Sciences and Exploration Directorate

Stephan Randolph Kawa


Stephan Randolph Kawa's Contact Card & Information.
Phone: 301.614.6004
Org Code: 614
Mail Code 614
Greenbelt, MD 20771
Employer: EMERITUS

Missions & Projects

Brief Bio

From a start measuring air quality for industry through graduate studies in atmospheric chemistry near the Earth's surface, a post-doc focussed on stratospheric ozone, and a NASA career in global composition modeling and data analysis, I have always valued research near the interface of observations and theoretical modeling.  Data from remote sensing, in situ, and the laboratory gives us the opportunity to view new things, and comparisons to models, either in agreement or not, enables us to apply the research to understanding problems such as air quality, ozone loss, and global warming for everyone's potential benefit.


Research Physical Scientist

NASA Goddard Space Flight Center - Greenbelt, MD

1995 - Present

Chemistry and transport of atmospheric trace species; global 3-D modeling and chemistry-along-trajectories for analysis of airborne and satellite data; atmospheric effects of aviation; measurements and modeling of carbon cycle fluxes and transport.

Associate Research Scientist

Universities Space Research Association - Greenbelt, MD

August 1992 - January 1995

Chemistry and transport of stratospheric trace species; three-dimensional global numerical modeling for analysis of aircraft and satellite data.

Research Associate

Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder - National Oceanic and Atmospheric Administration, Boulder, CO

September 1988 - August 1992

Chemistry and microphysics of atmospheric trace species related to stratospheric ozone loss; development of numerical models for comparison of theory and observations.

Graduate Research Assistant

Department of Atmospheric Science, Colorado State University - Fort Collins, CO

September 1981 - September 1988

Atmospheric chemistry, planetary boundary layer processes, airborne measurement of ozone flux.

Senior Field Technician

Aerovironment Inc. - Pasadena, CA

January 1979 - September 1981

Air Quality Monitoring


1988 - Ph.D. - Colorado State University, Department of Atmospheric Science
1985 - M.S. - Colorado State University, Department of Atmospheric Science
1972 - B.A. - University of Chicago, Biology

Professional Societies

American Geophysical Union

1983 - Present

American Meteorological Society

Colorado State University Chapter President, 1984-1985

1981 - Present


NASA Group Achievement Awards (9), 1991-2011
Goddard Exceptional Achievement Award for CO2 Sounder, 2007
Goddard Special Act Award for Leading Mission Concept Study, 2007
Goddard Laboratory for Atmospheres, Technology Achievement (Peer) Award, 2006
Goddard Laboratory for Atmospheres, Scientific Achievement (Peer) Award, 1998
Distinguished Graduate Award, National Catholic Educational Association, 1998
NOAA ERL Outstanding Scientific Paper Award, 1995
AGU Editor’s Citation for Excellence in Refereeing, 1994
Colorado Fellowship, 1983

Selected Publications


2021. "Bias-correcting carbon fluxes derived from land-surface satellite data for retrospective and near-real-time assimilation systems." Atmospheric Chemistry and Physics 21 9609–9628 [10.5194/acp-21-9609-2021] [Journal Article/Letter]

2021. "Retrieval algorithm for the column CO2 mixing ratio from pulsed multi-wavelength lidar measurements." Atmospheric Measurement Techniques 14 (5): 3909-3922 [10.5194/amt-14-3909-2021] [Journal Article/Letter]

2020. "Application of NASA-Unified WRF model to carbon dioxide simulation- model development and evaluation." Environmental Modelling & Software 132 104785 [10.1016/j.envsoft.2020.104785] [Journal Article/Letter]

2020. "Spatial heterogeneity in CO2, CH4, and energy fluxes: insights from airborne eddy covariance measurements over the Mid-Atlantic region." Environmental Research Letters 15 (3): 035008 [10.1088/1748-9326/ab7391] [Journal Article/Letter]

2020. "Space‐Based Observations for Understanding Changes in the Arctic‐Boreal Zone." Reviews of Geophysics 58 (1): 2019RG000652 [10.1029/2019rg000652] [Journal Article/Letter]

2018. "A global synthesis inversion analysis of recent variability in CO2 fluxes using GOSAT and in situ observations." Atmospheric Chemistry and Physics 18 (15): 11097-11124 [10.5194/acp-18-11097-2018] [Journal Article/Letter]

2018. "Spring photosynthetic onset and net CO2 uptake in Alaska triggered by landscape thawing." Global Change Biology 24 (8): 3416-3435 [10.1111/gcb.14283] [Journal Article/Letter]

2018. "Airborne measurements of CO2 column concentrations made with a pulsed IPDA lidar using a multiple-wavelength-locked laser and HgCdTe APD detector." Atmospheric Measurement Techniques 11 (4): 2001-2025 [10.5194/amt-11-2001-2018] [Journal Article/Letter]

2018. "The NASA Carbon Airborne Flux Experiment (CARAFE): instrumentation and methodology." Atmospheric Measurement Techniques 11 (3): 1757-1776 [10.5194/amt-11-1757-2018] [Journal Article/Letter]

2018. "On the Ability of Space-Based Passive and Active Remote Sensing Observations of CO2 to Detect Flux Perturbations to the Carbon Cycle." Journal of Geophysical Research: Atmospheres 123 (2): 1460-1477 [10.1002/2017jd027836] [Journal Article/Letter]

2018. "Measurement of atmospheric CO2 column concentrations to cloud tops with a pulsed multi-wavelength airborne lidar." Atmospheric Measurement Techniques 11 (1): 127-140 [10.5194/amt-11-127-2018] [Journal Article/Letter]

2017. "Methane optical density measurements with an integrated path differential absorption lidar from an airborne platform." Journal of Applied Remote Sensing 11 (03): 1 [10.1117/1.jrs.11.034001] [Journal Article/Letter]

2017. "Feasibility study of a space-based high pulse energy 2  μm CO_2 IPDA lidar." Applied Optics 56 (23): 6531 [10.1364/ao.56.006531] [Journal Article/Letter]

2015. "Tropical sources and sinks of carbonyl sulfide observed from space." Geophysical Research Letters 42 (22): 10,082-10,090 [10.1002/2015gl066293] [Journal Article/Letter]

2015. " Detectability of CO 2 flux signals by a space-based lidar mission ." J. Geophys. Res. Atmos. 120 (5): 1794-1807 [10.1002/2014jd022483] [Journal Article/Letter]

2015. "The global distribution of cloud gaps in CALIPSO data." Journal of Quantitative Spectroscopy and Radiative Transfer 153 95-101 [10.1016/j.jqsrt.2014.12.001] [Journal Article/Letter]

2015. "Assessing the magnitude of CO2 flux uncertainty in atmospheric CO2 records using products from NASA's Carbon Monitoring Flux Pilot Project." Journal of Geophysical Research - Atmospheres 120 734-765 [doi:10.1002/2014JD022411] [Journal Article/Letter]

2014. "Performance simulations for a spaceborne methane lidar mission." J. Geophys. Res. Atmos. 119 (7): 4365–4379 [10.1002/2013JD021253] [Journal Article/Letter]

2014. "A regional CO2 observing system simulation experiment for the ASCENDS satellite mission." Atmos. Chem. Phys. 14 12,897-12,914 [10.5194/acp-14-12897-2014] [Journal Article/Letter]

2014. "Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential of spaceborne lidar observations." Atmos. Chem. Phys. 14 2625-2637 [10.5194/acp-14-2625-2014] [Journal Article/Letter]

2013. "Background error covariance estimation for atmospheric CO2 data assimilation." Journal of Geophysical Research-Atmospheres 118 (17): 10140-10154 [10.1002/jgrd.50654] [Journal Article/Letter]

2012. "Ground demonstration of trace gas lidar based on optical parametric amplifier." Journal of Applied Remote Sensing 6 (1): 063561 [10.1117/1.JRS.6.063561] [Journal Article/Letter]

2012. "The United States' Next Generation of Atmospheric Composition and Coastal Ecosystem Measurements: NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission." Bulletin of the American Meteorological Society 93 (10): 1547-1566 [Full Text] [10.1175/BAMS-D-11-00201.1] [Journal Article/Letter]

2012. "Airborne measurements of atmospheric methane column abundance made using a pulsed IPDA lidar." Applied Optics 51 (34): 8296-8305 [10.1364/AO.51.008296] [Journal Article/Letter]

2012. "Mapping of CO2 at high spatiotemporal resolution using satellite observations: Global distributions from OCO-2." J. Geophys. Res. 117 (D6): D06306 [10.1029/2011JD017015] [Journal Article/Letter]

2012. "CO2 flux estimation errors associated with moist atmospheric processes." Atmos. Chem. Phys. 12 (14): 6405-6416 [10.5194/acp-12-6405-2012] [Journal Article/Letter]

2011. "Evaluating a 3-D transport model of atmospheric CO₂using ground-based, aircraft, and space-borne data." Atmos. Chem. Phys. 11 (6): 2789-2803 [10.5194/acp-11-2789-2011] [Journal Article/Letter]

2010. "Mechanisms and feedback causing changes in upper stratospheric ozone in the 21st century." J. Geophys. Res 115 [Journal Article/Letter]

2010. "Multiscale carbon monoxide and aerosol correlations from satellite measurements and the GOCART model: Implication for emissions and atmospheric evolution." J Geophys Res 115 (D7): D07302 [10.1029/2009JD012781] [Journal Article/Letter]

2010. "Finding the missing stratospheric Bry: a global modeling study of CHBr₃ and CH₂Br₂." Atmos. Chem. Phys. 10 (5): 2269-2286 [10.5194/acp-10-2269-2010] [Journal Article/Letter]

2010. "Simulation studies for a space-based CO2 lidar mission." Tellus B 62 (5): 759-769 [10.1111/j.1600-0889.2010.00486.X] [Journal Article/Letter]

2010. "Planning, implementation, and first results of the Tropical Composition, Cloud and Climate Coupling Experiment (TC4)." J. Geophys. Res. 115 D00J04 [10.1029/2009JD013073] [Journal Article/Letter]

2009. "Impacts of climate change on stratospheric ozone recovery." Geophysical Research Letters 36 (3): L03805 [10.1029/2008GL036223] [Journal Article/Letter]

2009. "What would have happened to the ozone layer if chlorofluorocarbons (CFCs) had not been regulated?." Atmos. Chem. Phys. 9 (6): 2113-2128 [10.5194/acp-9-2113-2009] [Journal Article/Letter]

2009. "Sensitivity of polar stratospheric ozone loss to uncertainties in chemical reaction kinetics." Atmos. Chem. Phys. 9 (22): 8651-8660 [10.5194/acp-9-8651-2009] [Journal Article/Letter]

2008. "A global evaluation of the regional spatial variability of column integrated CO2 distributions." J Geophys Res 113 (D20): 303-319 [10.1029/2007JD009693] [Journal Article/Letter]

2008. "An estimate of monthly global emissions of anthropogenic CO2: Impact on the seasonal cycle of atmospheric CO2." J Geophys Res 113 (G01023): 9 pp [10.1029/2007JG000435] [Journal Article/Letter]

2008. "Estimation of global CO2 fluxes at regional scale using the maximum likelihood ensemble filter." J. Geophys. Res. 113 (D20): D20110 [10.1029/2007JD009679] [Journal Article/Letter]

2008. "Mechanisms for synoptic variations of atmospheric CO₂ in North America, South America and Europe." Atmos. Chem. Phys. 8 (23): 7239-7254 [10.5194/acp-8-7239-2008] [Journal Article/Letter]

2008. "TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002." Global Biochem Cycles 22 (GB3009, doi:101029/): [Journal Article/Letter]

2008. "Using CO2 spatial variability to quantify representation errors of satellite CO2 retrievals." Geophy Res Lett 35 (L16813, doi:101029/): [Journal Article/Letter]

2007. "Stratospheric transport using 6-h-averaged winds from a data assimilation system." J Geophys Res 112 (D23103): 1-12 [Journal Article/Letter]

2006. "A test of sensitivity to convective transport in a global atmospheric CO2 simulation." Tellus B 58 (5): 463-475 [10.1111/j.1600-0889.2006.00212.x] [Journal Article/Letter]

2006. "Chemical observations of a polar vortex intrusion." J Geophys Res 111 D20306 [10.1029/2006JD007134] [Journal Article/Letter]

2006. "Chemical observations of a polar vortex intrusion." J. Geophys. Res. 111 (D20): D20306 [10.1029/2006JD007134] [Journal Article/Letter]

2006. "When will the Antarctic ozone hole recover?." Geophysical Research Letters 33 (12): L12814 [10.1029/2005GL025232] [Journal Article/Letter]

2005. "Fall vortex ozone as a predictor of springtime total ozone at high northern latitudes." Atmos Chem Phys 5 1655-1663 [Journal Article/Letter]

2005. "Sensitivity of atmospheric CO₂ inversions to seasonal and interannual variations in fossil fuel emissions." J. Geophys. Res. 110 (D10): D10308 [10.1029/2004JD005373] [Journal Article/Letter]

2004. "Use of radon for evaluation of atmospheric transport models: sensitivity to emissions." Tellus Ser B - Chem and Phys. Meteor 56 404-412 [Journal Article/Letter]

2004. "Sensitivity Studies for Space-based Measurement of Atmospheric Total Column Carbon Dioxide by Reflected Sunlight." Applied Optics 43 914-927. [Journal Article/Letter]

2004. "Global CO₂ transport simulations using meteorological data from the NASA data assimilation system." J. Geophys. Res. 109 (D18): D18312 [10.1029/2004JD004554] [Journal Article/Letter]

2004. "Interannual variability of stratospheric trace gases: The role of extratropical wave driving." Met. Soc 130 2459-2474 [Journal Article/Letter]

2004. "On the size of the Antarctic ozone hole." Geophys. Res. Lett 31 (21): L21104 [Journal Article/Letter]

2003. "Evaluation of the transport in the Goddard Space Flight Center three-dimensional chemical transport model using the equivalent length diagnostic." J. Geophys. Res. 108 (D6): [10.1029/2002JD002268] [Journal Article/Letter]

2003. "N2O and NOy observations in the 1999/2000 Arctic polar vortex: Implications for transport processes in a CTM." J. Geophys. Res. 108 (D5): 4170 [Full Text] [10.1029/2002JD002525] [Journal Article/Letter]

2002. "Interaction between dynamics and chemistry of ozone in the setup phase of the Northern Hemisphere polar vortex." J. Geophys. Res. 107 (D5): 8310 [10.1029/2001JD001527] [Journal Article/Letter]

2001. "Ozone and Tracer Transport Variations in the Summer Northern Hemisphere Stratosphere,." J. Geophys. Res. 106 12 [Full Text] [227-12] [Journal Article/Letter]

2000. "The Influence of Airmass Histories on Radical Species During POLARIS,." J. Geophys. Res. 105 15185-15199. [Journal Article/Letter]

1999. "Contrast Between 1992 and 1997 High Latitude Spring Halogen Occultation Experiment Observations of Lower Stratospheric HCl." J. Geophys. Res. 104 (D15): 18739-18754 [10.1029/1999JD900281] [Journal Article/Letter]

1999. "Assessment of the Effects of High-Speed Aircraft in the Stratosphere: 1998." NASA/TP-1999-209237 [Other]

1999. "Preface: Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS)." J. Geophys. Res 104 26481-26496 [Journal Article/Letter]

1998. "Low-Ozone Pockets Explained,." J. Geophys. Res. 103 3599-3610. [Journal Article/Letter]

1997. "An Analysis of Tropical Transport: Influence of the QBO." J. Geophys. Res. 102 (D14): 16453-16461 [10.1029/97JD01053] [Journal Article/Letter]

1997. "A 3D Simulation of the Evolution of the Middle Latitude Winter Ozone in the Middle Stratosphere." J. Geophys. Res. 102 (D15): 19,217-19,232 [Full Text] [10.1029/97JD01043] [Journal Article/Letter]

1997. "UARS First Global N2O5 Data Sets: Application to a Stratospheric Warming Event in January 1992,." J. Geophys. Res. 102 3575-3582. [Journal Article/Letter]

1997. "Lower Stratospheric Chlorine Partitioning During the Decay of the Mt. Pinatubo Aerosol Cloud,." Geophys. Res. Lett. 24 1623-1626. [Journal Article/Letter]

1997. "Activation of Chlorine in Sulfate Aerosol as Inferred from Aircraft Observations." J. Geophys. Res 102 (D3): 3921-3933 [10.1029/96JD01992] [Journal Article/Letter]

1996. "Development of the Antarctic Ozone Hole." J. Geophys. Res 101 (D15): 20909–20924 [10.1029/96JD01707] [Journal Article/Letter]

1996. "A Test of the Partitioning Between ClO and ClONO2 Based on Simultaneous UARS Measurements of ClO, NO2, and ClONO2." J. Geophys. Res. 101 (D7): 12515-12521 [10.1029/96JD00695] [Journal Article/Letter]

1996. "UARS Measurements of ClO and NO2 at 40 and 46 km and Implications for the 'Ozone Deficit',." Geophys. Res. Lett. 23 339-342. [Journal Article/Letter]

1996. "Interpretation of Nitric Oxide Profile Observed in January 1992 over Kiruna,." J. Geophys. Res. 101 12 [Full Text] [555-12] [Journal Article/Letter]

1995. "Missing Chemistry of Reactive Nitrogen in the Upper Stratospheric Polar Winter,." Geophys. Res. Lett. 22 2629-2632. [Journal Article/Letter]

1993. "New Observations of the Noy/N2O Correlation in the Lower Stratosphere." Geophys. Res. Lett 20 2531-2534 [Journal Article/Letter]

1993. "Interpretation of NOx/NOy Observations from AASE-II Using a Model of Chemistry Along Trajectories." Geophys. Res. Lett 20 2507-2510 [Journal Article/Letter]


2010. "Mechanisms and feedback causing changes in upper stratospheric ozone in the 21st century." J. Geophys. Res. 115 (D5): D05303 [10.1029/2009JD012397] [Journal Article/Letter]