2001: PhD in mathematics, the George Washington University. Washington, DC
1994: Master's degree in mathematics, University of Gdańsk, Gdańsk, Poland
Krzysztof Wargan
(RESEARCH SCIENTIST)
| Email: | krzysztof.wargan-1@nasa.gov |
| Phone: | 301.614.5521 |
| Org Code: | 610.1 |
| Address: |
NASA/GSFC Mail Code 610.1 Greenbelt, MD 20771 |
| Employer: | SCIENCE SYSTEMS AND APPLICATIONS INC |
Research Interests
Positions/Employment
Chief Research Scientist
Science Systems and Applications - Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA
February 2012 - Present
Research Scientist
Science Applications International Corporation - Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA
September 2010 - January 2012
Research Assistant
Imperial College London - Department of Physics Imperial College London London United Kingdom
June 2009 - August 2010
Support scientist
Science Applications International Corporation - Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA
January 2002 - February 2009
Education
Professional Service
- 2026 WMO/UNEP Scientific Assessment of Ozone Depletion: Co-lead author of Chapter 4
- APARC Reanalysis Intercomparison Project (A-RIP): activity co-lead (since 2024)
- APARC Hunga Stratospheric Impacts: Coauthor of the activity report
- 2022 WMO/UNEP Scientific Assessment of Ozone Depletion: Coauthor of Chapter 4
- 7th SPARC General Assembly 2022: Member of the organizing committee
- Co-organizer of the 21st Conference on Middle Atmosphere (January 2022)
- Member of the AMS Middle Atmosphere Committee (2019–2025)
- 2018 WMO/UNEP Scientific Assessment of Ozone Depletion: reviewer
- SPARC Reanalysis Intercomparison Project (S-RIP): point of contact for NASA reanalyses
- SPARC Reanalysis Intercomparison Project (S-RIP): Coauthor of Chapters 2, 4, and 7 of the S-RIP Report
Grants
A New Look at Stratospheric Chemistry With Multispecies Chemical Data Assimilation
Modeling Analysis and Prediction 16-MAP16-0165 - NASA - Awarded: 2017-04-20
Dates: -
Selected Publications
Refereed
2025. "Factors Contributing to the Unusually Low Antarctic Springtime Ozone in 2020–2023." Journal of Geophysical Research: Atmospheres 130 (19): e2025JD043621 [10.1029/2025jd043621] [Journal Article/Letter]
2025. "Changes in Stratospheric Climate and Age‐Of‐Air in Recent GEOS Systems Since MERRA‐2." Journal of Advances in Modeling Earth Systems 17 (6): [10.1029/2024ms004442] [Journal Article/Letter]
2025. "Stratospheric Water Vapor Beyond NASA's Aura MLS: Assimilating SAGE III/ISS Profiles for a Continued Climate Record." Geophysical Research Letters 52 (8): [10.1029/2024gl112610] [Journal Article/Letter]
2025. "The Imminent Data Desert: The Future of Stratospheric Monitoring in a Rapidly Changing World." Bulletin of the American Meteorological Society [10.1175/bams-d-23-0281.1] [Journal Article/Letter]
2023. "Tropospheric ozone data assimilation in the NASA GEOS composition forecast modeling system (GEOS-CF v2.0) using satellite data for ozone vertical profiles (MLS), total ozone columns (OMI), and thermal infrared radiances (AIRS, IASI)." Environmental Research Letters [10.1088/1748-9326/acf0b7] [Journal Article/Letter]
2023. "Multi-parameter dynamical diagnostics for upper tropospheric and lower stratospheric studies." Atmospheric Measurement Techniques 16 (11): 2957-2988 [10.5194/amt-16-2957-2023] [Journal Article/Letter]
2023. "M2‐SCREAM: A Stratospheric Composition Reanalysis of Aura MLS Data With MERRA‐2 Transport." Earth and Space Science 10 (2): e2022EA002632 [10.1029/2022ea002632] [Journal Article/Letter]
2023. "Polar Stratospheric Ozone: Past, Present, and Future, Chapter 4 in Scientific Assessment of Ozone Depletion." GAW Report No. 278, 509 pp., WMO, Geneva, 2022. [Report]
2022. "Stratospheric Circulation Changes Associated with the Hunga Tonga‐Hunga Ha'apai Eruption." Geophysical Research Letters 49 [10.1029/2022gl100982] [Journal Article/Letter]
2022. "Signatures of Anomalous Transport in the 2019/2020 Arctic Stratospheric Polar Vortex." Journal of Geophysical Research: Atmospheres 127 (20): [10.1029/2022jd037407] [Journal Article/Letter]
2022. "Introduction to Special Collection “The Exceptional Arctic Stratospheric Polar Vortex in 2019/2020: Causes and Consequences”." Journal of Geophysical Research: Atmospheres 127 (18): [10.1029/2022jd037381] [Journal Article/Letter]
2022. "NASA Satellite Measurements Show Global‐Scale Reductions in Free Tropospheric Ozone in 2020 and Again in 2021 During COVID‐19." Geophysical Research Letters 49 (15): [10.1029/2022gl098712] [Journal Article/Letter]
2022. "What's in a Name? On the Use and Significance of the Term “Polar Vortex”." Geophysical Research Letters 49 (10): [10.1029/2021gl097617] [Journal Article/Letter]
2022. "NASA GEOS Composition Forecast Modeling System GEOS‐CF v1.0: Stratospheric composition." Journal of Advances in Modeling Earth Systems 14 (e2021MS002852): [10.1029/2021ms002852] [Journal Article/Letter]
2022. "Optimized Umkehr profile algorithm for ozone trend analyses." Atmospheric Measurement Techniques 15 (6): 1849-1870 [10.5194/amt-15-1849-2022] [Journal Article/Letter]
2021. "Regional and Seasonal Trends in Tropical Ozone From SHADOZ Profiles: Reference for Models and Satellite Products." Journal of Geophysical Research: Atmospheres 126 (22): [10.1029/2021jd034691] [Journal Article/Letter]
2021. "Investigating the utility of hyperspectral sounders in the 9.6 μm band to improve ozone analyses." Quarterly Journal of the Royal Meteorological Society [10.1002/qj.4198] [Journal Article/Letter]
2021. "Evaluation of Version 3 Total and Tropospheric Ozone Columns From Earth Polychromatic Imaging Camera on Deep Space Climate Observatory for Studying Regional Scale Ozone Variations." Frontiers in Remote Sensing 2 [10.3389/frsen.2021.734071] [Journal Article/Letter]
2021. "A Moments View of Climatology and Variability of the Asian Summer Monsoon Anticyclone." Journal of Climate 1-69 [10.1175/jcli-d-20-0729.1] [Journal Article/Letter]
2020. "The Anomalous 2019 Antarctic Ozone Hole in the GEOS Constituent Data Assimilation System With MLS Observations." Journal of Geophysical Research: Atmospheres 125 (18): [10.1029/2020jd033335] [Journal Article/Letter]
2020. "Mechanisms Linked to Recent Ozone Decreases in the Northern Hemisphere Lower Stratosphere." Journal of Geophysical Research: Atmospheres 125 (9): [10.1029/2019jd031631] [Journal Article/Letter]
2020. "Toward a Reanalysis of Stratospheric Ozone for Trend Studies: Assimilation of the Aura Microwave Limb Sounder and Ozone Mapping and Profiler Suite Limb Profiler Data." Journal of Geophysical Research: Atmospheres 125 (4): [10.1029/2019jd031892] [Journal Article/Letter]
2020. "Temperature and tropopause characteristics from reanalyses data in the tropical tropopause layer." Atmospheric Chemistry and Physics 20 (2): 753-770 [10.5194/acp-20-753-2020] [Journal Article/Letter]
2018. "Reanalysis intercomparisons of stratospheric polar processing diagnostics." Atmospheric Chemistry and Physics 18 (18): 13547-13579 [10.5194/acp-18-13547-2018] [Journal Article/Letter]
2018. "Recent decline in extratropical lower stratospheric ozone attributed to circulation changes." Geophysical Research Letters [10.1029/2018gl077406] [Journal Article/Letter]
2018. "The Ozone Monitoring Instrument: overview of 14 years in space." Atmospheric Chemistry and Physics 18 (8): 5699-5745 [10.5194/acp-18-5699-2018] [Journal Article/Letter]
2017. "Chemical Mechanisms and Their Applications in the Goddard Earth Observing System (GEOS) Earth System Model." Journal of Advances in Modeling Earth Systems [10.1002/2017ms001011] [Journal Article/Letter]
2017. "Multi-year composite view of ozone enhancements and stratosphere-to-troposphere transport in dry intrusions of northern hemisphere extratropical cyclones." Journal of Geophysical Research: Atmospheres [10.1002/2017jd027656] [Journal Article/Letter]
2017. "Assessment of upper tropospheric and stratospheric water vapor and ozone in reanalyses as part of S-RIP." Atmospheric Chemistry and Physics 17 (20): 12743-12778 [10.5194/acp-17-12743-2017] [Journal Article/Letter]
2017. "Reanalysis comparisons of upper tropospheric–lower stratospheric jets and multiple tropopauses." Atmospheric Chemistry and Physics 17 (18): 11541-11566 [10.5194/acp-17-11541-2017] [Journal Article/Letter]
2017. "Stratospheric intrusion-influenced ozone air quality exceedances investigated in the NASA MERRA-2 Reanalysis." Geophysical Research Letters 44 (10): 691–10,701 [10.1002/2017gl074532] [Journal Article/Letter]
2017. "The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)." Journal of Climate 30 5419–5454 [10.1175/jcli-d-16-0758.1] [Journal Article/Letter]
2017. "Evaluation of the Ozone Fields in NASA’s MERRA-2 Reanalysis." Journal of Climate 30 (8): 2961–2988 [10.1175/jcli-d-16-0699.1] [Journal Article/Letter]
2017. "Causes of interannual variability over the southern hemispheric tropospheric ozone maximum." Atmospheric Chemistry and Physics 17 (5): 3279-3299 [10.5194/acp-17-3279-2017] [Journal Article/Letter]
2017. "Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems." Atmospheric Chemistry and Physics 1-52 [10.5194/acp-2016-652] [Journal Article/Letter]
2016. "Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data." Atmos. Chem. Phys. 16 (11): 7091-7103 [10.5194/acp-16-7091-2016] [Journal Article/Letter]
2016. "Frequency and impact of summertime stratospheric intrusions over Maryland during DISCOVER-AQ (2011): New evidence from NASA's GEOS-5 simulations." J. Geophys. Res. Atmos. [10.1002/2015jd024052] [Journal Article/Letter]
2016. "Structure and Dynamics of the Quasi-Biennial Oscillation in MERRA-2." J. Climate 29:14 5339-5354 [10.1175/jcli-d-15-0809.1] [Journal Article/Letter]
2016. "Strengthening of the Tropopause Inversion Layer During the 2009 Sudden Stratospheric Warming: A MERRA-2 Study." Journal of the Atmospheric Sciences [10.1175/jas-d-15-0333.1] [Journal Article/Letter]
2015. "The Global Structure of Upper Troposphere-Lower Stratosphere Ozone in GEOS-5: A Multi-Year Assimilation of EOS Aura Data." J. Geophys. Res. - Atmos 120 2013-2036 [10.1002/2014JD022493] [Journal Article/Letter]
2014. "Assessment and applications of NASA ozone data products derived from Aura OMI/MLS satellite measurements in context of the GMI chemical transport model." J. Geophys. Res. Atmos. 119 (9): 5671-5699 [10.1002/2013JD020914] [Journal Article/Letter]
2013. "On the inclusion of Limb Infrared Monitor of the Stratosphere version 6 ozone in a data assimilation system." J. Geophys. Res. Atmos. 118 (14): 7982-8000 [10.1002/jgrd.50566] [Journal Article/Letter]
2011. "An intercomparison of tropospheric ozone retrievals derived from two Aura instruments and in-situ measurements in western North America in 2006." J. Geophys. Res. doi: 116 D06303 [10.1029/2010JD014703] [Journal Article/Letter]
2010. "Spatial structure of assimilated ozone in the upper troposphere and lower stratosphere." J. Geophys. Res. 115 (D24): D24316 [10.1029/2010JD013941] [Journal Article/Letter]
2008. "Assimilated Ozone from EOS-Aura: Evaluation of the Tropopause Region and Tropospheric Columns." J. Geophys. Res.-Atmos. 113 D15S32 [doi:10.1029/2007JD008863] [Journal Article/Letter]
2006. "Assimilation of ozone profiles from the Improved Limb Atmospheric Spectrometer-II: Study of Antarctic ozone." JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 111 (D11): [10.1029/2005JD006448] [Journal Article/Letter]
2005. "Assimilation of ozone data from the Michelson Interferometer for Passive Atmospheric Sounding." QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 131 (611): [10.1256/qj.04.184] [Journal Article/Letter]
2004. "Antarctic stratospheric ozone from the assimilation of occultation data." GEOPHYSICAL RESEARCH LETTERS 31 (18): [10.1029/2004GL020846] [Journal Article/Letter]
Non-Refereed
2016. "MERRA-2 Input Observations: Summary and Assessment." Technical Report Series on Global Modeling and Data Assimilation 46 (NASA/TM–2016-104606): [Other]
2015. "MERRA-2: Initial Evaluation of the Climate." NASA Technical Report Series on Global Modeling and Data Assimilation 43 (NASA/TM–2015–10) 139 pp. [Report]
2015. "Evaluation of the 7-km GEOS-5 Nature Run." NASA Technical Report Series on Global Modeling and Data Assimilation 36 (NASA/TM-2014-104606): [Report]