NASA/Graduate student research
| Astrophysics | Microgravity Materials Sciences |
Climatology and Hydrology
Radar and Hydrometeorology Studies. This research is directed towards understanding precipitation processes and their relation to the larger scale environmental forcing. Cloud microphysics, precipitation processes, storm kinematics, and morphology studies are conducted using groundbased and airborne research data acquired during field campaigns. Ancillary data from satellite and airborne microwave and imaging remote sensor data are used to further describe the convective processes. Data collected from the operational National Weather Service WSR88D (NEXRAD) network are used to develop climatological rainfall estimates and water budgets to study the interannual variability of rainfall and its relation to changes in the synoptic and general circulation. This research will lead to improved understanding of precipitation processes and algorithms developed for new satellite sensor suites.
S. Goodman (205) 922-5891
Hydrometeorology/Land Surface Interface. Earth's surface characteristics and their linkages to the atmosphere and hydrologic cycles are being analyzed and modeled using remotely sensed data. Measurements from satellite and aircraft sensors, in conjunction with in situ measurements, are used to study spatial and spectral resolution and temporal variability effects on determination of land surface energy fluxes, hydrometeorological characteristics, and biophysical components. The effects of spatial and temporal scale on land surface interface processes are assessed using mesoscale hydrometeorological and Global Circulation Models. Geographic information systems play an important research role in integrating and modeling remote sensing and ancillary data for analysis of the spatial and temporal dynamics of land surface hydrometeorological interactions.
D. Quattrochi (205) 922-5887
Global Passive Microwave Studies. The Defense Satellite Meteorological Program has launched a series of satellites with passive microwave sensors. These instruments (Special Sensor Microwave Imager, Special Sensor Microwave Temperature-I and Special Sensor Microwave Temperature-2) are used to detect and measure atmospheric temperature and moisture profiles, bulk atmospheric water vapor and cloud liquid water amounts, precipitation, and land surface temperature and type. Future research in the usage of one or a combination of these data sets for global multi-year or seasonal assessments of hydrometeorological parameters is desired.
M. Goodman (205) 922-5890
Infrared Water Vapor Measurements. Water vapor is a key component of the Earth's hydrologic cycle. This research focuses on the measurement of atmospheric water to determine bulk water vapor variability and to infer upper-level winds by tracking of water vapor features. Geostationary satellite data from the GOES-VAS and GOES Next satellites are used for local, regional, and hemispheric analysis in support of budget and model studies of the hydrologic and energy cycles.
G. Jedlovec (205) 922-5966
Aerosol Backscatter and Lidar Studies. The research focuses on the assessment of global patterns of aerosol backscatter, the calibration and characterization CO2 Lidar systems, and the development of aircraft- and space-based Lidars for the determination of regional and global winds. major experimental efforts have included a network of CO2 Lidar stations, intensive field campaigns, and a host of aerosol sensors. Laboratory facilities exist to calibrate and characterize Lidar systems. A multi-agency program to develop and fly an airborne Doppler Lidar (MACAWS) will provide a wealth of unique measurements to support this research.
J. Rothermel (205) 922-5965
Atmospheric Electricity Studies. The research is directed toward understanding the physical processes leading to the generation of electrical energy within thunderstorms, developing global lightning climatologies, and understanding the global electric circuit. Modeling, analytic, and observational approaches are used in these studies. Particular emphasis is placed on ground-, aircraft-, and satellite-based optical sensors to study the distribution and variability of global lightning activity. The recently launched Optical Transient Detector and future EOS instruments will play a major role in this research.
R. Blakeslee (205) 922-5962
Microwave Measurements. Acquisition and analysis of aircraft and satellite microwave radiometer measurements lead to further understanding of the microphysical processes of precipitation systems and aid in monitoring global climate change. In this research, aircraft measurements are used to investigate the spatial and temporal structure of precipitation systems, improve inversion techniques for precipitation estimation, for the polarametric retrieval of surface wind velocity over oceans, and for increasing the understanding of heating profiles in tropical atmospheres. Pioneering work with the multi-year MSU satellite data sets are used for global temperature and precipitation studies.
R. Spencer (205) 922-5960
Atmospheric Chemistry. Measurements of trace species and temperature in the upper troposphere, stratosphere, and mesosphere have been made from the Space Shuttle and other space platforms. These measurements are utilized to study the interactions between chemistry, dynamics, and radiation that are important in Earth's physical climate system. Especially important are the varying concentrations of stratospheric ozone that are determined by these interactions. This research effort utilizes space-based observations along with detailed models of the atmosphere to better understand the processes that determine stratospheric ozone, the interactions between the troposphere and stratosphere (including the role of water vapor), and the influence that human activities have on the atmosphere through the release of chemicals.
T. Miller (205) 922-5882
Climate Diagnostics and the Global Hydrologic Cycle. Observational, numerical modeling, and analytical approaches are used to study the Earth's physical climate system. Diagnostic analysis of space-based observations are used to understand and validate models of global hydrologic cycle. Numerical models ranging in scope from atmospheric general circulation codes to mesoscale and cloud models are used to study water cycle processes and to quantify their role in climate. Sensitivity studies of climate models to surface boundary forcing, i.e., sea surface temperature, albedo and soil moisture anomalies are conducted. Simulations of remote sensors are used to understand how spacebased observations can be best applied to studying the Earth as a system.
X-Ray Astronomy. Experimental, observational, and theoretical research is conducted in x-ray astronomy and high-energy astrophysics. The experimental program concencrates on development of replicated x-ray optics, polarimeters, and hard-x-ray imaging detectors operating from 1 keV to above 100 keV using microschip and liquid-xenon technologies. Observational and theoretical specialties comprise the study of compact objects (neutron stars and black holes), cooling flows in clusters of galaxies, and astrophysics of high-temperacure plasmas. Opportunities include participation in balloon flights of sensors, analysis of data from the x-ray polarimeter on SPECTRUM-X (launch 1996) and other satellites, theoretical studies of physical processes in high-temperature astrophysical plasmas, and observations of clusters of galaxies and the Sunyaev-Zeldovich effect.
M.C.Weisskopf (205) 544-7740
Gamma Ray Astronomy. Gamma ray astronomy is performed with balloon-borne and orbiting instruments designed and developed at MSFC. The research includes experiments covering the 30 KeV to 10 MeV region to study gamma ray bursts and other transients sources, pulsars, and to study the variability and spectra of known sources. Present activities include analysis of data from the Burst and Transient Source Experiment on the Gamma Ray Observatory, and the development of new balloon-borne instruments. Studies of the gamma ray background in the atmosphere and on spacecraft are made with calculations and with measurements on Spacelab, LDEF and GRO.
G. Fishman (205) 544-7691
Cosmic Ray Research. Cosmic ray research at MSFC emphasizes the study of the chemical composition and energy spectra of cosmic ray nuclei above l0E+12 eV. Study of the interactions of heavy cosmic ray nuclei are also carried out to determine the behavior of nucleus interactions and to search for evidence of new states of nuclear matter. The research is carried out with emulsion chambers and with electronic counters, exposed on balloons at about 40 kilometers altitude for up to two weeks. Research includes laboratory work, data analysis. particle cascade calculations, and correlative accelerator experiments.
T. Parnell (205) 544-7690
Space Plasma Physics
Space Plasma and Upper Atmospheric Physics. We seek to better understand, and ultimately to predict, the flow of matter, momentum and energy through the region in which the Sun-Earth connection is made: the Earth's magnetosphere and ionosphere. We further seek to better understand basic physical processes that effect the operation of spacecraft in space and that are important in astrophysical plasmas; for example cometary, planetary, and stellar upper atmospheres. Plasma and gas dynamic processes are studied by means of in situ plasma and neutral particle measurements, and by remote optical and electromagnetic sensing of the constituent plasmas and gases. Activities include design, development, and calibration of flight instrumentation, with analysis and interpretation of the resulting data in terms of physical models.
T. Moore (205) 544-7633
Solar Physics. The influence of the magnetic field on the development and evolution of solar atmospheric structure is studied. The primary data are vector magnetograms obtained at Marshall's Solar Observatory. These observations are complemented by theoretical studies to characterize the nonpotential nature of these fields. This includes the development of MHD (magnetohydrodynamic) codes designed to simulate both coronal and large scale interplanetary dynamic. Instrument development programs in optical polarimetry, grazing, and normal incidence X-ray optics, and imaging detectors are being pursued.
J. Davis (205) 544-7600
Microgravity Materials Sciences
Microgravity Solidification. Theoretical and experimental research is conducted on the effects of gravity on the crystal growth or solidification of materials including semiconductors, metals, alloys, polymers, model systems, etc. Both the preparation and the characterization of materials are important. The areas of research include solid-state physics, surface physics, solidification phenomena, fluid modeling, analysis of crystal growth, and characterization techniques such as optical, X-ray, and electron microscopy. In addition to well-equipped laboratories for these activities, the division operates a drop tube 100 meters high.
F. Szofran (205) 544-7777
Biophysics. An opportunity exists to conduct research in the separation and purification of biological cells and proteins to develop a basic understanding of the separation phenomenon. The proposed research should include analysis of the fundamental behavior of a separation process by theoretical and/or experimental methods. A second activity involves laboratory and space experiments in protein crystal growth. High quality single crystals are required to obtain the three-dimensional structure of the proteins, and Shuttle space experiments confirm the advantages of the microgravity environment. Projects include experiments to define improved crystallization conditions and the analysis of crystals by X-ray diffraction.
D. Carter (205) 544-5492
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Author: Dave Dooling
Curator: Bryan Walls
NASA Official: John M. Horack
Updated Dec. 20, 1996