating atmospheric demand in the field are lacking. Consequently, the role of atmospheric demand is often not adequately factored into experiments or represented in models. Here we show that atmospheric demand limits surface conductance and evapotranspiration to a greater extent than soil moisture in many biomes, including mesic forests that are of particular importance to the terrestrial carbon sink. Further, using projections from ten general circulation models, we show that climate change will increase the importance of atmospheric constraints to carbon and water fluxes in all ecosystems. Consequently, atmospheric demand will become increasingly important for vegetation function, accounting for >70% of growing season limitation to surface conductance in mesic temperate forests. Our results suggest that failure to consider the limiting role of atmospheric demand in experimental designs, simulation models and land management strategies will lead to incorrect projections of ecosystem responses to future climate conditions.

  5. A Plant-Based Proxy for the Oxygen Isotope Ratio of Atmospheric Water Vapor

    NASA Astrophysics Data System (ADS)

    Helliker, B.

    2007-12-01

    Atmospheric water vapor is a major component of the global hydrological cycle, but the isotopic balance of vapor is largely unknown. It is shown here that the oxygen isotope ratio of leaf water in the epiphytic Crassulacean acid metabolism (CAM) plant Tillandsia usneoides (Spanish Moss) is controlled by the oxygen isotope ratio of atmospheric water vapor in both field and lab studies. Assuming that the leaf-water isotopic signature (and hence the atmospheric water vapor signature) is recorded in plant organic material, the atmospheric water vapor oxygen isotope ratios for Miami, Florida (USA) were reconstructed for several years from 1878 to 2005 using contemporary and herbarium specimens. T. usneoides ranges from Virginia, USA southwards through the tropics to Argentina, and the CAM epiphytic lifeform is widespread in other species. Therefore, epiphytes may be used to reconstruct the isotope ratio of atmospheric water for spatial scales that span over 60° of latitude and temporal scales that cover the last century of global temperature increase.

  6. Vapor hydrogen and oxygen isotopes reflect water of combustion in the urban atmosphere

    NASA Astrophysics Data System (ADS)

    Gorski, Galen; Strong, Courtenay; Good, Stephen P.; Bares, Ryan; Ehleringer, James R.; Bowen, Gabriel J.

    2015-03-01

    Anthropogenic modification of the water cycle involves a diversity of processes, many of which have been studied intensively using models and observations. Effective tools for measuring the contribution and fate of combustion-derived water vapor in the atmosphere are lacking, however, and this flux has received relatively little attention. We provide theoretical estimates and a first set of measurements demonstrating that water of combustion is characterized by a distinctive combination of H and O isotope ratios. We show that during periods of relatively low humidity and/or atmospheric stagnation, this isotopic signature can be used to quantify the concentration of water of combustion in the atmospheric boundary layer over Salt Lake City. Combustion-derived vapor concentrations vary between periods of atmospheric stratification and mixing, both on multiday and diurnal timescales, and respond over periods of hours to variations in surface emissions. Our estimates suggest that up to 13% of the boundary layer vapor during the period of study was derived from combustion sources, and both the temporal pattern and magnitude of this contribution were closely reproduced by an independent atmospheric model forced with a fossil fuel emissions data product. Our findings suggest potential for water vapor isotope ratio measurements to be used in conjunction with other tracers to refine the apportionment of urban emissions, and imply that water vapor emissions associated with combustion may be a significant component of the water budget of the urban boundary layer, with potential implications for urban climate, ecohydrology, and photochemistry.

  7. Vapor hydrogen and oxygen isotopes reflect water of combustion in the urban atmosphere

    PubMed Central

    Gorski, Galen; Strong, Courtenay; Good, Stephen P.; Bares, Ryan; Ehleringer, James R.; Bowen, Gabriel J.

    2015-01-01

    Anthropogenic modification of the water cycle involves a diversity of processes, many of which have been studied intensively using models and observations. Effective tools for measuring the contribution and fate of combustion-derived water vapor in the atmosphere are lacking, however, and this flux has received relatively little attention. We provide theoretical estimates and a first set of measurements demonstrating that water of combustion is characterized by a distinctive combination of H and O isotope ratios. We show that during periods of relatively low humidity and/or atmospheric stagnation, this isotopic signature can be used to quantify the concentration of water of combustion in the atmospheric boundary layer over Salt Lake City. Combustion-derived vapor concentrations vary between periods of atmospheric stratification and mixing, both on multiday and diurnal timescales, and respond over periods of hours to variations in surface emissions. Our estimates suggest that up to 13% of the boundary layer vapor during the period of study was derived from combustion sources, and both the temporal pattern and magnitude of this contribution were closely reproduced by an independent atmospheric model forced with a fossil fuel emissions data product. Our findings suggest potential for water vapor isotope ratio measurements to be used in conjunction with other tracers to refine the apportionment of urban emissions, and imply that water vapor emissions associated with combustion may be a significant component of the water budget of the urban boundary layer, with potential implications for urban climate, ecohydrology, and photochemistry. PMID:25733906

  8. An evaluation of atmospheric corrections to advanced very high resolution radiometer data

    USGS Publications Warehouse

    Meyer, David; Hood, Joy J.

    1993-01-01

    A data set compiled to analyze vegetation indices is used to evaluate the effect of atmospheric correction to AVHRR measurement in the solar spectrum. Such corrections include cloud screening and "clear sky" corrections. We used the "clouds from AVHRR" (CLAVR) method for cloud detection and evaluated its performance over vegetated targets. Clear sky corrections, designed to reduce the effects of molecular scattering and absorption due to ozone, water vapor, carbon dioxide, and molecular oxygen, were applied to data values determine to be cloud free. Generally, it was found that the screening and correction of the AVHRR data did not affect the maximum NDVI compositing process adversely, while at the same time improving estimates of the land-surface radiances over a compositing period.

  9. Advanced treatment of sodium acetate in water by ozone oxidation.

    PubMed

    Yang, De-Min; Yuan, Jian-Mei

    2014-02-01

    Ozone oxidation is an advanced oxidation process for treatment of organic and inorganic wastewater. In this paper, sodium acetate (according to chemical oxygen demand [COD]) was selected as the model pollutant in water, and the degradation efficiencies and mechanism of sodium acetate in water by ozone oxidation were investigated. The results showed that the ozone oxidation was an effective treatment technology for advanced treatment of sodium acetate in water; the COD removal rate obtained the maximum value of 45.89% from sodium acetate solution when the pH value was 10.82, ozone concentration was 100 mg/L, reaction time was 30 minutes, and reaction temperature was 25 degrees C. The COD removal rate increased first and decreased subsequently with the bicarbonate (HCO3-) concentration from 0 to 200 mg/L, the largest decline being 20.35%. The COD removal rate declined by 25.38% with the carbonate (CO3(2-)) concentration from 0 to 200 mg/L; CO3(2-) has a more obvious scavenging effect to inhibit the formation of hydroxyl free radicals than HCO3-. Calcium chloride (CaCl2) and calcium hydroxide (Ca(OH)2) could enhance the COD removal rate greatly; they could reach 77.35 and 96.53%, respectively, after a reaction time of 30 minutes, which was increased by 31.46 and 50.64%, respectively, compared with only ozone oxidation. It was proved that the main ozone oxidation product of sodium acetate was carbon dioxide (CO2), and the degradation of sodium acetate in the ozone oxidation process followed the mechanism of hydroxyl free radicals.

  10. Performance of Water Recirculation Loop Maintentance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  11. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  12. Characteristics of turbulence driven atmospheric blur over coastal water

    NASA Astrophysics Data System (ADS)

    de Jong, Arie N.; Schwering, Piet B. W.; Benoist, Koen W.; Gunter, Willem H.; Vrahimis, George; October, Faith J.

    2014-10-01

    For users of Electro-Optical (EO) sensors at sea, knowledge on their resolution is of key operational importance for the prediction of the obtainable classification ranges. Small targets may be located at ranges of 20 km and more and the present day sensor pixel size may be as small as 10 μrad. In this type of scenarios, sensor resolution will be limited by blur, generated by atmospheric turbulence, easily being greater than 30 μrad (at 20 km range). Predictions of the blur size are generally based upon the theory, developed by Fried [1]. In this theory, the turbulence strength is characterized by the structure parameter for the refractive index Cn 2, of which data are assumed to be available from secondary instruments. The theory predicts the atmospheric Modulation Transfer Function (MTF), which can be incorporated into the total system MTF, used in range performance predictions, as described by Holst [2]. Validation of blur predictions by measurements is a complex effort due to the rapid variations of the blur with time and the problems associated with the simultaneous acquisition of proper Cn 2 data. During the FATMOSE trial, carried out over a range of 15.7 km in the False Bay near Simon's Town (South Africa) from November 2009 to October 2010, these data were collected in a large variety of atmospheric conditions [3]. In stead of the atmospheric MTF, the horizontal and vertical line spread function (LSF) was measured with a camera with 5 μrad resolution. Various methods for the determination of the LSF and the associated problems are discussed in the paper. The width of the LSF is via its Fourier transform directly related to the MTF. Cn 2 data were collected with a standard BLS scintillometer over a nearby range. Additional Cn 2 data were obtained via conversion of the scintillation data from the same camera and from a high speed transmissometer, collecting data over the same range. Comparisons between blur and Beam Wander predictions and measurements from

  13. Advancement and application of gas chromatography isotope ratio mass spectrometry techniques for atmospheric trace gas analysis

    NASA Astrophysics Data System (ADS)

    Giebel, Brian M.

    2011-12-01

    The use of gas chromatography isotope ratio mass spectrometry (GC-IRMS) for compound specific stable isotope analysis is an underutilized technique because of the complexity of the instrumentation and high analytical costs. However stable isotopic data, when coupled with concentration measurements, can provide additional information on a compounds production, transformation, loss, and cycling within the biosphere and atmosphere. A GC-IRMS system was developed to accurately and precisely measure delta13C values for numerous oxygenated volatile organic compounds having natural and anthropogenic sources. The OVOCs include methanol, ethanol, acetone, methyl ethyl ketone, 2-pentanone, and 3-pentanone. Guided by the requirements for analysis of trace components in air, the GC-IRMS system was developed with the goals of increasing sensitivity, reducing dead-volume and peak band broadening, optimizing combustion and water removal, and decreasing the split ratio to the IRMS. The technique relied on a two-stage preconcentration system, a low-volume capillary reactor and water trap, and a balanced reference gas delivery system. Measurements were performed on samples collected from two distinct sources (i.e. biogenic and vehicle emissions) and ambient air collected from downtown Miami and Everglades National Park. However, the instrumentation and the method have the capability to analyze a variety of source and ambient samples. The measured isotopic signatures that were obtained from source and ambient samples provide a new isotopic constraint for atmospheric chemists and can serve as a new way to evaluate their models and budgets for many OVOCs. In almost all cases, OVOCs emitted from fuel combustion were enriched in 13C when compared to the natural emissions of plants. This was particularly true for ethanol gas emitted in vehicle exhaust, which was observed to have a uniquely enriched isotopic signature that was attributed to ethanol's corn origin and use as an alternative

  14. Nighttime Cirrus Detection using Atmospheric Infrared Sounder Window Channels and Total Column Water Vapor

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Liou, Kuo Nan; Lee, Sung-Yung; Fishbein, Evan F.; DeSouza-Machado, Sergio; Eldering, Annmarie; Fetzer, Eric J.; Hannon, Scott E.; Strow, L. Larrabee

    2005-01-01

    A method of cirrus detection at nighttime is presented that utilizes 3.8 and 10.4 (micro)m infrared (IR) window brightness temperature differences (dBT) and total column precipitable water (PW) measurements. This technique is applied to the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite on board EOS-Aqua, where dBT is determined from sets of carefully selected AIRS window channels, while PW is derived from the synergistic AIRS and AMSU-A water vapor retrievals. Simulated and observed dBT for a particular value of PW are not constant; several physical factors impact dBT, including the variability in temperature and relative humidity profiles, surface emissivity, instrument noise, and skin/ near-surface air temperature differences. We simulate clear-sky dBT over a realistic range of PWs using 8350 radiosondes that have varying temperature and relative humidity profiles. Thresholds between cloudy and uncertain sky conditions are derived once the scatter in the clear-sky dBT is determined. Simulations of optically thin cirrus indicate that this technique is most sensitive to cirrus optical depth in the 10 (micro)m window of 0.1-0.15 or greater over the tropical and subtropical oceans, where surface emissivity and skin/near-surface air temperature impacts on the IR radiances are minimal. The method at present is generally valid over oceanic regions only, specifically, the tropics and subtropics. The detection of thin cirrus, and other cloud types, is validated using observations at the Atmospheric Radiation Measurement (ARM) program site located at Manus Island in the tropical western Pacific for 89 coincident EOS-Aqua overpasses. Even though the emphasis of this work is on the detection of thin cirrus at nighttime, this technique is sensitive to a broad cloud morphology. The cloud detection technique agrees with ARM-detected clouds 82-84% of the time, which include thin cirrus, as well as other cloud types. Most of

  15. Advanced Water Recovery Technologies for Long Duration Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Liu, Scan X.

    2005-01-01

    Extended-duration space travel and habitation require recovering water from wastewater generated in spacecrafts and extraterrestrial outposts since the largest consumable for human life support is water. Many wastewater treatment technologies used for terrestrial applications are adoptable to extraterrestrial situations but challenges remain as constraints of space flights and habitation impose severe limitations of these technologies. Membrane-based technologies, particularly membrane filtration, have been widely studied by NASA and NASA-funded research groups for possible applications in space wastewater treatment. The advantages of membrane filtration are apparent: it is energy-efficient and compact, needs little consumable other than replacement membranes and cleaning agents, and doesn't involve multiphase flow, which is big plus for operations under microgravity environment. However, membrane lifespan and performance are affected by the phenomena of concentration polarization and membrane fouling. This article attempts to survey current status of membrane technologies related to wastewater treatment and desalination in the context of space exploration and quantify them in terms of readiness level for space exploration. This paper also makes specific recommendations and predictions on how scientist and engineers involving designing, testing, and developing space-certified membrane-based advanced water recovery technologies can improve the likelihood of successful development of an effective regenerative human life support system for long-duration space missions.

  16. Surface waters as a sink and source of atmospheric gas phase ethanol.

    PubMed

    Avery, G Brooks; Foley, Laura; Carroll, Angela L; Roebuck, Jesse Alan; Guy, Amanda; Mead, Ralph N; Kieber, Robert J; Willey, Joan D; Skrabal, Stephen A; Felix, J David; Mullaugh, Katherine M; Helms, John R

    2016-02-01

    This study reports the first ethanol concentrations in fresh and estuarine waters and greatly expands the current data set for coastal ocean waters. Concentrations for 153 individual measurements of 11 freshwater sites ranged from 5 to 598 nM. Concentrations obtained for one estuarine transect ranged from 56 to 77 nM and levels in five coastal ocean depth profiles ranged from 81 to 334 nM. Variability in ethanol concentrations was high and appears to be driven primarily by photochemical and biological processes. 47 gas phase concentrations of ethanol were also obtained during this study to determine the surface water degree of saturation with respect to the atmosphere. Generally fresh and estuarine waters were undersaturated indicating they are not a source and may be a net sink for atmospheric ethanol in this region. Aqueous phase ethanol is likely converted rapidly to acetaldehyde in these aquatic ecosystems creating the undersaturated conditions resulting in this previously unrecognized sink for atmospheric ethanol. Coastal ocean waters may act as either a sink or source of atmospheric ethanol depending on the partial pressure of ethanol in the overlying air mass. Results from this study are significant because they suggest that surface waters may act as an important vector for the uptake of ethanol emitted into the atmosphere including ethanol from biofuel production and usage.

  17. Extraction of Atmospheric Water on Mars for the Mars Reference Mission

    NASA Astrophysics Data System (ADS)

    Adan-Plaza, Sergio; Carpenter, Kirsten; Elias, Laila; Grover, Rob; Hilstad, Mark; Hoffman, Chris; Schneider, Matt; Bruckner, Adam

    1998-01-01

    The University of Washington has designed an in situ resource utilization system to provide water to a life support system in the laboratory module of the NASA Reference Mission to Mars. This system, the Water Vapor Adsorption Reactor (WAVAR), extracts water vapor from the Martian atmosphere by adsorption in a bed of type 3A zeolite molecular sieve. The zeolite 3A adsorbs the water vapor until nearly saturated and is then heated within a sealed chamber by microwave radiation to drive off the water for collection. The water vapor flows to a condenser where it freezes and is later liquefied for use in the life support system. In the NASA Reference Mission, water, methane, and oxygen are produced for life support and propulsion via the Sabatier/Electrolysis process from seed hydrogen brought from Earth and Martian atmospheric carbon dioxide. In order for the WAVAR system to be compatible with the NASA Reference Mission, its mass must be less than that of the seed hydrogen and cryogenic tanks apportioned for life support in the Sabatier/Electrolysis process. The WAVAR system is designed for atmospheric conditions observed by the Viking missions, which measured an average global atmospheric water vapor concentration of approx. 2 x 10-6kg/cubic meter. WAVAR performance is analyzed taking into consideration hourly and daily fluctuations in Martian ambient temperature and the corresponding effects on zeolite performance.

  18. The interpretation of data from the Viking Mars Atmospheric Water Detectors (MAWD): Some points for discussion

    NASA Technical Reports Server (NTRS)

    Clifford, Stephen M.

    1988-01-01

    Properly interpreted, water vapor column abundance measurements can provide important insights into many of the processes that govern the diurnal, seasonal, and climatic cycles of atmospheric water on Mars. The uncertain distribution of water vapor complicates this analysis. It is argued that if a significant fraction of the total atmospheric vapor content is concentrated within the lowermost scale height, then the hemispheric asymmetry in zonally averaged topography/air mass might itself explain the observed gradient in the annual and zonally averaged vapor abundance.

  19. A differential absorption technique to estimate atmospheric total water vapor amounts

    NASA Technical Reports Server (NTRS)

    Frouin, Robert; Middleton, Elizabeth

    1990-01-01

    Vertically integrated water-vapor amounts can be remotely determined by measuring the solar radiance reflected by the earth's surface with satellites or aircraft-based instruments. The technique is based on the method by Fowle (1912, 1913) and utilizes the 0.940-micron water-vapor band to retrieve total-water-vapor data that is independent of surface reflectance properties and other atmospheric constituents. A channel combination is proposed to provide more accurate results, the SE-590 spectrometer is used to verify the data, and the effects of atmospheric photon backscattering is examined. The spectrometer and radiosonde data confirm the accuracy of using a narrow and a wide channel centered on the same wavelength to determine water vapor amounts. The technique is suitable for cloudless conditions and can contribute to atmospheric corrections of land-surface parameters.

  20. Temporal variations in atmospheric water vapor and aerosol optical depth determined by remote sensing

    NASA Technical Reports Server (NTRS)

    Pitts, D. E.; Mcallum, W. E.; Heidt, M.; Jeske, K.; Lee, J. T.; Demonbrun, D.; Morgan, A.; Potter, J.

    1977-01-01

    By automatically tracking the sun, a four-channel solar radiometer was used to continuously measure optical depth and atmospheric water vapor. The design of this simple autotracking solar radiometer is presented. A technique for calculating the precipitable water from the ratio of a water band to a nearby nonabsorbing band is discussed. Studies of the temporal variability of precipitable water and atmospheric optical depth at 0.610, 0.8730 and 1.04 microns are presented. There was good correlation between the optical depth measured using the autotracker and visibility determined from National Weather Service Station data. However, much more temporal structure was evident in the autotracker data than in the visibility data. Cirrus clouds caused large changes in optical depth over short time periods. They appear to be the largest deleterious atmospheric effect over agricultural areas that are remote from urban pollution sources.

  1. Atmospheric profiling via satellite to satellite occultations near water and ozone absorption lines for weather and climate

    NASA Astrophysics Data System (ADS)

    Kursinski, E. R.; Ward, D.; Otarola, A. C.; McGhee, J.; Stovern, M.; Sammler, K.; Reed, H.; Erickson, D.; McCormick, C.; Griggs, E.

    2016-05-01

    Significantly reducing weather and climate prediction uncertainty requires global observations with substantially higher information content than present observations provide. While GPS occultations have provided a major advance, GPS observations of the atmosphere are limited by wavelengths chosen specifically to minimize interaction with the atmosphere. Significantly more information can be obtained via satellite to satellite occultations made at wavelengths chosen specifically to characterize the atmosphere. Here we describe such a system that will probe cm- and mmwavelength water vapor absorption lines called the Active Temperature, Ozone and Moisture Microwave Spectrometer (ATOMMS). Profiling both the speed and absorption of light enables ATOMMS to profile temperature, pressure and humidity simultaneously, which GPS occultations cannot do, as well as profile clouds and turbulence. We summarize the ATOMMS concept and its theoretical performance. We describe field measurements made with a prototype ATOMMS instrument and several important capabilities demonstrated with those ground based measurements including retrieving temporal variations in path-averaged water vapor to 1%, in clear, cloudy and rainy conditions, up to optical depths of 17, remotely sensing turbulence and determining rain rates. We conclude with a vision of a future ATOMMS low Earth orbiting satellite constellation designed to take advantage of synergies between observational needs for weather and climate, ATOMMS unprecedented orbital remote sensing capabilities and recent cubesat technological innovations that enable a constellation of dozens of very small spacecraft to achieve many critical, but as yet unfulfilled, monitoring and forecasting needs.

  2. Compensating Atmospheric Turbulence Effects at High Zenith Angles with Adaptive Optics Using Advanced Phase Reconstructors

    NASA Astrophysics Data System (ADS)

    Roggemann, M.; Soehnel, G.; Archer, G.

    Atmospheric turbulence degrades the resolution of images of space objects far beyond that predicted by diffraction alone. Adaptive optics telescopes have been widely used for compensating these effects, but as users seek to extend the envelopes of operation of adaptive optics telescopes to more demanding conditions, such as daylight operation, and operation at low elevation angles, the level of compensation provided will degrade. We have been investigating the use of advanced wave front reconstructors and post detection image reconstruction to overcome the effects of turbulence on imaging systems in these more demanding scenarios. In this paper we show results comparing the optical performance of the exponential reconstructor, the least squares reconstructor, and two versions of a reconstructor based on the stochastic parallel gradient descent algorithm in a closed loop adaptive optics system using a conventional continuous facesheet deformable mirror and a Hartmann sensor. The performance of these reconstructors has been evaluated under a range of source visual magnitudes and zenith angles ranging up to 70 degrees. We have also simulated satellite images, and applied speckle imaging, multi-frame blind deconvolution algorithms, and deconvolution algorithms that presume the average point spread function is known to compute object estimates. Our work thus far indicates that the combination of adaptive optics and post detection image processing will extend the useful envelope of the current generation of adaptive optics telescopes.

  3. Water cycles in closed ecological systems: effects of atmospheric pressure

    NASA Technical Reports Server (NTRS)

    Rygalov, Vadim Y.; Fowler, Philip A.; Metz, Joannah M.; Wheeler, Raymond M.; Bucklin, Ray A.; Sager, J. C. (Principal Investigator)

    2002-01-01

    In bioregenerative life support systems that use plants to generate food and oxygen, the largest mass flux between the plants and their surrounding environment will be water. This water cycle is a consequence of the continuous change of state (evaporation-condensation) from liquid to gas through the process of transpiration and the need to transfer heat (cool) and dehumidify the plant growth chamber. Evapotranspiration rates for full plant canopies can range from 1 to 10 L m-2 d-1 (1 to 10 mm m-2 d-1), with the rates depending primarily on the vapor pressure deficit (VPD) between the leaves and the air inside the plant growth chamber. VPD in turn is dependent on the air temperature, leaf temperature, and current value of relative humidity (RH). Concepts for developing closed plant growth systems, such as greenhouses for Mars, have been discussed for many years and the feasibility of such systems will depend on the overall system costs and reliability. One approach for reducing system costs would be to reduce the operating pressure within the greenhouse to reduce structural mass and gas leakage. But managing plant growth environments at low pressures (e.g., controlling humidity and heat exchange) may be difficult, and the effects of low-pressure environments on plant growth and system water cycling need further study. We present experimental evidence to show that water saturation pressures in air under isothermal conditions are only slightly affected by total pressure, but the overall water flux from evaporating surfaces can increase as pressure decreases. Mathematical models describing these observations are presented, along with discussion of the importance for considering "water cycles" in closed bioregenerative life support systems.

  4. On the Heat-Water Exchanges at the Surface Rock-Atmosphere in an Underground Cavity

    NASA Astrophysics Data System (ADS)

    hisashi, u; olivier, g

    2001-12-01

    The underground cavities are the object of several studies in view of nuclear waste storage, and to study the stability of abandoned quarry. A complete comprehension of this system needs a good understanding of the interactions between the rock and the atmosphere. Two point must be clarify: the transport of heat and water vapor in the atmosphere and the boundary condition at the interface rock-atmosphere (Gensane, 2001). In this talk we deal with the boundary condition. We use the observations of 3 different experiments at Meriel and Vincennes quarry (France), and Aburatsubo cavity (central Japan). In each experiments temperature, atmospheric pressure in the atmsophere are available and self potential for the quarries and resistivity of ground floor for the cavity (we have also ground temperature profile for the cavity). The electric measurements in rock are use to have information about the water content in rock and its flow. It is shown that the atmospheric pressure induce fluid flow in the rock, the heat transport through the interface is not conductive, and that a complex relation occurs between atmospheric pressure and temperature, in the atmosphere and in the ground. We observe also strange wave trains of self potential and atmsopheric parameters (Morrat, 1995, 1999; Gensane, 2001). These observations conduct us to propose a first model for the boundary condition. The water and heat transport in the atmosphere is convective, so a thin conductive layer exist above the surface, about 2 cm (Morrat et al, 1999, Perrier et al, 2000). We propose, like observations suggest, to consider two diffusive equations for temperature and water saturation in the rock, and two others in the conductive layer. These system of 4 equations are coupled at the interface by non linear processes due to evaporation-condensation of water. We show that we can rewrite this system in 2 equation coupled at the surface. Analytical solutions are given and numerical computation are performed

  5. Advances in laser technology for the atmospheric sciences; Proceedings of the Seminar, San Diego, Calif., August 25, 26, 1977

    NASA Technical Reports Server (NTRS)

    Trolinger, J. D. (Editor); Moore, W. W.

    1977-01-01

    These papers deal with recent research, developments, and applications in laser and electrooptics technology, particularly with regard to atmospheric effects in imaging and propagation, laser instrumentation and measurements, and particle measurement. Specific topics include advanced imaging techniques, image resolution through atmospheric turbulence over the ocean, an efficient method for calculating transmittance profiles, a comparison of a corner-cube reflector and a plane mirror in folded-path and direct transmission through atmospheric turbulence, line-spread instrumentation for propagation measurements, scaling laws for thermal fluctuations in the layer adjacent to ocean waves, particle sizing by laser photography, and an optical Fourier transform analysis of satellite cloud imagery. Other papers discuss a subnanosecond photomultiplier tube for laser application, holography of solid propellant combustion, diagnostics of turbulence by holography, a camera for in situ photography of cloud particles from a hail research aircraft, and field testing of a long-path laser transmissometer designed for atmospheric visibility measurements.

  6. Wash water reclamation technology for advanced manned spacecraft

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.

    1977-01-01

    The results of an analytical study and assessment of state-of-the-art wash water reclamation technology for advanced manned spacecraft is presented. All non-phase-change unit operations, unit processes, and subsystems currently under development by NASA are considered. Included among these are: filtration, ultrafiltration, carbon adsorption, ion exchange, chemical pretreatment, reverse osmosis, hyperfiltration, and certain urea removal techniques. Performance data are given together with the projected weights and sizes of key components and subsystems. In the final assessment, a simple multifiltration approach consisting of surface-type cartridge filters, carbon adsorption and ion exchange resins receives the highest rating for six-man orbital missions of up to 10 years in duration.

  7. Development and Validation of Water Vapor Tracers as Diagnostics for the Atmospheric Hydrologic Cycle

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Schubert, Siegfried D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Understanding of the local and remote sources of water vapor can be a valuable diagnostic in understanding the regional atmospheric hydrologic cycle. In the present study, we have implemented passive tracers as prognostic variables to follow water vapor evaporated in predetermined regions until the water tracer precipitates. The formulation of the sources and sinks of tracer water is generally proportional to the prognostic water vapor variable. Because all water has been accounted for in tracers, the water vapor variable provides the validation of the tracer water and the formulation of the sources and sinks. The tracers have been implemented in a GEOS General Circulation Model (GCM) simulation consisting of several summer periods to determine the source regions of precipitation for the United States and India. The recycling of water and interannual variability of the sources of water will be examined. Potential uses in GCM sensitivity studies, predictability studies and data assimilation will be discussed.

  8. The abundance and distribution of water vapor in Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Bjoraker, Gordon L.; Larson, Harold P.; Kunde, Virgil G.

    1986-01-01

    The atmospheric transmission window between 1800 and 2250 cm(-1) in Jupiter's atmosphere was observed from the Kuiper Airborne Observatory (KAO) and by the infrared spectrometer (IRIS) on Voyager. The vertical distribution of H2O was derived for the 1 to 6 bar portion of Jupiter's troposphere. The spatial variation of H2O was measured using IRIS spectra of the Hot Spots in the North and South Equatorial Belts, the Equatorial Zone, and for an average of the North and South Tropical Zones. The H2O column abundance above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amagat. The NEB Hot Spots are desiccated by a factor of 3 with respect to the rest of Jupiter. For an average between -40 to 40 deg latitude, the H2O mole fraction, qH2O, is saturated for P less than 2 bars, qH2O = 4x10 to the -6 in the 2 to 4 bar range and it increases to 3x10 to the -5 at 6 bars. A similar vertical profile applies to the spatially resolved zone and belt spectra, except that H2O falls off more rapidly at P less than 4 bars in the NEB Hot Spots. The massive H2O cloud at 5 bars, T = 273 K, proposed in solar composition models, is inconsistent with the observations. Instead, a thin H2O ice cloud would form at 2 bars, T = 200 K. The O/H ratio in Jupiter, inferred from H2O measurements in both belts and zones at 6 bars, is depleted by a factor of 50 with respect to the Sun. The implications for the origin of Jupiter of globally depleted O/H, but enhanced C/H and N/H, are discussed.

  9. The abundance and distribution of water vapor in Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Bjoraker, Gordon L.; Larson, Harold P.; Kunde, Virgil G.

    1986-01-01

    The atmospheric transmission window between 1800 and 2250/cm in Jupiter's atmosphere was observed from the Kuiper Airborne Observatory and by the IR spectrometer (IRIS) on Voyager. The vertical distribution of H2O was derived for the 1-6 bar portion of Jupiter's troposphere. The spatial variation of H2O was measured using IRIS spectra of the Hot Spots in the North and South Equatorial Belts (NEB, SEB) and the Equatorial Zone and for an average of the North and South Tropical Zones. The H2O column abundance above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm amagats. The NEB Hot Spots are desiccated by a factor of 3 with respect to the rest of Jupiter. For an average between -40 and +40 deg latitude, the H2O mole fraction, qH2O, is saturated for P less than 2 bars, qH2O = 4 millionths in the 2-4 bar range, and it increases to 3/100,000 at 6 bars. A similar vertical profile applies to the spatially resolved zone and belt spectra, except that H2O falls off more rapidly at P less than 4 bars in the NEB Hot Spots. A massive H2O cloud at 5 bars, T = 273 K is inconsistent with the observations. Instead, a thin H2O ice cloud would form at 2 bars, T = 200 K. The O/H ratio in Jupiter, inferred from H2O measurements in both belts and zones at 6 bars, is depleted by a factor of 50 with respect to the sun.

  10. Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs.

    PubMed

    Villanueva, G L; Mumma, M J; Novak, R E; Käufl, H U; Hartogh, P; Encrenaz, T; Tokunaga, A; Khayat, A; Smith, M D

    2015-04-10

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  11. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    NASA Technical Reports Server (NTRS)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  12. Raman lidar profiling of atmospheric water vapor: Simultaneous measurements with two collocated systems

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. E. M.; Bisson, Scott E.; Ferrare, Richard A.; Evans, Keith D.; Whiteman, David N.; Melfi, S. H.

    1994-01-01

    Raman lidar is a leading candidate for providing the detailed space- and time-resolved measurements of water vapor needed by a variety of atmospheric studies. Simultaneous measurements of atmospheric water vapor are described using two collocated Raman lidar systems. These lidar systems, developed at the NASA/Goddard Space Flight Center and Sandia National Laboratories, acquired approximately 12 hours of simultaneous water vapor data during three nights in November 1992 while the systems were collocated at the Goddard Space Flight Center. Although these lidar systems differ substantially in their design, measured water vapor profiles agreeed within 0.15 g/kg between altitudes of 1 and 5 km. Comparisons with coincident radiosondes showed all instruments agreed within 0.2 g/kg in this same altitude range. Both lidars also clearly showed the advection of water vapor in the middle troposphere and the pronounced increase in water vapor in the nocturnal boundary layer that occurred during one night.

  13. Estimating the effectiveness of using atmospheric deaerators for decarbonizing makeup water

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Larin, A. B.

    2015-02-01

    According to the water coolant quality standards, the makeup water supplied to a thermal power plant's (TPP) steam-generating systems must not have any content of free carbonic acid. As a rule, free and partially bound carbonic acid is removed from makeup water supplied to the power-generating boilers at TPPs in atmospheric deaerators. Their performance as decarbonizers can be evaluated by measuring the pH values of water supplied to the deaerator and of the deaerated water. A procedure for calculating the residual concentration of carbonic acid in deaerated water and the decarbonization effect from the change in the pH value (ΔpH) is presented together with an example of calculation carried out by specialists of the Ivanovo State Power Engineering University based on a long-term industrial experiment performed on DSA-300 atmospheric deaerators.

  14. Advancing Water and Water-Energy-Food Cluster Activities within Future Earth

    NASA Astrophysics Data System (ADS)

    Lawford, R. G.; Bhaduri, A.; Pahl-Wostl, C.

    2014-12-01

    In building its emerging program, Future Earth has encouraged former Earth System Science Partnership (ESSP) projects to redefine their objectives, priorities and problem approaches so they are aligned with those of Future Earth. These new projects will be characterized by more integrated applications of natural and social sciences as well as dialogue and science integrated across disciplinary boundaries to address a wide range of environmental and social issues. The Global Water System Project (GWSP) has had a heritage of integrating natural and social sciences, and recently started to also look at issues within the Water-Energy-Food (WEF) cluster using similar integrated approaches. As part of the growth of the scientific elements of this cluster, GWSP has approached Future Earth opportunities by addressing the sustainability for Water, Energy, and Food through integrated water information and improved governance.In this presentation the approaches being considered for promoting integration in both water and the WEF cluster will be discussed. In particular, potential contributions of Future Earth to research related to the use and management of water and to issues and science underpinning the W-E-F nexus deliberations will be identified. In both cases the increasing ability to utilize Earth observations and big data will advance this research agenda. In addition, the better understanding of the implications of governance structures in addressing these issues and the options for harmonizing the use of scientific knowledge and technological advances will be explored. For example, insights gained from water management studies undertaken within the GWSP are helping to focus plans for a "sustainable water futures" project and a WEF cluster within Future Earth. The potential role of the Sustainable Development Goals in bringing together the monitoring and science capabilities, and understanding of governance approaches, will be discussed as a framework for facilitating

  15. CALCIUM OXIDE SINTERING IN ATMOSPHERES CONTAINING WATER AND CARBON DIOXIDE

    EPA Science Inventory

    The paper gives results of measurements of the effects of water vapor and CO2 on the sintering rate of nascent CaO, as a function of partial pressure and temperature using CaO prepared by rapid decomposition of CaCO3 and CA(OH)2. Each gas strongly catalyzed the sintering process ...

  16. Visualization of Atmospheric Water Vapor Data for SAGE

    NASA Technical Reports Server (NTRS)

    Kung, Mou-Liang; Chu, W. P. (Technical Monitor)

    2000-01-01

    The goal of this project was to develop visualization tools to study the water vapor dynamics using the Stratospheric Aerosol and Gas Experiment 11 (SAGE 11) water vapor data. During the past years, we completed the development of a visualization tool called EZSAGE, and various Gridded Water Vapor plots, tools deployed on the web to provide users with new insight into the water vapor dynamics. Results and experiences from this project, including papers, tutorials and reviews were published on the main Web page. Additional publishing effort has been initiated to package EZSAGE software for CD production and distribution. There have been some major personnel changes since Fall, 1998. Dr. Mou-Liang Kung, a Professor of Computer Science assumed the PI position vacated by Dr. Waldo Rodriguez who was on leave. However, former PI, Dr. Rodriguez continued to serve as a research adviser to this project to assure smooth transition and project completion. Typically in each semester, five student research assistants were hired and trained. Weekly group meetings were held to discuss problems, progress, new research direction, and activity planning. Other small group meetings were also held regularly for different objectives of this project. All student research assistants were required to submit reports for conference submission.

  17. Forests, Water, and the Atmosphere in Northern California: Insights from Sap-Flow Data Analysis and Numerical Atmospheric Model Simulations

    NASA Astrophysics Data System (ADS)

    Link, Percy Anne

    Evapotranspiration cools the land surface by consuming a large fraction of the net radiative energy at the surface. In forested regions, trees actively control the rate of transpiration by modulating stomatal conductance in response to environmental conditions, and species with different stomatal dynamics can affect the atmosphere in distinct ways. Using principal component analysis (PCA) and Markov chain Monte Carlo (MCMC) parameter estimation with direct, tree-level measurements of water use, we show that Douglas-firs ( Pseudotsuga menziesii), a common evergreen needleleaf tree species in the Northern California Coast Range, decrease their transpiration sharply in the summer dry season in response to a dry root zone; and in contrast, broadleaf evergreen tree species, especially Pacific madrones (Arbutus menziesii), transpire maximally in the summer dry season because their transpiration is much less sensitive to a dry root zone and increases continually in response to increasing atmospheric evaporative demand. We scale up these tree-level observations to construct a bottom-up estimate of regional transpiration, and we use these regional estimates along with atmospheric models, one simple and one comprehensive, to quantify the potential impact of species transpiration differences on regional summertime climate. The atmospheric models suggest that these species differences in transpiration could affect the well-mixed atmospheric boundary layer temperature and humidity by 1-1.5 degrees C and 1 g/kg, respectively, and near-surface temperature and humidity by 1.5-2.5 degrees C and 2-3 g/kg, respectively. We further investigate the sensitivity of California climate to evapotranspiration by estimating the sensitivity of wind energy forecasts at a California wind farm to regional-scale perturbations in soil moisture using a regional atmospheric model. These tests show that forecasts at this particular farm are most sensitive to soil moisture in the Central Valley, and

  18. Relative Influence of Initial Surface and Atmospheric Conditions on Seasonal Water and Energy Balances

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Roads, John O.; Robertson, Franklin R.; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    We constructed and analyzed wet and dry soil moisture composites for the mid-latitude GCIP region of the central US using long climate model simulations made with the NCAR CCM3 and reanalysis products from NCEP. Using the diagnostic composites as a guide, we have completed a series of predictability experiments in which we imposed soil water initial conditions in CCM3 for the GCIP region for June 1 from anomalously wet and dry years, with atmospheric initial conditions taken from June 1 of a year with 'near-normal' soil water, and initial soil water from the near-normal year and atmospheric initial conditions from the wet and dry years. Preliminary results indicate that the initial state of the atmosphere is more important than the initial state of soil water determining the subsequent late spring and summer evolution of sod water over the GCIP region. Surprisingly, neither the composites or the predictability experiments yielded a strong influence of soil moisture on the atmosphere. To explore this further, we have made runs with extreme dry soil moisture initial anomalies imposed over the GCIP region (the soil close to being completely dry). These runs did yield a very strong effect on the atmosphere that persisted for at least three months. We conclude that the magnitude of the initial soil moisture anomaly is crucial, at least in CCM3, and are currently investigating whether a threshold exists, below which little impact is seen. In a complementary study, we compared the impact of the initial condition of snow cover versus the initial atmospheric state over the western US (corresponding to the westward extension of the GAPP program follow-on to GCIP). In this case, the initial prescription of snow cover is far more important than the initial atmospheric state in determining the subsequent evolution of snow cover. We are currently working to understand the very different soil water and snow cover results.

  19. Recent Experimental Advances to Determine (noble) Gases in Waters

    NASA Astrophysics Data System (ADS)

    Kipfer, R.; Brennwald, M. S.; Huxol, S.; Mächler, L.; Maden, C.; Vogel, N.; Tomonaga, Y.

    2013-12-01

    In aquatic systems noble gases, radon, and bio-geochemically conservative transient trace gases (SF6, CFCs) are frequently applied to determine water residence times and to reconstruct past environmental and climatic conditions. Recent experimental breakthroughs now enable ● to apply the well-established concepts of terrestrial noble gas geochemistry in waters to the minute water amounts stored in sediment pore space and in fluid inclusions (A), ● to determine gas exchange processes on the bio-geochemical relevant time scales of minutes - hours (B), and ● to separate diffusive and advective gas transport in soil air (C). A. Noble-gas analysis in water samples (< 1 g) facilitates determining the solute transport in the pore space and identifying the origin of bio- and geogenic fluids in (un) consolidated sediments [1]. Advanced techniques that combine crushing and sieving speleothem samples in ultra-high-vacuum to a specific grain size allow to separate air and water-bearing fluid inclusions and thus enables noble-gas-based reconstruction of environmental conditions from water masses as small as 1mg [2]. B. The coupling of noble gas analysis with approaches of gas chromatography permits combined analysis of noble gases and other gases species (e.g., SF6, CFCs, O2, N2) from a single water sample. The new method substantially improves ground water dating by SF6 and CFCs as excess air is quantified from the same sample and hence can adequately be corrected for [3]. Portable membrane-inlet mass spectrometers enable the quasi-continuous and real-time analysis of noble gases and other dissolved gases directly in the field, allowing, for instance, quantification of O2 turnover rates on small time scales [4]. C. New technical developments perfect 222Rn analysis in water by the synchronous the determination of the short-lived 220Rn. The combined 220,222Rn analysis sheds light on the emanation behaviour of radon by identifying soil water content to be the crucial

  20. Interaction between Late Holocene bottom water conditions in Skagerrak and Kattegat and predominant atmospheric forcing

    NASA Astrophysics Data System (ADS)

    Risebrobakken, B.; Kabel, K.; Jentzen, A.; Moros, M.; Jansen, E.

    2011-12-01

    The brackish and anoxic Baltic Sea is episodically ventilated when major inflow of Atlantic water occurs, Atlantic water that enters the Baltic Sea through Skagerrak and Kattegat. Periods with a stronger flux of Atlantic water increases the bottom water temperatures in Skagerrak, and temperatures and salinities in Kattegat. A tight connection between the major inflow events and the predominant atmospheric forcing over the North Atlantic and Nordic Seas are suggested in literature. How the atmospheric forcing and the inflow events are mechanistically connected is however discussed. To detect how periods of stronger inflow of Atlantic water through Skagerrak and Kattegat are related to the predominant atmospheric forcing at longer time scales, we investigate new high-resolution stable isotope, Mg/Ca and foraminiferal assemblage records documenting bottom water conditions in Skagerrak and Kattegat since approximately 1700 AD. Close to annual resolution through the last 30 years enables validation of our reconstructions towards local instrumental records of bottom water conditions and documented changes in atmospheric forcing. High-resolution stable isotope records covering the last 4000 years supplements the 300-year long records so that changes in climatic conditions in the Skagerrak/Kattegat area at longer time-scales through late Holocene are detected and the dynamical forcing behind these climatic changes investigated.

  1. Anticipatory Water Management in Phoenix using Advanced Scenario Planning and Analyses: WaterSim 5

    NASA Astrophysics Data System (ADS)

    Sampson, D. A.; Quay, R.; White, D. D.; Gober, P.; Kirkwood, C.

    2013-12-01

    Complexity, uncertainty, and variability are inherent properties of linked social and natural processes; sustainable resource management must somehow consider all three. Typically, a decision support tool (using scenario analyses) is used to examine management alternatives under suspected trajectories in driver variables (i.e., climate forcing's, growth or economic projections, etc.). This traditional planning focuses on a small set of envisioned scenarios whose outputs are compared against one-another in order to evaluate their differing impacts on desired metrics. Human cognition typically limits this to three to five scenarios. However, complex and highly uncertain issues may require more, often much more, than five scenarios. In this case advanced scenario analysis provides quantitative or qualitative methods that can reveal patterns and associations among scenario metrics for a large ensemble of scenarios. From this analysis, then, a smaller set of heuristics that describe the complexity and uncertainty revealed provides a basis to guide planning in an anticipatory fashion. Our water policy and management model, termed WaterSim, permits advanced scenario planning and analysis for the Phoenix Metropolitan Area. In this contribution we examine the concepts of advanced scenario analysis on a large scale ensemble of scenarios using our work with WaterSim as a case study. For this case study we created a range of possible water futures by creating scenarios that encompasses differences in water supplies (our surrogates for climate change, drought, and inherent variability in riverine flows), population growth, and per capital water consumption. We used IPCC estimates of plausible, future, alterations in riverine runoff, locally produced and vetted estimates of population growth projections, and empirical trends in per capita water consumption for metropolitan cities. This ensemble consisted of ~ 30, 700 scenarios (~575 k observations). We compared and contrasted

  2. Water security, global change and land-atmosphere feedbacks.

    PubMed

    Dadson, Simon; Acreman, Michael; Harding, Richard

    2013-11-13

    Understanding the competing pressures on water resources requires a detailed knowledge of the future water balance under uncertain environmental change. The need for a robust, scientifically rigorous evidence base for effective policy planning and practice has never been greater. Environmental change includes, but is not limited to, climate change; it also includes land-use and land-cover change, including deforestation for agriculture, and occurs alongside changes in anthropogenic interventions that are used in natural resource management such as the regulation of river flows using dams, which can have impacts that frequently exceed those arising in the natural system. In this paper, we examine the role that land surface models can play in providing a robust scientific basis for making resource management decisions against a background of environmental change. We provide some perspectives on recent developments in modelling in land surface hydrology. Among the range of current land surface and hydrology models, there is a large range of variability, which indicates that the specification and parametrization of several basic processes in the models can be improved. Key areas that require improvement in order to address hydrological applications include (i) the representation of groundwater in models, particularly at the scales relevant to land surface modelling, (ii) the representation of human interventions such as dams and irrigation in the hydrological system, (iii) the quantification and communication of uncertainty, and (iv) improved understanding of the impact on water resources availability of multiple use through treatment, recycling and return flows (and the balance of consumptive and conservative uses). Through a series of examples, we demonstrate that changes in water use could have important reciprocal impacts on climate over a wide area. The effects of water management decisions on climate feedbacks are only beginning to be investigated-they are

  3. Size resolved fog water chemistry and its atmospheric implications

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhishek; Gupta, Tarun; Tripathi, Sachchida; Ervens, Barbara; Bhattu, Deepika

    2015-04-01

    Fog is a natural meteorological phenomenon that occurs throughout the world. It usually contains substantial quantity of liquid water and results in severe visibility reduction leading to disruption of normal life. Fog is generally seen as a natural cleansing agent but it also has the potential to form Secondary Organic Aerosol (SOA) via aqueous processing of ambient aerosols. Size- resolved fog water chemistry for inorganics were reported in previous studies but processing of organics inside the fog water and quantification of aqSOA remained a challenge. To assess the organics processing via fog aqueous processing, size resolved fog water samples were collected in two consecutive winter seasons (2012-13, 2013-14) at Kanpur, a heavily polluted urban area of India. Caltech 3 stage fog collector was used to collect the fog droplets in 3 size fraction; coarse (droplet diameter > 22 µm), medium (22> droplet diameter >16 µm) and fine (16> droplet diameter >4 µm). Collected samples were atomized into various instruments such as Aerosol Mass Spectrometer (AMS), Cloud Condensation Nucleus Counter (CCNc), Total Organic Carbon (TOC) and a thermo denuder (TD) for the physico-chemical characterization of soluble constituents. Fine droplets are found to be more enriched with different aerosol species and interestingly contain more aged and less volatile organics compared to other coarser sizes. Organics inside fine droplets have an average O/C = 0.87 compared to O/C of 0.67 and 0.74 of coarse and medium droplets. Metal chemistry and higher residence time of fine droplets are seemed to be the two most likely reasons for this outcome from as the results of a comprehensive modeling carried out on the observed data indicate. CCN activities of the aerosols from fine droplets are also much higher than that of coarse or medium droplets. Fine droplets also contain light absorbing material as was obvious from their 'yellowish' solution. Source apportionment of fog water organics via

  4. Size matters in the water uptake and hygroscopic growth of atmospherically relevant multicomponent aerosol particles.

    PubMed

    Laskina, Olga; Morris, Holly S; Grandquist, Joshua R; Qin, Zhen; Stone, Elizabeth A; Tivanski, Alexei V; Grassian, Vicki H

    2015-05-14

    Understanding the interactions of water with atmospheric aerosols is crucial for determining the size, physical state, reactivity, and climate impacts of this important component of the Earth's atmosphere. Here we show that water uptake and hygroscopic growth of multicomponent, atmospherically relevant particles can be size dependent when comparing 100 nm versus ca. 6 μm sized particles. It was determined that particles composed of ammonium sulfate with succinic acid and of a mixture of chlorides typical of the marine environment show size-dependent hygroscopic behavior. Microscopic analysis of the distribution of components within the aerosol particles show that the size dependence is due to differences in the mixing state, that is, whether particles are homogeneously mixed or phase separated, for different sized particles. This morphology-dependent hygroscopicity has consequences for heterogeneous atmospheric chemistry as well as aerosol interactions with electromagnetic radiation and clouds.

  5. Measurement of atmospheric water vapor, leaf liquid water and reflectance with AVIRIS in the Boreal Ecosystem-Atmosphere Study: Initial results

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Conel, James E.; Roberts, Dar A.

    1995-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) acquired data as part of the Boreal Ecosystem-Atmosphere Study (BOREAS) in 1994. Flights occurred over the northern study area (NSA) in the region of 56 degrees north latitude and 98.5 degrees west longitude and over the southern study area (SSA) at 54 degrees north latitude and 105 degrees west longitude. These data will be used to directly derive spectral properties of the surface and atmosphere and to provide supporting data for other instruments, models, and experiments in support of the BOREAS objectives. We present a preliminary evaluation of the AVIRIS data collected in BOREAS in terms of the AVIRIS-derived parameters: water vapor, leaf water, and apparent spectral reflectance.

  6. Transient atmospheres on Charon and water-ice covered KBOs resulting from comet impacts

    NASA Astrophysics Data System (ADS)

    Stern, S. Alan; Gladstone, Randall; Zangari, Amanda; Fleming, Thadeus; Goldstein, David

    2015-01-01

    Evidence from stellar occultation datasets and Charon's H2O-ice dominated surface composition has long suggested a lack of any current atmosphere around this satellite planet. However, impacts from both Kuiper Belt and Oort Cloud comets must from time to time import N2, CH4, and other cometary super-volatiles that can create temporary atmospheres around Charon. Here we estimate the frequency of such cometary impacts on Charon and the imported mass of super-volatiles from each such impact. We then examine the characteristics of such transient atmospheric events, including their column densities, mean molecular weights, scale heights, and loss timescales. We then report on the detectability of such a transient atmosphere by New Horizons, and discuss the generalized case of cometary impact-created transient atmospheres on other satellites of Pluto and water-ice covered KBOs across the Kuiper Belt.

  7. An impact-induced terrestrial atmosphere and iron-water reactions during accretion of the Earth

    NASA Technical Reports Server (NTRS)

    Lange, M. A.; Ahrens, T. J.

    1985-01-01

    Shock wave data and theoretical calculations were used to derive models of an impact-generated terrestrial atmosphere during accretion of the Earth. The models showed that impacts of infalling planetesimals not only provided the entire budget of terrestrial water but also led to a continuous depletion of near-surface layers of water-bearing minerals of their structural water. This resulted in a final atmospheric water reservoir comparable to the present day total water budget of the Earth. The interaction of metallic iron with free water at the surface of the accreting Earth is considered. We carried out model calcualtions simulating these processes during accretion. It is assumed that these processes are the prime source of the terrestrial FeO component of silicates and oxides. It is demonstrated that the iron-water reaction would result in the absence of atmospheric/hydrospheric water, if homogeneous accretion is assumed. In order to obtain the necessary amount of terrestrial water, slightly heterogeneous accretion with initially 36 wt% iron planetesimals, as compared with a homogeneous value of 34 wt% is required.

  8. Water loss from terrestrial planets with CO{sub 2}-rich atmospheres

    SciTech Connect

    Wordsworth, R. D.; Pierrehumbert, R. T.

    2013-12-01

    Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study the dependence of water loss rates from terrestrial planets on a range of atmospheric and external parameters. We show that CO{sub 2} can only cause significant water loss by increasing surface temperatures over a narrow range of conditions, with cooling of the middle and upper atmosphere acting as a bottleneck on escape in other circumstances. Around G-stars, efficient loss only occurs on planets with intermediate CO{sub 2} atmospheric partial pressures (0.1-1 bar) that receive a net flux close to the critical runaway greenhouse limit. Because G-star total luminosity increases with time but X-ray and ultraviolet/ultravoilet luminosity decreases, this places strong limits on water loss for planets like Earth. In contrast, for a CO{sub 2}-rich early Venus, diffusion limits on water loss are only important if clouds caused strong cooling, implying that scenarios where the planet never had surface liquid water are indeed plausible. Around M-stars, water loss is primarily a function of orbital distance, with planets that absorb less flux than ∼270 W m{sup –2} (global mean) unlikely to lose more than one Earth ocean of H{sub 2}O over their lifetimes unless they lose all their atmospheric N{sub 2}/CO{sub 2} early on. Because of the variability of H{sub 2}O delivery during accretion, our results suggest that many 'Earth-like' exoplanets in the habitable zone may have ocean-covered surfaces, stable CO{sub 2}/H{sub 2}O-rich atmospheres, and high mean surface temperatures.

  9. Abundance and distribution of water vapor in Jupiter's atmosphere

    SciTech Connect

    Bjoraker, G.L.; Larson, H.P.; Kunde, V.G.

    1986-09-01

    The atmospheric transmission window between 1800 and 2250 cm(-1) in Jupiter's atmosphere was observed from the Kuiper Airborne Observatory (KAO) and by the infrared spectrometer (IRIS) on Voyager. The vertical distribution of H/sub 2/O was derived for the 1 to 6 bar portion of Jupiter's troposphere. The spatial variation of H/sub 2/O was measured using IRIS spectra of the Hot Spots in the North and South Equatorial Belts, the Equatorial Zone, and for an average of the North and South Tropical Zones. The H/sub 2/O column abundance above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amagat. The NEB Hot Spots are desiccated by a factor of 3 with respect to the rest of Jupiter. For an average between -40 to 40 deg latitude, the H/sub 2/O mole fraction, qH/sub 2/O, is saturated for P less than 2 bars, qH/sub 2/O = 4x10 to the -6 in the 2 to 4 bar range and it increases to 3x10 to the -5 at 6 bars. A similar vertical profile applies to the spatially resolved zone and belt spectra, except that H/sub 2/O falls off more rapidly at P less than 4 bars in the NEB Hot Spots. The massive H/sub 2/O cloud at 5 bars, T = 273 K, proposed in solar composition models, is inconsistent with the observations. Instead, a thin H/sub 2/O ice cloud would form at 2 bars, T = 200 K. The O/H ratio in Jupiter, inferred from H/sub 2/O measurements in both belts and zones at 6 bars, is depleted by a factor of 50 with respect to the Sun. The implications for the origin of Jupiter of globally depleted O/H, but enhanced C/H and N/H, are discussed.

  10. Modeling of Water Flow Processes in the Soil-Plant-Atmosphere System: The Soil-Tree-Atmosphere Continuum Model

    NASA Astrophysics Data System (ADS)

    Massoud, E. C.; Vrugt, J. A.

    2015-12-01

    Trees and forests play a key role in controlling the water and energy balance at the land-air surface. This study reports on the calibration of an integrated soil-tree-atmosphere continuum (STAC) model using Bayesian inference with the DREAM algorithm and temporal observations of soil moisture content, matric head, sap flux, and leaf water potential from the King's River Experimental Watershed (KREW) in the southern Sierra Nevada mountain range in California. Water flow through the coupled system is described using the Richards' equation with both the soil and tree modeled as a porous medium with nonlinear soil and tree water relationships. Most of the model parameters appear to be reasonably well defined by calibration against the observed data. The posterior mean simulation reproduces the observed soil and tree data quite accurately, but a systematic mismatch is observed between early afternoon measured and simulated sap fluxes. We will show how this points to a structural error in the STAC-model and suggest and test an alternative hypothesis for root water uptake that alleviates this problem.

  11. Precipitation chemistry - Atmospheric loadings to the surface waters of the Indian River lagoon basin by rainfall

    NASA Technical Reports Server (NTRS)

    Dreschel, Thomas W.; Madsen, Brooks C.; Maull, Lee A.; Hinkle, C. R.; Knott, William M., III

    1990-01-01

    Rain volume and chemistry monitoring as part of the Kennedy Space Center Long Term Environmental Monitoring Program included the years 1984-1987 as part of the National Atmospheric Deposition Program. Atmospheric deposition in rainfall consisted primarily of sea salt and hydrogen ion, sulfate, nitrate, and ammonium ions. The deposition of nitrogen (a principal plant nutrient) was on the order of 200-300 metric tons per year to the surface waters.

  12. A parameterization for the absorption of solar radiation by water vapor in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Wang, W.-C.

    1976-01-01

    A parameterization for the absorption of solar radiation as a function of the amount of water vapor in the earth's atmosphere is obtained. Absorption computations are based on the Goody band model and the near-infrared absorption band data of Ludwig et al. A two-parameter Curtis-Godson approximation is used to treat the inhomogeneous atmosphere. Heating rates based on a frequently used one-parameter pressure-scaling approximation are also discussed and compared with the present parameterization.

  13. Effects of Atmospheric Air Plasma Irradiation on pH of Water

    NASA Astrophysics Data System (ADS)

    Sarinont, Thapanut; Koga, Kazunori; Kitazaki, Satoshi; Uchida, Giichirou; Hayashi, Nobuya; Shiratani, Masaharu

    We have studied the effects of atmospheric air plasma irradiation to water using a scalable dielectric barrier discharge device. Measurements of the pH of water treated by the plasmas have shown the pH decreases due to peroxide molecules generated by plasma irradiation and depends on material of water container. We also found this plasma treated water has little effect on the growth enhancement on Radish sprouts compare with plasma irradiation on dry seeds and the plasma irradiation can affect them through the water buffer of 0.2 mm in thickness.

  14. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  15. Hydrogen production from water: Recent advances in photosynthesis research

    SciTech Connect

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    The great potential of hydrogen production by microalgal water splitting is predicated on quantitative measurement of the algae`s hydrogen-producing capability, which is based on the following: (1) the photosynthetic unit size of hydrogen production; (2) the turnover time of photosynthetic hydrogen production; (3) thermodynamic efficiencies of conversion of light energy into the Gibbs free energy of molecular hydrogen; (4) photosynthetic hydrogen production from sea water using marine algae; (5) the potential for research advances using modern methods of molecular biology and genetic engineering to maximize hydrogen production. ORNL has shown that sustained simultaneous photoevolution of molecular hydrogen and oxygen can be performed with mutants of the green alga Chlamydomonas reinhardtii that lack a detectable level of the Photosystem I light reaction. This result is surprising in view of the standard two-light reaction model of photosynthesis and has interesting scientific and technological implications. This ORNL discovery also has potentially important implications for maximum thermodynamic conversion efficiency of light energy into chemical energy by green plant photosynthesis. Hydrogen production performed by a single light reaction, as opposed to two, implies a doubling of the theoretically maximum thermodynamic conversion efficiency from {approx}10% to {approx}20%.

  16. Towards quantitative atmospheric water vapor profiling with differential absorption lidar.

    PubMed

    Dinovitser, Alex; Gunn, Lachlan J; Abbott, Derek

    2015-08-24

    Differential Absorption Lidar (DIAL) is a powerful laser-based technique for trace gas profiling of the atmosphere. However, this technique is still under active development requiring precise and accurate wavelength stabilization, as well as accurate spectroscopic parameters of the specific resonance line and the effective absorption cross-section of the system. In this paper we describe a novel master laser system that extends our previous work for robust stabilization to virtually any number of multiple side-line laser wavelengths for the future probing to greater altitudes. In this paper, we also highlight the significance of laser spectral purity on DIAL accuracy, and illustrate a simple re-arrangement of a system for measuring effective absorption cross-section. We present a calibration technique where the laser light is guided to an absorption cell with 33 m path length, and a quantitative number density measurement is then used to obtain the effective absorption cross-section. The same absorption cell is then used for on-line laser stabilization, while microwave beat-frequencies are used to stabilize any number of off-line lasers. We present preliminary results using ∼300 nJ, 1 μs pulses at 3 kHz, with the seed laser operating as a nanojoule transmitter at 822.922 nm, and a receiver consisting of a photomultiplier tube (PMT) coupled to a 356 mm mirror.

  17. Study of Pu consumption in Advanced Light Water Reactors. Evaluation of GE Advanced Boiling Water Reactor plants

    SciTech Connect

    Not Available

    1993-05-13

    Timely disposal of the weapons plutonium is of paramount importance to permanently safeguarding this material. GE`s 1300 MWe Advanced Boiling Water Reactor (ABWR) has been designed to utilize fill] core loading of mixed uranium-plutonium oxide fuel. Because of its large core size, a single ABWR reactor is capable of disposing 100 metric tons of plutonium within 15 years of project inception in the spiking mode. The same amount of material could be disposed of in 25 years after the start of the project as spent fuel, again using a single reactor, while operating at 75 percent capacity factor. In either case, the design permits reuse of the stored spent fuel assemblies for electrical energy generation for the remaining life of the plant for another 40 years. Up to 40 percent of the initial plutonium can also be completely destroyed using ABWRS, without reprocessing, either by utilizing six ABWRs over 25 years or by expanding the disposition time to 60 years, the design life of the plants and using two ABWRS. More complete destruction would require the development and testing of a plutonium-base fuel with a non-fertile matrix for an ABWR or use of an Advanced Liquid Metal Reactor (ALMR). The ABWR, in addition, is fully capable of meeting the tritium target production goals with already developed target technology.

  18. Water vapour absorption in the clear atmosphere of a Neptune-sized exoplanet.

    PubMed

    Fraine, Jonathan; Deming, Drake; Benneke, Bjorn; Knutson, Heather; Jordán, Andrés; Espinoza, Néstor; Madhusudhan, Nikku; Wilkins, Ashlee; Todorov, Kamen

    2014-09-25

    Transmission spectroscopy has so far detected atomic and molecular absorption in Jupiter-sized exoplanets, but intense efforts to measure molecular absorption in the atmospheres of smaller (Neptune-sized) planets during transits have revealed only featureless spectra. From this it was concluded that the majority of small, warm planets evolve to sustain atmospheres with high mean molecular weights (little hydrogen), opaque clouds or scattering hazes, reducing our ability to observe the composition of these atmospheres. Here we report observations of the transmission spectrum of the exoplanet HAT-P-11b (which has a radius about four times that of Earth) from the optical wavelength range to the infrared. We detected water vapour absorption at a wavelength of 1.4 micrometres. The amplitude of the water absorption (approximately 250 parts per million) indicates that the planetary atmosphere is predominantly clear down to an altitude corresponding to about 1 millibar, and sufficiently rich in hydrogen to have a large scale height (over which the atmospheric pressure varies by a factor of e). The spectrum is indicative of a planetary atmosphere in which the abundance of heavy elements is no greater than about 700 times the solar value. This is in good agreement with the core-accretion theory of planet formation, in which a gas giant planet acquires its atmosphere by accreting hydrogen-rich gas directly from the protoplanetary nebula onto a large rocky or icy core.

  19. Joint IAMAS/IAHS Symposium J1 on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere

    NASA Technical Reports Server (NTRS)

    Ohring, G.; Aoki, T.; Halpern D.; Henderson-Sellers, A.; Charlock, T.; Joseph, J.; Labitzke, K.; Raschke, E.; Smith, W.

    1994-01-01

    Seventy papers were presented at the two-and-a-half-day Symposium on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere. The symposium was jointly organized by the International Association of Meteorology and Atmospheric Sciences (IAMAS) and the International Association of Hydrological Sciences (IAHS). Global observing systems are receiving increased attention in connection with such problems as monitoring global climate change. The symposium included papers on observational requirements; measurement methodologies; descriptions of available datasets; results of analysis of observational data; plans for future observing systems, including the Global Climate Observing System (GCOS) and the Global Ocean Observing System (GOOS); and the programs and plans of the space agencies.

  20. The water cycle in the general circulation model of the martian atmosphere

    NASA Astrophysics Data System (ADS)

    Shaposhnikov, D. S.; Rodin, A. V.; Medvedev, A. S.

    2016-03-01

    Within the numerical general-circulation model of the Martian atmosphere MAOAM (Martian Atmosphere: Observation and Modeling), we have developed the water cycle block, which is an essential component of modern general circulation models of the Martian atmosphere. The MAOAM model has a spectral dynamic core and successfully predicts the temperature regime on Mars through the use of physical parameterizations typical of both terrestrial and Martian models. We have achieved stable computation for three Martian years, while maintaining a conservative advection scheme taking into account the water-ice phase transitions, water exchange between the atmosphere and surface, and corrections for the vertical velocities of ice particles due to sedimentation. The studies show a strong dependence of the amount of water that is actively involved in the water cycle on the initial data, model temperatures, and the mechanism of water exchange between the atmosphere and the surface. The general pattern and seasonal asymmetry of the water cycle depends on the size of ice particles, the albedo, and the thermal inertia of the planet's surface. One of the modeling tasks, which results from a comparison of the model data with those of the TES experiment on board Mars Global Surveyor, is the increase in the total mass of water vapor in the model in the aphelion season and decrease in the mass of water ice clouds at the poles. The surface evaporation scheme, which takes into account the turbulent rise of water vapor, on the one hand, leads to the most complete evaporation of ice from the surface in the summer season in the northern hemisphere and, on the other hand, supersaturates the atmosphere with ice due to the vigorous evaporation, which leads to worse consistency between the amount of the precipitated atmospheric ice and the experimental data. The full evaporation of ice from the surface increases the model sensitivity to the size of the polar cap; therefore, the increase in the

  1. Atmospheric Water Vapor: A Nemesis for Millimeter Wave Propagation

    DTIC Science & Technology

    1980-01-01

    Sulphur dioxide, for example, nucleates with water vapor to form sulfuric acid primary particles in large numbers (as high as 1015 m- 3 ), which are...electro- polished stainless steel (SS 304) cavity (3440 cm3 and 1265 cm2 , S/V = 0.37 cm-1 ) evacuated for > 24 hours to 10-4 torr and subjected to... electropolished -1.50 30 150 400 HMDSa silanizing -1.35 27 190 750 Parylene C (Union Carbine) -1.60 32 140 580 Silicone SR240 (GE) -2.10 42 200 550 Teflon REPI20

  2. Observations of atmospheric water vapor with the SAGE 2 instrument

    NASA Technical Reports Server (NTRS)

    Larsen, Jack C.; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.

    1988-01-01

    The Stratospheric Aerosol and Gas Experiment 2 (SAGE 2) is discussed. The SAGE 2 instrument was a multichannel spectrometer that inferred the vertical distribution of water vapor, aerosols, nitrogen dioxide, and ozone by measuring the extinction of solar radiation at spacecraft sunrise/sunset. At altitudes above 20 km, the SAGE 2 and LIMS (Limb Infrared Monitor of the Stratosphere) data are in close agreement. The discrepancies below this altitude may be attributed to differences in the instruments' field of view and time of data acquisition.

  3. Observations of atmospheric water vapor with the SAGE 2 instrument

    NASA Astrophysics Data System (ADS)

    Larsen, Jack C.; McCormick, M. P.; McMaster, L. R.; Chu, W. P.

    The Stratospheric Aerosol and Gas Experiment 2 (SAGE 2) is discussed. The SAGE 2 instrument was a multichannel spectrometer that inferred the vertical distribution of water vapor, aerosols, nitrogen dioxide, and ozone by measuring the extinction of solar radiation at spacecraft sunrise/sunset. At altitudes above 20 km, the SAGE 2 and LIMS (Limb Infrared Monitor of the Stratosphere) data are in close agreement. The discrepancies below this altitude may be attributed to differences in the instruments' field of view and time of data acquisition.

  4. An interim reference model for the variability of the middle atmosphere water vapor distribution

    NASA Technical Reports Server (NTRS)

    Remsberg, E. E.; Russell, J. M., III; Wu, C.-Y.

    1990-01-01

    A reference model for the middle atmosphere water vapor distribution for some latitudes and seasons was developed using two data sets. One is the seven months of Nimbus LIMS data obtained during November 1978 to May 1979 over the range 64 deg S - 84 deg N latitude and from about 100-mb to 1-mb altitude, and the other is represented by water vapor profiles from 0.2 mb to 0.01 mb in the mid-mesosphere, measured on ground at several fixed mid-latitude sites in the Northern Hemisphere, using microwave-emission techniques. This model provides an interim water vapor profile for the entire vertical range of the middle atmosphere, with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean is demonstrated, and information is provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means.

  5. Remote sensing of atmospheric water content from Bhaskara SAMIR data. [using statistical linear regression analysis

    NASA Technical Reports Server (NTRS)

    Gohil, B. S.; Hariharan, T. A.; Sharma, A. K.; Pandey, P. C.

    1982-01-01

    The 19.35 GHz and 22.235 GHz passive microwave radiometers (SAMIR) on board the Indian satellite Bhaskara have provided very useful data. From these data has been demonstrated the feasibility of deriving atmospheric and ocean surface parameters such as water vapor content, liquid water content, rainfall rate and ocean surface winds. Different approaches have been tried for deriving the atmospheric water content. The statistical and empirical methods have been used by others for the analysis of the Nimbus data. A simulation technique has been attempted for the first time for 19.35 GHz and 22.235 GHz radiometer data. The results obtained from three different methods are compared with radiosonde data. A case study of a tropical depression has been undertaken to demonstrate the capability of Bhaskara SAMIR data to show the variation of total water vapor and liquid water contents.

  6. An interim reference model for the variability of the middle atmosphere water vapor distribution

    NASA Astrophysics Data System (ADS)

    Remsberg, E. E.; Russell, J. M., III; Wu, C.-Y.

    A reference model for the middle atmosphere water vapor distribution for some latitudes and seasons was developed using two data sets. One is the seven months of Nimbus LIMS data obtained during November 1978 to May 1979 over the range 64 deg S - 84 deg N latitude and from about 100-mb to 1-mb altitude, and the other is represented by water vapor profiles from 0.2 mb to 0.01 mb in the mid-mesosphere, measured on ground at several fixed mid-latitude sites in the Northern Hemisphere, using microwave-emission techniques. This model provides an interim water vapor profile for the entire vertical range of the middle atmosphere, with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean is demonstrated, and information is provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means.

  7. The role of stationary and transient atmospheric waves in the Martian water cycle

    NASA Astrophysics Data System (ADS)

    Rodin, Alexander V.; Burlakov, Alexey; Evdokimova, Nadezda; Fedorova, Anna; Kuzmin, Ruslan; Wilson, R. John

    Extensive studies of the water cycle on Mars has resulted in detailed monitoring of the atmo-spheric water vapor contents, clouds, frosts, surface and subsurface ices during several consecu-tive Martian years. With help of simulations based on GCM models, this allowed for evaluation of the contribution of water different inventories and transport mechanisms in the water cycle. We present a detailed model of the Martian climate based on GFDL general circulation model with high resolution and comprehensive treatment of the microphysical processes in clouds and the interactions between the atmosphere and the planet's surface. Due to highly detailed description of cloud microphysics with a hybrid grid-moment scheme the model is able to re-produce such phenomena as formation of clouds, fogs, and precipitation. The mutual influence between frost deposition rates and water diffusion into the regolith from one side, and the surface thermal inertia from the other, provides notable feedback that may explain observed variations in the bound water contents in the upper soil layer. Another possible phenomenon that causes zonal variations in water deposition on the surface is the global and mesoscale wave activity in the atmosphere. Stationary wave 2 feature persists in the tropical atmosphere during the equinoctial seasons, while several times during the solstice season, a short-living wave-3 transients occur. Such transient waves, possibly caused by the inertial instability in the circumpolar vortex due to seasonally determined meridional velocity shear change, provide significant enhancement of the water transport between polar reservoirs and the tropical and extratropical atmosphere.

  8. Plant water-stress parameterization determines the strength of land-atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Combe, Marie; Vilà-Guerau de Arellano, Jordi; Ouwersloot, Huug G.; Peters, Wouter

    2016-04-01

    Land-surface models that are currently used in numerical weather predictions models and earth system models all assume various plant water-stress parameterizations. We investigate the impact of this variety of parametrizations on the performance of atmospheric models. For this, we use a conceptual framework where a convective atmospheric boundary-layer (ABL) model is coupled to a daytime model for the land surface fluxes of carbon, water, and energy. We first validate our coupled model for a set of surface and upper-atmospheric diurnal observations over a grown maize field in the Netherlands. We then perform a sensitivity analysis of this coupled land-atmosphere system by varying the modeled plant water-stress response from a very insensitive to a sensitive response during dry soil conditions. We first propose and verify a feedback diagram that ties plant water-stress response and large-scale atmospheric conditions to the diurnal cycles of ABL CO2, humidity and temperature. Based on our undertanstanding of the diurnal coupled system, we then explore the impact of the assumed water-stress reponse for the development of a dry spell on a synoptic time scale. We find that during a progressive 3-week soil drying caused by evapotranspiration, an insensitive plant will dampen atmospheric heating because the vegetation continues to transpire while soil moisture is available. In contrast, the sensitive plant reduces its transpiration to prevent soil moisture depletion. But when absolute soil moisture comes close to wilting point, the insensitive plant will suddenly close its stomata causing a switch to a land-atmosphere coupling regime dominated by sensible heat exchange. We find that in both cases, our modeled progressive soil moisture depletion contributes to further atmospheric warming up to 6 K, reduced photosynthesis up to 89 %, and CO2 enrichment up to 30 ppm, but the full impact is strongly delayed for the insensitive plant. Finally, we demonstrate that the assumed

  9. Foliar water uptake of Tamarix ramosissima from an atmosphere of high humidity.

    PubMed

    Li, Shuang; Xiao, Hong-lang; Zhao, Liang; Zhou, Mao-Xian; Wang, Fang

    2014-01-01

    Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants. Tamarix ramosissima was investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants.

  10. The atmosphere can be a source of certain water soluble volatile organic compounds in urban streams

    USGS Publications Warehouse

    Kenner, Scott J.; Bender, David A.; Zogorski, John S.; ,; James F. Pankow,

    2014-01-01

    Surface water and air volatile organic compound (VOC) data from 10 U.S. Geological Survey monitoring sites were used to evaluate the potential for direct transport of VOCs from the atmosphere to urban streams. Analytical results of 87 VOC compounds were screened by evaluating the occurrence and detection levels in both water and air, and equilibrium concentrations in water (Cws) based on the measured air concentrations. Four compounds (acetone, methyl tertiary butyl ether, toluene, and m- & p-xylene) were detected in more than 20% of water samples, in more than 10% of air samples, and more than 10% of detections in air were greater than long-term method detection levels (LTMDL) in water. Benzene was detected in more than 20% of water samples and in more than 10% of air samples. Two percent of benzene detections in air were greater than one-half the LTMDL in water. Six compounds (chloroform, p-isopropyltoluene, methylene chloride, perchloroethene, 1,1,1-trichloroethane, and trichloroethene) were detected in more than 20% of water samples and in more than 10% of air samples. Five VOCs, toluene, m- & p-xylene, methyl tert-butyl ether (MTBE), acetone, and benzene were identified as having sufficiently high concentrations in the atmosphere to be a source to urban streams. MTBE, acetone, and benzene exhibited behavior that was consistent with equilibrium concentrations in the atmosphere.

  11. Triple isotope composition of oxygen in atmospheric water vapor

    NASA Astrophysics Data System (ADS)

    Uemura, Ryu; Barkan, Eugeni; Abe, Osamu; Luz, Boaz

    2010-02-01

    Recently, an excess of 17O (17O-excess) has been demonstrated in meteoric water and ice cores. Based on theory and experiments, it has been suggested that this excess originates from evaporation of ocean water into under-saturated air. However, there has never been direct demonstration of this excess in marine vapor. Here, we present results of the first measurements of δ17O and δ18O in vapor samples collected over the South Indian and the Southern Oceans. Our data show the existence of 17O-excess in marine vapor and also clear negative correlation between 17O-excess and relative humidity. Thus, 17O-excess is useful for constraining oceanic humidity in hydrological and climatic models. Using the obtained values of 17O-excess, we estimated the fractionation factor between H218O and H216O for diffusion in air above the ocean (18αdiff). The new estimation of 18αdiff (1.008) is larger than the widely accepted value in hydrological studies.

  12. Assessment of Atmospheric Water Vapor Abundance Above RSL Locations on Mars

    NASA Astrophysics Data System (ADS)

    Berdis, Jodi R.; Murphy, Jim; Wilson, Robert John

    2016-10-01

    The possible signatures of atmospheric water vapor arising from Martian Recurring Slope Lineae (RSLs)1 are investigated. These RSLs appear during local spring and summer on downward slopes, and have been linked to liquid water which leaves behind streaks of briny material. Viking Orbiter Mars Atmospheric Water Detector (MAWD)2 and Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES)3-5 derived water vapor abundance values are interrogated to determine whether four RSL locations at southern mid-latitudes (Palikir Crater, Hale Crater, Horowitz Crater, and Coprates Chasma) exhibit episodic enhanced local water vapor abundance during southern summer solstice (Ls = 270°) and autumnal equinox (Ls = 360°) when RSLs are observed to develop6,7. Any detected atmospheric water vapor signal would expand upon current knowledge of RSLs, while non-detection would provide upper limits on RSL water content. Viking Orbiter Infrared Thermal Mapper (IRTM) and MGS TES derived temperature values are also investigated due to the appearance of active RSLs after the surface temperature of the slopes exceeds 250 K1.A high spatial resolution Martian atmospheric numerical model will be employed to assess the magnitude and temporal duration of water vapor content that might be anticipated in response to inferred RSL surface water release. The ability of past and future orbiter-based instruments to detect such water vapor quantities will be assessed.References1. McEwen, A. et al. 2011, Sci., 333, 7402. Jakosky, B. & Farmer, C. 1982, JGR, 87, 29993. Christensen, P. et al. 1992, JGR, 97, 77194. Christensen, P. et al. 2001, JGR, 106, 238235. Smith, M. 2002, JGR, 107, 51156. Ojha, L. et al. 2015, Nature Geosci., 8, 8297. Stillman, D. et al. 2014, Icarus, 233, 328

  13. Optimizing the electrical excitation of an atmospheric pressure plasma advanced oxidation process.

    PubMed

    Olszewski, P; Li, J F; Liu, D X; Walsh, J L

    2014-08-30

    The impact of pulse-modulated generation of atmospheric pressure plasma on the efficiency of organic dye degradation has been investigated. Aqueous samples of methyl orange were exposed to low temperature air plasma and the degradation efficiency was determined by absorbance spectroscopy. The plasma was driven at a constant frequency of 35kHz with a duty cycle of 25%, 50%, 75% and 100%. Relative concentrations of dissolved nitrogen oxides, pH, conductivity and the time evolution of gas phase ozone were measured to identify key parameters responsible for the changes observed in degradation efficiency. The results indicate that pulse modulation significantly improved dye degradation efficiency, with a plasma pulsed at 25% duty showing a two-fold enhancement. Additionally, pulse modulation led to a reduction in the amount of nitrate contamination added to the solution by the plasma. The results clearly demonstrate that optimization of the electrical excitation of the plasma can enhance both degradation efficiency and the final water quality.

  14. Application of Vacuum Swing Adsorption for Carbon Dioxide and Water Vapor Removal from Manned Spacecraft Atmospheres

    NASA Technical Reports Server (NTRS)

    Knox, J.; Fulda, P.; Howard, D.; Ritter, J.; Levan, M.

    2007-01-01

    The design and testing of a vacuum-swing adsorption process to remove metabolic 'water and carbon dioxide gases from NASA's Orion crew exploration vehicle atmosphere is presented. For the Orion spacecraft, the sorbent-based atmosphere revitalization (SBAR) system must remove all metabolic water, a technology approach 1Lhathas not been used in previous spacecraft life support systems. Design and testing of a prototype SBAR in sub-scale and full-scale configurations is discussed. Experimental and analytical investigations of dual-ended and single-ended vacuum desorption are presented. An experimental investigation of thermal linking between adsorbing and desorbing columns is also presented.

  15. Retrieval Assimilation and Modeling of Atmospheric Water Vapor from Ground- and Space-Based GPS Networks: Investigation of the Global and Regional Hydrological Cycles

    NASA Technical Reports Server (NTRS)

    Dickey, Jean O.

    1999-01-01

    Uncertainty over the response of the atmospheric hydrological cycle (particularly the distribution of water vapor and cloudiness) to anthropogenic forcing is a primary source of doubt in current estimates of global climate sensitivity, which raises severe difficulties in evaluating its likely societal impact. Fortunately, a variety of advanced techniques and sensors are beginning to shed new light on the atmospheric hydrological cycle. One of the most promising makes use of the sensitivity of the Global Positioning System (GPS) to the thermodynamic state, and in particular the water vapor content, of the atmosphere through which the radio signals propagate. Our strategy to derive the maximum benefit for hydrological studies from the rapidly increasing GPS data stream will proceed in three stages: (1) systematically analyze and archive quality-controlled retrievals using state-of-the-art techniques; (2) employ both currently available and innovative assimilation procedures to incorporate these determinations into advanced regional and global atmospheric models and assess their effects; and (3) apply the results to investigate selected scientific issues of relevance to regional and global hydrological studies. An archive of GPS-based estimation of total zenith delay (TZD) data and water vapor where applicable has been established with expanded automated quality control. The accuracy of the GPS estimates is being monitored; the investigation of systematic errors is ongoing using comparisons with water vapor radiometers. Meteorological packages have been implemented. The accuracy and utilization of the TZD estimates has been improved by implementing a troposphere gradient model. GPS-based gradients have been validated as real atmospheric moisture gradients, establishing a link between the estimated gradients and the passage of weather fronts. We have developed a generalized ray tracing inversion scheme that can be used to analyze occultation data acquired from space

  16. The ISS Water Processor Catalytic Reactor as a Post Processor for Advanced Water Reclamation Systems

    NASA Technical Reports Server (NTRS)

    Nalette, Tim; Snowdon, Doug; Pickering, Karen D.; Callahan, Michael

    2007-01-01

    Advanced water processors being developed for NASA s Exploration Initiative rely on phase change technologies and/or biological processes as the primary means of water reclamation. As a result of the phase change, volatile compounds will also be transported into the distillate product stream. The catalytic reactor assembly used in the International Space Station (ISS) water processor assembly, referred to as Volatile Removal Assembly (VRA), has demonstrated high efficiency oxidation of many of these volatile contaminants, such as low molecular weight alcohols and acetic acid, and is considered a viable post treatment system for all advanced water processors. To support this investigation, two ersatz solutions were defined to be used for further evaluation of the VRA. The first solution was developed as part of an internal research and development project at Hamilton Sundstrand (HS) and is based primarily on ISS experience related to the development of the VRA. The second ersatz solution was defined by NASA in support of a study contract to Hamilton Sundstrand to evaluate the VRA as a potential post processor for the Cascade Distillation system being developed by Honeywell. This second ersatz solution contains several low molecular weight alcohols, organic acids, and several inorganic species. A range of residence times, oxygen concentrations and operating temperatures have been studied with both ersatz solutions to provide addition performance capability of the VRA catalyst.

  17. EPA Science Matters Newsletter: Advancing Ways to Clean Up Drinking Water Systems (Published November 2013)

    EPA Pesticide Factsheets

    To advance the science and engineering of decontaminating pipe systems and safely disposing of high-volumes of contaminated water, Agency homeland security researchers are developing a Water Security Test Bed (WSTB).

  18. Formation of thermal flow fields and chemical transport in air and water by atmospheric plasma

    NASA Astrophysics Data System (ADS)

    Shimizu, Tetsuji; Iwafuchi, Yutaka; Morfill, Gregor E.; Sato, Takehiko

    2011-05-01

    Cold atmospheric plasma is a potential tool for medical purposes, e.g. disinfection/sterilization. In order for it to be effective and functional, it is crucial to understand the transport mechanism of chemically reactive species in air as well as in liquid. An atmospheric plasma discharge was produced between a platinum pin electrode and the surface of water. The thermal flow field of a cold atmospheric plasma as well as its chemical components was measured. A gas flow with a velocity of around 15 m s-1 to the water's surface was shown to be induced by the discharge. This air flow induced a circulating flow in the water from the discharge point at the water's surface because of friction. It was also demonstrated that the chemical components generated in air dissolved in water and the properties of the water changed. The reactive species were believed to be distributed mainly by convective transport in water, because the variation in the pH profile indicated by a methyl red solution resembled the induced flow pattern.

  19. Effects of atmospheric deposition of energy-related pollutants on water quality: a review and assessment

    SciTech Connect

    Davis, M.J.

    1981-05-01

    The effects on surface-water quality of atmospheric pollutants that are generated during energy production are reviewed and evaluated. Atmospheric inputs from such sources to the aquatic environment may include trace elements, organic compounds, radionuclides, and acids. Combustion is the largest energy-related source of trace-element emissions to the atmosphere. This report reviews the nature of these emissions from coal-fired power plants and discusses their terrestrial and aquatic effects following deposition. Several simple models for lakes and streams are developed and are applied to assess the potential for adverse effects on surface-water quality of trace-element emissions from coal combustion. The probability of acute impacts on the aquatic environment appears to be low; however, more subtle, chronic effects are possible. The character of acid precipitation is reviewed, with emphasis on aquatic effects, and the nature of existing or potential effects on water quality, aquatic biota, and water supply is considered. The response of the aquatic environment to acid precipitation depends on the type of soils and bedrock in a watershed and the chemical characteristics of the water bodies in question. Methods for identifying regions sensitive to acid inputs are reviewed. The observed impact of acid precipitation ranges from no effects to elimination of fish populations. Coal-fired power plants and various stages of the nuclear fuel cycle release radionuclides to the atmosphere. Radioactive releases to the atmosphere from these sources and the possible aquatic effects of such releases are examined. For the nuclear fuel cycle, the major releases are from reactors and reprocessing. Although aquatic effects of atmospheric releases have not been fully quantified, there seems little reason for concern for man or aquatic biota.

  20. Water Vapor Permeability of the Advanced Crew Escape Suit

    NASA Technical Reports Server (NTRS)

    Bue, Grant; Kuzneth, Larry; Gillis, David; Jones, Jeffery; Daniel, Brian; Gernhardt, Michael; Hamilton, Douglas

    2009-01-01

    Crew Exploration Vehicle (CEV) crewmembers are expected to return to earth wearing a suit similar to the current Advanced Crew Escape Suit (ACES). To ensure optimum cognitive performance, suited crewmembers must maintain their core body temperature within acceptable limits. There are currently several options for thermal maintenance in the post-landing phase. These include the current baseline, which uses an ammonia boiler, purge flow using oxygen in the suit, accessing sea water for liquid cooling garment (LCG) cooling and/or relying on the evaporative cooling capacity of the suit. These options vary significantly in mass, power, engineering and safety factors, with relying on the evaporative cooling capacity of the suit being the least difficult to implement. Data from previous studies indicates that the evaporative cooling capacity of the ACES was much higher than previously expected, but subsequent tests were performed for longer duration and higher metabolic rates to better define the water vapor permeability of the ACES. In these tests five subjects completed a series of tests performing low to moderate level exercise in order to control for a target metabolic rate while wearing the ACES in an environmentally controlled thermal chamber. Four different metabolic profiles at a constant temperature of 95 F and relative humidity of 50% were evaluated. These tests showed subjects were able to reject about twice as much heat in the permeable ACES as they were in an impermeable suit that had less thermal insulation. All of the heat rejection differential is attributed to the increased evaporation capability through the Gortex bladder of the suit.

  1. Investigating understory flora species as an isotope proxy for atmospheric water vapor

    NASA Astrophysics Data System (ADS)

    Rambo, J. P.; Lai, C.; Farlin, J. P.

    2011-12-01

    An understanding of stable isotope variation in leaf water is useful in quantifying water fluxes through different pathways. Little is known about species specific variations of leaf water 18O and 2H enrichment and their interactions with atmospheric water vapor in understory flora. Toward this end, we measured stable 18O and 2H signatures of leaf water and atmospheric water vapor in an old growth forest in the Pacific Northwest. A LGR off-axis cavity-enhanced absorption spectroscopy analyzer was used to measure hourly 18O/16O and 2H/1H ratios of atmospheric water vapor (δ18Ov and δ2Hv) at 3 canopy heights (1m aboveground, mid- and above-canopy). By employing a routine, in-situ calibration, we were able to account for the concentration and temperature dependency from the instrument-reported δ18Ov and δ2Hv values using a single reference water. By using a 3-point calibration procedure we were able to produce accurate (±0.2% for δ18Ov, ±0.5% for δ2Hv) and precise (±0.3% for δ18Ov, ±3.0% for δ2Hv) measurements on the VSMOW scale. During our sampling campaign we observed large variations ranging from -175.0% to -125.1% for δ2Hv and -23.9% to -13.5% for δ18Ov. Leaf tissue of four dominant understory plant species were sampled every 2 hours over a three day period. Previous studies showed that leaf water becomes isotopically enriched from evaporative fractionation during the day, and then returns to an isotopic equilibrium with atmospheric water vapor during nighttime, reaching a complete equilibrium at pre-dawn in wet environments (i.e. Amazon forests). This diurnal pattern in leaf water isotope ratios was ubiquitous in terrestrial ecosystems, however, leading to the potential of using this plant-based signature as a proxy to infer δ18Ov and δ2Hv in remote locations. In the present study we investigate how leaf water of understory flora and atmospheric water vapor interact in a temperate forest.

  2. Recent advances in the vertical coupling in the Atmosphere-Ionosphere System

    NASA Astrophysics Data System (ADS)

    Knížová, Petra Koucká; Georgieva, Katya; Ward, William; Yiğit, Erdal

    2015-12-01

    Welcome to this special issue of the Journal of Atmospheric and Solar-Terrestrial Physics, dedicated to the investigation of the coupling phenomena in the neutral Atmosphere-Ionosphere System. This special issue covers processes in the Atmosphere-Ionosphere System that significantly influence and/or rule the coupling within the regions. Earth's atmospheric regions are intricately coupled to one another via various dynamical, chemical, and electrodynamic processes. The coupling effects can be seen on the modulation of the waves from the lower to upper atmosphere as well as from low- to high-latitudes, electrodynamic and compositional changes, and plasma irregularities at different latitudinal regions around the globe due to the varying energy inputs. A special attention is paid to the Mesosphere-Lower Thermosphere region that represents a critical region in various coupling processes between the lower/middle atmosphere and the upper atmosphere/ionosphere since it forms physical processes filter and shape the flux of waves ascending through the mesosphere into the overlying thermosphere. Varying energy inputs from the Sun and from the lower atmosphere is one of the topics. Processes contributing to the vertical coupling in the atmosphere are discussed on theoretical basis and with respect to recent and long-term experimental measurements as well. Solar activity represents an important factor that directly or indirectly modulates the coupling processes.

  3. On the relationship between atmospheric water vapour transport and extra-tropical cyclones development

    NASA Astrophysics Data System (ADS)

    Ferreira, Juan A.; Liberato, Margarida L. R.; Ramos, Alexandre M.

    2016-08-01

    In this study we seek to investigate the role of atmospheric water vapour on the intensification of extra-tropical cyclones over the North Atlantic Ocean and more specifically to investigate the linkage between atmospheric rivers' conditions leading to the explosive development of extra-tropical cyclones. Several WRF-ARW simulations for three recent extra-tropical storms that had major negative socio-economic impacts in the Iberian Peninsula and south-western Europe (Klaus, 2009; Gong, 2013 and Stephanie, 2014) are performed in which the water vapour content of the initial and boundary conditions are tuned. Analyses of the vertically integrated vapour transport show the dependence of the storms' development on atmospheric water vapour. In addition, results also show changes in the shape of the jet stream resulting in a reduction of the upper wind divergence, which in turn affects the intensification of the extra-tropical cyclones studied. This study suggests that atmospheric rivers tend to favour the conditions for explosive extra-tropical storms' development in the three case studies, as simulations performed without the existence of atmospheric rivers produce shallow mid-latitude cyclones, that is, cyclones that are not so intense as those on the reference simulations.

  4. Comparison of activity coefficient models for atmospheric aerosols containing mixtures of electrolytes, organics, and water

    NASA Astrophysics Data System (ADS)

    Tong, Chinghang; Clegg, Simon L.; Seinfeld, John H.

    Atmospheric aerosols generally comprise a mixture of electrolytes, organic compounds, and water. Determining the gas-particle distribution of volatile compounds, including water, requires equilibrium or mass transfer calculations, at the heart of which are models for the activity coefficients of the particle-phase components. We evaluate here the performance of four recent activity coefficient models developed for electrolyte/organic/water mixtures typical of atmospheric aerosols. Two of the models, the CSB model [Clegg, S.L., Seinfeld, J.H., Brimblecombe, P., 2001. Thermodynamic modelling of aqueous aerosols containing electrolytes and dissolved organic compounds. Journal of Aerosol Science 32, 713-738] and the aerosol diameter dependent equilibrium model (ADDEM) [Topping, D.O., McFiggans, G.B., Coe, H., 2005. A curved multi-component aerosol hygroscopicity model framework: part 2—including organic compounds. Atmospheric Chemistry and Physics 5, 1223-1242] treat ion-water and organic-water interactions but do not include ion-organic interactions; these can be referred to as "decoupled" models. The other two models, reparameterized Ming and Russell model 2005 [Raatikainen, T., Laaksonen, A., 2005. Application of several activity coefficient models to water-organic-electrolyte aerosols of atmospheric interest. Atmospheric Chemistry and Physics 5, 2475-2495] and X-UNIFAC.3 [Erdakos, G.B., Change, E.I., Pandow, J.F., Seinfeld, J.H., 2006. Prediction of activity coefficients in liquid aerosol particles containing organic compounds, dissolved inorganic salts, and water—Part 3: Organic compounds, water, and ionic constituents by consideration of short-, mid-, and long-range effects using X-UNIFAC.3. Atmospheric Environment 40, 6437-6452], include ion-organic interactions; these are referred to as "coupled" models. We address the question—Does the inclusion of a treatment of ion-organic interactions substantially improve the performance of the coupled models over

  5. Mesoscale Modeling of Water Vapor and Dust in Valles Marineris: Atmospheric Influences on Recurring Slope Lineae.

    NASA Astrophysics Data System (ADS)

    Leung, C. W. S.; Rafkin, S. C.; McEwen, A. S.

    2015-12-01

    Extensive recurring slope lineae (RSL) activity has been detected in Valles Marineris on Mars and coincides with regions where water ice fogs appear [1]. The origin of the water driving RSL flow is not well understood, but observational evidence suggests atmospheric processes play a crucial role [2]. Provided the atmospheric vapor concentration is high enough, water ice fogs can form overnight if the surface temperature cools below the condensation temperature. Correlations between dust storms and flow rates suggest that atmospheric dust opacity, and its influence on air temperature, also has a significant effect on RSL activity. We investigate planetary boundary layer processes that govern the hydrological cycle and dust cycle on Mars using a mesoscale atmospheric model to simulate the distribution of water and dust with respect to regional atmospheric circulations. Our simulations in Valles Marineris show a curious temperature structure, where the inside of the canyon appears warmer relative to the plateaus immediately outside. For a well-mixed atmosphere, this temperature structure indicates that when the atmosphere inside the canyon is saturated and fog is present within Valles Marineris, fog and low-lying clouds should also be present on the cooler surrounding plateaus as well. However, images taken with the Mars Express High Resolution Stereo Camera (HRSC) show instances where water ice fog appeared exclusively inside the canyon. These results have important implications for the origin and concentration of water vapor in Valles Marineris, with possible connections to RSL. The potential temperatures from our simulations show a high level of stability inside the canyon produced dynamically by sinking air. However, afternoon updrafts along the canyon walls indicate that over time, water vapor within the chasm would escape along the sides of the canyon. Again, this suggests a local source or mechanism to concentrate water vapor is needed to explain the fog

  6. Regional scale monitoring of atmospheric water vapor content with GNSS infrastructure and numerical model predictions

    NASA Astrophysics Data System (ADS)

    Rozsa, Szabolcs; Zeno Gyongyosi, Andras; Bartholy, Judit; Kern, Aniko; Weidinger, Tamas; Decsi, Anna; Kenyeres, Ambrus; Dombai, Ferenc; Adam, Jozsef

    2013-04-01

    Water, which is present in the troposphere in all three phases, has a unique feature among atmospheric components. Besides the formation of clouds and precipitation, it has a key role in atmospheric energy transport and it is the most important greenhouse gas. Due to its temporal and spatial variability, the monitoring of water in the atmosphere requires observations with high temporal and spatial resolution. The water content in the air can be measured directly by radiosondes, in order to monitor the vertical structure of the lower 30-35 km. In addition, remote sensing devices installed on spacecrafts, airframes and the Earth's surface are also available for the measurement of water content. These sensors yield the total water amount of a column of air, the so-called precipitable water (PW) content, in units of kg m-2 or mm. Global Navigation Satellite Systems (GNSS) are capable to monitor various parameters of the atmosphere. With the establishment of the active GNSS network in Hungary, it became feasible to quantify and monitor PW from GNSS observations. The advantage of this solution is the high spatial and temporal resolution of the observations. Modeling of the weather system is performed by the numerical solution of the atmospheric hydro-thermodynamic set of equations. Based on the actual weather as initial condition, the parameters of the expected weather can be estimated. In this study two different meteorological models (WRF and DBCRAS) - run at the Department of Meteorology at Eotvos Lorand University for weather research and forecasting purposes - are compared with the PW estimates provided by the GNSS infrastructure for 7 months in 2011. Deviation between measured data from different sources is near 1 mm in most cases. Forecast PW values show larger deviation from measured data, which results from weather condition dependent forecast errors.

  7. Escape of H and D from Mars' Atmosphere and the Evolution of its Crustal Water Reservoirs

    NASA Technical Reports Server (NTRS)

    Hartle, Richard E.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The evolution of water on Mars involves preferential escape of hydrogen over deuterium, producing its deuterium rich atmosphere with a D/H ratio 5.2 times that of terrestrial water. In the past decade, several estimates have been made of the magnitudes of current and ancient crustal water reservoirs on Mars that freely exchange with its atmosphere. Some of the differences in the magnitudes of the reservoirs are influenced by differences in the following basic parameters: composition of H, D, H2 and HD at the exobase; thermal history of the atmosphere; escape mechanisms; and the D/H ratio of earlier epochs as inferred from meteorites. The dominant escape mechanism used in the estimates is Jeans escape. However, the Jeans escape flux is enhanced considerably when atmospheric winds and rotation are applied at the exobase . This constraint is of particular importance because the enhancement of the D escape flux can be an order of magnitude greater than the enhancement of the H escape flux. This preferential enhancement of the D escape flux over that of H means that a great deal more H must escape (than in the case without winds and rotation) to attain the same D/H ratio in the today's atmosphere. Another new constraint on reservoir magnitudes comes from the recent interpretation of Martian meteorite data, which suggests that the D/H ratio was 2 times that of terrestrial water at the end of the heavy bombardment period (1). These two constraints together lead to larger current and ancient crustal water reservoirs. Applying Rayleigh fractionation, new estimates of the sizes of the water reservoirs are made using the above constraints along with plausible values for hydrogen and deuterium densities, temperatures, wind speeds and rotation rates at the exobase.

  8. Atmospheric water vapor flux, bifurcation of the thermohaline circulation, and climate change

    SciTech Connect

    Wang, H.; Birchfield, G.E.

    1992-10-01

    Latitudinal heat transport in the ocean and atmosphere represents a fundamental process of the Earth`s climate system. The ocean component of heat transport is effected by the thermohaline circulation. Changes in this circulation have a significant effect on global climate. Paleoclimate evidence from the Greenland ice and deep sea sediment core suggests during much of glacial time the climate system oscillated between two different states. The role of atmospheric hydrological cycle on the global thermohaline circulation and the feedback to the climate system through changes in the ocean`s latitudinal heat transport, with a simple coupled ocean-atmosphere energy-salt balance model is addressed here. Two components of the atmospheric hydrological cycle, i.e., latitudinal water vapor transport and the net flux of water vapor from the Atlantic to the Pacific Ocean appear to play separate roles. If the inter-basin transport is sufficiently large, small changes in water vapor transport over the North Atlantic can effect bifurcation or a rapid transition between two different equilibria in the global thermohaline circulation. If the inter-basin transport is from the Pacific to the Atlantic and sufficiently large, latitudinal vapor transport in the North Pacific controls the bifurcations. For intermediate values of inter-basin transport, no rapid transitions occur in either basin. For estimated values of water vapor transport for the present climate the model asserts that while vapor transport from the Atlantic to the Pacific Ocean is sufficiently large to make the North Atlantic the dominant region for deep water production, latitudinal water vapor transport is sufficiently low that the thermohaline circulation appears stable, i.e., far from a bifurcation point. This conclusion is supported to some extent by the fact that the high latitude temperature of the atmosphere as recorded in the Greenland ice cores has changes little over the last 9000 years. 31 refs., 5 figs.

  9. Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

    NASA Astrophysics Data System (ADS)

    Lainer, M.; Kämpfer, N.; Tschanz, B.; Nedoluha, G. E.; Ka, S.; Oh, J. J.

    2015-08-01

    The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change). Keeping in mind that the instruments are based on different hardware and calibration setups, a height-dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different data sets, the Microwave Limb Sounder (MLS) on the Aura satellite is used to serve as a kind of traveling standard. A domain-averaging TM (trajectory mapping) method is applied which simplifies the subsequent validation of the quality of the trajectory-mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW) accompanied by the polar vortex breakdown; a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high potential of a

  10. Trajectory mapping of middle atmospheric water vapor by a mini network of NDACC instruments

    NASA Astrophysics Data System (ADS)

    Lainer, M.; Kämpfer, N.; Tschanz, B.; Nedoluha, G. E.; Ka, S.; Oh, J. J.

    2015-04-01

    The important task to observe the global coverage of middle atmospheric trace gases like water vapor or ozone usually is accomplished by satellites. Climate and atmospheric studies rely upon the knowledge of trace gas distributions throughout the stratosphere and mesosphere. Many of these gases are currently measured from satellites, but it is not clear whether this capability will be maintained in the future. This could lead to a significant knowledge gap of the state of the atmosphere. We explore the possibilities of mapping middle atmospheric water vapor in the Northern Hemisphere by using Lagrangian trajectory calculations and water vapor profile data from a small network of five ground-based microwave radiometers. Four of them are operated within the frame of NDACC (Network for the Detection of Atmospheric Composition Change). Keeping in mind that the instruments are based on different hardware and calibration setups, a height dependent bias of the retrieved water vapor profiles has to be expected among the microwave radiometers. In order to correct and harmonize the different datasets, the Microwave Limb Sounder (MLS) on the Aura satellite is used to serve as a kind of travelling standard. A domain-averaging TM (trajectory mapping) method is applied which simplifies the subsequent validation of the quality of the trajectory mapped water vapor distribution towards direct satellite observations. Trajectories are calculated forwards and backwards in time for up to 10 days using 6 hourly meteorological wind analysis fields. Overall, a total of four case studies of trajectory mapping in different meteorological regimes are discussed. One of the case studies takes place during a major sudden stratospheric warming (SSW) accompanied by the polar vortex breakdown, a second takes place after the reformation of stable circulation system. TM cases close to the fall equinox and June solstice event from the year 2012 complete the study, showing the high potential of a

  11. Tracer water transport and subgrid precipitation variation within atmospheric general circulation models

    NASA Technical Reports Server (NTRS)

    Koster, Randal D.; Eagleson, Peter S.; Broecker, Wallace S.

    1988-01-01

    A capability is developed for monitoring tracer water movement in the three-dimensional Goddard Institute for Space Science Atmospheric General Circulation Model (GCM). A typical experiment with the tracer water model follows water evaporating from selected grid squares and determines where this water first returns to the Earth's surface as precipitation or condensate, thereby providing information on the lateral scales of hydrological transport in the GCM. Through a comparison of model results with observations in nature, inferences can be drawn concerning real world water transport. Tests of the tracer water model include a comparison of simulated and observed vertically-integrated vapor flux fields and simulations of atomic tritium transport from the stratosphere to the oceans. The inter-annual variability of the tracer water model results is also examined.

  12. Possible impact of the atmospheric water vapor absorption on the total ozone amount

    NASA Astrophysics Data System (ADS)

    Makogon, Mikail M.; Nesmelova, Ljudmila I.; Rodimova, Olga B.

    2004-02-01

    The total ozone amount (TOA) is determined as a rule by classic spectrophotometric method: TOA is found from a measured difference of the atmospheric optical thicknesses at two specially selected wavelengths in the region 305-340 nm. In this region the aerosol and molecular scattering takes place and it is traditionally believed, that the molecular absorption in this spectral region is conditioned only by ozone. Researches performed in the Institute of Atmospheric Optics SB RAS at the end of 1980s have shown, that there is also gentle absorption of a water vapor in this region, which can make a contribution to the measured difference of atmospheric optical thicknesses and can result in some methodical error. Thus, the TOA value which is determined without considering the water vapor, may be overstated.

  13. Effect of gaseous atmosphere on photoinduced water wetting of ZnO nanowires

    NASA Astrophysics Data System (ADS)

    Yadav, Kavita; Mehta, B. R.; Singh, J. P.

    2016-05-01

    ZnO nanowires were synthesized by using chemical vapor deposition system at 1000°C temperature. The as synthesized ZnO nanowires show superhydrophilic nature with water contact angle value of 0°. After dark storage for about 50 days, the nanowires show superhydrophobic nature with contact angle value of about 155°. When these nanowires were exposed to ultraviolet light in air atmosphere, the nanowires becomes superhydrophilic. It was found that the rate of change of contact angle depends on the gases atmosphere during UV light illumination. The rate of change of contact angle with UV light illumination is higher in presence of oxygen gas whereas it is very slow in presence of hydrogen gas. Possible mechanism for the dependence of photo induced water wetting on ZnO nanowires in gaseous atmosphere is discussed.

  14. Line-by-line calculations of atmospheric fluxes and cooling rates: Application to water vapor

    SciTech Connect

    Clough, S.A.; Iacono, M.J.; Moncet, J.L.

    1992-10-20

    A model for the accelerated calculation of clear sky fluxes based on the line-by-line radiance model FASCODE has been developed and applied to the calculation of cooling rates for atmospheric water vapor. The model achieves computational accuracies for the longwave upwelling and downwelling fluxes of the order of 0.2%, an accuracy well within current limitations imposed by uncertainties in the spectral parameters, the line shape, and the associated continua. For the same treatment of line shape, the Voigt profile with a 10 cm{sup {minus}1} cutoff and no continuum, the results from the present model are in acceptable agreement with those from two other line-by-line models reported as part of the intercomparison of radiation codes used in climate models (ICRCCM). For this line profile and the mid-latitude summer atmosphere, the largest difference between the results from the authors model and the Goddard Laboratory for Atmospheres (GLA) model occurs for the downwelling flux at the surface, with the present model providing a value greater than that from GLA. The differences are generally consistent with greater atmospheric opacity from the present model, attributable to the inclusion of a self-broadening component for the half width for water and to finer spectral sampling in the lower-pressure regime. In the spectral domain there exists a mapping between the altitude and the molecular absorption strength as weighted by the Planck function. The extremely high correlation between the outgoing spectral radiance at the top of the atmosphere and the spectral cooling rate profile suggests that the measurement of the outgoing spectral radiance can provide important information about atmospheric state that is not available from spectrally integrated quantities. These results also indicate the critical importance of the spectral region from 100 to 600 cm{sup {minus}1} for the radiative transfer associated with atmospheric water vapor. 30 refs., 28 figs., 5 tabs.

  15. Uncertainty Analysis And Synergy Of Aerosol Products From Multiple Satellite Sensors For Advanced Atmospheric Research

    NASA Astrophysics Data System (ADS)

    Ichoku, C. M.; Petrenko, M.

    2013-05-01

    Aerosols are tiny particles suspended in the air, and can be made up of wind-blown dust, smoke from fires, and particulate emissions from automobiles, industries, and other natural and man-made sources. Aerosols can have significant impacts on the air quality, and can interact with clouds and solar radiation in such a way as to affect the water cycle and climate. However, the extent and scale of these impacts are still poorly understood, and this represents one of the greatest uncertainties in climate research to date. To fill this gap in our knowledge, the global and local properties of atmospheric aerosols are being extensively observed and measured, especially during the last decade, using both satellite and ground-based instruments, including such spaceborne sensors as MODIS on the Terra and Aqua satellites, MISR on Terra, OMI on Aura, POLDER on PARASOL, CALIOP on CALIPSO, SeaWiFS on SeaStar, and the ground-based Aerosol Robotic Network (AERONET) of sunphotometers. The aerosol measurements collected by these instruments over the last decade contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. Still, to be able to utilize these measurements synergistically, they have to be carefully and uniformly analyzed and inter-compared, in order to understand the uncertainties and limitations of the products - a process that is greatly complicated by the diversity of differences that exist among them. In this presentation, we will show results of a coherent comparative uncertainty analysis of aerosol measurements from the above-named satellite sensors relative to AERONET. We use these results to demonstrate how these sensors perform in different parts of the world over different landcover types as well as their performance relative to one another, thereby facilitating product selection and integration for specific research and applications needs.

  16. Modeling plant-atmosphere carbon and water fluxes along a CO2 gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At short time scales (hourly to daily), plant photosynthesis and transpiration respond nonlinearly to atmospheric CO2 concentration and vapor pressure deficit, depending on plant water status and thus soil moisture. Modeling vegetation and soil responses to different values of CO2 at multiple time s...

  17. Implications of elevated atmospheric CO2 on plant growth and water relations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Empirical records provide incontestable evidence for the global rise in CO2 concentration in the earth’s atmosphere. Plant growth can be stimulated by elevation of CO2; photosynthesis increases and economic yield is often enhanced. The application of more CO2 can result in less water use. Competitio...

  18. Atmospheric dispersion modeling for the worst-case detonation accident at the proposed Advanced Hydrotest Facility

    SciTech Connect

    Bowen, B.M., LLNL

    1996-10-01

    The Atmospheric Release Advisory Capability (ARAC) was requested to estimate credible worst-case dose, air concentration, and deposition of airborne hazardous materials that would result from a worst-case detonation accident at the proposed Advanced Hydrotest Facility (AHT) at the Nevada Test Site (NTS). Consequences were estimated at the closest onsite facility, the Device Assembly Facility (DOFF), and offsite location (intersection of Highway and U.S. 95). The materials considered in this analysis were weapon-grade plutonium, beryllium, and hydrogen fluoride which is a combustion product whose concentration is dependent upon the quantity of high explosives. The analysis compares the calculated results with action guidelines published by the Department of Defense in DoD 5100.52-M (Nuclear Weapon Accident Response Procedures). Results indicate that based on a one kg release of plutonium the whole body radiation dose could be as high as 3 Rem at the DOFF. This level approaches the 5 Rem level for which the Department of Defense requires respiratory protection, recommends sheltering and the consideration of evacuation. Deposition levels at the DOFF could approach 6 uCi/m{sup 2} for which the Department of Defense recommends access on a need-only basis and suggests that a possible controlled evacuation might be required. For a one kg release of plutonium, the dose at the nearest off-site location could reach 0.5. At this level, the Department of Defense suggests that sheltering be considered. For a one kg release of beryllium, the peak 5-minute concentration at the DOFF could be as as 20% of 6xlO{sup -3} mg/m{sup 2} which is the applicable by Response Planning Guideline (ERPG-1). At the nearest offsite location, the beryllium concentrations from a one kg release would be two orders of magnitude less than the same guideline. For the detonation of 100 kg of the explosive LX-17, the concentration of hydrogen fluoride at both the DOFF and the nearest offsite location

  19. 77 FR 3009 - Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... COMMISSION Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors..., ``Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors.'' DATES... developed using this Catalog along with the Operator Licensing Examination Standards for Power...

  20. Validation of the Atmospheric Infrared Sounder Water Vapor Retrievals Using Global Positioning System: Case Study in South Korea

    NASA Astrophysics Data System (ADS)

    Won, Jihye; Park, Kwan-Dong; Kim, Dusik; Ha, Jihyun

    2011-12-01

    The atmospheric infrared sounder (AIRS) sensor loaded on the Aqua satellite observes the global vertical structure of atmosphere and enables verification of the water vapor distribution over the entire area of South Korea. In this study, we performed a comparative analysis of the accuracy of the total precipitable water (TPW) provided as the AIRS level 2 standard retrieval product by Jet Propulsion Laboratory (JPL) over the South Korean area using the global positioning system (GPS) TPW data. The analysis TPW for the period of one year in 2008 showed that the accuracy of the data produced by the combination of the Advanced Microwave Sounding Unit sensor with the AIRS sensor to correct the effect of clouds (AIRS-X) was higher than that of the AIRS IR-only data (AIRS-I). The annual means of the root mean square error with reference to the GPS data were 5.2 kg/m2 and 4.3 kg/m2 for AIRS-I and AIRS-X, respectively. The accuracy of AIRS-X was higher in summer than in winter while measurement values of AIRS-I and AIRS-X were lower than those of GPS TPW to some extent.

  1. Water vapor in Titan's atmosphere observed by Cassini/CIRS data

    NASA Astrophysics Data System (ADS)

    Cottini, V.; Nixon, C. A.; Jennings, D. E.; Teanby, N. A.; Anderson, C. M.; Irwin, P. G.; Flasar, F. M.

    2011-12-01

    Water vapor in Titan's atmosphere has only been detected by whole-disk observations from the Infrared Space Observatory [1]. In fact an earlier attempt to measure water vapor with NASA's Cassini Composite Infrared Spectrometer (CIRS, [2]) was unsuccessful, due to poor signal-to-noise in early versions of the calibration pipeline. In this paper we show the detection of the water vapor in Titan's atmosphere through the analysis of the emission lines present in the spectral range (60 - 300 cm-1) observed by the far-IR Focal Plane 1 (FP1) detector. We model high spectral resolution (0.5 cm-1) disk versus limb data to determine the water mixing ratio as a function of latitude and time (using data acquired from December 2004 to late 2011), also exploring differences between the leading and trailing side of Saturn's moon. The opacity sources in the atmospheric model include thermal emission from the moon, collision-induced absorption (CIA) from pairs of Titan's main atmospheric molecules, the stratospheric aerosol and emission lines from atmospheric gases across the FP1 spectral range (see Cottini et al., 2011 [3] for description of the model). The radiative transfer model and retrieval code (NEMESIS) is based on the method of optimal estimation to perform a correlated-k computation of synthetic spectra.Our determination of the atmospheric abundance of water vapor yields a value of ~0.14 ppb assuming a constant vertical profile, which corresponds to a column abundance of 4.3x1014 molecules/cm2. Preliminary results suggest a change in the atmospheric water vapour abundance during northern winter into early northern spring. We also detected water in CIRS high resolution limb spectra. Modeling these limb observations, mainly centered on two tangent heights, 125 and 225 km, allows us to constrain the water vapor abundance vertical profile; utilizing the limb data allows us to retrieve the water vapor from disk observations using a water vapor mixing ratio that varies in

  2. Sources of Atmospheric Pollutants Impacting Air and Water Quality in the Lake Tahoe Basin

    NASA Astrophysics Data System (ADS)

    Gertler, A. W.; Cahill, T. A.; Gillies, J.; Kuhns, H.

    2008-12-01

    Starting in the second half of the 20th century, decline in Lake Tahoe's water clarity and degradation in the basin's air quality have become major concerns due to its unique scenic features. Gaseous and particulate nitrogen (N) and particulate phosphorus (P) loading via direct atmospheric deposition and sediment transport to the lake have also been implicated as responsible for its eutrophication and decline in water clarity. Estimates suggest that atmospheric N deposition contributes 55% of the total N loading to the lake, while atmospheric P deposition contributes 15% of the total P loading. In order to improve both air quality and, as a consequence, water quality, it is necessary to develop an understanding of the sources of the atmospheric pollutants. Once this is accomplished, it is possible to implement cost-effective strategies to reduce this impact. This paper summarizes the findings of a series of studies performed to determine the levels and sources of ambient air pollutants in the basin. Projects have included the development of a Tahoe-specific emissions inventory, long-term measurements of road dust resuspension, modeling to determine the fraction of pollutants coming from in-basin vs. out-of-basin sources, particulate source apportionment, and estimates of nitric acid deposition. These studies found that the pollutants most closely connected to the decline in water quality come largely from within basin sources, as opposed to those coming from the Central Valley and upwind urban areas of California. These results indicate regulators need to control pollutant emissions within the Tahoe basin in order to reduce the impact of atmospheric pollutants on both air and water quality.

  3. Listing Waters Impaired by Atmospheric Mercury: Voluntary Subcategory 5m for States with Comprehensive Mercury Reduction Programs

    EPA Pesticide Factsheets

    The document presents information regarding a voluntary approach for listing waters impaired by mercury predominantly from atmospheric sources pursuant to Clean Water Act Section 303(d), also known as “subcategory 5m.”

  4. Increase in forest water-use efficiency as atmospheric carbon dioxide concentrations rise.

    PubMed

    Keenan, Trevor F; Hollinger, David Y; Bohrer, Gil; Dragoni, Danilo; Munger, J William; Schmid, Hans Peter; Richardson, Andrew D

    2013-07-18

    Terrestrial plants remove CO2 from the atmosphere through photosynthesis, a process that is accompanied by the loss of water vapour from leaves. The ratio of water loss to carbon gain, or water-use efficiency, is a key characteristic of ecosystem function that is central to the global cycles of water, energy and carbon. Here we analyse direct, long-term measurements of whole-ecosystem carbon and water exchange. We find a substantial increase in water-use efficiency in temperate and boreal forests of the Northern Hemisphere over the past two decades. We systematically assess various competing hypotheses to explain this trend, and find that the observed increase is most consistent with a strong CO2 fertilization effect. The results suggest a partial closure of stomata-small pores on the leaf surface that regulate gas exchange-to maintain a near-constant concentration of CO2 inside the leaf even under continually increasing atmospheric CO2 levels. The observed increase in forest water-use efficiency is larger than that predicted by existing theory and 13 terrestrial biosphere models. The increase is associated with trends of increasing ecosystem-level photosynthesis and net carbon uptake, and decreasing evapotranspiration. Our findings suggest a shift in the carbon- and water-based economics of terrestrial vegetation, which may require a reassessment of the role of stomatal control in regulating interactions between forests and climate change, and a re-evaluation of coupled vegetation-climate models.

  5. Precipitation recycling in West Africa - regional modeling, evaporation tagging and atmospheric water budget analysis

    NASA Astrophysics Data System (ADS)

    Arnault, Joel; Kunstmann, Harald; Knoche, Hans-Richard

    2015-04-01

    Many numerical studies have shown that the West African monsoon is highly sensitive to the state of the land surface. It is however questionable to which extend a local change of land surface properties would affect the local climate, especially with respect to precipitation. This issue is traditionally addressed with the concept of precipitation recycling, defined as the contribution of local surface evaporation to local precipitation. For this study the West African monsoon has been simulated with the Weather Research and Forecasting (WRF) model using explicit convection, for the domain (1°S-21°N, 18°W-14°E) at a spatial resolution of 10 km, for the period January-October 2013, and using ERA-Interim reanalyses as driving data. This WRF configuration has been selected for its ability to simulate monthly precipitation amounts and daily histograms close to TRMM (Tropical Rainfall Measuring Mission) data. In order to investigate precipitation recycling in this WRF simulation, surface evaporation tagging has been implemented in the WRF source code as well as the budget of total and tagged atmospheric water. Surface evaporation tagging consists in duplicating all water species and the respective prognostic equations in the source code. Then, tagged water species are set to zero at the lateral boundaries of the simulated domain (no inflow of tagged water vapor), and tagged surface evaporation is considered only in a specified region. All the source terms of the prognostic equations of total and tagged water species are finally saved in the outputs for the budget analysis. This allows quantifying the respective contribution of total and tagged atmospheric water to atmospheric precipitation processes. The WRF simulation with surface evaporation tagging and budgets has been conducted two times, first with a 100 km2 tagged region (11-12°N, 1-2°W), and second with a 1000 km2 tagged region (7-16°N, 6°W -3°E). In this presentation we will investigate hydro-atmospheric

  6. The Atmospheric Water Vapor Cycle in South America and theTropospheric Circulation.

    NASA Astrophysics Data System (ADS)

    Labraga, J. C.; Frumento, O.; López, M.

    2000-06-01

    The main characteristics of the atmospheric water vapor cycle over the South American continent and the adjacent oceans are investigated using the 22-yr period, from 1976 to 1997, of the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) 40-Year Reanalysis Project database. Precipitation rate and water vapor content fields obtained from this dataset are compared over the region with newly available observed datasets, which combine ground-based and satellite-derived observations. The temporal variation and spatial distribution of the atmospheric water vapor balance equation terms (precipitation rate, evaporation rate, and water vapor flux convergence) are examined with regard to their consistency and relative importance. The net effect of the atmospheric water vapor transport, represented in the last term of the balance equation, is decomposed into the horizontal and vertical convergence terms. The analysis of the latter highlights those regions where the topographic uplift makes a substantial contribution to the total precipitation rate. The former term is further decomposed into the stationary and transient water vapor flux contributions. The comparison of these terms with relevant characteristics of the large-scale tropospheric circulation provides a better understanding of the different precipitation regimes in South America. The mean annual balance satisfactorily closes over most of the oceanic regions. However, important imbalances found in the vicinity of high topographic features, such as in the central Andes, are attributed to large errors in the local computation of the atmospheric water vapor flux. The current results corroborate previous findings on the role of the stationary water vapor flux convergence in the spatial distribution and seasonal variation of the rainfall rate in tropical and subtropical latitudes and extend over the less-investigated continental midlatitudes. The magnitude of the transient

  7. Toxicity of irradiated advanced heavy water reactor fuels.

    PubMed

    Priest, N D; Richardson, R B; Edwards, G W R

    2013-02-01

    The good neutron economy and online refueling capability of the CANDU® heavy water moderated reactor (HWR) enable it to use many different fuels such as low enriched uranium (LEU), plutonium, or thorium, in addition to its traditional natural uranium (NU) fuel. The toxicity and radiological protection methods for these proposed fuels, unlike those for NU, are not well established. This study uses software to compare the fuel composition and toxicity of irradiated NU fuel against those of two irradiated advanced HWR fuel bundles as a function of post-irradiation time. The first bundle investigated is a CANFLEX® low void reactor fuel (LVRF), of which only the dysprosium-poisoned central element, and not the outer 42 LEU elements, is specifically analyzed. The second bundle investigated is a heterogeneous high-burnup (LEU,Th)O(2) fuelled bundle, whose two components (LEU in the outer 35 elements and thorium in the central eight elements) are analyzed separately. The LVRF central element was estimated to have a much lower toxicity than that of NU at all times after shutdown. Both the high burnup LEU and the thorium fuel had similar toxicity to NU at shutdown, but due to the creation of such inhalation hazards as (238)Pu, (240)Pu, (242)Am, (242)Cm, and (244)Cm (in high burnup LEU), and (232)U and (228)Th (in irradiated thorium), the toxicity of these fuels was almost double that of irradiated NU after 2,700 d of cooling. New urine bioassay methods for higher actinoids and the analysis of thorium in fecal samples are recommended to assess the internal dose from these two fuels.

  8. Trace Hydrogen in Helium Atmosphere White Dwarfs as a Possible Signature of Water Accretion

    NASA Astrophysics Data System (ADS)

    Gentile-Fusillo, N. P.; Gänsicke, B. T.; Farihi, J.; Koester, D.; Schreiber, M. R.; Pala, A. F.

    2017-03-01

    A handful of white dwarfs with helium-dominated atmospheres contain exceptionally large masses of hydrogen in their convection zones, with the metal-polluted white dwarf GD 16 being one of the earliest recognised examples. We report the discovery of a similar star: the white dwarf coincidentally named GD 17. We obtained medium-resolution spectroscopy of both GD 16 and GD 17 and calculated accretion rates and abundances of photospheric H, Mg, Ca, Ti, Fe and Ni. The metal abundance ratios indicate that the two stars recently accreted debris which is Mg-poor compared to the composition of bulk Earth. However, unlike the metal pollutants, H never diffuses out of the atmosphere of white dwarfs and we propose that the exceptionally high atmospheric H content of GD 16 and GD 17 (2.2× 1024g and 2.9× 1024g respectively) could result from previous accretion of water bearing planetesimals. Comparing the detection of trace H and metal pollution among 729 helium atmosphere white dwarfs, we find that the presence of H is nearly twice as common in metal-polluted white dwarfs compared to their metal-free counterparts. This statistically highly significant correlation indicates that a significant amount of H is accreted alongside the metal pollutants in many He atmosphere white dwarfs (including GD 16 and GD 17). We argue that H is most likely accreted in the form of water which must therefore be commonly present in systems with rocky planetesimals.

  9. Fortnightly atmospheric tides forced by spring and neap tides in coastal waters

    PubMed Central

    Iwasaki, Shinsuke; Isobe, Atsuhiko; Miyao, Yasuyuki

    2015-01-01

    The influence of sea surface temperature (SST) on atmospheric processes over the open ocean has been well documented. However, atmospheric responses to SST in coastal waters are poorly understood. Oceanic stratification (and consequently, SST) in coastal waters largely depends on the fortnightly spring–neap tidal cycle, because of variations in vertical tidal mixing. Here we investigate how changes in SST during the fortnightly tidal cycle affect the lower-level atmosphere over the Seto Inland Sea, Japan. We use a combination of in situ measurements, satellite observations and a regional atmospheric model. We find that the SST in summer shows cool (warm) anomalies over most of the inland sea during spring (neap) tides. Additionally, surface air temperature is positively correlated with the SST as it varies during the fortnightly tidal cycle. Moreover, the fortnightly spring–neap cycle also influences the surface wind speed because the atmospheric boundary layer becomes stabilized or destabilized in response to the difference between air temperature and SST. PMID:25984948

  10. [Water-soluble anions of atmosphere on Tianwan nuclear power station].

    PubMed

    Zhao, Heng-Qiang; He, Ying; Zheng, Xiao-Ling; Chen, Fa-Rong; Pang, Shi-Ping; Wang, Cai-Xia; Wang, Xiao-Ru

    2010-11-01

    Three major water-soluble anions (Cl-, SO4(2-) and NO3-) in the atmosphere of the Tianwan nuclear power station in Lianyungang were determined by ion chromatography from June 2005 to May 2006. The results showed that the annual average concentration of Cl-, SO4(2-) and NO3- in the atmosphere of Tianwan nuclear power station was (33.12 +/- 53.63) microg x m(-3), (53.34 +/- 30.34) microg x m(-3) and (8.34 +/- 4.47) microg x m(-3), respectively. The concentrations of the three water-soluble anions showed evident trend of seasonal variation. The concentrations of Cl-, SO4(2-) reached the highest level in summer and the lowest level in winter, while the concentration of NO3- in autumn and winter was higher than those in summer and spring. Meteorological parameters such as wind direction, wind speed, temperature and relative humidity were studied and showed definite influence to the anions concentration of the atmosphere. This is the first simultaneous monitoring of corrosive anions in the atmosphere of Chinese coastal nuclear power plant, and it will provide basis for the prevention of marine atmospheric corrosion, which will ensure the safely operating of our nuclear power industry.

  11. Water accounting and vulnerability evaluation (WAVE): considering atmospheric evaporation recycling and the risk of freshwater depletion in water footprinting.

    PubMed

    Berger, Markus; van der Ent, Ruud; Eisner, Stephanie; Bach, Vanessa; Finkbeiner, Matthias

    2014-04-15

    Aiming to enhance the analysis of water consumption and resulting consequences along the supply chain of products, the water accounting and vulnerability evaluation (WAVE) model is introduced. On the accounting level, atmospheric evaporation recycling within drainage basins is considered for the first time, which can reduce water consumption volumes by up to 32%. Rather than predicting impacts, WAVE analyzes the vulnerability of basins to freshwater depletion. Based on local blue water scarcity, the water depletion index (WDI) denotes the risk that water consumption can lead to depletion of freshwater resources. Water scarcity is determined by relating annual water consumption to availability in more than 11,000 basins. Additionally, WDI accounts for the presence of lakes and aquifers which have been neglected in water scarcity assessments so far. By setting WDI to the highest value in (semi)arid basins, absolute freshwater shortage is taken into account in addition to relative scarcity. This avoids mathematical artifacts of previous indicators which turn zero in deserts if consumption is zero. As illustrated in a case study of biofuels, WAVE can help to interpret volumetric water footprint figures and, thus, promotes a sustainable use of global freshwater resources.

  12. Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling

    SciTech Connect

    Boone, Eric J.; Laskin, Alexander; Laskin, Julia; Wirth, Christopher; Shepson, Paul B.; Stirm, Brian H.; Pratt, Kerri A.

    2015-07-21

    Cloud water and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry with nanospray desorption electrospray ionization and direct infusion electrospray ionization were utilized to compare the organic composition of the particle and cloud water samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloud water, showing the significant influence of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloud water samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloud water when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.

  13. Remote sensing of atmospheric water vapor from synthetic aperture radar interferometry: case studies in Shanghai, China

    NASA Astrophysics Data System (ADS)

    Chang, Liang; Liu, Min; Guo, Lixin; He, Xiufeng; Gao, Guoping

    2016-10-01

    The estimation of atmospheric water vapor with high resolution is important for operational weather forecasting, climate monitoring, atmospheric research, and numerous other applications. The 40 m×40 m and 30 m×30 m differential precipitable water vapor (ΔPWV) maps are generated with C- and L-band synthetic aperture radar interferometry (InSAR) images over Shanghai, China, respectively. The ΔPWV maps are accessed via comparisons with the spatiotemporally synchronized PWV measurements from the European Centre for Medium-Range Weather Forecasts Interim reanalysis at the finest resolution and global positioning system observations, respectively. Results reveal that the ΔPWV maps can be estimated from both C- and L-band InSAR images with an accuracy of better than 2.0 mm, which, therefore, demonstrates the ability of InSAR observations at both C- and L-band to detect the water vapor distribution with high spatial resolution.

  14. Atmospheric chemistry. Direct kinetic measurement of the reaction of the simplest Criegee intermediate with water vapor.

    PubMed

    Chao, Wen; Hsieh, Jun-Ting; Chang, Chun-Hung; Lin, Jim Jr-Min

    2015-02-13

    Carbonyl oxides, or Criegee intermediates, are important transient species formed in the reactions of unsaturated hydrocarbons with ozone. Although direct detection of Criegee intermediates has recently been realized, the main atmospheric sink of Criegee intermediates remains unclear. We report ultraviolet absorption spectroscopic measurements of the lifetime of the simplest Criegee intermediate, CH2OO, at various relative humidity levels up to 85% at 298 kelvin. An extremely fast decay rate of CH2OO was observed at high humidity. The observed quadratic dependence of the decay rate on water concentration implied a predominant reaction with water dimer. On the basis of the water dimer equilibrium constant, the effective rate coefficient of the CH2OO + (H2O)2 reaction was determined to be 6.5 (±0.8) × 10(-12) cubic centimeters per second. This work would help modelers to better constrain the atmospheric concentrations of CH2OO.

  15. Alexandrite lidar for the atmospheric water vapor detection and development of powerful tunable sources in IR

    NASA Technical Reports Server (NTRS)

    Uchiumi, M.; Maeda, M.; Muraoka, K.; Uchino, O.

    1992-01-01

    New tunable solid-state lasers, such as alexandrite and Ti-sapphire lasers, provide a powerful technique to detect various molecules in the atmosphere whose absorption bands are in the infrared region. The differential absorption lidar (DIAL) system to measure the tropospheric water vapor has been investigated by many authors, in an early stage, by dye and ruby lasers. Using the alpha band of water vapor, the longest detection range can be obtained with high accuracy, and the alexandrite laser is the most suitable laser for this purpose. In this paper, we describe the detection of water vapor in the atmosphere by an alexandrite lidar, and the development of powerful tunable sources based on Raman lasers in the infrared region.

  16. Atmospheric depression-mediated water temperature changes affect the vertical movement of chum salmon Oncorhynchus keta.

    PubMed

    Kitagawa, Takashi; Hyodo, Susumu; Sato, Katsufumi

    2016-08-01

    The Sanriku coastal area, Japan, is one of the southern-most natural spawning regions of chum salmon Oncorhynchus keta. Here, we report their behavioral response to changes in ambient temperature after the passage of an atmospheric depression during the early spawning season. Before the passage, all electrically tagged fish moved vertically for several hours to depths below the shallow thermocline at >100 m. However, during the atmospheric depression, the salmon shortened the duration of their vertical movements and spent most time at the surface. The water column was homogenous at <150 m deep except for the surface. The descending behavior may have been discontinued because the cooler water below the thermocline was no longer in a thermally defined layer, due to strong vertical mixing by high wave action. Instead, they likely spent time within the cooler water temperatures at the surface of bays to minimize metabolic energy cost during migration.

  17. Exchange of polycyclic aromatic hydrocarbons among the atmosphere, water, and sediment in coastal embayments of southern California, USA.

    PubMed

    Sabin, Lisa D; Maruya, Keith A; Lao, Wenjian; Diehl, Dario; Tsukada, David; Stolzenbach, Keith D; Schiff, Kenneth C

    2010-02-01

    The present study investigated cross-media transport between both the sediment and the water column and between the water column and the atmosphere, to understand the role of each compartment as a source or a sink of polycyclic aromatic hydrocarbons (PAH) in southern California, USA, coastal waters. Concentrations of PAH were measured in the atmosphere, water column, and sediment at four water-quality-impaired sites in southern California: Ballona Creek Estuary, Los Angeles Harbor, Upper Newport Bay, and San Diego Bay. These concentrations were used to calculate site-specific sediment-water and atmosphere-water exchange fluxes. The net sediment-water exchange of total PAH (t-PAH) was positive, indicating that sediments were a source to the overlying water column. Furthermore, the net atmosphere-water exchange (gas exchange + dry particle deposition) of t-PAH was typically positive also, indicating the water column was a net source of PAH to the surrounding atmosphere through gas exchange. However, in all cases, the magnitude of the diffusive flux of PAH out of the sediments and into the water column far exceeded input or output of PAH through air/water exchange processes. These results demonstrate the potential importance of contaminated sediments as a source of PAH to the water column in coastal waters of southern California.

  18. Advances in geophysics. Volume 28 - issues in atmospheric and oceanic modeling. Part A - climate dynamics

    SciTech Connect

    Manabe, S.

    1985-01-01

    Papers are presented on large-scale eddies and the general circulation of the troposphere; the role of barotropic energy conversions in the general circulation; balance conditions in the earth's climate system, climate sensitivity; CO2 and hydrology; modeling of paleoclimates; and the southern oscillation and El Nino. Topics treated include the stratospheric dynamics of the middle atmosphere, wave-mean-flow interaction in the middle atmosphere, radiative-dynamical interactions in the middle atmosphere, and a mechanistic interpretation of stratospheric tracer transport. Consideration is given to the general circulation of Venus, and Jovian and comparative atmospheric modeling. Also discussed are the modeling of ocean circulation, tropical oceanography, the simulation of mesoscale ocean variability in midlatitude gyres, modeling circulation and mixing in estuaries and coastal oceans, and the modeling of sea-ice dynamics.

  19. Liquid water on Mars - An energy balance climate model for CO2/H2O atmospheres

    NASA Technical Reports Server (NTRS)

    Hoffert, M. I.; Callegari, A. J.; Hsieh, C. T.; Ziegler, W.

    1981-01-01

    A simple climatic model is developed for a Mars atmosphere containing CO2 and sufficient liquid water to account for the observed hydrologic surface features by the existence of a CO2/H2O greenhouse effect. A latitude-resolved climate model originally devised for terrestrial climate studies is applied to Martian conditions, with the difference between absorbed solar flux and emitted long-wave flux to space per unit area attributed to the divergence of the meridional heat flux and the poleward heat flux assumed to equal the atmospheric eddy heat flux. The global mean energy balance is calculated as a function of atmospheric pressure to assess the CO2/H2O greenhouse liquid water hypothesis, and some latitude-resolved cases are examined in detail in order to clarify the role of atmospheric transport and temperature-albedo feedback. It is shown that the combined CO2/H2O greenhouse at plausible early surface pressures may account for climates hot enough to support a hydrological cycle and running water at present-day insolation and visible albedo levels.

  20. Land atmosphere feedbacks and their role in the water resources of the Ganges basin.

    PubMed

    Harding, R J; Blyth, E M; Tuinenburg, O A; Wiltshire, A

    2013-12-01

    The northern Indian subcontinent has frequently been identified as a hotspot for land atmosphere interactions. It is also a region with the highest concentration of irrigated land and highest (and increasing) population density in the world. The available water in the region with which to grow food depends on the Asian monsoon, groundwater and melt from Himalayan snows. Any changes or disruptions to these sources of water could threaten the food supply. It is therefore essential to understand how the land surface, and in particular irrigated land, interacts with the atmosphere. It is anticipated that the interactions will occur on many scales. To an extent the magnitude and form of these will depend on the depth of the atmosphere which is affected. Thus at the local, or micro, scale it is the surface layer (some 10 s m deep) which is cooled and moistened by the evaporation of irrigated water, at the meso-scale the Planetary boundary layer (up to 1 or 2 km) will be modified - with possible atmospheric moistening, increased cloud and rain formation and at very large scales the whole dynamics of the south Asian Monsoon will be affected. This illustrates a strong interaction between the Asian monsoon and the regional topography. Of considerable significance is the finding in this paper that up to 60% of the evaporation from irrigated areas in the summer months is ultimately recycled to Himalayan rainfall and so feedbacks to river flows in the Ganges.

  1. Development of an advanced atmospheric/transport model for emergency response purposes

    SciTech Connect

    Fast, J.D.; O'Steen, B.L.; Addis, R.P.

    1991-07-12

    Atmospheric transport and diffusion models have been developed for real-time calculations of the location and concentration of toxic or radioactive materials during an accidental release at the Savannah River Site (SRS). These models are based Gaussian distributions and have been incorporated into an automated menu-driven program called the WIND (Weather INformation and Display) system. The WIND system atmospheric models employ certain assumptions that allow the computations of the ground-level concentration of toxic or radioactive materials to be made quickly. Gaussian models, such as PF/PL and 2DPUF, suffer from serious limitations including the inability to represent recirculation of pollutants in complex terrain, the use of one stability class at a given time to represent turbulent mixing over heterogeneous terrain, and the use of a wind field computed at only one height in the atmosphere. These limitations arise because the fundamental conservation relations of the atmosphere have been grossly simplified. Three-dimensional coupled atmospheric-dispersion models are not limited by the over-simplifications of the Gaussian assumption and have been used in the past to predict the transport of pollutants in a variety of atmospheric circulations. The disadvantage of these models is that they require large amounts of computational time; however, technology has progressed enough so that real-time simulations of dispersion may be made. These complex models can be run in an operational mode so that routine forecasts of the wind field and particulate concentration can be made.

  2. SSWR Water Systems Project 2: Next Steps – Technology Advances

    EPA Science Inventory

    EPA is responsible for protecting America’s water resources under the Clean Water Act (CWA) and for ensuring that the Nation’s drinking water is safe under the Safe Drinking Water Act (SDWA). Further, it is the responsibility of EPA to conduct research and analyses t...

  3. Flared natural gas-based onsite atmospheric water harvesting (AWH) for oilfield operations

    NASA Astrophysics Data System (ADS)

    Wikramanayake, Enakshi D.; Bahadur, Vaibhav

    2016-03-01

    Natural gas worth tens of billions of dollars is flared annually, which leads to resource waste and environmental issues. This work introduces and analyzes a novel concept for flared gas utilization, wherein the gas that would have been flared is instead used to condense atmospheric moisture. Natural gas, which is currently being flared, can alternatively power refrigeration systems to generate the cooling capacity for large scale atmospheric water harvesting (AWH). This approach solves two pressing issues faced by the oil-gas industry, namely gas flaring, and sourcing water for oilfield operations like hydraulic fracturing, drilling and water flooding. Multiple technical pathways to harvest atmospheric moisture by using the energy of natural gas are analyzed. A modeling framework is developed to quantify the dependence of water harvest rates on flared gas volumes and ambient weather. Flaring patterns in the Eagle Ford Shale in Texas and the Bakken Shale in North Dakota are analyzed to quantify the benefits of AWH. Overall, the gas currently flared annually in Texas and North Dakota can harvest enough water to meet 11% and 65% of the water consumption in the Eagle Ford and the Bakken, respectively. Daily harvests of upto 30 000 and 18 000 gallons water can be achieved using the gas currently flared per well in Texas and North Dakota, respectively. In fifty Bakken sites, the water required for fracturing or drilling a new well can be met via onsite flared gas-based AWH in only 3 weeks, and 3 days, respectively. The benefits of this concept are quantified for the Eagle Ford and Bakken Shales. Assessments of the global potential of this concept are presented using data from countries with high flaring activity. It is seen that this waste-to-value conversion concept offers significant economic benefits while addressing critical environmental issues pertaining to oil-gas production.

  4. Satellite Retrieval of Atmospheric Water Budget over Gulf of Mexico- Caribbean Basin: Seasonal Variability

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Santos, Pablo; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This study presents results from a multi-satellite/multi-sensor retrieval system designed to obtain the atmospheric water budget over the open ocean. A combination of hourly-sampled monthly datasets derived from the GOES-8 5 Imager and the DMSP 7-channel passive microwave radiometer (SSM/I) have been acquired for the Gulf of Mexico-Caribbean Sea basin. Whereas the methodology is being tested over this basin, the retrieval system is designed for portability to any open-ocean region. Algorithm modules using the different datasets to retrieve individual geophysical parameters needed in the water budget equation are designed in a manner that takes advantage of the high temporal resolution of the GOES-8 measurements, as well as the physical relationships inherent to the SSM/I passive microwave signals in conjunction with water vapor, cloud liquid water, and rainfall. The methodology consists of retrieving the precipitation, surface evaporation, and vapor-cloud water storage terms in the atmospheric water balance equation from satellite techniques, with the water vapor advection term being obtained as the residue needed for balance. Thus, we have sought to develop a purely satellite-based method for obtaining the full set of terms in the atmospheric water budget equation without requiring in situ sounding information on the wind profile. The algorithm is partly validated by first cross-checking all the algorithm components through multiple-algorithm retrieval intercomparisons. More fundamental validation is obtained by directly comparing water vapor transports into the targeted basin diagnosed from the satellite algorithm to those obtained observationally from a network of land-based upper air stations that nearly uniformly surround the basin. Total columnar atmospheric water budget results will be presented for an extended annual cycle consisting of the months of October-97, January-98, April-98, July-98, October-98, and January-1999. These results are used to emphasize

  5. The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques

    NASA Astrophysics Data System (ADS)

    Fahey, D. W.; Gao, R.-S.; Möhler, O.; Saathoff, H.; Schiller, C.; Ebert, V.; Krämer, M.; Peter, T.; Amarouche, N.; Avallone, L. M.; Bauer, R.; Bozóki, Z.; Christensen, L. E.; Davis, S. M.; Durry, G.; Dyroff, C.; Herman, R. L.; Hunsmann, S.; Khaykin, S. M.; Mackrodt, P.; Meyer, J.; Smith, J. B.; Spelten, N.; Troy, R. F.; Vömel, H.; Wagner, S.; Wienhold, F. G.

    2014-09-01

    The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques was conducted at the aerosol and cloud simulation chamber AIDA (Aerosol Interaction and Dynamics in the Atmosphere) at the Karlsruhe Institute of Technology, Germany, in October 2007. The overall objective was to intercompare state-of-the-art and prototype atmospheric hygrometers with each other and with independent humidity standards under controlled conditions. This activity was conducted as a blind intercomparison with coordination by selected referees. The effort was motivated by persistent discrepancies found in atmospheric measurements involving multiple instruments operating on research aircraft and balloon platforms, particularly in the upper troposphere and lower stratosphere, where water vapor reaches its lowest atmospheric values (less than 10 ppm). With the AIDA chamber volume of 84 m3, multiple instruments analyzed air with a common water vapor mixing ratio, by extracting air into instrument flow systems, by locating instruments inside the chamber, or by sampling the chamber volume optically. The intercomparison was successfully conducted over 10 days during which pressure, temperature, and mixing ratio were systematically varied (50 to 500 hPa, 185 to 243 K, and 0.3 to 152 ppm). In the absence of an accepted reference instrument, the absolute accuracy of the instruments was not established. To evaluate the intercomparison, the reference value was taken to be the ensemble mean of a core subset of the measurements. For these core instruments, the agreement between 10 and 150 ppm of water vapor is considered good with variation about the reference value of about ±10% (±1σ). In the region of most interest between 1 and 10 ppm, the core subset agreement is fair with variation about the reference value of ±20% (±1σ). The upper limit of precision was also derived for each instrument from the reported data. The implication for atmospheric measurements is that the

  6. The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques

    NASA Astrophysics Data System (ADS)

    Fahey, D. W.; Gao, R.-S.; Möhler, O.; Saathoff, H.; Schiller, C.; Ebert, V.; Krämer, M.; Peter, T.; Amarouche, N.; Avallone, L. M.; Bauer, R.; Bozóki, Z.; Christensen, L. E.; Davis, S. M.; Durry, G.; Dyroff, C.; Herman, R. L.; Hunsmann, S.; Khaykin, S. M.; Mackrodt, P.; Meyer, J.; Smith, J. B.; Spelten, N.; Troy, R. F.; Vömel, H.; Wagner, S.; Wienhold, F. G.

    2014-04-01

    The AquaVIT-1 Intercomparison of Atmospheric Water Vapor Measurement Techniques was conducted at the aerosol and cloud simulation chamber AIDA at the Karlsruhe Institute of Technology, Germany, in October 2007. The overall objective was to intercompare state-of-the-art and prototype atmospheric hygrometers with each other and with independent humidity standards under controlled conditions. This activity was conducted as a blind intercomparison with coordination by selected referees. The effort was motivated by persistent discrepancies found in atmospheric measurements involving multiple instruments operating on research aircraft and balloon platforms, particularly in the upper troposphere and lower stratosphere where water vapor reaches its lowest atmospheric values (less than 10 ppm). With the AIDA chamber volume of 84 m3, multiple instruments analyzed air with a common water vapor mixing ratio, either by extracting air into instrument flow systems, locating instruments inside the chamber, or sampling the chamber volume optically. The intercomparison was successfully conducted over 10 days during which pressure, temperature, and mixing ratio were systematically varied (50 to 500 hPa, 185 to 243 K, and 0.3 to 152 ppm). In the absence of an accepted reference instrument, the reference value was taken to be the ensemble mean of a core subset of the measurements. For these core instruments, the agreement between 10 and 150 ppm of water vapor is considered good with variation about the reference value of about ±10% (±1σ). In the region of most interest between 1 and 10 ppm, the core subset agreement is fair with variation about the reference value of ±20% (±1σ). The upper limit of precision was also derived for each instrument from the reported data. These results indicate that the core instruments, in general, have intrinsic skill to determine unknown water vapor mixing ratios with an accuracy of at least ±20%. The implication for atmospheric measurements is

  7. A process-based evapotranspiration model incorporating coupled soil water-atmospheric controls

    NASA Astrophysics Data System (ADS)

    Haghighi, Erfan; Kirchner, James

    2016-04-01

    Despite many efforts to develop evapotranspiration models (in the framework of the Penman-Monteith equation) with improved parametrizations of various resistance terms to water vapor transfer into the atmosphere, evidence suggests that estimates of evapotranspiration and its partitioning are prone to bias. Much of this bias could arise from the exclusion of surface hydro-thermal properties and of physical interactions close to the surface where heat and water vapor fluxes originate. Recent progress has been made in mechanistic modeling of surface-turbulence interactions, accounting for localized heat and mass exchange rates from bare soil surfaces covered by protruding obstacles. We seek to extend these results partially vegetated surfaces, to improve predictive capabilities and accuracy of remote sensing techniques quantifying evapotranspiration fluxes. The governing equations of liquid water, water vapor, and energy transport dynamics in the soil-plant-atmosphere system are coupled to resolve diffusive vapor fluxes from isolated pores (plant stomata and soil pores) across a near-surface viscous sublayer, explicitly accounting for pore-scale transport mechanisms and environmental forcing. Preliminary results suggest that this approach offers unique opportunities for directly linking transport properties in plants and adjacent bare soil with resulting plant transpiration and localized bare soil evaporation rates. It thus provides an essential building block for interpreting and upscaling results to field and landscape scales for a range of vegetation cover and atmospheric conditions.

  8. GPS meteorology - Remote sensing of atmospheric water vapor using the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Bevis, Michael; Businger, Steven; Herring, Thomas A.; Rocken, Christian; Anthes, Richard A.; Ware, Randolph H.

    1992-01-01

    We present a new approach to remote sensing of water vapor based on the Global Positioning System (GPS). Geodesists and geophysicists have devised methods for estimating the extent to which signals propagating from GPS satellites to ground-based GPS receivers are delayed by atmospheric water vapor. This delay is parameterized in terms of a time-varying zenith wet delay (ZWD) which is retrieved by stochastic filtering of the GPS data. Given surface temperature and pressure readings at the GPS receiver, the retrieved ZWD can be transformed with very little additional uncertainty into an estimate of the integrated water vapor (IWV) overlying that receiver. Networks of continuously operating GPS receivers are being constructed by geodesists, geophysicists, and government and military agencies, in order to implement a wide range of positioning capabilities. These emerging GPS networks offer the possibility of observing the horizontal distribution of IWV or, equivalently, precipitate water with unprecedented coverage and a temporal resolution of the order of 10 min. These measurements could be utilized in operational weather forecasting and in fundamental research into atmospheric storm systems, the hydrologic cycle, atmospheric chemistry, and global climate change.

  9. First results of the tomographic reconstruction of atmospheric water vapour using GNSS observations in Hungary

    NASA Astrophysics Data System (ADS)

    Rozsa, Szabolcs; Horvath, Tivadar

    2013-04-01

    The continuously operating GNSS networks play an important role not only in surveying but in geodesy and other geosciences, too. Using the precise coordinates of these stations, the tropospheric delay of the GNSS signals can be estimated. This shows a strong correlation with the integrated water vapour in the atmosphere. Nowadays the vertically intergated water vapour is routinely estimated from 52 GNSS stations over the territory of Hungary on an hourly basis. A more detailed model of the distribution of atmospheric water vapour can be created using the slant tropospheric delays estimated along the propagation path of the satellite signals. In this paper a four-dimensional tomographic model is introduced based on modeled and observed slant tropospheric delays. The modeled slant delays are computed using the estimated vertical delays and the Niell-mapping function. Since the real distribution of the atmospheric water vapour may not follow the isotropic Niell-mapping function, slant tropospheric delays are estimated from the double-difference residuals of the GNSS observations using a zero-mean assumption. The first results of the tomographic reconstruction are presented in the paper and they are validated with radiosonde observations at both of the Hungarian Radiosonde launching sites.

  10. On the stability of ion water clusters at atmospheric conditions: Open system Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Zidi, Zouhaier S.

    2012-09-01

    The formation of water clusters on Li+, Na+, K+, Cl-, and I- ions from water vapor at atmospheric conditions have been studied using Monte Carlo simulations. The extended simple point charge model has been employed for water molecules. The polarization of ions in the field of molecules and the polarization of molecules in the field of ions have been considered explicitly in the total Hamiltonian of the molecular system. The cluster formation work and the Gibbs free energy and enthalpy of attachment reactions of one water molecule to the cluster have been calculated via the bicanonical ensemble method. Our results reveal the formation of stable clusters in equilibrium with the moist atmosphere in a wide range of vapor pressure values, with largest clusters are formed around cations. Decreasing the temperature, from 293 K to 253 K, leads to the formation of larger equilibrium clusters, and enhances the stability of systems as whole. According to clusters' molecular structures, negative ions are expected to be more active in atmospheric processes, including chemical reactions and cloud formation, than positive ones.

  11. Atmospheric Pressure Glow Discharge for Point-of-Use Water Treatment

    NASA Astrophysics Data System (ADS)

    Lindsay, Alexander; Byrns, Brandon; Shannon, Steven; Knappe, Detlef

    2012-10-01

    Treatment of biological and chemical contaminants is an area of growing global interest where atmospheric pressure plasmas can make a significant contribution. Addressing key challenges of volume processing and operational cost, a large volume 162 MHz coaxial air-plasma source has been developed.footnotetextByrns (2012) J. Phys. D: Appl. Phys. 45 (2012) 195204 Because of VHF ballasting effects, the electric discharge is maintained at a steady glow, allowing formation of critical non-equilibrium chemistry. High densities, ne = 10^11-10^12, have been recorded. The atmospheric nature of the device permits straightforward and efficient treatment of water samples. [H^+] concentrations in 150 milliliter tap water samples have been shown to increase by 10^5 after five minutes of discharge exposure. Recent literature has demonstrated that increasing acidity is strongly correlated with a solution's ability to deactivate microbial contaminants.footnotetextTraylor (2011) J. Phys. D: Appl. Phys. 44 (2011) 472001 The work presented here will explore the impact of treatment gas, system configuration, and power density on water disinfection and PFC abatement. An array of plasma diagnostics, including OES and electrical measurements, are combined with post-process water analysis, including GC-MS and QT analysis of coliform and E.coli bacteria. Development of volume processing atmospheric plasma disinfection methods offers promise for point-of-use treatments in developing areas of the world, potentially supplementing or replacing supply and weather-dependent disinfection methods.

  12. [Research advances in simulating land water-carbon coupling].

    PubMed

    Liu, Ning; Sun, Peng-Sen; Liu, Shi-Rong

    2012-11-01

    The increasing demand of adaptive management of land, forest, and water resources under the background of global change and water resources crisis has promoted the comprehensive study of coupling ecosystem water and carbon cycles and their restrictive relations. To construct the water-carbon coupling model and to approach the ecosystem water-carbon balance and its interactive response mechanisms under climate change at multiple spatiotemporal scales is nowadays a major concern. After reviewing the coupling relationships of water and carbon at various scales, this paper explored the implications and estimation methods of the key processes and related parameters of water-carbon coupling, the construction of evapotranspiration model at large scale based on RS, and the importance of this model in water-carbon coupling researches. The applications of assimilative multivariate data in water-carbon coupling researches under future climate change scenarios were also prospected.

  13. Chlorophyll Concentration Estimates for Coastal Waters using Pixel-Based Atmospheric Correction of Landsat Images

    NASA Astrophysics Data System (ADS)

    Kouba, E.; Xie, H.

    2014-12-01

    Ocean color analysis is more challenging for coastal regions than the global ocean due the effects of optical brightness, shallow and turbid water, higher phytoplankton growth rates, and the complex geometry of coastal bays and estuaries. Also, one of the key atmospheric correction assumptions (zero water leaving radiance in the near infrared) is not valid for these complex conditions. This makes it difficult to estimate the spectral radiance noise caused by atmospheric aerosols, which can vary rapidly with time and space. This project evaluated using Landsat-7 ETM+ observations over a set of coastal bays, and allowing atmospheric correction calculations to vary with time and location as much as practical. Precise satellite orbit vector data was combined with operational weather and climate data to create interpolated arrays of atmospheric profiles which varied with time and location, allowing separate calculation of the Rayleigh and aerosol radiance corrections for all pixels. The resulting normalized water-leaving radiance values were compared with chlorophyll fluorescence measurements made at five in-situ stations inside a set of Texas coastal bays: the Mission-Aransas National Estuarine Research Reserve. Curve-fitting analysis showed it was possible to estimate chlorophyll surface area concentrations by using ETM+ water-leaving radiance values and a third-order polynomial equation. Two pairs of ETM+ bands were identified as inputs (Bands 1 and 3, and the Log10 values of Bands 3 and 4), both achieving R2 of 0.69. Additional research efforts were recommended to obtain additional data, identify better curve fitting equations, and potentially extend the radiative transfer model into the water column.

  14. Chlorophyll concentration estimates for coastal water using pixel-based atmospheric correction of Landsat images

    NASA Astrophysics Data System (ADS)

    Kouba, Eric

    Ocean color analysis is more challenging for coastal regions than the global ocean due the effects of optical brightness, shallow and turbid water, higher phytoplankton growth rates, and the complex geometry of coastal bays and estuaries. Also, one of the key atmospheric correction assumptions (zero water leaving radiance in the near infrared) is not valid for these complex conditions. This makes it difficult to estimate the spectral radiance noise caused by atmospheric aerosols, which can vary rapidly with time and space. This study conducts pixel-based atmospheric correction of Landsat-7 ETM+ images over the Texas coast. Precise satellite orbit data, operational weather data, and climate data are combined to create interpolated arrays of viewing angles and atmospheric profiles. These arrays vary with time and location, allowing calculation of the Rayleigh and aerosol radiances separately for all pixels. The resulting normalized water-leaving radiances are then compared with in situ chlorophyll fluorescence measurements from five locations inside a set of Texas coastal bays: the Mission-Aransas National Estuarine Research Reserve. Curve-fitting analysis shows it is possible to estimate chlorophyll-a surface area concentrations by using ETM+ water-leaving radiance values and a third-order polynomial equation. Two pairs of ETM+ bands are identified as inputs (Bands 1 and 3, and the Log10 values of Bands 3 and 4), both achieving good performance (R2 of 0.69). Further research efforts are recommended to obtain additional data, identify better curve fitting equations, and potentially extend the radiative transfer model into the water column.

  15. Joint IAMAS/IAHS symposium J1 on global monitoring and advanced observing techniques in the atmosphere and hydrosphere

    SciTech Connect

    Ohring, G. ); Aoki, T. ); Halpern, D. ); Henderson-Sellers, A. ); Charlock, T. ); Joseph, J. ); Labitzke, K. ); Raschke, E. ); Smith, W. )

    1994-04-01

    Seventy papers were presented at the two-and-a-half-day Symposium on Global Monitoring and Advanced Observing Techniques in the Atmosphere and Hydrosphere. The symposium was jointly organized by the International Association of Meteorology and Atmospheric Sciences (IAMAS) and the International Association of Hydrological Sciences (IAHS) and took place in Yokohama, Japan, 13-15 July 1993, as part of the IAMAS/IAHS Join Assembly. Global observing systems are receiving increased attention in connection with such problems as monitoring global climate change. The symposium included papers on observational requirements; measurement methodologies; descriptions of available datasets; results of analysis of observational data; plans for future observing systems, including the Global Climate Observing System (GCOS) and the Global Ocean Observing System (GOOS); and the programs and plans of the space agencies.

  16. The Texas Water Observatory: Utilizing Advanced Observing System Design for Understanding Water Resources Sustainability Across Climatic and Geologic Gradients of Texas

    NASA Astrophysics Data System (ADS)

    Mohanty, B.; Moore, G. W.; Miller, G. R.; Quiring, S. M.; Everett, M. E.; Morgan, C.

    2015-12-01

    The Texas Water Observatory (TWO) is a new distributed network of field observatories for better understanding of the hydrologic flow in the critical zone (encompassing groundwater, soil water, surface water, and atmospheric water) at various space and time scales. Core sites in the network will begin in Brazos River corridor and expand from there westward. Using many advanced observational platforms and real-time / near-real time sensors, this observatory will monitor high frequency data of water stores and fluxes, critical for understanding and modeling the in the state of Texas and Southern USA. Once implemented, TWO will be positioned to support high-impact water science that is highly relevant to societal needs and serve as a regional resource for better understanding and/or managing agriculture, water resources, ecosystems, biodiversity, disasters, health, energy, and weather/climate. TWO infrastructure will span land uses (cultivation agriculture, range/pasture, forest), landforms (low-relief erosional uplands to depositional lowlands), and across climatic and geologic gradients of Texas to investigate the sensitivity and resilience of fertile soils and the ecosystems they support. Besides developing a network of field water observatory infrastructure/capacity for accounting water flow and storage, TWO will facilitate developing a new generation interdisciplinary water professionals (from various TAMU Colleges) with better understanding and skills for attending to future water challenges of the region. This holistic growth will have great impact on TAMU research enterprise related to water resources, leading to higher federal and state level competitiveness for funding and establishing a center of excellence in the region

  17. Use of OLCI and SLSTR Bands for Atmospheric Correction over Turbid Coastal and Inland Waters

    NASA Astrophysics Data System (ADS)

    Ruddick, Kevin; Vanhellement, Quinten

    2015-12-01

    The OLCI sensor has strong heritage from MERIS and some new bands, e.g. 400nm and 1020nm. The SLSTR spectral bands at 1.61μm and 2.25μm may also help improve the OLCI atmospheric correction. At 1020nm the water-leaving radiance is much lower than at shorter wavelengths and the spectral shapes of water and aerosol reflectance over the range 709-1020nm will be quite different, even in the most turbid waters. This band may therefore help improve the aerosol correction in extremely turbid waters. At 1.61μm and 2.25μm water-leaving radiance is negligible even for the most turbid waters. The advantage of these bands for atmospheric correction has been demonstrated previously for MODIS and Landsat-8. Exploiting these new bands will involve many challenges including: low signal:noise for the SWIR bands, SWIR contamination by objects at sea, straylight, calibration, OLCI/SLSTR colocation, etc.

  18. Effect of Water Vapor Absorption on Measurements of Atmospheric Nitrate Radical by LP-DOAS

    NASA Astrophysics Data System (ADS)

    Li, Su-wen; Liu, Wen-qing; Xie, Pin-hua; Yang, Yi-jun; Chen, De-bao; Li, Zheng

    2008-10-01

    During the measurement of atmospheric nitrate radical by long-path differential optical absorption spec-troscopy, water vapor strong absorption could affect the measurement of nitrate radical and detection limits of system. Under the tropospheric condition, the optical density of water vapor absorption is non-linearly dependent on column density. An effective method was developed to eliminate the effect of water vapor absorption. Reference spectra of water vapor based on the daytime atmospheric absorption spectra, when fitted together with change of cross section with water vapor column densities, gave a more accurate fitting of water vapor absorptions, thus its effect on the measurements of nitrate radical could be restricted to a minimum and detection limits of system reached 3.6 ppt. The modified method was applied during an intensive field campaign in the Pearl River Delta, China. The NO3 concentration in polluted air masses varied from 3.6 ppt to 82.5 ppt with an average level of 23.6±1.8 ppt.

  19. Loss of Water in Early Earth's Atmosphere and Its Effects on Habitability

    NASA Astrophysics Data System (ADS)

    Airapetian, Vladimir; Glocer, Alex; Khazanov, George

    2015-08-01

    The short wavelength emission from the Sun has a profound impact on the Earth’s atmosphere. High energy photons ionize the atmosphere and produce photoelectrons. This process provides a major contribution to the acceleration of atmospheric ions due to the vertical separation of ions and electrons, and the formation of the resulting ambipolar electric field. Observations and theory suggest that even a relatively small fraction of super-thermal electrons (photoelectrons) produced due to photoionization can drive the ”polar wind” that is responsible for the transport of ionospheric constituents to the Earth’s magnetosphere.The young Sun was a magnetically active star generating powerful radiative output from its chromosphere, transition region and corona which was a few hundred times greater than that observed today. What effects would the photoionization processes due to the X-ray-UV solar flux from early Sun have on the loss of water from the early Earth?We use the Fokker-Plank code coupled with 1D hydrodynamic code to model the effect of intensive short-wavelength (X-rays to UV band) emission from the young Sun (3.8 and 4.4 Ga) on Earth's atmosphere. Our simulations include the photoionization processes of the Earth’s atmosphere forming a population of photoelectrons (E<600 eV), the kinetic effects of their propagation associated and their contribution in ionosphere - magnetosphere energy redistribution. Our coupled simulations show that the ambipolar electric field can drag atmospheric ions of oxygen and hydrogen to the magnetosphere and produce significant mass loss that can affect the loss of water from the early Earth in the first half a billion years. This process became less efficient in the next 0.2-0.3 Ga that could have provided a window of opportunity for origin of life.

  20. Soil Water: Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the fourth of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil water. Upon completing the three day module, the student will be able to classify water as to its presence in the soil, outline the hydrological cycle, list the ways water is lost from the soil,…

  1. The interaction of radio frequency electromagnetic fields with atmospheric water droplets and applications to aircraft ice prevention. Thesis

    NASA Technical Reports Server (NTRS)

    Hansman, R. J., Jr.

    1982-01-01

    The feasibility of computerized simulation of the physics of advanced microwave anti-icing systems, which preheat impinging supercooled water droplets prior to impact, was investigated. Theoretical and experimental work performed to create a physically realistic simulation is described. The behavior of the absorption cross section for melting ice particles was measured by a resonant cavity technique and found to agree with theoretical predictions. Values of the dielectric parameters of supercooled water were measured by a similar technique at lambda = 2.82 cm down to -17 C. The hydrodynamic behavior of accelerated water droplets was studied photograhically in a wind tunnel. Droplets were found to initially deform as oblate spheroids and to eventually become unstable and break up in Bessel function modes for large values of acceleration or droplet size. This confirms the theory as to the maximum stable droplet size in the atmosphere. A computer code which predicts droplet trajectories in an arbitrary flow field was written and confirmed experimentally. The results were consolidated into a simulation to study the heating by electromagnetic fields of droplets impinging onto an object such as an airfoil. It was determined that there is sufficient time to heat droplets prior to impact for typical parameter values. Design curves for such a system are presented.

  2. Characterization of atmospheric deposition and runoff water in a small suburban catchment.

    PubMed

    Lamprea, Katerine; Ruban, Véronique

    2011-07-01

    A study has been carried out as part of the mission assigned to IRSTV (Research Institute of Urban Sciences and Techniques), a federative research network supported by the Loire Valley Region, with the objective of characterizing atmospheric deposition, roof runoff and street runoff in a small (31 ha) suburban catchment in Nantes equipped with a separate sewer system. Trace metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides were investigated. The characterization of atmospheric deposition reveals a high variability of trace metal concentrations, which could not be explained by rainfall characteristics. The relative abundance order of the metals was as follows: Zn > Cu > Cr approximately Ni > Cd. Organic pollutants, i.e., PAHs and pesticides, were only rarely detected in the atmospheric deposition. Zn and Pb appear to be the major contaminants in runoff water, whereas the concentrations of Ni, Cu, Cr, Cd, PAHs and pesticides tend to remain low. On the whole, concentrations were similar to the lowest range reported in the literature. According to statutory thresholds, runoff water quality is poor because of the high Pb and Zn concentrations. Based on scanning electron microscopy observations, atmospheric particles do not apparently differ from runoff particles, with a predominance of pollen, bacteria and particles resulting from soil erosion. Spherical organic particles produced during fuel combustion have also been observed.

  3. Advanced Decentralized Water/Energy Network Design for Sustainable Infrastructure

    EPA Science Inventory

    In order to provide a water infrastructure that is more sustainable into and beyond the 21st century, drinking water distribution systems and wastewater collection systems must account for our diminishing water supply, increasing demands, climate change, energy cost and availabil...

  4. ADVANCES IN DRINKING WATER TREATMENT IN THE UNITED STATES

    EPA Science Inventory

    The United States drinking water public health protection goal is to provide water that meets all health-based standards to ninety-five percent of the population served by public drinking water supplies by 2005. In 2002, the level of compliance with some eighty-five health-based ...

  5. Coupled atmospheric, land surface, and subsurface modeling: Exploring water and energy feedbacks in three-dimensions

    NASA Astrophysics Data System (ADS)

    Davison, Jason H.; Hwang, Hyoun-Tae; Sudicky, Edward A.; Lin, John C.

    2015-12-01

    Human activities amplified by climate change pose a significant threat to the sustainability of water resources. Coupled climate-hydrologic simulations commonly predict these threats by combining shallow 1-D land surface models (LSMs) with traditional 2-D and 3-D hydrology models. However, these coupled models limit the moisture and energy-feedback dynamics to the shallow near-surface. This paper presents a novel analysis by applying an integrated variably-saturated subsurface/surface hydrology and heat transport model, HydroGeoSphere (HGS), as a land surface model (LSM). Furthermore, this article demonstrates the coupling of HGS to a simple 0-D atmospheric boundary layer (ABL) model. We then applied our coupled HGS-ABL model to three separate test cases and reproduced the strong correlation between the atmospheric energy balance to the depth of the groundwater table. From our simulations, we found that conventional LSMs may overestimate surface temperatures for extended drought periods because they underestimate the heat storage in the groundwater zone. Our final test case of the atmospheric response to drought conditions illustrated that deeper roots buffered the atmosphere better than shallow roots by maintaining higher latent heat fluxes, lower sensible heat fluxes, and lower surface and atmospheric temperatures.

  6. 20-micron transparency and atmospheric water vapor at the Wyoming Infrared Observatory

    NASA Technical Reports Server (NTRS)

    Grasdalen, G. L.; Gehrz, R. D.; Hackwell, J. A.; Freedman, R.

    1985-01-01

    The atmospheric transparency at 19.5 and 23 microns from the Wyoming Infrared Observatory over the past six years has been examined. It is found that the transparency is largely controlled by the season. Four months: June, July, August, and September have very poor 20-micron transparency. During the rest of the year the transparency is usually quite good at 19.5 microns and moderately good at 23 microns. Using rawinsonde data and theoretical calculations for the expected infrared transparency, the measures of 20-micron transparency were calibrated in terms of atmospheric water-vapor content. The water vapor over the Wyoming Infrared Observatory is found to compare favorably with that above other proposed or developed sites: Mauna Kea, Mount Graham, and Wheeler Peak.

  7. Water Vapor Tacers as Diagnostics of the Regional Atmospheric Hydrologic Cycle

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Schubert, Siegfried D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Understanding of the local and remote sources of water vapor can be a valuable diagnostic in understanding the regional atmospheric hydrologic cycle, especially in North America where moisture transport and local evaporation are important sources of water for precipitation. In the present study, we have implemented passive tracers as prognostic variables to follow water vapor evaporated in predetermined regions until the water tracer precipitates. All evaporative sources of water are accounted for by tracers, and the water vapor variable provides the validation of the tracer water and the formulation of the sources and sinks. The Geostationary Operational Environmental Satellites General Circulation Model (GEOS GCM) is used to simulate several summer periods to determine the source regions of precipitation for the United States and India. Using this methodology, a detailed analysis of the recycling of water, interannual variability of the sources of water and links to the Great Plains low-level jet and North American monsoon will be presented. Potential uses in GCM sensitivity studies, predictability studies and data assimilation especially regarding the North American monsoon and GEWEX America Prediction Project (GAPP) will be discussed.

  8. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  9. Determining Large Scale Tendency Terms for the Navy Over-Water Local Atmospheric Prediction System (NOWLAPS)

    DTIC Science & Technology

    1987-04-01

    Liver Water i..oca,j. Htinosofiei-i c rreaiccion Syscem ( NUWLAP’D ) « (U5 i"’ -L n a.(. r’ e p c a j. o xJ e c o o -™’ Ar...OR 97331 DR. CLIFFORD MASS DEPT. OF ATMOSPHERIC SCIENCES UNIVERSITY OF WASHINGTON SEATTLE, WA 98195 64 DUDLEY KNOX LIBRARY ^ RESE*"CM " EPO ^If 5 6853 01078613 0 yi- 6bp^

  10. Microwave radiometer studies of atmospheric water over the oceans, volume 1

    NASA Technical Reports Server (NTRS)

    Katsaros, Kristina B.

    1992-01-01

    Since Seasat carried the Scanning Multichannel Microwave Radiometer (SMMR) into space, shortly followed by the SMMR on Nimbus 7, a new type of data source on atmospheric water vapor and other meteorological parameters has been available for analysis of weather systems over the ocean. Since 1987, the Scanning Multichannel Microwave/Imager (SMM/I) has provided similar data. A collection of work using this data is presented.

  11. Calculated slant-path absorption and distribution of atmospheric water vapor.

    PubMed

    Calfee, R F; Gates, D M

    1966-02-01

    A procedure is described for determining the amount and distribution of water vapor along a slant path through the atmosphere above 13.7 km. A multilayer analysis is used in which the transmittance of each layer is calculated and the accumulative effect obtained at the altitude of observation. The method depends upon the contribution of each line to the absorptance in a finite spectral region.

  12. Detection of Atmospheric Water Deposits in Porous Media Using the TDR Technique

    PubMed Central

    Nakonieczna, Anna; Kafarski, Marcin; Wilczek, Andrzej; Szypłowska, Agnieszka; Janik, Grzegorz; Albert, Małgorzata; Skierucha, Wojciech

    2015-01-01

    Investigating the intensity of atmospheric water deposition and its diurnal distribution is essential from the ecological perspective, especially regarding dry geographic regions. It is also important in the context of monitoring the amount of moisture present within building materials in order to protect them from excessive humidity. The objective of this study was to test a constructed sensor and determine whether it could detect and track changes in the intensity of atmospheric water deposition. An operating principle of the device is based on the time-domain reflectometry technique. Two sensors of different plate volumes were manufactured. They were calibrated at several temperatures and tested during field measurements. The calibration turned out to be temperature independent. The outdoor measurements indicated that the upper limits of the measurement ranges of the sensors depended on the volumes of the plates and were equal to 1.2 and 2.8 mm H2O. The respective sensitivities were equal to 3.2 × 10−3 and 7.5 × 10−3 g·ps−1. The conducted experiments showed that the construction of the designed device and the time-domain reflectometry technique were appropriate for detecting and tracing the dynamics of atmospheric water deposition. The obtained outcomes were also collated with the readings taken in an actual soil sample. For this purpose, an open container sensor, which allows investigating atmospheric water deposition in soil, was manufactured. It turned out that the readings taken by the porous ceramic plate sensor reflected the outcomes of the measurements performed in a soil sample. PMID:25871717

  13. Advances in research on atmospheric energy propagation and the interactions between different latitudes

    NASA Astrophysics Data System (ADS)

    Yang, Song; Deng, Kaiqiang; Ting, Mingfang; Hu, Chundi

    2015-12-01

    Early theoretical analyses indicated that the tropics and extratropics are relatively independent due to the existence of critical latitudes. However, considerable observational evidence has shown that a clear dynamical link exists between the tropics and midlatitudes. To better understand such atmospheric teleconnection, several theories of wave energy propagation are reviewed in this paper: (1) great circle theory, which reveals the characteristics of Rossby waves propagating in the spherical atmosphere; (2) westerly duct theory, which suggests a "corridor" through which the midlatitude disturbances in one hemisphere can propagate into the other hemisphere; (3) energy accumulation-wave emanation theory, which proposes processes through which tropical disturbances can affect the atmospheric motion in higher latitudes; (4) equatorial wave expansion theory, which further explains the physical mechanisms involved in the interaction between the tropics and extratropics; and (5) meridional basic flow theory, which argues that stationary waves can propagate across the tropical easterlies under certain conditions. In addition, the progress made in diagnosing wave-flow interaction, particularly for Rossby waves, inertial-gravity waves, and Kelvin waves, is also reviewed. The meridional propagation of atmospheric energy exhibits significant annual and interannual variations, closely related to ENSO and variation in the westerly jets and tropical upper-tropospheric troughs, amongst others.

  14. The water vapour self- and water-nitrogen continuum absorption in the 1000 and 2500 cm(-1) atmospheric windows.

    PubMed

    Baranov, Yu I; Lafferty, W J

    2012-06-13

    The pure water vapour and water-nitrogen continuum absorption in the 1000 and 2500 cm(-1) atmospheric windows has been studied using a 2 m base-length White-type multi-pass cell coupled with a BOMEM DA3-002 Fourier transform infrared spectrometer. The measurements were carried out at the National Institute of Standards and Technology (NIST, Gaithersburg, MD) over the course of several years (2004, 2006-2007, 2009). New data on the H(2)O:N(2) continuum in the 1000 cm(-1) window are presented and summarized along with the other experimental results and the continuum model. The experimental data reported on the water vapour continuum in these atmospheric windows basically agree with the most reliable laboratory data from the other sources. The MT_CKD (Mlawer-Tobin-Clough-Kneizys-Davies) continuum model significantly departs from the experimental data in both windows. The deviation observed includes the continuum magnitude, spectral behaviour and temperature dependence. In the 2500 cm(-1) region, the model does not allow for the nitrogen fundamental collision-induced absorption (CIA) band intensity enhancement caused by H(2)O:N(2) collisions and underestimates the actual absorption by over two orders of magnitude. The water vapour continuum interpretation as a typical CIA spectrum is reviewed and discussed.

  15. Materials, methods and devices to detect and quantify water vapor concentrations in an atmosphere

    DOEpatents

    Allendorf, Mark D; Robinson, Alex L

    2014-12-09

    We have demonstrated that a surface acoustic wave (SAW) sensor coated with a nanoporous framework material (NFM) film can perform ultrasensitive water vapor detection at concentrations in air from 0.05 to 12,000 ppmv at 1 atmosphere pressure. The method is extendable to other MEMS-based sensors, such as microcantilevers, or to quartz crystal microbalance sensors. We identify a specific NFM that provides high sensitivity and selectivity to water vapor. However, our approach is generalizable to detection of other species using NFM to provide sensitivity and selectivity.

  16. Sparsity-driven tomographic reconstruction of atmospheric water vapor using GNSS and InSAR observations

    NASA Astrophysics Data System (ADS)

    Heublein, Marion; Alshawaf, Fadwa; Zhu, Xiao Xiang; Hinz, Stefan

    2016-04-01

    An accurate knowledge of the 3D distribution of water vapor in the atmosphere is a key element for weather forecasting and climate research. On the other hand, as water vapor causes a delay in the microwave signal propagation within the atmosphere, a precise determination of water vapor is required for accurate positioning and deformation monitoring using Global Navigation Satellite Systems (GNSS) and Interferometric Synthetic Aperture Radar (InSAR). However, due to its high variability in time and space, the atmospheric water vapor distribution is difficult to model. Since GNSS meteorology was introduced about twenty years ago, it has increasingly been used as a geodetic technique to generate maps of 2D Precipitable Water Vapor (PWV). Moreover, several approaches for 3D tomographic water vapor reconstruction from GNSS-based estimates using the simple least squares adjustment were presented. In this poster, we present an innovative and sophisticated Compressive Sensing (CS) concept for sparsity-driven tomographic reconstruction of 3D atmospheric wet refractivity fields using data from GNSS and InSAR. The 2D zenith wet delay (ZWD) estimates are obtained by a combination of point-wise estimates of the wet delay using GNSS observations and partial InSAR wet delay maps. These ZWD estimates are aggregated to derive realistic wet delay input data of 100 points as if corresponding to 100 GNSS sites within an area of 100 km × 100 km in the test region of the Upper Rhine Graben. The made-up ZWD values can be mapped into different elevation and azimuth angles. Using the Cosine transform, a sparse representation of the wet refractivity field is obtained. In contrast to existing tomographic approaches, we exploit sparsity as a prior for the regularization of the underdetermined inverse system. The new aspects of this work include both the combination of GNSS and InSAR data for water vapor tomography and the sophisticated CS estimation. The accuracy of the estimated 3D water

  17. Oceanographic, atmospheric and water-quality measurements Sandwich Town Neck Beach, Massachusetts, 2016

    USGS Publications Warehouse

    Sherwood, Christopher R.; Montgomery, Ellyn; Suttles, Steven; Brosnahan, Sandra M.

    2016-01-01

    This web page provides access to oceanographic, atmospheric, and water quality observations near Sandwich Town Neck Beach, Massachusetts. These measurements were made in conjunction with two U.S. Geological Survey (USGS) projects; the Coastal Model Applications and Measurements Project, and the Barrier Island Evolution Research project, both supported by the USGS Coastal and Marine Geology Program. These measurements provide information about waves, tides, and overwash during a winter storm in January 2016; about waves, tides, currents, and water properties between February and May, 2016; and about waves and tides between May and June 2016, during a period that overlaps with offshore bathymetric surveys.

  18. To estimation of the fluxes of carbon dioxide in the Lake Baikal water-atmosphere system

    NASA Astrophysics Data System (ADS)

    Pestunov, D. A.; Panchenko, Mikhail V.; Domysheva, V. M.; Belan, Boris D.

    2004-12-01

    Separate many-day series of measurements of the carbon dioxide concentration were carried out at the stationary site of the Limnological Institute SB RAS near village Bol"shie Koty in July, August and October 2003. The CO2 fluxes from the water surface are estimated. Maximum amplitude of the diurnal variations of the CO2 concentration in the chamber in August was 100 ppmV, and minimum was 45 ppmV. Comparison with the results of measurements in the atmosphere and the data on the CO2 content in the near-surface water of Lake Baikal is performed.

  19. Energy requirements for a swimming pool through a water-atmosphere energy balance

    SciTech Connect

    Almanza, F.; Lara, J. )

    1994-07-01

    The methodology displayed here is to calculate the energy requirements for heating a swimming pool to a desired temperature. This methodology consists of an energy balance between water-atmosphere as is used in the temperature evaluation of cooling ponds in power plants. Different mathematical expressions are given to calculate such a balance. It is necessary to know the month of the year, the ambient temperature, relative humidity, wind velocity, and solar radiation. With these parameters it is possible to know the natural temperature of the water, natural evaporation, energy needed to reach a determined swimming pool temperature and the evaporation of the heated pool.

  20. Characterization of atmosphere-water exchange processes of CO 2 in estuaries using dynamic simulation

    NASA Astrophysics Data System (ADS)

    García-Luque, E.; Forja, J. M.; Gómez-Parra, A.

    2005-12-01

    CO 2 is one of the so-called "greenhouse effect" gases; therefore, its rates of water-atmosphere exchange are very relevant for studies of climate change. Coastal zones (which include estuarine systems) are of special interest in relation to the global carbon cycle. Thus, an estuary simulator, which operates in a dynamic mixing regime, is specifically applied in an initial study of the estuarine dynamic of inorganic carbon, focusing basically on the influence of salinity and pH on the water-atmosphere fluxes of CO 2 in these zones. The simulation has been performed under two assumptions: (i) considering that the system is subjected to a stationary gradient of salinity and (ii) taking into account the effect of the tides, owing to the daily oscillations introduced by this phenomenon in the process of CO 2 transfer between the water and the atmosphere. After analysing the results, it has been observed that a potential source of error exists when choosing the coefficients of gas exchange ( k) for CO 2 studies. Nevertheless, the evolution of CO 2 fluxes along the salinity and pH gradients achieved shows the same trends with those observed in a wide variety of real estuaries described in the related literature.

  1. Probing water vapor and CO in the atmosphere of HD 209458b

    NASA Astrophysics Data System (ADS)

    Tinetti, Giovanna; Carey, Sean; Allard, Nicole; Ballester, Gilda; Barber, Bob; Beaulieu, Jean-Philippe; Liang, Mao-Chang; Noriega-Crespo, Alberto; Ribas, Ignasi; Selsis, Franck; Sing, David; Tennyson, Jonathan; Yung, Yuk

    2007-08-01

    The success obtained with the 3.6, 5.8 and 8 um IRAC observations of HD 189733 leading to the discovery of the signature of water vapor in the atmosphere of the hot Jupiter HD 189733b, has prompted us to submit this DDT proposal. 13.4 hours are required for similar observations with the transiting Hot Jupiter HD 209458b: in particular we propose here to observe all the four IRAC bands and to search for water vapor and CO in the atmosphere of HD 209458b. The signal will be weaker than the one on HD 189733b but, according to our calculations, it will be detectable at 3 sigma in each band. HD 209458b is the gas giant with the lowest density and, because of its orbital parameters and stellar companion, it is warmer than HD 189733b. These characteristics guarantee that its atmosphere is very extended, hence it is an ideal target to be observed in primary transit. Despite the plethora of Spitzer observations of exoplanets, the ability to coadd different epochs of IRAC data to improve signal-to-noise in spite of systematics has not been demonstrated. We ask for an additional 6.7 hours (for a total of 20.2) for a second epoch observation of the transit at 3.6 and 5.8 um to beat the noise further down and provide better constraints on the temperature profile and water abundance.

  2. Water loss and evolution of the upper atmosphere and exosphere over martian history

    NASA Astrophysics Data System (ADS)

    Valeille, Arnaud; Bougher, Stephen W.; Tenishev, Valeriy; Combi, Michael R.; Nagy, Andrew F.

    2010-03-01

    The loss of water from Mars can be evaluated by studying the evolution of the escape rate of atomic oxygen over time. Throughout martian history, the evolution of solar radiation has led to significant variations in the macroscopic parameters of the thermosphere/ionosphere, which in turn govern the hot species population of the exosphere and especially the atmospheric loss rates. In this study, the combination of our Direct Simulation Monte Carlo (DSMC) kinetic model and the 3D Mars Thermosphere General Circulation Model (MTGCM) [Valeille, A., Combi, M.R., Tenishev, V., Bougher, S.W., Nagy, A., 2009. Icarus. doi:10.1016/j.icarus.2008.08.018] is used to describe self-consistently ancient upper atmospheres of Mars for different solar inputs. 3D descriptions from the MTGCM of the ancient thermosphere/ionosphere are presented and discussed for the first time, including density profiles and temperature maps of the background neutrals and ions for the three epochs considered, which can be related to a solar EUV (Extreme Ultraviolet) flux enhancement of 1, 3 and 6 times the present values. Furthermore, solar cycle effects are quantified and discussed for both present and past conditions. Along with maps of ion production by photoionization (PI), charge exchange (CE) and electron impact (EI), the DSMC model provides density and temperature profiles, return fluxes and atmospheric loss rates of suprathermal exospheric oxygen as functions of the Solar Zenith Angle (SZA). This approach allows us to study the effects of dynamics on the ancient Mars upper atmosphere structure. Thermospheric variations are found to be not as large as previous 1D models predicted. The study of the evolution of the heat balance suggests that the ancient Mars thermosphere, of about 3.5 billion years (Gyr) ago, was relatively similar to the present Venus thermosphere. While O2+ dissociative recombination (DR) is by far the main source of atmospheric escape at present, its relative contribution is

  3. Retrieval of Marine Water Constituents Using Atmospherically Corrected AVIRIS Hyperspectral Data

    NASA Technical Reports Server (NTRS)

    Bagheri, Sima; Peters, Steef

    2004-01-01

    This paper reports on the validation of bio-optical models in estuarine and nearshore (case 2) waters of New Jersey-New York to retrieve accurate water-leaving radiance spectra and chlorophyll concentration from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imaging spectrometer data. MODTRAN-4 was applied to remove the effects of the atmosphere so as to infer the water-leaving radiance. The study area - Hudson/Raritan of New York and New Jersey (Figure 1) is an extremely complex estuarine system where tidal and wind-driven currents are modified by freshwater discharges from the Hudson, Raritan, Hackensack, and Passaic rivers. Over the last century, the estuarine water quality has degraded in part due to eutrophication, which has disrupted the preexisting natural balance, resulting in phytoplankton blooms of both increased frequency and intensity, increasing oxygen demand, and leading to episodes of hypoxia. As the end result, a thematic map of chlorophyll-a concentration was generated using an atmospherically corrected AVIRIS ratio image. This thematic map serves as an indication of phytoplankton concentration. Such maps are important input into the geographic information system (GIS) for use as a management tool for monitoring water resources.

  4. Atmospheric transport and deposition, an additional input pathway for triazine herbicides to surface waters

    SciTech Connect

    Muir, D.C.G.; Rawn, D.F.

    1996-10-01

    Although surface runoff from treated fields is regarded as the major route of entry of triazine herbicides to surface waters, other pathways such as deposition via precipitation, gas absorption and dryfall may also be important. Triazine herbicides have been detected in precipitation but there has been only a very limited amount of work on gas phase and aerosols. To examine the importance of atmospheric inputs concentrations of atrazine, cyanazine and terbuthylazine in gas phase/aerosols, precipitation, and surface waters were determined (along with other herbicides) using selected ion GC-MS. Atrazine was detected at low ng/L concentrations in surface waters (<0.04-5.3 ng/L) and precipitation (0.1-53 ng/L), and at 0.02-0.1 ng/m{sup 3} in air. Cyanazine and terbuthylazine were detected in air and infrequently in water. Highest atrazine concentrations in air were found during June each year on both gas phase and particles. Concentrations of atrazine in surface waters at both locations increased during June, even in the absence of precipitation or overland flow, presumably due to inputs from dryfall and to gas areas and boreal forest lakes due to transport and deposition. Ecological risk assessment of triazines, especially for pristine aquatic environments should include consideration of this atmospheric pathway.

  5. Differential Absorption Measurements of Atmospheric Water Vapor with a Coherent Lidar at 2050.532 nm

    NASA Technical Reports Server (NTRS)

    Koch, Grady J.; Dharamsi, Amin; Davis, Richard E.; Petros, Mulugeta; McCarthy, John C.

    1999-01-01

    Wind and water vapor are two major factors driving the Earth's atmospheric circulation, and direct measurement of these factors is needed for better understanding of basic atmospheric science, weather forecasting, and climate studies. Coherent lidar has proved to be a valuable tool for Doppler profiling of wind fields, and differential absorption lidar (DIAL) has shown its effectiveness in profiling water vapor. These two lidar techniques are generally considered distinctly different, but this paper explores an experimental combination of the Doppler and DIAL techniques for measuring both wind and water vapor with an eye-safe wavelength based on a solid-state laser material. Researchers have analyzed and demonstrated coherent DIAL water vapor measurements at 10 micrometers wavelength based on CO2 lasers. The hope of the research presented here is that the 2 gm wavelength in a holmium or thulium-based laser may offer smaller packaging and more rugged operation that the CO2-based approach. Researchers have extensively modeled 2 um coherent lasers for water vapor profiling, but no published demonstration is known. Studies have also been made, and results published on the Doppler portion, of a Nd:YAG-based coherent DIAL operating at 1.12 micrometers. Eye-safety of the 1.12 micrometer wavelength may be a concern, whereas the longer 2 micrometer and 10 micrometer systems allow a high level of eyesafety.

  6. Observing atmospheric water in storms with the Nimbus 7 scanning multichannel microwave radiometer

    NASA Technical Reports Server (NTRS)

    Katsaros, K. B.; Lewis, R. M.

    1984-01-01

    Employing data on integrated atmospheric water vapor, total cloud liquid water and rain rate obtainable from the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR), we study the frontal structure of several mid-latitude cyclones over the North Pacific Ocean as they approach the West Coast of North America in the winter of 1979. The fronts, analyzed with all available independent data, are consistently located at the leading edge of the strongest gradient in integrated water vapor. The cloud liquid water content, which unfortunately has received very little in situ verification, has patterns which are consistent with the structure seen in visible and infrared imagery. The rain distribution is also a good indicator of frontal location and rain amounts are generally within a factor of two of what is observed with rain gauges on the coast. Furthermore, the onset of rain on the coast can often be accurately forecast by simple advection of the SMMR observed rain areas.

  7. Bio-Decontamination of Water and Surfaces by DC Discharges in Atmospheric Air

    NASA Astrophysics Data System (ADS)

    Machala, Zdenko; Tarabová, Barbora; Pelach, Michal; Šipoldová, Zuzana; Hensel, Karol; Janda, Mário; Šikurová, Libuša

    Two types of DC-driven atmospheric air discharges, including a streamer corona and a transient spark with short high current pulses of limited energy, were employed for bio-decontamination of water and various surfaces (agar plates, plastic foils, human teeth) contaminated by bacteria or spores (Salmonella typhimurium, Bacillus cereus). Both discharges generate cold non-equilibrium plasma. The discharges combined with the electro-spraying of the treated water through the needle electrode lead to fast and efficient bio-decontamination. Experiments comparing direct and indirect plasma effects, oxidation stress measurements in the cell membranes, and chemical changes induced in the treated water enable assessment of the plasma agents being responsible for microbial inactivation. Radicals and reactive oxygen species seem to be dominant biocidal agents, although deeper understanding of the plasma-induced water chemistry and of the temporal evolution of the bio-inactivation processes is needed.

  8. Recent Advances in Point-of-Access Water Quality Monitoring

    NASA Astrophysics Data System (ADS)

    Korostynska, O.; Arshak, K.; Velusamy, V.; Arshak, A.; Vaseashta, Ashok

    Clean water is one of our most valuable natural resources. In addition to providing safe drinking water it assures functional ecosystems that support fisheries and recreation. Human population growth and its associated increased demands on water pose risks to maintaining acceptable water quality. It is vital to assess source waters and the aquatic systems that receive inputs from industrial waste and sewage treatment plants, storm water systems, and runoff from urban and agricultural lands. Rapid and confident assessments of aquatic resources form the basis for sound environmental management. Current methods engaged in tracing the presence of various bacteria in water employ bulky laboratory equipment and are time consuming. Thus, real-time water quality monitoring is essential for National and International Health and Safety. Environmental water monitoring includes measurements of physical characteristics (e.g. pH, temperature, conductivity), chemical parameters (e.g. oxygen, alkalinity, nitrogen and phosphorus compounds), and abundance of certain biological taxa. Monitoring could also include assays of biological activity such as alkaline phosphatase, tests for toxins such as microcystins and direct measurements of pollutants such as heavy metals or hydrocarbons. Real time detection can significantly reduce the level of damage and also the cost to remedy the problem. This paper presents overview of state-of-the-art methods and devices used for point-of-access water quality monitoring and suggest further developments in this area.

  9. Hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their influence on the water uptake of ammonium sulfate

    NASA Astrophysics Data System (ADS)

    Wu, Z. J.; Nowak, A.; Poulain, L.; Herrmann, H.; Wiedensohler, A.

    2011-12-01

    The hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their effects on ammonium sulfate were investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). No hygroscopic growth is observed for disodium oxalate, while ammonium oxalate shows slight growth (growth factor = 1.05 at 90%). The growth factors at 90% RH for sodium acetate, disodium malonate, disodium succinate, disodium tartrate, diammonium tartrate, sodium pyruvate, disodium maleate, and humic acid sodium salt are 1.79, 1.78, 1.69, 1.54, 1.29, 1.70, 1.78, and 1.19, respectively. The hygroscopic growth of mixtures of organic salts with ammonium sulfate, which are prepared as surrogates of atmospheric aerosols, was determined. A clear shift in deliquescence relative humidity to lower RH with increasing organic mass fraction was observed for these mixtures. Above 80% RH, the contribution to water uptake by the organic salts was close to that of ammonium sulfate for the majority of investigated compounds. The observed hygroscopic growth of the mixed particles at RH above the deliquescence relative humidity of ammonium sulfate agreed well with that predicted using the Zdanovskii-Stokes-Robinson (ZSR) mixing rule. Mixtures of ammonium sulfate with organic salts are more hygroscopic than mixtures with organic acids, indicating that neutralization by gas-phase ammonia and/or association with cations of dicarbonxylic acids may enhance the hygroscopicity of the atmospheric particles.

  10. 77 FR 62270 - Proposed Revision Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-12

    ... Non-Safety Systems for Passive Advanced Light Water Reactors AGENCY: Nuclear Regulatory Commission... Systems (RTNSS) for Passive Advanced Light Water Reactors.'' The current SRP does not contain guidance on the proposed RTNSS for Passive Advance Light Water Reactors. DATES: Submit comments by November...

  11. 78 FR 41436 - Proposed Revision to Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... COMMISSION Proposed Revision to Treatment of Non-Safety Systems for Passive Advanced Light Water Reactors... Treatment of Non-Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.'' The NRC seeks public...- Safety Systems (RTNSS) for Passive Advanced Light Water Reactors.'' This area includes a revised...

  12. Effects of atmospheric CO/sub 2/ concentration and water stress on water relations of wheat

    SciTech Connect

    Sionit, N.; Strain, B.R.; Hellmers, H.; Kramer, P.J.

    1981-06-01

    Water status and growth responses of wheat (Triticum aestivuum L. (GWO-1809)) to increased CO/sub 2/ concentration and water stress were studied in controlled-environment chambers. Plants were grown in 350 ..mu..l/liter or 1000 ..mu..1/liter CO/sub 2/ at similar temperature, irradiance, and photoperiod conditions. Groups of plants were subjected to water stress by withholding irrigation for one or two cycles of treatment. In most treatments, decreasing leaf water potential was correlated with decreasing osmotic potential. In leaves grown in both low and high CO/sub 2/ concentrations, the osmotic potentials were lower during the second stress cycle than during the first cycle. The stomata of plants in the low CO/sub 2/ concentration closed at a higher leaf water potential than those in the high CO/sub 2/ concentration. Stem and head production was greater in plants grown in high CO/sub 2/ concentrations than those grown in low CO/sub 2/, perhaps the result of turgor-pressure maintenance as leaf water potential decreased. In controlled-environment chambers, wheat plants adapted to water stress, apparently because of high CO/sub 2/ concentration and repeated stress cycles.

  13. ADVANCED TOOLS FOR ASSESSING SELECTED PRESCRIPTION AND ILLICIT DRUGS IN TREATED SEWAGE EFFLUENTS AND SOURCE WATERS

    EPA Science Inventory

    The purpose of this poster is to present the application and assessment of advanced technologies in a real-world environment - wastewater effluent and source waters - for detecting six drugs (azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, and methylenedioxy...

  14. Overview of advances in water management in agricultural production:Sensor based irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technological advances in irrigated agriculture are crucial to meeting the challenge of increasing demand for agricultural products given limited quality and quantity of water resources for irrigation, impacts of climate variability, and the need to reduce environmental impacts. Multidisciplinary ap...

  15. Advanced Technology Used to Monitor Ground Water in a Restricted Access Area of Fort Riley, Kansas

    USGS Publications Warehouse

    Breedlove, J.D.; Finnegan, P.J.; Myers, N.C.

    1998-01-01

    The purpose of this fact sheet is to describe how advanced communication technology is being used to overcome difficulties in collecting reliable ground-water data in areas with restricted access, such as at Fort Riley in northeast Kansas.

  16. Effects of salinity, temperature, and polarization on top of atmosphere and water leaving radiances for case 1 waters.

    PubMed

    Hollstein, André; Fischer, Jürgen

    2012-11-20

    The effects of polarization, sea water salinity, and temperature on top of atmosphere radiances and water leaving radiances (WLRs) are discussed using radiative transfer simulations for MEdium resolution imaging spectrometer (MERIS) channels from 412 to 900 nm. A coupled system of an aerosol-free atmosphere and an ocean bulk containing chlorophyll and colored dissolved organic matter (CDOM) (case 1 waters) was simulated. A simple, but realistic, bio-optical model was set up to relate chlorophyll concentration and wavelength to scattering matrices and absorption coefficients for chlorophyll and colored CDOM. The model of the optical properties of the sea water accounts for the salinity, temperature, and wavelength dependence of the relative refractive index, as well as the absorption and the bulk scattering coefficient. The results show that the relative difference of WLRs at zenith for a salinity of 5 practical salinity units (PSUs) and 35 PSU can reach values of 16% in the 412 nm channel, decreasing to 4% in the 900 nm channel. For the more realistic case of 25 PSU compared to 35 PSU, the effect is reduced to 5% for the 412 nm channel and decreasing to 2% for the 900 nm channel. The effect on radiance caused by changing sea water temperature is dominated by changes of sea water absorption and shows strong spectral features. For WLRs, a change of 10°C can cause relative changes of above 3%. The effects of neglecting polarization in the radiative transfer depends strongly on direction and wavelength, and can reach values of ±8% for the 412 nm channel. The effect is discussed for MERIS channels, viewing geometry, and chlorophyll content.

  17. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below 273 K

    SciTech Connect

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias R.; Gilles, Marry K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2012-09-25

    Atmospheric ice formation induced by particles with complex chemical and physical properties through heterogeneous nucleation is not well understood. Heterogeneous ice nucleation and water uptake by ambient particles collected from urban environments in Los Angeles and Mexico City are presented. Using a vapour controlled cooling system equipped with an optical microscopy, the range of onset conditions for ice nucleation and water uptake by the collected particles was determined as a function of temperature (200{273 K) and relative humidity with respect to ice (RHice) up to water saturation. Three distinctly different types of authentic atmospheric particles were investigated including soot particles associated with organics/inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn containing inorganic particles apportioned to anthropogenic emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption ne structure spectroscopy (STXM/NEXAFS). Above 230 K, signicant differences in water uptake and immersion freezing effciencies of the different particle types were observed. Below 230 K, the particles exhibited high deposition ice nucleation effciencies and formed ice at RHice values well below homogeneous ice nucleation limits. The data show that the chemical composition of these eld{collected particles plays an important role in determining water uptake and immersion freezing. Heterogeneous ice nucleation rate coeffcients, cumulative ice nuclei (IN) spectrum, and IN activated fraction for deposition ice nucleation are derived. The presented ice nucleation data demonstrate that anthropogenic and marine particles comprising of various chemical and physical properties exhibit distinctly different ice

  18. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) - Total Water

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Born in the Atlantic, Hurricane Frances became a category 4 hurricane on August 31, 2004. Expectations are the hurricane will hit the Space Coast of Florida in Brevard County early Sunday morning.

    This movie is a time-series of maps that show AIRS observations of the total amount of water vapor present in the atmospheric column above each point of the Earth's surface. If all the water vapor in the column were forced to fall as rain, the depth of the resulting puddle on the surface at that point is equal to the value shown on the map. Fifty millimeters (mm) is about 2 inches. The large band of maximum water vapor in the neighborhood of the equator is the Intertropical Convergence Zone (ITCZ), a region of strong convection and powerful thunderstorms.

    This movie shows the total precipitable water vapor from August 23 through September 2, 2004. You can see Hurricane Frances as it moves through the Caribbean toward Florida, and the changes in intensity are visible. The eye has been marked with a red spot. The water vapor encompassed by the hurricane is also the result of the very strong convection which is an integral part of the formation and intensification of tropical storms. If you look at the last frame of the movie in the lower right corner, you can see the emergence of a new tropical storm. Ivan makes its debut in the Atlantic.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft

  19. An advanced open-path atmospheric pollution monitor for large areas

    SciTech Connect

    Taylor, L.

    1995-10-01

    Large amounts of toxic waste materials, generated in manufacturing fuel for nuclear reactors, are stored in tanks buried over large areas at DOE sites. Flammable and hazardous gases are continually generated by chemical reactions in the waste materials. To prevent explosive concentrations of these gases, the gases are automatically vented to the atmosphere when the pressure exceeds a preset value. Real-time monitoring of the atmosphere above the tanks with automatic alarming is needed to prevent exposing workers to unsafe conditions when venting occurs. This report describes the development of a monitor which can measure concentrations of hazardous gases over ranges as long as 4km. The system consists of a carbon dioxide laser combined with an acousto-optic tunable filter.

  20. Application of an advanced atmospheric mesoscale model to dispersion in the Rocky Flats, Colorado vicinity

    SciTech Connect

    Poulos, G.S.; Bossert, J.E.

    1993-01-01

    Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. We use the Regional Atmospheric Modeling System (RAMS), originally developed at Colorado State University, to simulate meteorological conditions and tracer dispersion on the case night of 4-5 February 1991. The simulations described herein reveal considerable information about the extent to which the Rocky Mountains influence the flow along the Front Range , the importance of diffusion when simulating drainage flows and the computing needs of simulations in complex terrain regions.

  1. Application of an advanced atmospheric mesoscale model to dispersion in the Rocky Flats, Colorado vicinity

    SciTech Connect

    Poulos, G.S.; Bossert, J.E.

    1993-02-01

    Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. We use the Regional Atmospheric Modeling System (RAMS), originally developed at Colorado State University, to simulate meteorological conditions and tracer dispersion on the case night of 4-5 February 1991. The simulations described herein reveal considerable information about the extent to which the Rocky Mountains influence the flow along the Front Range , the importance of diffusion when simulating drainage flows and the computing needs of simulations in complex terrain regions.

  2. On Sensitivity of Spectral Radiative Fluxes to Atmospheric Water Vapor in the 940 nm Region (Numerical Simulation)

    SciTech Connect

    Zhuravleva, T.B.; Firsov, K.M.

    2005-03-18

    Water vapor is well known to be a critical component in many aspects of atmospheric research, such as radiative transfer and cloud and aerosol processes. This requires both improved measurements of the columnar water vapor and its profiles in the atmosphere in a wide range of conditions, and adjustment of water vapor parameterizations in radiation codes including the perfection of spectroscopic parameters. In this paper we will present the results of comparison of our calculations and downward solar fluxes measured with Rotating Shadowband Spectroradiometer under conditions of horizontally homogeneous clouds. We also will discuss the sensitivity of atmospheric radiation characteristics to variations of water vapor in the band 940 nm: these results may be useful for development of new methods of retrieval of the total column water vapor content (WVC) in the atmosphere from data of radiation observations.

  3. Summary status of advanced water electrolysis and hydrogen storage/transport R and D

    SciTech Connect

    Mezzina, A.

    1984-04-01

    Major projects within the framework of the U.S. DOE Chemical/Hydrogen Energy Systems Program are described. Goals, accomplishments and status of investigations into advanced water electrolysis and hydrogen storage/transport are summarized. Electrolytic hydrogen production systems include: SPE electrolyzers; static feed water electrolysis; high temperature electrolysis; and other advanced concepts. Hydrogen transport studies have emphasized the characterization of hydrogen embrittlement effects on conventional natural gas pipeline steels.

  4. Dynamically Resolved Simulation of Atmospheric Features and Turbulence Using Advanced Models and Adaptive Algorithms

    DTIC Science & Technology

    2008-10-30

    the dissipation rate of the variance of potential temperature and e is the dissipat ion rate of the variance of velocity or turbulent kinetic energy ...structure function Cn2, a quantitative measure of atmospheric optical turbulence. These four equations are used to model the turbulence kinetic energy , the...NWP Numerical weather Prediction PBL Planetary boundary layer PPM Piecewise parabolic method SGS Subgrid scale TKE Turbulent kinetic energy UTC

  5. An advanced method for classifying atmospheric circulation types based on prototypes connectivity graph

    NASA Astrophysics Data System (ADS)

    Zagouras, Athanassios; Argiriou, Athanassios A.; Flocas, Helena A.; Economou, George; Fotopoulos, Spiros

    2012-11-01

    Classification of weather maps at various isobaric levels as a methodological tool is used in several problems related to meteorology, climatology, atmospheric pollution and to other fields for many years. Initially the classification was performed manually. The criteria used by the person performing the classification are features of isobars or isopleths of geopotential height, depending on the type of maps to be classified. Although manual classifications integrate the perceptual experience and other unquantifiable qualities of the meteorology specialists involved, these are typically subjective and time consuming. Furthermore, during the last years different approaches of automated methods for atmospheric circulation classification have been proposed, which present automated and so-called objective classifications. In this paper a new method of atmospheric circulation classification of isobaric maps is presented. The method is based on graph theory. It starts with an intelligent prototype selection using an over-partitioning mode of fuzzy c-means (FCM) algorithm, proceeds to a graph formulation for the entire dataset and produces the clusters based on the contemporary dominant sets clustering method. Graph theory is a novel mathematical approach, allowing a more efficient representation of spatially correlated data, compared to the classical Euclidian space representation approaches, used in conventional classification methods. The method has been applied to the classification of 850 hPa atmospheric circulation over the Eastern Mediterranean. The evaluation of the automated methods is performed by statistical indexes; results indicate that the classification is adequately comparable with other state-of-the-art automated map classification methods, for a variable number of clusters.

  6. Recent Advances in Remote Sensing of Natural Hazards-Induced Atmospheric and Ionospheric Perturbations

    NASA Astrophysics Data System (ADS)

    Yang, Y. M.; Komjathy, A.; Meng, X.; Verkhoglyadova, O. P.; Langley, R. B.; Mannucci, A. J.

    2015-12-01

    Traveling ionospheric disturbances (TIDs) induced by acoustic-gravity waves in the neutral atmosphere have significant impact on trans-ionospheric radio waves such as Global Navigation Satellite System (GNSS, including Global Position System (GPS)) measurements. Natural hazards and solid Earth events, such as earthquakes, tsunamis and volcanic eruptions are actual sources that may trigger acoustic and gravity waves resulting in traveling ionospheric disturbances (TIDs) in the upper atmosphere. Trans-ionospheric radio wave measurements sense the total electron content (TEC) along the signal propagation path. In this research, we introduce a novel GPS-based detection and estimation technique for remote sensing of atmospheric wave-induced TIDs including space weather phenomena induced by major natural hazard events, using TEC time series collected from worldwide ground-based dual-frequency GNSS (including GPS) receiver networks. We demonstrate the ability of using ground- and space-based dual-frequency GPS measurements to detect and monitor tsunami wave propagation from the 2011 Tohoku-Oki earthquake and tsunami. Major wave trains with different propagation speeds and wavelengths were identified through analysis of the GPS remote sensing observations. Dominant physical characteristics of atmospheric wave-induced TIDs are found to be associated with specific tsunami propagations and oceanic Rayleigh waves. In this research, we compared GPS-based observations, corresponding model simulations and tsunami wave propagation. Results are shown to lead to a better understanding of the tsunami-induced ionosphere responses. Based on current distribution of Plate Boundary Observatory GPS stations, the results indicate that tsunami-induced TIDs may be detected about 60 minutes prior to tsunamis arriving at the U.S. west coast. It is expected that this GNSS-based technology will become an integral part of future early-warning systems.

  7. Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations

    NASA Astrophysics Data System (ADS)

    Zellweger, Christoph; Emmenegger, Lukas; Firdaus, Mohd; Hatakka, Juha; Heimann, Martin; Kozlova, Elena; Spain, T. Gerard; Steinbacher, Martin; van der Schoot, Marcel V.; Buchmann, Brigitte

    2016-09-01

    Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements.

  8. Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical review of the most recent advances

    SciTech Connect

    Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey A.

    2012-06-29

    This manuscript presents an overview of the most recent instrument developments for the field and laboratory applications of mass spectrometry (MS) to investigate the chemistry and physics of atmospheric aerosols. A range of MS instruments, employing different sample introduction methods, ionisation and mass detection techniques are used both for ‘online’ and ‘offline’ characterisation of aerosols. Online MS techniques enable detection of individual particles with simultaneous measurement of particle size distributions and aerodynamic characteristics and are ideally suited for field studies that require high temporal resolution. Offline MS techniques provide a means for detailed molecular-level analysis of aerosol samples, which is essential to gain fundamental knowledge regarding aerosol chemistry, mechanisms of particle formation and atmospheric aging. Combined, complementary MS techniques provide comprehensive information on the chemical composition, size, morphology and phase of aerosols – data of key importance for evaluating hygroscopic and optical properties of particles, their health effects, understanding their origins and atmospheric evolution. Over the last few years, developments and applications of MS techniques in aerosol research have expanded remarkably as evident by skyrocketing publication statistics. Finally, the goal of this review is to present the most recent developments in the field of aerosol mass spectrometry for the time period of late 2010 to early 2012, which have not been conveyed in previous reviews.

  9. Characteristics of meter-scale surface electrical discharge propagating along water surface at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Hoffer, Petr; Sugiyama, Yuki; Hosseini, S. Hamid R.; Akiyama, Hidenori; Lukes, Petr; Akiyama, Masahiro

    2016-10-01

    This paper reports physical characteristics of water surface discharges. Discharges were produced by metal needle-to-water surface geometry, with the needle electrode driven by 47 kV (FWHM) positive voltage pulses of 2 µs duration. Propagation of discharges along the water surface was confined between glass plates with 2 mm separation. This allowed generation of highly reproducible 634 mm-long plasma filaments. Experiments were performed using different atmospheres: air, N2, and O2, each at atmospheric pressure. Time- and spatially-resolved spectroscopic measurements revealed that early spectra of discharges in air and nitrogen atmospheres were dominated by N2 2nd positive system. N2 radiation disappeared after approx. 150 ns, replaced by emissions from atomic hydrogen. Spectra of discharges in O2 atmosphere were dominated by emissions from atomic oxygen. Time- and spatially-resolved emission spectra were used to determine temperatures in plasma. Atomic hydrogen emissions showed excitation temperature of discharges in air to be about 2  ×  104 K. Electron number densities determined by Stark broadening of the hydrogen H β line reached a maximum value of ~1018 cm-3 just after plasma initiation. Electron number densities and temperatures depended only slightly on distance from needle electrode, indicating formation of high conductivity leader channels. Direct observation of discharges by high speed camera showed that the average leader head propagation speed was 412 km · s-1, which is substantially higher value than that observed in experiments with shorter streamers driven by lower voltages.

  10. Investigating the terrestrial-atmospheric water balance for the Tana River basin, East Africa

    NASA Astrophysics Data System (ADS)

    Kerandi, Noah; Laux, Patrick; Arnault, Joel; Kunstmann, Harald

    2016-04-01

    The fully coupled atmospheric-hydrological WRF-Hydro modeling system is applied to the Tana River basin (TRB) in East Africa for the period 2011-2014 in order to analyze the terrestrial-atmospheric water balance components and their feedback mechanisms. The outputs from the fully coupled modeling system are compared to those of the WRF stand-alone model. The study area encompasses the Mathioya-Sagana subcatchment (3279 km²) in the upper TRB. Our model set up consists of two domains at 25 km and 5 km horizontal resolution covering East Africa and the study area, respectively. The WRF-Hydro inner domain is enhanced with hydrological routing at a 500 m horizontal grid resolution. The simulated monthly precipitation over the subcatchment compared with the Tropical Rainfall Measuring Mission (TRMM) satellite data gives an overall correlation coefficient of 0.8/0.7 for fully coupled/stand-alone model and a mean absolute error (MAE) of 1.5 mm/day for both models for the entire simulation period. Overall the models yield more annual total precipitation compared to TRMM. The two models are drier during the March, April, May (MAM) season and wetter during the October, November, December (OND) season. Compared to observation stations, both modeling systems provide a correlation coefficient of 0.6 for precipitation. The simulated and observed discharges at the Tana Rukanga gauge, located in the subcatchment, exhibit a correlation coefficient of 0.5 at daily resolution. The WRF-Hydro also overestimates the cumulated discharge (2011-2014) by about 50 %. The analysis of the atmospheric water balance in both WRF and WRF-Hydro simulation reveals a positive moisture divergence during the MAM and OND rainy seasons. Precipitation recycling and efficiency measures derived from the atmospheric water budget are also investigated.

  11. High Relative Humidity of Water-Rich Atmospheres and Its Implications

    NASA Astrophysics Data System (ADS)

    Ding, F.; Pierrehumbert, R.

    2015-12-01

    The onset of the runaway greenhouse of water vapor is one of the important criteria defining the inner edge of the habitable zone, and has been extensively studied in one-dimensional (1D) radiative-convective models. One limitation of 1D simulations is the assumption of the fully saturated troposphere. In the real atmosphere, sub-saturated regions are created by the large-scale subsidence of air. These regions significantly delay the onset of the runaway greenhouse by playing the role of "radiator fins" that allow more infrared radiation escaping the planet. Here, we show that the degree of sub-saturation in the atmosphere strongly depends on the mass of background non-condensable component (e.g., N2) in an idealized three-dimensional general circulation model (3D GCM). We specially develop the GCM to simulate the climate dynamics of water-rich atmospheres, based on the GFDL finite-volume dynamical core, a two-stream gray-radiation scheme and an energy-conserving convection scheme. Numerical simulation shows that the mid-troposphere becomes more saturated by reducing the background partial pressure from 105 Pa to 500 Pa. The increase in relative humidity can be explained by the increase in static stability of the atmosphere when water vapor becomes dominated. In general, the mass of the background non-condensable components on potentially habitable planets could be regulated by many processes including the volcanic outgassing, stellar wind and impact erosion. These processes may also play an important role in determining the inner edge of the habitable zone besides the stellar spectral type and planetary rotation.

  12. Advances in water resources assessment with SWAT - an overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper introduces a Special Issue containing 12 research articles which present current applications of the Soil and Water Assessment Tool (SWAT) for water resources assessment. Firstly, an overview of selected recently published articles with application of SWAT is given. The articles address ...

  13. Study of Pu consumption in advanced light water reactors: Evaluation of GE advanced boiling water reactor plants - compilation of Phase 1B task reports

    SciTech Connect

    1993-09-15

    This report contains an extensive evaluation of GE advanced boiling water reactor plants prepared for United State Department of Energy. The general areas covered in this report are: core and system performance; fuel cycle; infrastructure and deployment; and safety and environmental approval.

  14. Development of a 266 nm Raman lidar for profiling atmospheric water vapor

    NASA Astrophysics Data System (ADS)

    Uesugi, T.; Tsuda, T.; Yabuki, M.; Liu, Y.

    2014-12-01

    It is projected that localized extreme weather events could increase due to the effects of global warming, resulting in severe weather disasters, such as a torrential rain, floods, and so on. Understanding water vapor's behavior in the atmosphere is essen- tial to understand a fundamental mechanism of these weather events. Therefore, continuous monitoring system to measure the atmospheric water vapor with good spatio-temporal resolution is required. We have developed several water vapor Raman lidar systems employing the laser wavelengths of 355 and 532 nm. However, the signal-to-noise ratio of the Raman lidar strongly depends on the sky background because of the detection of the weak inelastic scattering of light by molecules. Therefore, these systems were mainly used during nighttime. Hence, we have newly developed a water vapor Raman lidar using a quadrupled Nd:YAG laser at a wavelength of 266 nm. This wavelength is in the ultraviolet (UV) range below 300 nm known as the "solar-blind" region, because practically all radiation at these wavelengths is absorbed by the ozone layer in the stratosphere. It has the advantage of having no daytime solar background radiation in the system. The lidar is equipped with a 25 cm receiving telescope and is used for measuring the light separated into an elastic backscatter signal and vibrational Raman signals of nitrogen and water vapor at wavelengths of 266.1, 283.6, and 294.6 nm, respectively. This system can be used for continuous water vapor measurements in the lower troposphere. This study introduces the design of the UV lidar system and shows the preliminary results of water vapor profiles.

  15. Hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their influence on the water uptake of ammonium sulfate

    NASA Astrophysics Data System (ADS)

    Wu, Z. J.; Nowak, A.; Poulain, L.; Herrmann, H.; Wiedensohler, A.

    2011-03-01

    The hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their effects on ammonium sulfate was investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). No hygroscopic growth is observed for sodium oxalate, while ammonium oxalate shows slight growth (growth factor = 1.05 at 90%). The growth factors at 90% RH for sodium acetate, sodium malonate, sodium succinate, sodium tartrate, ammonium tartrate, sodium pyruvate, sodium maleate, and humic acid sodium salt are 1.79, 1.78, 1.69, 1.54, 1.29, 1.70, 1.78, and 1.19, respectively. The mixtures of organic salts with ammonium sulfate, which are prepared simulating the atmospheric aerosols, are determined. A clear shift in DRH of mixture to lower RH is observed with increasing organic mass fraction. Above RH = 80%, the humidograms of the different mixtures are quite close to that of pure ammonium sulfate. Köhler theory is used to predict the effective hygroscopicity parameter, κ, for mixtures at 90% RH. The results show that Köhler theory underestimated kappa for mixtures without considering the water solubility of ammonium oxalate. However, if the water solubility of ammonium oxalate is taken into account, the results show a much better agreement with those derived from H-TDMA measurements.

  16. Elevated atmospheric CO2 increases water use efficiency in Florida scrub oak

    NASA Astrophysics Data System (ADS)

    Drake, B. G.; Hayek, L. C.; Johnson, D. P.; Li, J.; Powell, T. L.

    2009-12-01

    Plants are expected to have higher rates of photosynthesis and reduced transpiration as atmospheric CO2 (Ca) continues to rise. But will higher Ca reduce water loss, and increase water use efficiency and soil water in native ecosystems? We tested this question using large (3.0m by 2.8m) open top chambers to expose Florida scrub oak on Merritt Island Wildlife Refuge, Kennedy Space Center, FL, from May 1996 to June 2007 to elevated levels of atmospheric CO2, (Ce = Ca + 350ppm) compared to ambient Ca. Although Ce stimulated total shoot biomass 68% by the end of the study, the effect of Ce on annual growth declined each year (Seiler et al. 2009, Global Change Biology15, 356-367). Compared with the effects of Ca, Ce increased net ecosystem CO2 exchange approximately 70% on average for the entire study, increased leaf area index (LAI) seasonally, reduced evapotranspiration except during mid-summer of some years, and, depending on the relative effect of Ce on LAI, increased volumetric soil water content.. These results are consistent with the observation that continental river discharge has increased as Ca has risen throughout the past 50 years (Gedney et al., Nature, Vol. 439, 16 February 2006).

  17. Large-scale atmospheric carbon and surface water dynamics inferred from satellite-based observations

    NASA Astrophysics Data System (ADS)

    Jensen, K.; McDonald, K. C.; Krakauer, N.; Schroeder, R.

    2013-12-01

    The sensitivity of Earth's wetlands to observed shifts in global precipitation and temperature patterns and their ability to produce large quantities of climate-active gases are key global change questions. Surface inundation is a crucial state variable that affects the rate of land-atmosphere carbon exchange and the partitioning of carbon between CO2 and CH4. Ground observation networks of large-scale inundation patterns are sparse because they require large fiscal, technological and human resources. Thus, satellite remote sensing products for global inundation dynamics, as well as total water storage and atmospheric carbon, can provide a complete synoptic view of past and current carbon - surface water dynamics over large areas that otherwise could not be assessed. We present results from a correlative analysis between spaceborne measurements of CO2 and CH4 as observed by SCIAMACHY and AIRS, water storage (derived from gravity anomalies provided by NASA's GRACE mission), and inundated water fraction derived from a combination of active and passive microwave remote sensing datasets. A general assessment is conducted globally, and further time-series analysis is focused on four regions of interest: North Amazon, Congo, Ob, and Ganges-Brahmaputra river basins. This analysis was supported by a grant from the NASA Terrestrial Ecology Program and the development of the inundation datasets was supported by the NASA MEaSUREs program.

  18. Characterization and migration of atmospheric REE in soils and surface waters

    NASA Astrophysics Data System (ADS)

    Aubert, Dominique; Stille, Peter; Probst, Anne; Gauthier-lafaye, François; Pourcelot, Laurent; Del nero, Mireille

    2002-10-01

    Rainwater and snow collected from three different sites in France (Vosges Mountains, French Alps and Strasbourg) show more or less similar shapes of their REE distribution patterns. Rainwater from Strasbourg is the most REE enriched sample, whereas precipitations from the two mountainous, less polluted catchments are less REE enriched and have concentrations close to seawater. They are all strongly LREE depleted. Different water samples from an Alpine watershed comprising snow, interstitial, puddle and streamwater show similar REE distributions with LREE enrichment (rainwater normalized) but MREE and HREE depletion. In this environment, where water transfer from the soil to the river is very quick due to the low thickness of the soils, it appears that REE in streamwater mainly originate from atmospheric inputs. Different is the behaviour of the REE in the spring- and streamwaters from the Vosges Mountains. These waters of long residence time in the deep soil horizons react with soil and bedrock REE carrying minerals and show especially significant negative Eu anomalies compared to atmospheric inputs. Their Sr and Nd isotopic data suggest that most of the Sr and Nd originate from apatite leaching or dissolution. Soil solutions and soil leachates from the upper soil horizons due to alteration processes strongly depleted in REE carrying minerals, have REE distribution patterns close to those of lichens and throughfall. Throughfall is slightly more enriched especially in light REE than filtered rainwater probably due to leaching of atmospheric particles deposited on the foliage and also to leaf excretion. Data suggest that Sr and Nd isotopes of the soil solutions in the upper soil horizons originate from two different sources: 1) An atmospheric source with fertilizer, dust and seawater components and 2) A source mainly determined by mineral dissolution in the soil. These two different sources are also recognizable in the Sr and Nd isotopic composition of the tree

  19. Direct atmospheric deposition of water-soluble nitrogen to the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Jordan, C. E.; Talbot, R. W.

    2000-12-01

    Measurements were made at New Castle, New Hampshire, on the shore of the Gulf of Maine from 1994 to 1997 to assess direct atmospheric deposition of water-soluble nitrogen to the surface waters of the gulf. Daily dry deposition was highly variable and ranged from ˜ 1 to 144 μmol N m-2 d-1 (median 16 μmol N m-2 d-1). Wet deposition dominated dry deposition, contributing 80-90% of the total flux annually. Wet deposition was also highly variable and ranged from 3 to 4264 μmol N m-2 d-1 (median 214 μmol N m-2 d-1). Fog water nitrogen deposition could contribute as much as large precipitation nitrogen deposition events, in excess of 500 μmol N m-2d-1. Dissolved organic nitrogen (DON) in precipitation constituted only a small fraction (3%) of the total precipitation nitrogen flux most of the year, except in spring where it comprised 14%, on average, of the total. The total atmospheric direct nitrogen (ADN) deposition numbers reported here do not include the contributions of fog and DON as they were not sampled regularly over the course of this study. The total ADN flux ranged from 1 to 4262 μmol N m-2 d-1 (median 23 μmol N m-2 d-1), depositing 52 mmol N m-2 yr-1 to the surface waters of the Gulf of Maine, 3% of the total N input to those waters annually. However, this deposition was highly episodic with events over 500 μmol N m-2 d-1 occurring in 8% of the days sampled but contributing 56% of the total measured flux and events in excess of 1000 μmol N m-2 d-1 occurring in 2% of the samples and contributing 22% of the total measured flux. It is these large events that may influence biological productivity of the Gulf of Maine. The annual wet deposition of inorganic N measured at New Castle exceeded that reported by two National Atmospheric Deposition Program (NADP) sites by 42% on average of that reported from Cape Cod, Massachusetts, and by 69% ofthat at Mt. Dessert Island, Maine. Estimates of the episodic atmospheric nitrogen flux to the surface waters of the

  20. Advanced Water Purification System for In Situ Resource Utilization

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

    2013-01-01

    A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extraterrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtration material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removal technique. Our studies have shown a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

  1. Advanced Water Purification System for In Situ Resource Utilization Project

    NASA Technical Reports Server (NTRS)

    Anthony, Stephen M.

    2014-01-01

    A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extratrrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtrtion material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removable technique. Our studies have show a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

  2. Trapping of water vapor from an atmosphere by condensed silicate matter formed by high-temperature pulse vaporization

    NASA Technical Reports Server (NTRS)

    Gerasimov, M. V.; Dikov, Yu. P.; Yakovlev, O. I.; Wlotzka, F.

    1993-01-01

    The origin of planetary atmospheres is thought to be the result of bombardment of a growing planet by massive planetesimals. According to some models, the accumulation of released water vapor and/or carbon dioxide can result in the formation of a dense and hot primordial atmosphere. Among source and sink processes of atmospheric water vapor the formation of hydroxides was considered mainly as rehydration of dehydrated minerals (foresterite and enstatite). From our point of view, the formation of hydroxides is not limited to rehydration. Condensation of small silicate particles in a spreading vapor cloud and their interaction with a wet atmosphere can also result in the origin of hydrated phases which have no genetic connections with initial water bearing minerals. We present results of two experiments of a simulated interaction of condensed silicate matter which originated during vaporization of dry clinopyroxene in a wet helium atmosphere.

  3. New technique for online measurement of water-soluble Fe(II) in atmospheric aerosols.

    PubMed

    Rastogi, Neeraj; Oakes, Michelle M; Schauer, James J; Shafer, Martin M; Majestic, Brian J; Weber, Rodney J

    2009-04-01

    A prototype instrument has been developed for online analysis of water-soluble Fe(II) (WS_Fe(II)) in atmospheric aerosols using a particle-into-liquid-sampler (PILS), which concentrates particles into a small flow of purified water, coupled with a liquid waveguide capillary cell (LWCC) and absorbance spectrophotometryto detect iron-ferrozine colored complexes. The analytical method is highly precise (<3% RSD), and the overall measurement uncertainty and limit of detection for the complete PILS-LWCC system are estimated at 12% and 4.6 ng m(-3), respectively. The online measurements compared well with those of 24 h integrated filter samples collected at two different sampling sites (n=27, R2 = 0.82, slope 0.90 +/- 0.08, and intercept 3.08 +/- 1.99 ng m(-3)). In urban Atlanta, fine particle WS_Fe(II) concentrations measured every 12 min exhibited large variability, ranging from below the detection limit (4.6) to 370 ng m(-3) during a 24 day period in June 2008. This instrument provides new capabilities for investigating the sources and atmospheric processing of fine particle WS_Fe(II) and may prove useful in studies ranging from effects of particle WS_Fe(II) on human health to effects of particle WS_Fe(II) on atmospheric chemistry and ocean biogeochemistry.

  4. Heat treatment's effects on hydroxyapatite powders in water vapor and air atmosphere

    NASA Astrophysics Data System (ADS)

    Karabulut, A.; Baştan, F. E.; Erdoǧan, G.; Üstel, F.

    2015-03-01

    Hydroxyapatite (HA; Ca10(PO4)6(OH)2) is the main chemical constituent of bone tissue (~70%) as well as HA which is a calcium phosphate based ceramic material forms inorganic tissue of bone and tooth as hard tissues is used in production of prosthesis for synthetic bone, fractured and broken bone restoration, coating of metallic biomaterials and dental applications because of its bio compatibility. It is known that Hydroxyapatite decomposes with high heat energy after heat treatment. Therefore hydroxyapatite powders that heated in water vapor will less decomposed phases and lower amorphous phase content than in air atmosphere. In this study high purity hydroxyapatite powders were heat treated with open atmosphere furnace and water vapor atmosphere with 900, 1000, 1200 °C. Morphology of same powder size used in this process by SEM analyzed. Chemical structures of synthesized coatings have been examined by XRD. The determination of particle size and morphological structure of has been characterized by Particle Sizer, and SEM analysis, respectively. Weight change of sample was recorded by thermogravimetric analysis (TGA) during heating and cooling.

  5. Monitoring of Sahelian aerosol and Atmospheric water vapor content characteristics from sun photometer measurements

    NASA Astrophysics Data System (ADS)

    Faizoun, C. A.; Podaire, A.; Dedieu, G.

    1994-11-01

    Atmospheric measurements in two Sahelian sites in West Africa are presented and analyzed. The measurements were performed using a sun photometer with five bands in the visible and near-infrared range of the solar spectrum. This instrument measures spectral values of the solar irradiances that are used to derive the aerosol optical thickness in three bands; the two other bands are used to derive the integrated atmospheric water vapor content using a differential absorption method. The Angstroem exponent, which is an estimate of the aerosol particle size, is derived from the spectral dependence of the optical thickness. Although the sites were located far from Sahara Desert aerosol sources, the observed aerosol optical thicknesses were high, with a mean annual value of 0.5 at 550 nm. The spectral dependence of aerosol optical thickness is generally low, with a mean annual value of Angstroem exponent of 0.4. The aerosol optical thickness and the atmosphereic water vapor content are both characterized by high temporal variability and exhibit seasonal cycles. From these measurements, climatological values and associated probability distribution laws are proposed.

  6. Water Clouds in the Atmosphere of a Jupiter-Like Brown Dwarf

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-07-01

    Lying a mere 7.2 light-years away, WISE 0855 is the nearest known planetary-mass object. This brown dwarf, a failed star just slightly more massive than Jupiter, is also the coldest known compact body outside of our solar system and new observations have now provided us with a first look at its atmosphere.Temperaturepressure profiles of Jupiter, WISE 0855, and what was previously the coldest extrasolar object with a 5-m spectrum, Gl 570D. Thicker lines show the location of each objects 5-m photospheres. WISE 0855s and Jupiters photospheres are near the point where water starts to condense out into clouds (dashed line). [Skemer et al. 2016]Challenging ObservationsWith a chilly temperature of 250 K, the brown dwarf WISE 0855 is the closest thing weve been able to observe to a body resembling Jupiters ~130 K. WISE 0855 therefore presents an intriguing opportunity to directly study the atmosphere of an object whose physical characteristics are similar to our own gas giants.But studying the atmospheric characteristics of such a body is tricky. WISE 0855 is too cold and faint to be able to obtain traditional optical or near-infrared ( 2.5 m) spectroscopy of it. Luckily, like Jupiter, the opacity of its gas allows thermal emission from its deep atmosphere to escape through an atmospheric window around ~5 m.A team of scientists led by Andrew Skemer (UC Santa Cruz) set out to observe WISE 0855 in this window with the Gemini-North telescope and the Gemini Near-Infrared Spectrograph. Though WISE 0855 is five times fainter than the faintest object previously detected with ground-based 5-m spectroscopy, the dry air of Mauna Kea (and a lot of patience!) allowed the team to obtain unprecedented spectra of this object.WISE 0855s spectrum shows absorption features consistent with water vapor, and its best fit by a cloudy brown-dwarf model. [Skemer et al. 2016]Water Clouds FoundExoplanets and brown dwarfs cooler than ~350 K are expected to form water ice clouds in upper atmosphere

  7. Pressure-dependent water absorption cross sections for exoplanets and other atmospheres

    NASA Astrophysics Data System (ADS)

    Barton, Emma J.; Hill, C.; Yurchenko, Sergei N.; Tennyson, Jonathan; Dudaryonok, Anna S.; Lavrentieva, Nina N.

    2017-01-01

    Many atmospheres (cool stars, brown dwarfs, giant planets, extrasolar planets) are predominately composed of molecular hydrogen and helium. H216O is one of the best measured molecules in extrasolar planetary atmospheres to date and a major compound in the atmospheres of brown-dwarfs and oxygen-rich cool stars, yet the scope of experimental and theoretical studies on the pressure broadening of water vapour lines by collision with hydrogen and helium remains limited. Theoretical H2- and He-broadening parameters of water vapour lines (rotational quantum number J up to 50) are obtained for temperatures in the range 300-2000 K. Two approaches for calculation of line widths were used: (i) the averaged energy difference method and (ii) the empirical expression for J ‧ J ″ -dependence. Voigt profiles based on these widths and the BT2 line list are used to generate high resolution (Δ ν ˜ = 0.01cm-1) pressure broadened cross sections for a fixed range of temperatures and pressures between 300 and 2000 K and 0.001-10 bar. An interpolation procedure which can be used to determine cross sections at intermediate temperature and pressure is described. Pressure broadening parameters and cross sections are presented in new ExoMol format.

  8. A moist Boussinesq shallow water equations set for testing atmospheric models

    SciTech Connect

    Zerroukat, M. Allen, T.

    2015-06-01

    The shallow water equations have long been used as an initial test for numerical methods applied to atmospheric models with the test suite of Williamson et al. being used extensively for validating new schemes and assessing their accuracy. However the lack of physics forcing within this simplified framework often requires numerical techniques to be reworked when applied to fully three dimensional models. In this paper a novel two-dimensional shallow water equations system that retains moist processes is derived. This system is derived from three-dimensional Boussinesq approximation of the hydrostatic Euler equations where, unlike the classical shallow water set, we allow the density to vary slightly with temperature. This results in extra (or buoyancy) terms for the momentum equations, through which a two-way moist-physics dynamics feedback is achieved. The temperature and moisture variables are advected as separate tracers with sources that interact with the mean-flow through a simplified yet realistic bulk moist-thermodynamic phase-change model. This moist shallow water system provides a unique tool to assess the usually complex and highly non-linear dynamics–physics interactions in atmospheric models in a simple yet realistic way. The full non-linear shallow water equations are solved numerically on several case studies and the results suggest quite realistic interaction between the dynamics and physics and in particular the generation of cloud and rain. - Highlights: • Novel shallow water equations which retains moist processes are derived from the three-dimensional hydrostatic Boussinesq equations. • The new shallow water set can be seen as a more general one, where the classical equations are a special case of these equations. • This moist shallow water system naturally allows a feedback mechanism from the moist physics increments to the momentum via buoyancy. • Like full models, temperature and moistures are advected as tracers that interact

  9. Recent advances in drinking water disinfection: successes and challenges.

    PubMed

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    Drinking water is the most important single source of human exposure to gastroenteric diseases, mainly as a result of the ingestion of microbial contaminated water. Waterborne microbial agents that pose a health risk to humans include enteropathogenic bacteria, viruses, and protozoa. Therefore, properly assessing whether these hazardous agents enter drinking water supplies, and if they do, whether they are disinfected adequately, are undoubtedly aspects critical to protecting public health. As new pathogens emerge, monitoring for relevant indicator microorganisms (e.g., process microbial indicators, fecal indicators, and index and model organisms) is crucial to ensuring drinking water safety. Another crucially important step to maintaining public health is implementing Water Safety Plans (WSPs), as is recommended by the current WHO Guidelines for Drinking Water Quality. Good WSPs include creating health-based targets that aim to reduce microbial risks and adverse health effects to which a population is exposed through drinking water. The use of disinfectants to inactivate microbial pathogens in drinking water has played a central role in reducing the incidence of waterborne diseases and is considered to be among the most successful interventions for preserving and promoting public health. Chlorine-based disinfectants are the most commonly used disinfectants and are cheap and easy to use. Free chlorine is an effective disinfectant for bacteria and viruses; however, it is not always effective against C. parvum and G. lamblia. Another limitation of using chlorination is that it produces disinfection by-products (DBPs), which pose potential health risks of their own. Currently, most drinking water regulations aggressively address DBP problems in public water distribution systems. The DBPs of most concern include the trihalomethanes (THMs), the haloacetic acids (HAAs), bromate, and chlorite. However, in the latest edition of the WHO Guidelines for Drinking Water Quality

  10. Cold atmospheric plasma discharged in water and its potential use in cancer therapy

    NASA Astrophysics Data System (ADS)

    Chen, Zhitong; Cheng, Xiaoqian; Lin, Li; Keidar, Michael

    2017-01-01

    Cold atmospheric plasma (CAP) has emerged as a novel technology for cancer treatment. CAP can directly treat cells and tissue but such direct application is limited to skin or can be invoked as a supplement during open surgery. In this study we report indirect plasma treatment using CAP discharged in deionized (DI) water using three gases as carriers (argon (Ar), helium (He), and nitrogen (N2)). Plasma stimulated water was applied to the human breast cancer cell line (MDA-MB-231). MTT (3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay tests showed that using Ar plasma had the strongest effect on inducing apoptosis in cultured human breast cancer cells. This result is attributed to the elevated production of reactive oxygen species and reactive nitrogen species in water.

  11. The Search for Atmospheric Water in the Transiting Planet HD189733b

    NASA Astrophysics Data System (ADS)

    Sing, David

    2007-07-01

    We propose to use the NICMOS camera to search for transit NIR signatures of atmospheric water in HD189733b. While water absorption bands exist in the optical and IR, space-based NIR signatures are uniquely positioned to offer the best chance at detection. Using narrow band photometric filters, we will be able to detect absorption signatures while the planet is in primary transit. A positive detection would be the first proof of water on an extrasolar planet. Furthermore, it would provide invaluable planetary information, constraining the entire chemistry. As a byproduct of the high SNR required for our primary science goal, we will be able to improve on the value of the planetary radius, a result independent of our primary science objective. The accurate radius estimate, together with planet structure models, will allow constraining the planet interior and its relationship with formation models and stellar metallicity.

  12. Water Ice Clouds and Dust in the Martian Atmosphere Observed by Mars Climate Sounder

    NASA Technical Reports Server (NTRS)

    Benson, Jennifer L.; Kass, David; Heavens, Nicholas; Kleinbohl, Armin

    2011-01-01

    The water ice clouds are primarily controlled by the temperature structure and form at the water condensation level. Clouds in all regions presented show day/night differences. Cloud altitude varies between night and day in the SPH and tropics: (1) NPH water ice opacity is greater at night than day at some seasons (2) The diurnal thermal tide controls the daily variability. (3) Strong day/night changes indicate that the amount of gas in the atmosphere varies significantly. See significant mixtures of dust and ice at the same altitude planet-wide (1) Points to a complex radiative and thermal balance between dust heating (in the visible) and ice heating or cooling in the infrared. Aerosol layering: (1) Early seasons reveal a zonally banded spatial distribution (2) Some localized longitudinal structure of aerosol layers (3) Later seasons show no consistent large scale organization

  13. Water vapor from a lunar breccia - Implications for evolving planetary atmospheres.

    NASA Technical Reports Server (NTRS)

    Cadenhead, D. A.; Buergel, W. G.

    1973-01-01

    The exposure of a typical complex lunar breccia to hydrogen after a through outgassing produces a fully reduced surface state. Subsequent outgassing over a wide temperature range results in the production of water vapor formed from the chemisorbed hydrogen and oxygen from the lunar sample; the proposed mechanism has been confirmed in terms of the chemisorption of deuterium and the release of heavy water. Since the conditions of the experiments are consistent with those on the lunar surface, it is postulated that water vapor will be produced on the moon through the interaction of the solar wind with lunar soil. It is also proposed that such a process could play an important role in the early history of many planets where an oxygen-rich soil is exposed to a reducing atmosphere.

  14. Water ice nucleation characteristics of JSC Mars-1 regolith simulant under simulated Martian atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Phebus, Bruce D.; Johnson, Alexandria V.; Mar, Brendan; Stone, Bradley M.; Colaprete, Anthony; Iraci, Laura T.

    2011-04-01

    Water ice clouds in the Martian atmosphere are governed by parameters such as number density and particle size distribution that in turn affect how they influence the climate. With some of the underlying properties of cloud formation well known only for Earth, extrapolations to Mars are potentially misleading. We report here continued laboratory experiments to identify critical onset conditions for water ice formation under Martian cloud forming temperatures and water partial pressures (155-182 K, 7.6 × 10-5 to 7.7 × 10-3 Pa H2O). By observing the 3 μm infrared band to monitor nucleation and growth, we observe significant temperature dependence in the nucleation of ice on JSC Mars-1 regolith simulant, with critical saturation ratios, Scrit, as high as 3.8 at 155 K. At temperatures below ˜180 K, ice nucleation on JSC Mars-1 requires significant supersaturation, potentially impacting the Martian hydrological cycle.

  15. Computational studies of atmospherically-relevant chemical reactions in water clusters and on liquid water and ice surfaces.

    PubMed

    Gerber, R Benny; Varner, Mychel E; Hammerich, Audrey D; Riikonen, Sampsa; Murdachaew, Garold; Shemesh, Dorit; Finlayson-Pitts, Barbara J

    2015-02-17

    CONSPECTUS: Reactions on water and ice surfaces and in other aqueous media are ubiquitous in the atmosphere, but the microscopic mechanisms of most of these processes are as yet unknown. This Account examines recent progress in atomistic simulations of such reactions and the insights provided into mechanisms and interpretation of experiments. Illustrative examples are discussed. The main computational approaches employed are classical trajectory simulations using interaction potentials derived from quantum chemical methods. This comprises both ab initio molecular dynamics (AIMD) and semiempirical molecular dynamics (SEMD), the latter referring to semiempirical quantum chemical methods. Presented examples are as follows: (i) Reaction of the (NO(+))(NO3(-)) ion pair with a water cluster to produce the atmospherically important HONO and HNO3. The simulations show that a cluster with four water molecules describes the reaction. This provides a hydrogen-bonding network supporting the transition state. The reaction is triggered by thermal structural fluctuations, and ultrafast changes in atomic partial charges play a key role. This is an example where a reaction in a small cluster can provide a model for a corresponding bulk process. The results support the proposed mechanism for production of HONO by hydrolysis of NO2 (N2O4). (ii) The reactions of gaseous HCl with N2O4 and N2O5 on liquid water surfaces. Ionization of HCl at the water/air interface is followed by nucleophilic attack of Cl(-) on N2O4 or N2O5. Both reactions proceed by an SN2 mechanism. The products are ClNO and ClNO2, precursors of atmospheric atomic chlorine. Because this mechanism cannot result from a cluster too small for HCl ionization, an extended water film model was simulated. The results explain ClNO formation experiments. Predicted ClNO2 formation is less efficient. (iii) Ionization of acids at ice surfaces. No ionization is found on ideal crystalline surfaces, but the process is efficient on

  16. Advanced definition study for the determination of atmospheric ozone using the satellite eclipse technique

    NASA Technical Reports Server (NTRS)

    Emmons, R.; Preski, R. J.; Kierstead, F. H., Jr.; Doll, F. C.; Wight, D. T.; Romick, D. C.

    1973-01-01

    A study was made to evaluate the potential for remote ground-based measurement of upper atmospheric ozone by determining the absorption ratio of selected narrow bands of sunlight as reflected by satellites while passing into eclipse, using the NASA Mobile Satellite Photometric Observatory (MOSPO). Equipment modifications to provide optimum performance were analyzed and recommendations were made for improvements to the system to accomplish this. These included new sensor tubes, pulse counting detection circuitry, filters, beam splitters and associated optical revision, along with an automatic tracking capability plus corresponding operational techniques which should extend the overall measurement capability to include use of satellites down to 5th magnitude.

  17. Investigation of Advanced Radar Techniques for Atmospheric Hazard Detection with Airborne Weather Radar

    NASA Technical Reports Server (NTRS)

    Pazmany, Andrew L.

    2014-01-01

    In 2013 ProSensing Inc. conducted a study to investigate the hazard detection potential of aircraft weather radars with new measurement capabilities, such as multi-frequency, polarimetric and radiometric modes. Various radar designs and features were evaluated for sensitivity, measurement range and for detecting and quantifying atmospheric hazards in wide range of weather conditions. Projected size, weight, power consumption and cost of the various designs were also considered. Various cloud and precipitation conditions were modeled and used to conduct an analytic evaluation of the design options. This report provides an overview of the study and summarizes the conclusions and recommendations.

  18. The function of advanced treatment process in a drinking water treatment plant with organic matter-polluted source water.

    PubMed

    Lin, Huirong; Zhang, Shuting; Zhang, Shenghua; Lin, Wenfang; Yu, Xin

    2015-08-07

    To understand the relationship between chemical and microbial treatment at each treatment step, as well as the relationship between microbial community structure in biofilms in biofilters and their ecological functions, a drinking water plant with severe organic matter-polluted source water was investigated. The bacterial community dynamics of two drinking water supply systems (traditional and advanced treatment processes) in this plant were studied from the source to the product water. Analysis by 454 pyrosequencing was conducted to characterize the bacterial diversity in each step of the treatment processes. The bacterial communities in these two treatment processes were highly diverse. Proteobacteria, which mainly consisted of beta-proteobacteria, was the dominant phylum. The two treatment processes used in the plant could effectively remove organic pollutants and microbial polution, especially the advanced treatment process. Significant differences in the detection of the major groups were observed in the product water samples in the treatment processes. The treatment processes, particularly the biological pretreatment and O3-biological activated carbon in the advanced treatment process, highly influenced the microbial community composition and the water quality. Some opportunistic pathogens were found in the water. Nitrogen-relative microorganisms found in the biofilm of filters may perform an important function on the microbial community composition and water quality improvement.

  19. Biological efficacy and toxic effect of emergency water disinfection process based on advanced oxidation technology.

    PubMed

    Tian, Yiping; Yuan, Xiaoli; Xu, Shujing; Li, Rihong; Zhou, Xinying; Zhang, Zhitao

    2015-12-01

    An innovative and removable water treatment system consisted of strong electric field discharge and hydrodynamic cavitation based on advanced oxidation technologies was developed for reactive free radicals producing and waterborne pathogens eliminating in the present study. The biological efficacy and toxic effects of this advanced oxidation system were evaluated during water disinfection treatments. Bench tests were carried out with synthetic microbial-contaminated water, as well as source water in rainy season from a reservoir of Dalian city (Liaoning Province, China). Results showed that high inactivation efficiency of Escherichia coli (>5 log) could be obtained for synthetic contaminated water at a low concentration (0.5-0.7 mg L(-1)) of total oxidants in 3-10 s. The numbers of wild total bacteria (108 × 10(3) CFU mL(-1)) and total coliforms (260 × 10(2) MPN 100 mL(-1)) in source water greatly reduced to 50 and 0 CFU mL(-1) respectively after treated by the advanced oxidation system, which meet the microbiological standards of drinking water, and especially that the inactivation efficiency of total coliforms could reach 100%. Meanwhile, source water qualities were greatly improved during the disinfection processes. The values of UV254 in particular were significantly reduced (60-80%) by reactive free radicals. Moreover, the concentrations of possible disinfection by-products (formaldehyde and bromide) in treated water were lower than detection limits, indicating that there was no harmful effect on water after the treatments. These investigations are helpful for the ecotoxicological studies of advanced oxidation system in the treatments of chemical polluted water or waste water. The findings of this work suggest that the developed water treatment system is ideal in the acute phases of emergencies, which also could offer additional advantages over a wide range of applications in water pollution control.

  20. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations

    PubMed Central

    2012-01-01

    The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006) and future (2025-2100) time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3). The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site) has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21). The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82) between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm) over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm) by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively. PMID:23369617

  1. Modeling Caspian Sea water level oscillations under different scenarios of increasing atmospheric carbon dioxide concentrations.

    PubMed

    Roshan, Gholamreza; Moghbel, Masumeh; Grab, Stefan

    2012-12-12

    The rapid rise of Caspian Sea water level (about 2.25 meters since 1978) has caused much concern to all five surrounding countries, primarily because flooding has destroyed or damaged buildings and other engineering structures, roads, beaches and farm lands in the coastal zone. Given that climate, and more specifically climate change, is a primary factor influencing oscillations in Caspian Sea water levels, the effect of different climate change scenarios on future Caspian Sea levels was simulated. Variations in environmental parameters such as temperature, precipitation, evaporation, atmospheric carbon dioxide and water level oscillations of the Caspian sea and surrounding regions, are considered for both past (1951-2006) and future (2025-2100) time frames. The output of the UKHADGEM general circulation model and five alternative scenarios including A1CAI, BIASF, BIMES WRE450 and WRE750 were extracted using the MAGICC SCENGEN Model software (version 5.3). The results suggest that the mean temperature of the Caspian Sea region (Bandar-E-Anzali monitoring site) has increased by ca. 0.17°C per decade under the impacts of atmospheric carbon dioxide changes (r=0.21). The Caspian Sea water level has increased by ca. +36cm per decade (r=0.82) between the years 1951-2006. Mean results from all modeled scenarios indicate that the temperature will increase by ca. 3.64°C and precipitation will decrease by ca. 10% (182 mm) over the Caspian Sea, whilst in the Volga river basin, temperatures are projected to increase by ca. 4.78°C and precipitation increase by ca. 12% (58 mm) by the year 2100. Finally, statistical modeling of the Caspian Sea water levels project future water level increases of between 86 cm and 163 cm by the years 2075 and 2100, respectively.

  2. Field and Laboratory Studies of Reactions between Atmospheric Water Soluble Organic Acids and Inorganic Particles

    SciTech Connect

    Wang, Bingbing; Kelly, Stephen T.; Sellon, Rachel E.; Shilling, John E.; Tivanski, Alexei V.; Moffet, Ryan C.; Gilles, Mary K.; Laskin, Alexander

    2013-06-25

    Atmospheric inorganic particles undergo complex heterogeneous reactions that change their physicochemical properties. Depletion of chloride in sea salt particles was reported in previous field studies and was attributed to the acid displacement of chlorides with inorganic acids, such as nitric and sulfuric acids [1-2]. Recently, we showed that NaCl can react with water soluble organic acids (WSOA) and release gaseous hydrochloric acid (HCl) resulting in formation of organic salts [3]. A similar mechanism is also applicable to mixed WSOA/nitrate particles where multi-phase reactions are driven by the volatility of nitric acid. Furthermore, secondary organic material, which is a complex mixture of carboxylic acids, exhibits the same reactivity towards chlorides and nitrates. Here, we present a systematic study of reactions between atmospheric relevant WSOA, SOM, and inorganic salts including NaCl, NaNO3, and Ca(NO3)2 using complementary micro-spectroscopy analysis.

  3. The observation of atmospheric structure with TOMS and some potential advancements. [Total Ozone Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Krueger, A. J.

    1985-01-01

    An overview is given of the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) which was designed to observe the spatial characteristics of total ozone that were not resolved by the nadir-viewing Nimbus BUV and SBUV instruments. At the wavelengths suitable for total ozone measurements, the radiance is large enough that the entire daytime atmosphere could be surveyed with about 50-km resolution from a polar orbiting satellite. The resulting high spatial resolution TOMS ozone images are found to reflect the internal dynamic structure of the lower atmosphere. Features which can be identified and tracked include: planetary wave scale troughs and ridges, mesoscale cutoff lows and rapidly moving troughs, jet stream confluence and difluence areas, hurricanes, and polar night lows. These features control the ozone above any given location and account for nearly all the variance in the total ozone. The instrument has been used to track the volcanic eruption clouds from El Chichon, Mount St. Helens, Alaid, and smaller eruptions such as Galunggung. It would be feasible to use a similar instrument on a geostationary platform to obtain half-hourly maps. Determination of the vertical ozone distribution in the lower stratosphere using Radon transform principles would be of importance in measuring jet stream folds and the related troposphere-stratosphere exchange.

  4. Advances in Atmospheric Radiation Measurements and Modeling Needed to Improve Air Safety

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent; Atwell, William; Beck, Peter; Benton, Eric; Copeland, Kyle; Dyer, Clive; Gersey, Brad; Getley, Ian; Hands, Alex; Holland, Michael; Hong, Sunhak; Hwang, Junga; Jones, Bryn; Malone, Kathleen; Meier, Matthias M.; Mertens, Chris; Phillips, Tony; Ryden, Keith; Schwadron, Nathan; Wender, Stephen A.; Wilkins, Richard; Xapsos, Michael A.

    2015-04-01

    Air safety is tied to the phenomenon of ionizing radiation from space weather, primarily from galactic cosmic rays but also from solar energetic particles. A global framework for addressing radiation issues in this environment has been constructed, but more must be done at international and national levels. Health consequences from atmospheric radiation exposure are likely to exist. In addition, severe solar radiation events may cause economic consequences in the international aviation community due to exposure limits being reached by some crew members. Impacts from a radiation environment upon avionics from high-energy particles and low-energy, thermalized neutrons are now recognized as an area of active interest. A broad community recognizes that there are a number of mitigation paths that can be taken relative to the human tissue and avionics exposure risks. These include developing active monitoring and measurement programs as well as improving scientific modeling capabilities that can eventually be turned into operations. A number of roadblocks to risk mitigation still exist, such as effective pilot training programs as well as monitoring, measuring, and regulatory measures. An active international effort toward observing the weather of atmospheric radiation must occur to make progress in mitigating radiation exposure risks. Stakeholders in this process include standard-making bodies, scientific organizations, regulatory organizations, air traffic management systems, aircraft owners and operators, pilots and crew, and even the public.

  5. Organic coal-water fuel: Problems and advances (Review)

    NASA Astrophysics Data System (ADS)

    Glushkov, D. O.; Strizhak, P. A.; Chernetskii, M. Yu.

    2016-10-01

    The study results of ignition of organic coal-water fuel (OCWF) compositions were considered. The main problems associated with investigation of these processes were identified. Historical perspectives of the development of coal-water composite fuel technologies in Russia and worldwide are presented. The advantages of the OCWF use as a power-plant fuel in comparison with the common coal-water fuels (CWF) were emphasized. The factors (component ratio, grinding degree of solid (coal) component, limiting temperature of oxidizer, properties of liquid and solid components, procedure and time of suspension preparation, etc.) affecting inertia and stability of the ignition processes of suspensions based on the products of coaland oil processing (coals of various types and metamorphism degree, filter cakes, waste motor, transformer, and turbine oils, water-oil emulsions, fuel-oil, etc.) were analyzed. The promising directions for the development of modern notions on the OCWF ignition processes were determined. The main reasons limiting active application of the OCWF in power generation were identified. Characteristics of ignition and combustion of coal-water and organic coal-water slurry fuels were compared. The effect of water in the composite coal fuels on the energy characteristics of their ignition and combustion, as well as ecological features of these processes, were elucidated. The current problems associated with pulverization of composite coal fuels in power plants, as well as the effect of characteristics of the pulverization process on the combustion parameters of fuel, were considered. The problems hindering the development of models of ignition and combustion of OCWF were analyzed. It was established that the main one was the lack of reliable experimental data on the processes of heating, evaporation, ignition, and combustion of OCWF droplets. It was concluded that the use of high-speed video recording systems and low-inertia sensors of temperature and gas

  6. CalWater Field Studies Designed to Quantify the Roles of Atmospheric Rivers and Aerosols in Modulating U.S. West Coast Precipitation in a Changing Climate

    SciTech Connect

    Ralph, F. M.; Prather, K. A.; Cayan, D.; Spackman, J. R.; DeMott, P.; Dettinger, M.; Fairall, C.; Leung, R.; Rosenfeld, D.; Rutledge, S.; Waliser, D.; White, A. B.; Cordeira, J.; Martin, A.; Helly, J.; Intrieri, J.

    2016-07-01

    The variability of precipitation and water supply along the U.S. West Coast creates major challenges to the region’s economy and environment, as evidenced by the recent California drought. This variability is strongly influenced by atmospheric rivers (AR), which deliver much of the precipitation along the U.S. West Coast and can cause flooding, and by aerosols (from local sources and transported from remote continents and oceans) that modulate clouds and precipitation. A better understanding of these processes is needed to reduce uncertainties in weather predictions and climate projections of droughts and floods, both now and under changing climate conditions.To address these gaps a group of meteorologists, hydrologists, climate scientists, atmospheric chemists, and oceanographers have created an interdisciplinary research effort, with support from multiple agencies. From 2009-2011 a series of field campaigns (CalWater 1) collected atmospheric chemistry, cloud microphysics and meteorological measurements in California and associated modeling and diagnostic studies were carried out. Based on remaining gaps, a vision was developed to extend these studies offshore over the Eastern North Pacific and to enhance land based measurements from 2014-2018 (CalWater 2). The data set and selected results from CalWater 1 are summarized here. The goals of CalWater-2, and measurements to date, are then described. CalWater is producing new findings and exploring new technologies to evaluate and improve global climate models and their regional performance and to develop tools supporting water and hydropower management. These advances also have potential to enhance hazard mitigation by improving near-term weather prediction and subseasonal and seasonal outlooks.

  7. Reliable determination of oxygen and hydrogen isotope ratios in atmospheric water vapour adsorbed on 3A molecular sieve.

    PubMed

    Han, Liang-Feng; Gröning, Manfred; Aggarwal, Pradeep; Helliker, Brent R

    2006-01-01

    The isotope ratio of atmospheric water vapour is determined by wide-ranging feedback effects from the isotope ratio of water in biological water pools, soil surface horizons, open water bodies and precipitation. Accurate determination of atmospheric water vapour isotope ratios is important for a broad range of research areas from leaf-scale to global-scale isotope studies. In spite of the importance of stable isotopic measurements of atmospheric water vapour, there is a paucity of published data available, largely because of the requirement for liquid nitrogen or dry ice for quantitative trapping of water vapour. We report results from a non-cryogenic method for quantitatively trapping atmospheric water vapour using 3A molecular sieve, although water is removed from the column using standard cryogenic methods. The molecular sieve column was conditioned with water of a known isotope ratio to 'set' the background signature of the molecular sieve. Two separate prototypes were developed, one for large collection volumes (3 mL) and one for small collection volumes (90 microL). Atmospheric water vapour was adsorbed to the column by pulling air through the column for several days to reach the desired final volume. Water was recovered from the column by baking at 250 degrees C in a dry helium or nitrogen air stream and cryogenically trapped. For the large-volume apparatus, the recovered water differed from water that was simultaneously trapped by liquid nitrogen (the experimental control) by 2.6 per thousand with a standard deviation (SD) of 1.5 per thousand for delta(2)H and by 0.3 per thousand with a SD of 0.2 per thousand for delta(18)O. Water-vapour recovery was not satisfactory for the small volume apparatus.

  8. Tracing atmospheric nitrate in groundwater using triple oxygen isotopes: evaluation based on bottled drinking water

    NASA Astrophysics Data System (ADS)

    Nakagawa, F.; Suzuki, A.; Daita, S.; Ohyama, T.; Komatsu, D. D.; Tsunogai, U.

    2013-06-01

    The stable isotopic compositions of nitrate dissolved in 49 brands of bottled drinking water collected worldwide were measured, to trace the fate of atmospheric nitrate (NO3- atm) that had been deposited into subaerial ecosystems, using the 17O anomalies (Δ17O) of nitrate as tracers. The use of bottled water enables collection of groundwater recharged at natural, background watersheds. The nitrate in groundwater had small Δ17O values ranging from -0.2‰ to +4.5‰ n = 49). The average Δ17O value and average mixing ratio of atmospheric nitrate to total nitrate in the groundwater samples were estimated to be 0.8‰ and 3.1%, respectively. These findings indicated that the majority of atmospheric nitrate had undergone biological processing before being exported from the surface ecosystem to the groundwater. Moreover, the concentrations of atmospheric nitrate were estimated to range from less than 0.1 μmol L-1 to 8.5 μmol L-1 with higher NO3-atm concentrations being obtained for those recharged in rocky, arid or elevated areas with little vegetation and lower NO3-atm concentrations being obtained for those recharged in forested areas with high levels of vegetation. Additionally, many of the NO3-atm-depleted samples were characterized by elevated δ15N values of more than +10‰. Uptake by plants and/or microbes in forested soils subsequent to deposition and the progress of denitrification within groundwater likely plays a significant role in the removal of NO3-atm.

  9. Tracing atmospheric nitrate in groundwater using triple oxygen isotopes: evaluation based on bottled drinking water

    NASA Astrophysics Data System (ADS)

    Tsunogai, U.; Suzuki, A.; Daita, S.; Ohyama, T.; Komatsu, D. D.; Nakagawa, F.

    2012-11-01

    The stable isotopic compositions of nitrate dissolved in 49 types of bottled drinking water collected worldwide were determined, to trace the fate of atmospheric nitrate (NO3-atm) that had been deposited into subaerial ecosystems, using the 17O anomalies (Δ17O) of nitrate as tracers. The use of bottled water enables collection of groundwater recharged at natural, background watersheds. The nitrate in groundwater had small Δ17O values ranging from -0.2‰ to +4.5‰ (n = 49). The average Δ17O value and average mixing ratio of atmospheric nitrate to total nitrate in the groundwater samples were estimated to be 0.8‰ and 3.1%, respectively. These findings indicated that the majority of atmospheric nitrate had undergone biological processing before being exported from the surface ecosystem to the groundwater. Moreover, the concentrations of atmospheric nitrate were estimated to range from less than 0.1 μmol l-1 to 8.5 μmol l-1, with higher NO3-atm concentrations being obtained for those recharged in rocky, arid or elevated areas with little vegetation and lower NO3-atm concentrations being obtained for those recharged in forested areas with high levels of vegetation. Additionally, many of the NO3-atm-depleted samples were characterized by elevated δ15N values of more than +10‰. Uptake by plants and/or microbes in forested soils subsequent to deposition and the progress of denitrification within groundwater likely plays a significant role in the removal of NO3-atm.

  10. Size-resolved particulate water-soluble organic compounds in the urban, mountain and marine atmosphere

    NASA Astrophysics Data System (ADS)

    Wang, G.; Kawamura, K.; Xie, M.; Hu, S.; Zhou, B.; Li, J.; Cao, J.; An, Z.

    2010-07-01

    Primary (i.e., sugars and sugar alcohols) and secondary water-soluble organic compounds (WSOCs) (i.e., dicarboxylic acids and aromatic acids) were characterised on a molecular level in size-segregated aerosols from the urban and mountain atmosphere of China and from the marine atmosphere in the outflow region of East Asia. Levoglucosan is the most abundant WSOCs in the urban and mountain atmosphere, whose accumulated concentrations in all stages are 1-3 orders of magnitude higher than those of marine aerosols. In contrast, malic, succinic and phthalic acids are dominant in the marine aerosols, which are 3-6 times more abundant than levoglucosan. This suggests that a continuous formation of secondary organic aerosols is occurring in the marine atmosphere during the long-range transport of air mass from inland China to the North Pacific. Sugars and sugar-alcohols, except for levoglucosan, gave a bimodal size distribution in the urban and mountain areas, peaking at 0.7-1.1 μm and >3.3 μm, and a unimodal distribution in the marine region, peaking at >3.3 μm. In contrast, levoglucosan and all the secondary WSOCs, except for benzoic and azelaic acids, showed a unimodal size distribution with a peak at 0.7-1.1 μm. Geometric mean diameters (GMDs) of the WSOCs in fine particles (<2.1 μm) at the urban site are larger in winter than in spring, due to an enhanced coagulation effect under the development of an inversion layer. However, GMDs of levoglucosan and most of the secondary WSOCs in the coarse mode are larger in the mountain and marine air and smaller in the urban air. This is most likely caused by an enhanced hygroscopic growth due to the high humidity of the mountain and marine atmosphere.

  11. Advances in the hydrogeochemistry and microbiology of acid mine waters

    USGS Publications Warehouse

    Nordstrom, D. Kirk

    2000-01-01

    The last decade has witnessed a plethora of research related to the hydrogeochemistry and microbiology of acid mine waters and associated tailings and waste-rock waters. Numerous books, reviews, technical papers, and proceedings have been published that examine the complex bio-geochemical process of sulfide mineral oxidation, develop and apply geochemical models to site characterization, and characterize the microbial ecology of these environments. This review summarizes many of these recent works, and provides references for those investigating this field. Comparisons of measured versus calculated Eh and measured versus calculated pH for water samples from several field sites demonstrate the reliability of some current geochemical models for aqueous speciation and mass balances. Geochemical models are not, however, used to predict accurately time-dependent processes but to improve our understanding of these systems and to constrain possible processes that contribute to actual or potential water quality issues. Microbiological studies are demonstrating that there is much we have yet to learn about the types of different microorganisms and their function and ecology in mine-waste environments. A broad diversity of green algae, bacteria, archaea, yeasts, and fungi are encountered in acid mine waters, and a better understanding of their ecology and function may potentially enhance remediation possibilities as well as our understanding of the evolution of life.

  12. Atmosphere and water loss from early Mars under extreme solar wind and extreme ultraviolet conditions.

    PubMed

    Terada, Naoki; Kulikov, Yuri N; Lammer, Helmut; Lichtenegger, Herbert I M; Tanaka, Takashi; Shinagawa, Hiroyuki; Zhang, Tielong

    2009-01-01

    The upper limits of the ion pickup and cold ion outflow loss rates from the early martian atmosphere shortly after the Sun arrived at the Zero-Age-Main-Sequence (ZAMS) were investigated. We applied a comprehensive 3-D multi-species magnetohydrodynamic (MHD) model to an early martian CO(2)-rich atmosphere, which was assumed to have been exposed to a solar XUV [X-ray and extreme ultraviolet (EUV)] flux that was 100 times higher than today and a solar wind that was about 300 times denser. We also assumed the late onset of a planetary magnetic dynamo, so that Mars had no strong intrinsic magnetic field at that early period. We found that, due to such extreme solar wind-atmosphere interaction, a strong magnetic field of about approximately 4000 nT was induced in the entire dayside ionosphere, which could efficiently protect the upper atmosphere from sputtering loss. A planetary obstacle ( approximately ionopause) was formed at an altitude of about 1000 km above the surface due to the drag force and the mass loading by newly created ions in the highly extended upper atmosphere. We obtained an O(+) loss rate by the ion pickup process, which takes place above the ionopause, of about 1.5 x 10(28) ions/s during the first < or =150 million years, which is about 10(4) times greater than today and corresponds to a water loss equivalent to a global martian ocean with a depth of approximately 8 m. Consequently, even if the magnetic protection due to the expected early martian magnetic dynamo is neglected, ion pickup and sputtering were most likely not the dominant loss processes for the planet's initial atmosphere and water inventory. However, it appears that the cold ion outflow into the martian tail, due to the transfer of momentum from the solar wind to the ionospheric plasma, could have removed a global ocean with a depth of 10-70 m during the first < or =150 million years after the Sun arrived at the ZAMS.

  13. Photon and Water Mediated Sulfur Oxide and Acid Chemistry in the Atmosphere of Venus

    NASA Astrophysics Data System (ADS)

    Kroll, Jay A.; Vaida, Veronica

    2014-06-01

    Sulfur compounds have been observed in the atmospheres of a number of planetary bodies in our solar system including Venus, Earth, Mars, Io, Europa, and Callisto. The global cloud cover on Venus located at an altitude between 50 and 80 kilometers is composed primarily of sulfuric acid (H_2SO_4) and water. Planetary photochemical models have attempted to explain observations of sulfuric acid and sulfur oxides with significant discrepancies remaining between models and observation. In particular, high SO_2 mixing ratios are observed above 90 km which exceed model predictions by orders of magnitude. Work recently done in the Vaida lab has shown red light can drive photochemistry through overtone pumping for acids like H_2SO_4 and has been successful in explaining much of the sulfur chemistry in Earth's atmosphere. Water can have a number of interesting effects such as catalysis, suppression, and anti-catalysis of thermal and photochemical processes. We investigate the role of water complexes in the hydration of sulfur oxides and dehydration of sulfur acids and present spectroscopic studies to document such effects. We investigate these reactions using FTIR and UV/Vis spectroscopy and will report on our findings.

  14. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below 273 K

    NASA Astrophysics Data System (ADS)

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias; Gilles, Mary K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2011-11-01

    Ice formation induced by atmospheric particles through heterogeneous nucleation is not well understood. Onset conditions for heterogeneous ice nucleation and water uptake by particles collected in Los Angeles and Mexico City were determined as a function of temperature (200-273 K) and relative humidity with respect to ice (RHice). Four dominant particle types were identified including soot associated with organics, soot with organic and inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn-containing particles apportioned to emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Above 230 K, significant differences in onsets of water uptake and immersion freezing of different particle types were observed. Below 230 K, particles exhibited high deposition ice nucleation efficiencies and formed ice atRHicewell below homogeneous ice nucleation limits. The data suggest that water uptake and immersion freezing are more sensitive to changes in particle chemical composition compared to deposition ice nucleation. The data demonstrate that anthropogenic and marine influenced particles, exhibiting various chemical and physical properties, possess distinctly different ice nucleation efficiencies and can serve as efficient IN at atmospheric conditions typical for cirrus and mixed-phase clouds.

  15. Heterogeneous ice nucleation and water uptake by field-collected atmospheric particles below 273 K

    NASA Astrophysics Data System (ADS)

    Wang, Bingbing; Laskin, Alexander; Roedel, Tobias; Gilles, Mary K.; Moffet, Ryan C.; Tivanski, Alexei V.; Knopf, Daniel A.

    2012-09-01

    Ice formation induced by atmospheric particles through heterogeneous nucleation is not well understood. Onset conditions for heterogeneous ice nucleation and water uptake by particles collected in Los Angeles and Mexico City were determined as a function of temperature (200-273 K) and relative humidity with respect to ice (RHice). Four dominant particle types were identified including soot associated with organics, soot with organic and inorganics, inorganic particles of marine origin coated with organic material, and Pb/Zn-containing particles apportioned to emissions relevant to waste incineration. Single particle characterization was provided by micro-spectroscopic analyses using computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Above 230 K, significant differences in onsets of water uptake and immersion freezing of different particle types were observed. Below 230 K, particles exhibited high deposition ice nucleation efficiencies and formed ice atRHicewell below homogeneous ice nucleation limits. The data suggest that water uptake and immersion freezing are more sensitive to changes in particle chemical composition compared to deposition ice nucleation. The data demonstrate that anthropogenic and marine influenced particles, exhibiting various chemical and physical properties, possess distinctly different ice nucleation efficiencies and can serve as efficient IN at atmospheric conditions typical for cirrus and mixed-phase clouds.

  16. Diagnosis of Systematic Errors in Atmospheric River Forecasts Using Satellite Observations of Integrated Water Vapor

    NASA Astrophysics Data System (ADS)

    Wick, G. A.; Neiman, P. J.; Ralph, F. M.

    2011-12-01

    Narrow regions of strong water vapor transport in the atmosphere, termed atmospheric rivers, have been observed to be present and an important contributor to recent major winter flooding events along the west coast of the United States. CalWater research objectives include documenting the influence of atmospheric river (AR) events and assessing the uncertainty of their representation in numerical weather prediction forecast and reanalysis models. Understanding how well AR events are reproduced in model forecast fields is particularly important as we look forward to how their frequency and intensity might evolve in a changing climate. To support these goals, previous work defined objective characteristics for the identification of AR events in satellite-based integrated water vapor (IWV) retrievals. These techniques have been extended in the development of an automated tool to identify and characterize AR events in both satellite-derived and model fields of IWV. To evaluate how accurately present models reproduce the occurrence and representation of AR events, forecasts and analyses of IWV from multiple models are compared with corresponding satellite-based retrievals over several cool seasons. The automated AR detection procedure is applied to compare the representation of such characteristics as the frequency, size, position, and intensity of AR events in both the analyses and forecasts. Forecast fields are taken from several of the operational models included in the THORPEX Interactive Grand Global Ensemble (TIGGE). Results are presented as a function of forecast lead time in terms of quantities including probability of detection and false alarm rate. Overall the frequency and timing of events is generally well forecast but the size and position are subject to larger errors, particularly at longer forecast lead times.

  17. Numerical Simulations of Optical Turbulence Using an Advanced Atmospheric Prediction Model: Implications for Adaptive Optics Design

    NASA Astrophysics Data System (ADS)

    Alliss, R.

    2014-09-01

    Optical turbulence (OT) acts to distort light in the atmosphere, degrading imagery from astronomical telescopes and reducing the data quality of optical imaging and communication links. Some of the degradation due to turbulence can be corrected by adaptive optics. However, the severity of optical turbulence, and thus the amount of correction required, is largely dependent upon the turbulence at the location of interest. Therefore, it is vital to understand the climatology of optical turbulence at such locations. In many cases, it is impractical and expensive to setup instrumentation to characterize the climatology of OT, so numerical simulations become a less expensive and convenient alternative. The strength of OT is characterized by the refractive index structure function Cn2, which in turn is used to calculate atmospheric seeing parameters. While attempts have been made to characterize Cn2 using empirical models, Cn2 can be calculated more directly from Numerical Weather Prediction (NWP) simulations using pressure, temperature, thermal stability, vertical wind shear, turbulent Prandtl number, and turbulence kinetic energy (TKE). In this work we use the Weather Research and Forecast (WRF) NWP model to generate Cn2 climatologies in the planetary boundary layer and free atmosphere, allowing for both point-to-point and ground-to-space seeing estimates of the Fried Coherence length (ro) and other seeing parameters. Simulations are performed using a multi-node linux cluster using the Intel chip architecture. The WRF model is configured to run at 1km horizontal resolution and centered on the Mauna Loa Observatory (MLO) of the Big Island. The vertical resolution varies from 25 meters in the boundary layer to 500 meters in the stratosphere. The model top is 20 km. The Mellor-Yamada-Janjic (MYJ) TKE scheme has been modified to diagnose the turbulent Prandtl number as a function of the Richardson number, following observations by Kondo and others. This modification

  18. Effects of flux emergence in the outer solar atmosphere. Observational advances

    NASA Astrophysics Data System (ADS)

    Ortiz Carbonell, Ada; De Pontieu, Bart; Bellot Rubio, L. R.; Hansteen, Viggo; Rouppe van der Voort, Luc; Carlsson, Mats

    We study granular sized magnetic flux emergence events that occur in a flux emergence region in NOAA 11850 on September 25, 2013. During that time, the first co-observing campaign between the Swedish 1 m Solar Telescope and the IRIS spacecraft was carried out. Simultaneous observations of the Halpha 656.28 nm and Ca II 854.2 nm chromospheric lines, and the Fe I 630.25 nm photospheric line, were made with the CRISP/SST spectropolarimeter reaching a spatial resolution of 0."14. At the same time, IRIS was performing a four-step dense raster of the said emerging flux region, taking slit-jaw images at 133 (C II transiti on region), 140 (Si IV, transition region), 279.6 (Mg II k, core, upper chromosphere), and 283.2 nm (Mg II k, wing, photosphere), obtaining thus the highest resolution images ever taken of the upper chromosphere and transition region. The photospheric and chromospheric properties of the emerging magnetic flux bubbles have been described in detail in Ortiz et al. (2014). However, in the current work we are able to follow such lower atmosphere observations of flux emergence up to the transition region with unprecedented spatial and temporal resolution. We describe the properties (size, time delays, lifetime, velocities, temperature) of the observed signatures of flux emergence in the transition region. We believe this may be an important mechanism of transporting energy and magnetic flux to the upper layers of the solar atmosphere, namely the transition region and corona, at least in cases when active regions are formed by flux emerging through the photosphere. * Ortiz et al. (2014) ApJ 781, 126

  19. The investigation of advanced remote sensing, radiative transfer and inversion techniques for the measurement of atmospheric constituents

    NASA Technical Reports Server (NTRS)

    Deepak, Adarsh; Wang, Pi-Huan

    1985-01-01

    The research program is documented for developing space and ground-based remote sensing techniques performed during the period from December 15, 1977 to March 15, 1985. The program involved the application of sophisticated radiative transfer codes and inversion methods to various advanced remote sensing concepts for determining atmospheric constituents, particularly aerosols. It covers detailed discussions of the solar aureole technique for monitoring columnar aerosol size distribution, and the multispectral limb scattered radiance and limb attenuated radiance (solar occultation) techniques, as well as the upwelling scattered solar radiance method for determining the aerosol and gaseous characteristics. In addition, analytical models of aerosol size distribution and simulation studies of the limb solar aureole radiance technique and the variability of ozone at high altitudes during satellite sunrise/sunset events are also described in detail.

  20. Performance modeling of daytime Raman lidar systems for profiling atmospheric water vapor

    NASA Technical Reports Server (NTRS)

    Goldsmith, J. E. M.; Ferrare, Richard A.

    1992-01-01

    We describe results from a comprehensive computer model developed to guide optimization of an ultraviolet Raman lidar system for measuring daytime profiles of atmospheric water vapor. Daytime measurements present added challenges because of the difficulties inherent in detecting Raman signals against solar backgrounds. We are pursuing two concepts for optimizing the daytime performance of a Raman lidar system. The first involves operating the system in the solar blind region of the ultraviolet spectrum. The second concept involves operation of the system in a narrowband, narrow field-of-view mode. Calculations for lidar systems based on both concepts are presented.

  1. Microwave radiometer studies of atmospheric water over the oceans, volume 2

    NASA Technical Reports Server (NTRS)

    Katsaros, Kristina B.

    1992-01-01

    Since the Seasat carried the Scanning Multichannel Microwave Radiometer (SMMR) into space in July of 1978, shortly followed by the SMMR on Nimbus 7, which operated for almost a decade, a new type of data source on atmospheric water vapor and other meteorological parameters has been available for analysis of weather systems over the ocean. Since 1987, we have had the Scanning Multichannel Microwave/Imager (SSM/I) instrument on Defense Meteorological Satellites providing similar data. We present a collection of our work performed over the last years of the study.

  2. Moist convection and the vertical structure and water abundance of Jupiter's atmosphere

    NASA Technical Reports Server (NTRS)

    Del Genio, Anthony D.; Mcgrattan, Kevin B.

    1990-01-01

    The cumulative effects of an ensemble of moist convective plumes on a conditionally unstable atmosphere are predicted by a model of moist convection on Jupiter in which the heating/cooling and drying/moistening of the environment occur through (1) compensating subsidence, (2) detrainment of updraft air at cloud tops, and (3) the evaporation and melting of falling condensate. Parahydrogen is transported as a passive tracer. Pure moist convective, mixed moist-dry convective, and primarily dry convective regimes are possible, depending on the assumed deep-water abundance, efficiency of condensate evaporation, and initial temperature profile.

  3. Water relations in grassland and desert ecosystems exposed to elevated atmospheric CO2.

    PubMed

    Morgan, J A; Pataki, D E; Körner, C; Clark, H; Del Grosso, S J; Grünzweig, J M; Knapp, A K; Mosier, A R; Newton, P C D; Niklaus, P A; Nippert, J B; Nowak, R S; Parton, W J; Polley, H W; Shaw, M R

    2004-06-01

    Atmospheric CO2 enrichment may stimulate plant growth directly through (1) enhanced photosynthesis or indirectly, through (2) reduced plant water consumption and hence slower soil moisture depletion, or the combination of both. Herein we describe gas exchange, plant biomass and species responses of five native or semi-native temperate and Mediterranean grasslands and three semi-arid systems to CO2 enrichment, with an emphasis on water relations. Increasing CO2 led to decreased leaf conductance for water vapor, improved plant water status, altered seasonal evapotranspiration dynamics, and in most cases, periodic increases in soil water content. The extent, timing and duration of these responses varied among ecosystems, species and years. Across the grasslands of the Kansas tallgrass prairie, Colorado shortgrass steppe and Swiss calcareous grassland, increases in aboveground biomass from CO2 enrichment were relatively greater in dry years. In contrast, CO2-induced aboveground biomass increases in the Texas C3/C4 grassland and the New Zealand pasture seemed little or only marginally influenced by yearly variation in soil water, while plant growth in the Mojave Desert was stimulated by CO2 in a relatively wet year. Mediterranean grasslands sometimes failed to respond to CO2-related increased late-season water, whereas semiarid Negev grassland assemblages profited. Vegetative and reproductive responses to CO2 were highly varied among species and ecosystems, and did not generally follow any predictable pattern in regard to functional groups. Results suggest that the indirect effects of CO2 on plant and soil water relations may contribute substantially to experimentally induced CO2-effects, and also reflect local humidity conditions. For landscape scale predictions, this analysis calls for a clear distinction between biomass responses due to direct CO2 effects on photosynthesis and those indirect CO2 effects via soil moisture as documented here.

  4. Watts nickel and rinse water recovery via an advanced reverse osmosis system

    SciTech Connect

    Schmidt, C.; White, I.E.; Ludwig, R.

    1993-08-01

    The report summarizes the results of an eight month test program conducted at the Hewlett Packard Printed Circuit Board Production Plant, Sunnyvale, CA (H.P.) to assess the effectiveness of an advanced reverse osmosis system (AROS). The AROS unit, manufactured by Water Technologies, Inc. (WTI) of Minneapolis, MN, incorporates membrane materials and system components designed to treat metal plating rinse water and produce two product streams; (1) a concentrated metal solution suitable for the plating bath, and (2) rinse water suitable for reuse as final rinse. Waste water discharge can be virtually eliminated and significant reductions realized in the need for new plating bath solution and rinse water.

  5. Enhancing our Understanding of the Arctic Atmospheric Hydrological Cycle using Observations from an International Arctic Water Vapor Isotope Network

    NASA Astrophysics Data System (ADS)

    Masson-Delmotte, V.; Steen-Larsen, H. C.; Werner, M.

    2014-12-01

    Due to the role of water vapor and clouds in positive feedback mechanisms, water vapor is a key player in the future of Arctic climate. Ecosystems and human societies are vulnerable to climate change through even minor changes in precipitation patterns, including the occurrence of extreme events. It is therefore essential to monitor, understand and model correctly the mechanisms of transport of moisture, at the regional scale. Water isotopes - the relative abundance of heavy and light water in the atmosphere - hold the key to understanding the physical processes influencing future Arctic climate. Water isotope observations in the atmosphere are a modern analog to the Rosetta Stone for understanding the processes involved in evaporation, moisture transport, cloud formation and to track moisture origin. Indeed, technological progress now allows continuous, in situ or remote sensing monitoring of water isotopic composition. In parallel, a growing number of atmospheric circulation models are equipped with the explicit modeling of water stable isotopes, allowing evaluation at the process scale. We present here data obtained through national or bi-national initiatives from stations onboard an icebreaker and land based stations in Greenland, Iceland, Svalbard, and Siberia - together forming an emerging international Arctic water vapor isotope network. Using water tagging and back trajectories we show water vapor of Arctic origin to have a high d-excess fingerprint. This show the potential of using water vapor isotopes as tracer for changes in the Arctic hydrological cycle. Using the network of monitoring stations we quantify using the isotopes advection of air masses and the key processes affecting the water vapor en-route between stations. We have successfully used the obtained atmospheric water vapor isotope observations to benchmark isotope-enabled general circulation models. This comparison allows us to address key processes of the atmospheric hydrological cycle for

  6. Recent advances in modified atmosphere packaging and edible coatings to maintain quality of fresh-cut fruits and vegetables.

    PubMed

    Ghidelli, Christian; Pérez-Gago, María B

    2016-07-28

    Processing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf-life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O2 and high CO2 levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and non-conventional atmospheres such as the use of pressurized inert/noble gases and high levels of O2 have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.

  7. Gas chromatography: Possible application of advanced instrumentation developed for solar system exploration to space station cabin atmospheres

    NASA Technical Reports Server (NTRS)

    Carle, G. C.

    1985-01-01

    Gas chromatography (GC) technology was developed for flight experiments in solar system exploration. The GC is a powerful analytical technique with simple devices separating individual components from complex mixtures to make very sensitive quantitative and qualitative measurements. It monitors samples containing mixtures of fixed gases and volatile organic molecules. The GC was used on the Viking mission in support of life detection experiments and on the Pioneer Venus Large Probe to determine the composition of the venusian atmosphere. A flight GC is under development to study the progress and extent of STS astronaut denitrogenation prior to extravehicular activity. Advanced flight GC concepts and systems for future solar system exploration are also studied. Studies include miniature ionization detectors and associated control systems capable of detecting from ppb up to 100% concentration levels. Further miniaturization is investigated using photolithography and controlled chemical etching in silicon wafers. Novel concepts such as ion mobility drift spectroscopy and multiplex gas chromatography are also developed for future flight experiments. These powerful analytical concepts and associated hardware are ideal for the monitoring of cabin atmospheres containing potentially dangerous volatile compounds.

  8. Generation of an atmospheric plasmoid from a water discharge: An analysis of the dissipated energy

    NASA Astrophysics Data System (ADS)

    Fantz, U.; Kalafat, S.; Friedl, R.; Briefi, S.

    2013-07-01

    A plasmoid in air at atmospheric pressure of about 20 cm in diameter and up to 500 ms duration is generated from a water discharge which is powered for a short time period by a capacitor bank. The analysis of the electrical circuit and the comparison with experimental values show that the energy dissipated into the system is given by the conventional equation for discharging capacitors. The resistance of the system is governed by the resistances of the water reservoir, the plasma, and the plasma-water transition, which are represented as one time-averaged resistance in the equation. Thus, the dissipated energy can be influenced by the energy available (capacitance and voltage), the voltage-on time, the conductivity of the water, the electrode gap and the size of the container (plate electrode) within the experimental boundaries. An estimation of the energy channels for a discharge at standard conditions revealed that the dominant part of the energy is dissipated into the water reservoir. About 25% of the energy is dissipated directly into the plasmoid and is available for plasma formation, plasma kinetics and chemical processes.

  9. Low-level water vapor fields from the VISSR Atmospheric Sounder (VAS) 'split window' channels

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L. W.; Robinson, W. D.

    1983-01-01

    A simple physical algorithm is presented which calculates the water vapor content of the lower troposphere from the 11 and 12 micron (split window) channels on the VISSR Atmospheric Sounder (VAS) on the Geostationary Operational Environmental Satellites. The algorithm is used to analyze a time series of VAS split window radiances observed at 15 km horizontal resolution over eastern North America during a 12 hr period on 13 July 1981. Results of the color coded images of the derived precipitable water fields are found to show vivid water vapor features whose broad structure and evolution are verified by the radiosonde and surface networks. The satellite moisture fields also show significant mesoscale features and rapid developments which are not resolved by the conventional networks. The VAS split window is determined to clearly differentiate those areas in which water vapor extends over a deep layer and is more able to support convective cells from those areas in which water vapor is confined to a shallow layer and is therefore less able to support convection. It is concluded that the VAS split windows can be used operationally to monitor mesoscale developments in the low-level moisture fields over relatively cloud-free areas of the United States.

  10. Upper atmosphere modifications due to chronic discharges of water vapor from space launch vehicle exhausts

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1980-01-01

    The influences of transport, photodissociation, and frequency of injection on the global redistribution of water deposited in the earth's upper atmosphere by repeated launches of large rockets are investigated. Measurable environmental effects of the injected water are found to occur when the mesospheric water vapor mixing ratio exceeds 100 ppmv, which occurs over areas of order 20,000 sq km in connection with possible future Satellite Power System activities. These effects include (1) a 50% reduction in D-region ionization due to screening of L alpha radiation by water; (2) a 50% reduction of D-region ionization as a result of converting NO(+) to water cluster ions which possess more rapid recombination rates; (3) a doubling of OH concentrations below 100 km; and (4) a global doubling of nighttime E-region ionization due to L alpha and L beta radiations geocoronally scattered by atomic hydrogen released by photolysis of H2O. Mixing ratios of 1,000 ppmv necessary for the maintenance of clouds at the mesopause are reached only over areas of order 200 sq km.

  11. Europa's Atmosphere and Aurora: Recent Advances from HST-STIS and Plans for Plume Searches with JUICE-UVS

    NASA Astrophysics Data System (ADS)

    Retherford, K. D.; Gladstone, R.; Roth, L.; McGrath, M. A.; Saur, J.; Feldman, P. D.; Steffl, A. J.; Strobel, D. F.; Greathouse, T. K.; Spencer, J. R.; Bagenal, F.; Fletcher, L. N.; Eterno, J. S.

    2013-12-01

    Space Telescope Imaging System (STIS) images of Europa's neutral oxygen 130.4 nm and 135.6 nm emissions contain a wealth of information about the molecular oxygen atmosphere, discovered using previous Hubble far-UV observations. Europa's magnetospheric plasma interaction generates auroral emissions, which exhibit a morphology that has been difficult to interpret. Recent observations in Nov. & Dec. 2012 allow a new understanding of how Jupiter's magnetic field orientation and relation to the plasma sheet control the emission variability, yet explanations for this general behavior, including the likely role of ocean-induced magnetic fields and possible local atmospheric density enhancements, remain incomplete (cf. Roth et al. this meeting). NASA's Ultraviolet Spectrograph (UVS) instrument contribution to the ESA-led Jupiter Icy Moons Explorer (JUICE) mission will obtain excellent imaging of these atmospheric and auroral emissions from Europa during two flybys currently planned, with the objective of investigating these and other unanswered questions. UVS's stellar occultation technique will be used to characterize Europa's atmosphere structure and composition and to also search for local enhancements created by plumes. This stellar occultation technique, demonstrated by Cassini-UVIS at Enceladus, has the benefit of being useful at relatively large distances (several 10's of Jupiter radii) as well as during the Europa flyby sequences (several 10's of Europa radii). A robust search for plumes is planned in JUICE's first year at Jupiter to provide a roughly 30-degree grid of global coverage, followed by focused targeting of likely plumes/active-regions during early and late stages of the flyby sequences. High spatial resolution limb imaging is also planned near closest approaches, which could directly image plume gases in a manner analogous with plume aurora imaging of Io. A UV spectrograph on the planned Europa Clipper mission could perform an even more robust search

  12. Evolutionary/advanced light water reactor data report

    SciTech Connect

    1996-02-09

    The US DOE Office of Fissile Material Disposition is examining options for placing fissile materials that were produced for fabrication of weapons, and now are deemed to be surplus, into a condition that is substantially irreversible and makes its use in weapons inherently more difficult. The principal fissile materials subject to this disposition activity are plutonium and uranium containing substantial fractions of plutonium-239 uranium-235. The data in this report, prepared as technical input to the fissile material disposition Programmatic Environmental Impact Statement (PEIS) deal only with the disposition of plutonium that contains well over 80% plutonium-239. In fact, the data were developed on the basis of weapon-grade plutonium which contains, typically, 93.6% plutonium-239 and 5.9% plutonium-240 as the principal isotopes. One of the options for disposition of weapon-grade plutonium being considered is the power reactor alternative. Plutonium would be fabricated into mixed oxide (MOX) fuel and fissioned (``burned``) in a reactor to produce electric power. The MOX fuel will contain dioxides of uranium and plutonium with less than 7% weapon-grade plutonium and uranium that has about 0.2% uranium-235. The disposition mission could, for example, be carried out in existing power reactors, of which there are over 100 in the United States. Alternatively, new LWRs could be constructed especially for disposition of plutonium. These would be of the latest US design(s) incorporating numerous design simplifications and safety enhancements. These ``evolutionary`` or ``advanced`` designs would offer not only technological advances, but also flexibility in siting and the option of either government or private (e.g., utility) ownership. The new reactor designs can accommodate somewhat higher plutonium throughputs. This data report deals solely with the ``evolutionary`` LWR alternative.

  13. Recent advances in developing COS as a tracer of Biosphere-atmosphere exchange of CO2

    NASA Astrophysics Data System (ADS)

    Asaf, D.; Stimler, K.; Yakir, D.

    2012-04-01

    Potential use of COS as tracer of CO2 flux into vegetation, based on its co-diffusion with CO2 into leaves without outflux, stimulated research on COS-CO2 interactions. Atmospheric measurements by NOAA in recent years, across a global latitudinal transect, indicated a ratio of the seasonal drawdowns in COS and CO2 (normalized to their respective ambient concentrations) of about 6. We carried out leaf-scale gas exchange measurements of COS and CO2 in 22 plant species of deciduous, evergreen trees, grasses, and shrubs, under a range of light intensities and ambient COS concentrations (using mid IR laser spectroscopy). A narrow range in the normalized ratio of the net uptake rates of COS and CO2 (termed leaf relative uptake; LRU) was observed with a mean value of 1.61±0.26. These results reflect the dominance of stomatal conductance over both COS and CO2 uptake, imposing a relatively constant ratio between the two fluxes, except under low light conditions when CO2, but not COS, metabolism is light limited. A relatively constant ratio under common ambient conditions will facilitate the application of COS as a tracer of gross photosynthesis from leaf to global scales. We also report first eddy flux measurements of COS/CO2 at the ecosystem scales. Preliminarily results indicate a ratio of the COS flux, Fcos, to net ecosystem CO2 exchange, NEE, of 3-5 (termed ecosystem relative uptake; ERU). Combining measurements of COS and CO2 and the new information on their ratios at different scales should permit the direct estimation of gross CO2 uptake, GPP, by land ecosystems according to: GPP=NEE*ERU/LRU. In addition, we show that COS effect on stomatal conductance may require a special attention. Increasing COS concentrations between 250 and 2800 pmol mol-1 (enveloping atmospheric levels) stimulate stomatal conductance. It seems likely that the stomata are responding to H2S produced in the leaves from COS.

  14. Seasonal Dependence of the Escape of Water from the Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Clarke, John

    2014-10-01

    This proposal is to obtain ACS/SBC images and STIS spectra of the extended H Ly alpha and O 1304 emissions from H and O atoms in the atmosphere of Mars to study seasonal changes in the escape rate of H and O atoms, and thereby water. Prior HST observations have revealed a surprising rapid change in the H escape rate in late martian summer following a global dust storm, and have shown that STIS spectra can easily detect superthermal O atoms. The relative degree of influence of seasons and dust storms on the H density and escape flux are not known, and little is known about variations in the hot O density and escape rate. The timing of these observations is key to these scientific goals. Mars is now approaching the Sun, HST can observe Mars over a wide range of seasons from April - Nov 2014, and HST will not be able to observe Mars again until after the prime mission of MAVEN. The observations will also bracket in time the close approach of Comet Siding Spring on 19 Oct. 2014 and see any effects of the energy deposition in the martian upper atmosphere. These observations will provide strong support for the NASA MAVEN mission, scheduled to arrive at Mars in Sept. 2014, and STScI has granted 3 orbits to establish the baseline conditions in the martin atmosphere in late spring 2014, when Mars is far from the Sun.

  15. Atmospheric water-soluble organic nitrogen (WSON) over marine environments: a global perspective

    NASA Astrophysics Data System (ADS)

    Violaki, K.; Sciare, J.; Williams, J.; Baker, A. R.; Martino, M.; Mihalopoulos, N.

    2015-05-01

    To obtain a comprehensive picture of the spatial distribution of water-soluble organic nitrogen (WSON) in marine aerosols, samples were collected during research cruises in the tropical and southern Atlantic Ocean and also in the southern Indian Ocean (Amsterdam Island) for a 1-year period (2005). Samples were analyzed for both organic and inorganic forms of nitrogen, and the factors controlling their levels were examined. Fine-mode WSON was found to play a significant role in the remote marine atmosphere with enhanced biogenic activity, with concentrations of WSON (11.3 ± 3.3 nmol N m-3) accounting for about 84 % of the total dissolved nitrogen (TDN). Such concentrations are similar to those observed in the polluted marine atmosphere of the eastern Mediterranean (11.6 ± 14.0 nmol N m-3). Anthropogenic activities were found to be an important source of atmospheric WSON as evidenced by the levels in the Northern Hemisphere (NH) being 10 times higher than in the remote Southern Hemisphere (SH). Furthermore, the higher contribution of fine-mode WSON to TDN (51%) in the SH, compared to the NH (13%), underlines the important role of organic nitrogen in remote marine areas. Finally, there was a strong association of WSON with dust in coarse-mode aerosols in the NH.

  16. Use of Atmospheric Budget to Reduce Uncertainty in Estimated Water Availability over South Asia from Different Reanalyses.

    PubMed

    Sebastian, Dawn Emil; Pathak, Amey; Ghosh, Subimal

    2016-07-08

    Disagreements across different reanalyses over South Asia result into uncertainty in assessment of water availability, which is computed as the difference between Precipitation and Evapotranspiration (P-E). Here, we compute P-E directly from atmospheric budget with divergence of moisture flux for different reanalyses and find improved correlation with observed values of P-E, acquired from station and satellite data. We also find reduced closure terms for water cycle computed with atmospheric budget, analysed over South Asian landmass, when compared to that obtained with individual values of P and E. The P-E value derived with atmospheric budget is more consistent with energy budget, when we use top-of-atmosphere radiation for the same. For analysing water cycle, we use runoff from Global Land Data Assimilation System, and water storage from Gravity Recovery and Climate Experiment. We find improvements in agreements across different reanalyses, in terms of inter-annual cross correlation when atmospheric budget is used to estimate P-E and hence, emphasize to use the same for estimations of water availability in South Asia to reduce uncertainty. Our results on water availability with reduced uncertainty over highly populated monsoon driven South Asia will be useful for water management and agricultural decision making.

  17. Use of Atmospheric Budget to Reduce Uncertainty in Estimated Water Availability over South Asia from Different Reanalyses

    PubMed Central

    Sebastian, Dawn Emil; Pathak, Amey; Ghosh, Subimal

    2016-01-01

    Disagreements across different reanalyses over South Asia result into uncertainty in assessment of water availability, which is computed as the difference between Precipitation and Evapotranspiration (P–E). Here, we compute P–E directly from atmospheric budget with divergence of moisture flux for different reanalyses and find improved correlation with observed values of P–E, acquired from station and satellite data. We also find reduced closure terms for water cycle computed with atmospheric budget, analysed over South Asian landmass, when compared to that obtained with individual values of P and E. The P–E value derived with atmospheric budget is more consistent with energy budget, when we use top-of-atmosphere radiation for the same. For analysing water cycle, we use runoff from Global Land Data Assimilation System, and water storage from Gravity Recovery and Climate Experiment. We find improvements in agreements across different reanalyses, in terms of inter-annual cross correlation when atmospheric budget is used to estimate P–E and hence, emphasize to use the same for estimations of water availability in South Asia to reduce uncertainty. Our results on water availability with reduced uncertainty over highly populated monsoon driven South Asia will be useful for water management and agricultural decision making. PMID:27388837

  18. The High Altitude Water Cherenlov (HAWC) Gamma ray Detector Response to Atmospheric Electric Field Variations

    NASA Astrophysics Data System (ADS)

    Lara, A.

    2015-12-01

    The High Altitude Water Cherenkov (HAWC) observatory is located at 4100 m a.s.l. in Mexico. HAWC's primary purpose is the study of both: galactic and extra-galactic sources of high energy gamma rays. HAWC consists of 300 large water Cherenkov detectors (WCD), each instrumented with 4 photo-multipliers (PMTs). The HAWC scaler system records the rates of individual PMTs giving the opportunity of study relatively low energy transients as solar energetic particles, the solar modulation of galactic cosmic rays and possible variations of the cosmic ray rate due to atmospheric electric field changes. In this work, we present the observations of scaler rate enhancements associated with thunderstorm activity observed at the HAWC site.In particular, we present preliminary results of the analysis of the time coincidence of the electric field changes and the scaler enhancements.

  19. Implications of the high D/H ratio for the sources of water in Venus' atmosphere

    NASA Astrophysics Data System (ADS)

    Grinspoon, D. H.

    1993-06-01

    The abundance ratio of D relative to H in the Venus atmosphere is 120 times greater than that of the earth. A recent reanalysis of collisional ejection has increased estimates of the D escape efficiency by a factor of 10, implying that, for a steady-state Venusian water budget, the D/H ratio of the source water must be 10-15 times higher than that of the earth. It is presently suggested that these observations can be understood either as a result of continuous outgassing from a highly fractionated mantle source, or Rayleigh fractionation after massive outgassing from catastrophic resurfacing of the planet over the last 0.5-1.0 Gyr.

  20. Comparison of Atmospheric Water Vapor in Observational and Model Data Sets

    SciTech Connect

    Boyle, J.S.

    2000-03-01

    The global water vapor distribution for five observational based data sets and three GCM integrations are compared. The variables considered are the mean and standard deviation values of the precipitable water for the entire atmospheric column and the 500 to 300 hPa layer for January and July. The observationally based sets are the radiosonde data of Ross and Elliott, the ERA and NCEP reanalyses, and the NVAP blend of sonde and satellite data. The three GCM simulations all use the NCAR CCM3 as the atmospheric model. They include: a AMIP type simulation using observed SSTs for the period 1979 to 1993, the NCAR CSM 300 year coupled ocean--atmosphere integration, and a CSM integration with a 1% CO2 increase per year. The observational data exhibit some serious inconsistencies. There are geographical patterns of differences related to interannual variations and national instrument biases. It is clear that the proper characterization of water vapor is somewhat uncertain. Some conclusions about these data appear to be robust even given the discrepancies. The ERA data are too dry especially in the upper levels. The observational data evince much better agreement in the data rich Northern Hemisphere compared to the Southern. Distinct biases are quite pronounced over the Southern Ocean. The mean values and particularly the standard deviations of the three reanalyses are very dependent upon the GCM used as the assimilation vehicle for the analyses. This is made clear by the much enhanced tropical variability in the NCEP/DOE/ AMIP reanalyses compared the initial NCEP/NCAR Reanalysis. The NCAR CCM3 shows consistent evidence of a dry bias. The 1% CO2 experiment shows a very similar pattern of disagreement with the sonde data as the other integrations, once account is taken of the warming trend. No new modes of difference are evident in the 1% CO2 experiment. All the CCM3 runs indicated too much Tropical variability especially in the western Tropical Pacific and Southeast Asia

  1. Climatological features of atmospheric and terrestrial water cycles in the three great Siberian rivers based on six atmospheric reanalyses and observed river discharges

    NASA Astrophysics Data System (ADS)

    Oshima, K.; Tachibana, Y.; Hiyama, T.

    2013-12-01

    The three great Siberian rivers: Lena, Yenisei and Ob Rivers, are top three discharges (R) among all rivers flowing into the Arctic Ocean and play a role as a large source of freshwater inflow. This study revealed the regional differences in some climatological features of the atmospheric and terrestrial water cycles in the Siberian rivers on the basis of the Rs observed at the mouth of the rivers and net precipitations (precipitation minus evapotranspiration, P-E) estimated from six atmospheric reanalyses. As pointed out in previous studies, it is obvious that the precipitation is a key player in the water cycles, but also the east-west contrast of evapotranspicarion over Siberia affects the climatological mean and seasonal cycle of P-E and R in each of the Siberian river basins. The moisture transports associated with the P-E are also different among the rivers. The transient (stationary) flux associated with cyclone activity (mean atmospheric flow) dominates over the Lena (Ob) River basin in the east (west). In addition to the climatological distributions of SAT, humidity and atmospheric circulation over Siberia, the geographical and terrestrial conditions of this region such as topography, distance from the ocean, mainstream of the river, permafrost and vegetation type make the unique features of the water cycles in the individual Siberian rivers. Comparison of the six atmospheric reanalyses indicated that the estimations of P-E by using the reanalyses are reasonable compared to the observed R, and that is an effective way to evaluate and quantify the water cycles in the Lena, Yenisei and Ob Rivers.

  2. Humidity-independent conducting polyaniline films synthesized using advanced atmospheric pressure plasma polymerization with in-situ iodine doping

    NASA Astrophysics Data System (ADS)

    Park, Choon-Sang; Kim, Do Yeob; Kim, Dong Ha; Lee, Hyung-Kun; Shin, Bhum Jae; Tae, Heung-Sik

    2017-01-01

    This study reports on the synthesis and characterization of conducting polyaniline (PANI) thin films when using advanced atmospheric pressure plasma jets (APPJs). A simple method for synthesizing conducting polymers (CPs) with humidity-independent characteristics is introduced using advanced APPJs and an in-situ iodine doping method. In the case of ex-situ I2 doping, a humidity effect study showed that increasing the relative humidity produced significant changes in the electrical resistance (R) of the PANI, indicating strong humidity-dependent characteristics similar to conventional CPs. In contrast, in the case of in-situ I2 doping, the R and sensitivity of the PANI remained essentially unchanged when increasing the relative humidity, except for a very low sensitivity of 0.5% under 94% relative humidity. In addition, the R for the PANI with in-situ I2 doping showed no aging effect, while the R for the ex-situ-doped PANI increased dramatically over time. Thus, it is anticipated that the use of in-situ doping during plasma polymerization can be widely used to design stable and high-performance CPs with humidity-independent characteristics for a variety of applications.

  3. The influence of water table depth and the free atmospheric state on convective rainfall predisposition

    NASA Astrophysics Data System (ADS)

    Bonetti, Sara; Manoli, Gabriele; Domec, Jean-Christophe; Putti, Mario; Marani, Marco; Katul, Gabriel G.

    2015-04-01

    A mechanistic model for the soil-plant system is coupled to a conventional slab representation of the atmospheric boundary layer (ABL) to explore the role of groundwater table (WT) variations and free atmospheric (FA) states on convective rainfall predisposition (CRP) at a Loblolly pine plantation site situated in the lower coastal plain of North Carolina. Predisposition is quantified using the crossing between modeled lifting condensation level (LCL) and convectively grown ABL depth. The LCL-ABL depth crossing is necessary for air saturation but not sufficient for cloud formation and subsequent convective rainfall occurrence. However, such crossing forms the main template for which all subsequent dynamical processes regulating the formation (or suppression) of convective rainfall operate on. If the feedback between surface fluxes and FA conditions is neglected, a reduction in latent heat flux associated with reduced WT levels is shown to enhance the ABL-LCL crossing probability. When the soil-plant system is fully coupled with ABL dynamics thereby allowing feedback with ABL temperature and humidity, FA states remain the leading control on CRP. However, vegetation water stress plays a role in controlling ABL-LCL crossing when the humidity supply by the FA is within an intermediate range of values. When FA humidity supply is low, cloud formation is suppressed independent of surface latent heat flux. Similarly, when FA moisture supply is high, cloud formation can occur independent of surface latent heat flux. In an intermediate regime of FA moisture supply, the surface latent heat flux controlled by soil water availability can supplement (or suppress) the necessary water vapor leading to reduced LCL and subsequent ABL-LCL crossing. It is shown that this intermediate state corresponds to FA values around the mode in observed humidity lapse rates γw (between -2.5 × 10-6 and -1.5 × 10-6 kg kg-1m-1), suggesting that vegetation water uptake may be controlling CRP at

  4. Water Isotope Tracers of Indo-Pacific Atmospheric Circulation: A Modern Take on Past Dynamics

    NASA Astrophysics Data System (ADS)

    Konecky, B. L.; Noone, D. C.; Nusbaumer, J. M.; Cobb, K. M.; Conroy, J. L.

    2015-12-01

    Stable oxygen and hydrogen isotope ratios (δ18O, δD) in precipitation, terrestrial water bodies, groundwater, and surface seawater are powerful integrators of the atmospheric water cycle. As such, proxy archives of δ18O and δD form the basis for much of our understanding of past changes in Indo-Pacific climate. Water isotope studies of the past millennium suggest that both internal variability and forced changes in global temperature drove decadal to centennial changes in monsoons, the Intertropical Convergence Zone, ENSO, and other modes of variability. However, recent observations as well as proxy data have shown that δ18O and δD signatures are far more complex than previously believed. Testing hypotheses about the drivers of past Indo-Pacific hydroclimate therefore requires an improved understanding of modern-day isotope ratios. In this study, we present new analyses of Indo-Pacific climate/isotope relationships from satellite and in situ observations, as well as new simulations with water isotope-enabled components of the Community Earth System Model. We evaluate the mechanisms that reinforce or weaken the tropical amount effect, which is often invoked in interpreting paleo-isotope data as hydroclimate proxies. We find that the amount effect is highly variable through space and time. Generally, it is strongest at sites with large-amplitude variations in the seasonal cycle. Circulation and moisture convergence play key roles in determining the strength of the amount effect, although cloud processes such as Rayleigh distillation and rain evaporation are still important, especially in determining initial isotope ratios of transported moisture. The relative influence of these mechanisms on vapor δ18O and δD varies in different parts of the tropics, affecting how regional archives record ENSO and other circulation patterns. We discuss these differences, and their implications for reconstructing Indo-Pacific atmospheric variability on decadal and longer

  5. CalWater 2 - Precipitation, Aerosols, and Pacific Atmospheric Rivers Experiment

    NASA Astrophysics Data System (ADS)

    Spackman, J. R.; Ralph, F. M.; Prather, K. A.; Cayan, D. R.; DeMott, P. J.; Dettinger, M. D.; Fairall, C. W.; Leung, L. R.; Rosenfeld, D.; Rutledge, S. A.; Waliser, D. E.; White, A. B.

    2014-12-01

    Emerging research has identified two phenomena that play key roles in the variability of the water supply and the incidence of extreme precipitation events along the West Coast of the United States. These phenomena include the role of (1) atmospheric rivers (ARs) in delivering much of the precipitation associated with major storms along the U.S. West Coast, and (2) aerosols—from local sources as well as those transported from remote continents—and their modulating effects on western U.S. precipitation. A better understanding of these processes is needed to reduce uncertainties in weather predictions and climate projections of extreme precipitation and its effects, including the provision of beneficial water supply. This presentation summarizes the science objectives and strategies to address gaps associated with (1) the evolution and structure of ARs including cloud and precipitation processes and air-sea interaction, and (2) aerosol interaction with ARs and the impact on precipitation, including locally-generated aerosol effects on orographic precipitation along the U.S. West Coast. Observations are proposed for multiple winter seasons as part of a 5-year broad interagency vision referred to as CalWater 2 to address these science gaps (http://esrl.noaa.gov/psd/calwater). In January-February 2015, a field campaign has been planned consisting of a targeted set of aircraft and ship-based measurements and associated evaluation of data in near-shore regions of California and in the eastern Pacific. In close coordination with NOAA, DOE's Atmospheric Radiation Measurement (ARM) program is also contributing air and shipborne facilities for ACAPEX (ARM Cloud Aerosol and Precipitation Experiment), a DOE-sponsored study complementing CalWater 2. Ground-based measurements from NOAA's HydroMeteorological Testbed (HMT) network in California and aerosol chemical instrumentation at Bodega Bay, California have been designed to add important near surface-level context for the

  6. Impact of biomass burning on ocean water quality in Southeast Asia through atmospheric deposition: field observations

    NASA Astrophysics Data System (ADS)

    Sundarambal, P.; Balasubramanian, R.; Tkalich, P.; He, J.

    2010-12-01

    Atmospheric nutrients have recently gained considerable attention as a significant additional source of new nitrogen (N) and phosphorus (P) loading to the ocean. The effect of atmospheric macro nutrients on marine productivity depends on the biological availability of both inorganic and organic N and P forms. During October 2006, the regional smoke haze episodes in Southeast Asia (SEA) that resulted from uncontrolled forest and peat fires in Sumatra and Borneo blanketed large parts of the region. In this work, we determined the chemical composition of nutrients in aerosols and rainwater during hazy and non-hazy days to assess their impacts on aquatic ecosystem in SEA for the first time. We compared atmospheric dry and wet deposition of N and P species in aerosol and rainwater in Singapore between hazy and non-hazy days. Air mass back trajectories showed that large-scale forest and peat fires in Sumatra and Kalimantan were a significant source of atmospheric nutrients to aquatic environments in Singapore and SEA region on hazy days. It was observed that the average concentrations of nutrients increased approximately by a factor of 3 to 8 on hazy days when compared with non-hazy days. The estimated mean dry and wet atmospheric fluxes (mg/m2/day) of total nitrogen (TN) were 12.72 ± 2.12 and 2.49 ± 1.29 during non-hazy days and 132.86 ± 38.39 and 29.43 ± 10.75 during hazy days; the uncertainty estimates are represented as 1 standard deviation (1σ) here and throughout the text. The estimated mean dry and wet deposition fluxes (mg/m2/day) of total phosphorous (TP) were 0.82 ± 0.23 and 0.13 ± 0.03 for non-hazy days and 7.89 ± 0.80 and 1.56 ± 0.65 for hazy days. The occurrences of higher concentrations of nutrients from atmospheric deposition during smoke haze episodes may have adverse consequences on receiving aquatic ecosystems with cascading impacts on water quality.

  7. Organization of water and atmospherically relevant ions and solutes: vibrational sum frequency spectroscopy at the vapor/liquid and liquid/solid interfaces.

    PubMed

    Jubb, Aaron M; Hua, Wei; Allen, Heather C

    2012-01-17

    The nature of water's hydrogen-bonding network is a vital influence on the chemistry that occurs at interfaces, but a complete understanding of interfacial water has proven elusive. Even-order nonlinear optical spectroscopies, such as vibrational sum frequency generation (VSFG) spectroscopy and heterodyne detected phase-sensitive sum frequency generation (PS-SFG) spectroscopy, are inherently surface specific. With the advent of advances in these spectroscopic techniques, researchers can now explore many long-standing questions about the dynamics and structures present at the vapor-water and water-solid interfaces. Of special interest to the atmospheric chemistry community is the accommodation of ions and solutes by water's hydrogen-bonding network. A better understanding of how ions and solutes behave in hydrogen-bonded water has afforded a fresh perspective of aqueous aerosols, because the interactions involved therein drive phenomena such as the hydrolysis of atmospheric chemical species. In this Account, we present work from our laboratory focusing on applying VSFG and the recently developed PS-SFG techniques to probe the perturbation of water's hydrogen-bonding network at the vapor-water interface by a variety of ions and solutes. We also present very recent results from our laboratory on the direct observation of the adsorption of ions at the water-CaF(2) interface. We begin by discussing the influence of ions and solutes on interfacial water structure. Results for halide salts and the acid analogs on interfacial water structure are shown to be quite different, as would be expected from differences in surface tension measurements that have been known for a long time. Also examined are systems with the largely polarizable molecular anions nitrate (NO(3)(-)), sulfate (SO(4)(2-)), carbonate (CO(3)(2-)), and bicarbonate (HCO(3)(-)).These systems feature more complicated influences on interfacial water structure than halide-containing solutions; however, our

  8. Meeting Summary Advanced Light Water Reactor Fuels Industry Meeting Washington DC October 27 - 28, 2011

    SciTech Connect

    Not Listed

    2011-11-01

    The Advanced LWR Fuel Working Group first met in November of 2010 with the objective of looking 20 years ahead to the role that advanced fuels could play in improving light water reactor technology, such as waste reduction and economics. When the group met again in March 2011, the Fukushima incident was still unfolding. After the March meeting, the focus of the program changed to determining what we could do in the near term to improve fuel accident tolerance. Any discussion of fuels with enhanced accident tolerance will likely need to consider an advanced light water reactor with enhanced accident tolerance, along with the fuel. The Advanced LWR Fuel Working Group met in Washington D.C. on October 72-18, 2011 to continue discussions on this important topic.

  9. Water vapor in the Martian atmosphere by SPICAM IR/Mars-Express

    NASA Astrophysics Data System (ADS)

    Trokhimovskiy, Alexander; Fedorova, Anna; Korablev, Oleg; Bertaux, Jean-Loup; Villard, Eric; Rodin, Alexander V.

    Introduction SPICAM experiment along with PFS and OMEGA spectrometers on Mars Express has a capability to sound the water vapor in the atmosphere. The results of H2O measurements have been intensively published during last years [1-6]. Here we present the new analysis of SPICAM IR water vapor measurements, covering two Martian years. The near-IR channel of SPICAM experiment on Mars Express spacecraft is a 800-g acousto-optic tunable filter (AOTF)-based spectrometer operating in the spectral range of 1-1.7 m with resolving power of 2000 [7, 8]. The nadir measurements of H2O in the 1.37-m spectral band is one of the main objectives of the experiment. Data treatment As compared with previous analysis of water vapor presented in [4] we used the spectroscopic database HITRAN2004 [9] instead of HITRAN 2000 and the most recent measurements of the water line-width broadening in CO2 atmosphere. Latest version HITRAN2008 doesn't have any meaningful changes in water vapour lines, which are used for retrievment. Martian Climate Database V4.2 [10] was adopted for modelling of synthetic spectra and a scenario based on TES MY24 was used. The spare model of SPICAM IR instrument was recalibrated in June 2007 in Reims, to analyze specifically the sensitivity to the H2O vapor band. According to laboratory measurements, a leakage from the AOTF is responsible up to 5 Radiative transfer modelling and results Sensitivity of retrieval to aerosol scattering and different vertical distributions of aerosol and water vapor was analyzed for H2O absorption band at 1.38 m and 2.56 m for different dust particles. Dependences of equivalent width of the H2O band on the water vapor abundance and aerosol optical depth for different vertical distribution of water vapor and aerosol optical depth are obtained. A number of orbits processed with "honest" aerosol account, in some cases difference to clear atmosphere approach is meaningful. Open questions for further processing are great demand in computer

  10. Performance of a Water Recirculation Loop Maintenance Device and Process for the Advanced Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2012-01-01

    A water loop maintenance device and process to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been undergoing a performance evaluation. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the water recirculation maintenance device and process is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance process further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware. This

  11. Hydrogen Isotopic Composition of Water in the Martian Atmosphere and Released from Rocknest Fines

    NASA Technical Reports Server (NTRS)

    Leshin, L. A.; Webster, C. R.; Mahaffy, P. R.; Flesh, G. J.; Christensen, L. E.; Stern, J. C.; Franz, H. B.; McAdam, A. C.; Niles, P. B.; Archer, P. B., Jr.; Sutter, B.; Jones, J. H.; Ming, D. W.; Atreya, S. K.; Owen, T. C.; Conrad, P.

    2013-01-01

    The Mars Science Laboratory Curiosity rover sampled the aeolian bedform called Rocknest as its first solid samples to be analyzed by the analytical instruments CheMin and SAM. The instruments ingested aliquots from a sieved sample of less than 150 micrometer grains. As discussed in other reports at this conference [e.g., 1], CheMin discovered many crystalline phases, almost all of which are igneous minerals, plus some 10s of percent of x-ray amorphous material. The SAM instrument is focused on understanding volatiles and possible organics in the fines, performing evolved gas analysis (EGA) with the SAM quadrapole mass spectrometer (QMS), isotope measurements using both the QMS and the tunable laser spectrometer (TLS), which is sensitive to CO2, water and methane, and organics with the gas chromatograph mass spectrometer (GCMS). As discussed in the abstract by Franz et al. [2] and others, EGA of Rocknest fines revealed the presence of significant amounts of H2O as well as O-, C- and S-bearing materials. SAM has also tasted the martian atmosphere several times, analyzing the volatiles in both the TLS and QMS [e.g., 3,4]. This abstract will focus on presentation of initial hydrogen isotopic data from the TLS for Rocknest soils and the atmosphere, and their interpretation. Data for CO2 isotopes and O isotopes in water are still being reduced, but should be available by at the conference.

  12. Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

    2014-01-01

    NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

  13. Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings

    NASA Astrophysics Data System (ADS)

    Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger

    2012-06-01

    Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.

  14. Benefits of Application of Advanced Technologies for a Neptune Orbiter, Atmospheric Probes and Triton Lander

    NASA Technical Reports Server (NTRS)

    Somers, Alan; Celano, Luigi; Kauffman, Jeffrey; Rogers, Laura; Peterson, Craig

    2005-01-01

    Missions with planned launch dates several years from today pose significant design challenges in properly accounting for technology advances that may occur in the time leading up to actual spacecraft design, build, test and launch. Conceptual mission and spacecraft designs that rely solely on off the shelf technology will result in conservative estimates that may not be attractive or truly representative of the mission as it actually will be designed and built. This past summer, as part of one of NASA s Vision Mission Studies, a group of students at the Laboratory for Spacecraft and Mission Design (LSMD) have developed and analyzed different Neptune mission baselines, and determined the benefits of various assumed technology improvements. The baseline mission uses either a chemical propulsion system or a solar-electric system. Insertion into orbit around Neptune is achieved by means of aerocapture. Neptune s large moon Triton is used as a tour engine. With these technologies a comprehensive Cassini-class investigation of the Neptune system is possible. Technologies under investigation include the aerocapture heat shield and thermal protection system, both chemical and solar electric propulsion systems, spacecraft power, and energy storage systems.

  15. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    Jensen, F. C.; Schubert, F. H.

    1977-01-01

    Some results are presented of a research and development program to continue the development of a method to generate oxygen for crew metabolic consumption during extended manned space flights. The concept being pursued is that of static feed water electrolysis. Specific major results of the work included: (1) completion of a 30-day electrode test using a Life Systems, Inc.-developed high performance catalyst. During startup the cell voltages were as low as 1.38 V at current densities of 108 mA/sq cm (100 ASF) and temperatures of 355 K (180 F). At the end of 30 days of testing the cell voltages were still only 1.42 V at 108 mA/sq cm, (2) determination that the Static Feed Water Electrolysis Module does not release an aerosol of the cell electrolyte into the product gas streams after a break-in period of 24 hours following a new electrolyte charge, and (3) completion of a detailed design analysis of an electrochemical Oxygen Generation Subsystem at a three-man level (4.19 kg/day (9.24 lb/day) of oxygen).

  16. Tapping Water from the Atmosphere: The Bureau of Reclamation's Project Skywater (Invited)

    NASA Astrophysics Data System (ADS)

    Harper, K.

    2010-12-01

    Since President Theodore Roosevelt signed the Reclamation Act on 17 June 1902—creating the forerunner of today’s Bureau of Reclamation that was established under Interior in 1907—this agency has been tasked with developing water resources in the US West. These efforts focused on building dams, reservoirs, and irrigation systems. But by the early 1960s, the federal government’s increasing interest in weather control began to attract the attention of BuRec’s leaders. Deciding that it was time to track down solid information on rainmaking techniques, the bureau called upon weather control pioneer Vincent Schaefer for assistance with its plan use weather modification as an adjunct to its water resources development portfolio. In response, Schaefer—writing to the National Science Foundation’s Earl Droessler in late 1961—declared that the Bureau’s proposed project would bring a “responsible, capable, and enthusiastic” group to represent the government and take over the engineering parts of weather modification. Enthusiastic was a bit of an understatement. BuRec was eager to use the atmosphere as a water reservoir, which could dispense moisture to watersheds feeding their earth-bound reservoirs. Contracting with universities—and working to get ahead of its nemesis, the skeptical US Weather Bureau—BuRec announced the artificial precipitation successes of its “Laboratory in the Sky” in early 1963. Although this headquarters-announced “success” was disputed by BuRec’s Denver field office, BuRec’s colorful commissioner Floyd Dominy was determined to press forward. Within months, the bureau was publishing reports indicating that the US West was a “potential future food deficit area” due to an increasing population that was outstripping the availability of ground and surface waters for agriculture. New approaches would be necessary to bring water to BuRec reservoirs for further distribution to municipalities, irrigators, and industries

  17. Atmospheric aerosol deposition influences marine microbial communities in oligotrophic surface waters of the western Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Maki, Teruya; Ishikawa, Akira; Mastunaga, Tomoki; Pointing, Stephen B.; Saito, Yuuki; Kasai, Tomoaki; Watanabe, Koichi; Aoki, Kazuma; Horiuchi, Amane; Lee, Kevin C.; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2016-12-01

    Atmospheric aerosols contain particulates that are deposited to oceanic surface waters. These can represent a major source of nutrients, trace metals, and organic compounds for the marine environment. The Japan Sea and the western Pacific Ocean are particularly affected by aerosols due to the transport of desert dust and industrially derived particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) from continental Asia. We hypothesized that supplementing seawater with aerosol particulates would lead to measurable changes in surface water nutrient composition as well as shifts in the marine microbial community. Shipboard experiments in the Pacific Ocean involved the recovery of oligotrophic oceanic surface water and subsequent supplementation with aerosol particulates obtained from the nearby coastal mountains, to simulate marine particulate input in this region. Initial increases in nitrates due to the addition of aerosol particulates were followed by a decrease correlated with the increase in phytoplankton biomass, which was composed largely of Bacillariophyta (diatoms), including Pseudo-nitzschia and Chaetoceros species. This shift was accompanied by changes in the bacterial community, with apparent increases in the relative abundance of heterotrophic Rhodobacteraceae and Colwelliaceae in aerosol particulate treated seawater. Our findings provide empirical evidence revealing the impact of aerosol particulates on oceanic surface water microbiology by alleviating nitrogen limitation in the organisms.

  18. Significance of apparent discrepanices in water ages derived from atmospheric radionuclides at Yucca Mountain, Nevada

    SciTech Connect

    Liu, B.; Fabryka-Martin, J.; Wolfsberg, A.; Robinson, B.; Sharma, P.

    1995-02-23

    Cosmogenic {sup 36}Cl and {sup 14}C produced in the atmosphere are being used to estimate water residence times in the unsaturated zone at Yucca Mountain. Results thus far show a systematic discordance in that {sup 14}C-based ages are generally one to two orders of magnitude younger than {sup 36}Cl-based ages. This lack of concordance probably arises from one or more of the following reasons: (1) different transport mechanisms, e.g., vapor transport for {sup 14}C; (2) different magnitudes and timing of bomb-pulse signals; (3) mixing of waters from different flow paths; and (4) possibly inadequate methods for correcting for the effect of sample contamination by carbon or chlorine from sources other than the infiltrating water. Preliminary numerical simulation results using the FEHMN code suggest that spatial variation in infiltration rates can enhance lateral flow and mixing that leads to discordance in apparent ages depending on the dating technique. Examples are presented to show that disparate radiometric ages are inevitable and to be expected where mixing of waters of markedly different ages occurs.

  19. Atmospheric Pre-Corrected Differential Absorption Techniques to Retrieve Columnar Water Vapor: Theory and Simulations

    NASA Technical Reports Server (NTRS)

    Borel, Christoph C.; Schlaepfer, Daniel

    1996-01-01

    Two different approaches exist to retrieve columnar water vapor from imaging spectrometer data: (1) Differential absorption techniques based on: (a) Narrow-Wide (N/W) ratio between overlapping spectrally wide and narrow channels; (b) Continuum Interpolated Band Ratio (CIBR) between a measurement channel and the weighted sum of two reference channels. (2) Non-linear fitting techniques which are based on spectral radiative transfer calculations. The advantage of the first approach is computational speed and of the second, improved retrieval accuracy. Our goal was to improve the accuracy of the first technique using physics based on radiative transfer. Using a modified version of the Duntley equation, we derived an "Atmospheric Pre-corrected Differential Absorption" (APDA) technique and described an iterative scheme to retrieve water vapor on a pixel-by-pixel basis. Next we compared both, the CIBR and the APDA using the Duntley equation for MODTRAN3 computed irradiances, transmissions and path radiance (using the DISORT option). This simulation showed that the CIBR is very sensitive to reflectance effects and that the APDA performs much better. An extensive data set was created with the radiative transfer code 6S over 379 different ground reflectance spectra. The calculated relative water vapor error was reduced significantly for the APDA. The APDA technique had about 8% (vs. over 35% for the CIBR) of the 379 spectra with a relative water vapor error of greater than +5%. The APDA has been applied to 1991 and 1995 AVIRIS scenes which visually demonstrate the improvement over the CIBR technique.

  20. Micropatterned Surfaces for Atmospheric Water Condensation via Controlled Radical Polymerization and Thin Film Dewetting.

    PubMed

    Wong, Ian; Teo, Guo Hui; Neto, Chiara; Thickett, Stuart C

    2015-09-30

    Inspired by an example found in nature, the design of patterned surfaces with chemical and topographical contrast for the collection of water from the atmosphere has been of intense interest in recent years. Herein we report the synthesis of such materials via a combination of macromolecular design and polymer thin film dewetting to yield surfaces consisting of raised hydrophilic bumps on a hydrophobic background. RAFT polymerization was used to synthesize poly(2-hydroxypropyl methacrylate) (PHPMA) of targeted molecular weight and low dispersity; spin-coating of PHPMA onto polystyrene films produced stable polymer bilayers under appropriate conditions. Thermal annealing of these bilayers above the glass transition temperature of the PHPMA layer led to complete dewetting of the top layer and the formation of isolated PHPMA domains atop the PS film. Due to the vastly different rates of water nucleation on the two phases, preferential dropwise nucleation of water occurred on the PHPMA domains, as demonstrated by optical microscopy. The simplicity of the preparation method and ability to target polymers of specific molecular weight demonstrate the value of these materials with respect to large-scale water collection devices or other materials science applications where patterning is required.

  1. Electrochemical Advanced Oxidation Process for Shipboard Final Purification of Filtered Black Water, Gray Water, and Bilge Water, Vol. 1

    DTIC Science & Technology

    2001-08-01

    Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water O. Weres, PhD and H.E. O’Donnell Sonoma Research Company Napa...Process for Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...Shipboard Final Purification of Filtered Black Water , Gray Water , and Bilge Water Final Report Submitted to: SERDP Office 901 North Stuart Street, Suite

  2. Movement of Water Vapor in the Atmosphere Measured by an Imaging Spectrometer at Rogers Dry Lake, California

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Conel, James E.

    1995-01-01

    Water vapor in the atmosphere has been derived from the AVIRIS spectra measured in five overpasses acquired above Rogers Dry Lake, California. The abundance of water vapor in these data is shown to be spatially heterogeneous at the 25 percent level over a range of spatial scales.

  3. CANOPY CONDUCTANCE OF PINUS TAEDA, LIQUIDAMBAR STYRACIFLUA AND QUERCUS PHELLOS UNDER VARYING ATMOSPHERIC AND SOIL WATER CONDITION

    EPA Science Inventory

    Sap flow, and atmospheric and soil water data were collected in closed-top chambers under conditions of high soil water potential for saplings of Liquidambar styraciflua L., Quercus phellos L., and Pinus taeda L., three co-occurring species in the southeastern USA. Responses of c...

  4. OTEC Advanced Composite Cold Water Pipe: Final Technical Report

    SciTech Connect

    Dr. Alan Miller; Matthew Ascari

    2011-09-12

    Ocean Thermal Energy Conversion can exploit natural temperature gradients in the oceans to generate usable forms of energy (for example, cost-competitive baseload electricity in tropical regions such as Hawaii) free from fossil fuel consumption and global warming emissions.The No.1 acknowledged challenge of constructing an OTEC plant is the Cold Water Pipe (CWP), which draws cold water from 1000m depths up to the surface, to serve as the coolant for the OTEC Rankine cycle. For a commercial-scale plant, the CWP is on the order of 10m in diameter.This report describes work done by LMSSC developing the CWP for LM MS2 New Ventures emerging OTEC business. The work started in early 2008 deciding on the minimum-cost CWP architecture, materials, and fabrication process. In order to eliminate what in previous OTEC work had been a very large assembly/deployment risk, we took the innovative approach of building an integral CWP directly from theOTEC platform and down into the water. During the latter half of 2008, we proceeded to a successful small-scale Proof-of-Principles validation of the new fabrication process, at the Engineering Development Lab in Sunnyvale. During 2009-10, under the Cooperative Agreement with the US Dept. of Energy, we have now successfully validated key elements of the process and apparatus at a 4m diameter scale suitable for a future OTEC Pilot Plant. The validations include: (1) Assembly of sandwich core rings from pre-pultruded hollow 'planks,' holding final dimensions accurately; (2) Machine-based dispensing of overlapping strips of thick fiberglass fabric to form the lengthwise-continuous face sheets, holding accurate overlap dimensions; (3) Initial testing of the fabric architecture, showing that the overlap splices develop adequate mechanical strength (work done under a parallel US Naval Facilities Command program); and (4) Successful resin infusion/cure of 4m diameter workpieces, obtaining full wet-out and a non-discernable knitline between

  5. [Study advance on haloacetic acids in drinking water].

    PubMed

    Ye, Bi-Xiong; Wang, Wu-Yi; Yang, Lin-Sheng; Wang, Yong-Hua

    2006-05-01

    Haloacetic acids (HAAs) in drinking water have attracted more and more attention of researchers due to their higher potential combination of chlorine, their carcinogenic and mutagenic effects and higher carcinogenic. The formation mechanism, analytical methods, the effects of many factors on HAAs formation such as precursor types, chlorine doses, pH, temperature, bromide, reaction time and seasonal change, toxicological character and the minimizing technology of HAAs in resent studies about HAAs are discussed in details in this paper. Further researches are still needed to clarify the formation mechanism of HAAs and find a feasible minimizing technology. New concerns including toxicological characters that correlate with human and other HAAs exposure routes besides oral ingestion (i.e., inhalation and dermal adsorption) should be put forward.

  6. Advances and Limitations of Atmospheric Boundary Layer Observations with GPS Occultation over Southeast Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Xie, F.; Wu, D. L.; Ao, C. O.; Mannucci, A. J.; Kursinski, E. R.

    2012-01-01

    The typical atmospheric boundary layer (ABL) over the southeast (SE) Pacific Ocean is featured with a strong temperature inversion and a sharp moisture gradient across the ABL top. The strong moisture and temperature gradients result in a sharp refractivity gradient that can be precisely detected by the Global Positioning System (GPS) radio occultation (RO) measurements. In this paper, the Constellation Observing System for Meteorology, Ionosphere & Climate (COSMIC) GPS RO soundings, radiosondes and the high-resolution ECMWF analysis over the SE Pacific are analyzed. COSMIC RO is able to detect a wide range of ABL height variations (1-2 kilometer) as observed from the radiosondes. However, the ECMWF analysis systematically underestimates the ABL heights. The sharp refractivity gradient at the ABL top frequently exceeds the critical refraction (e.g., -157 N-unit per kilometer) and becomes the so-called ducting condition, which results in a systematic RO refractivity bias (or called N-bias) inside the ABL. Simulation study based on radiosonde profiles reveals the magnitudes of the N-biases are vertical resolution dependent. The N-bias is also the primary cause of the systematically smaller refractivity gradient (rarely exceeding -110 N-unit per kilometer) at the ABL top from RO measurement. However, the N-bias seems not affect the ABL height detection. Instead, the ver