Sciences and Exploration Directorate

Brad Weir



Org Code: 610.1

Mail Code: 610.1
Greenbelt, MD 20771


Brief Bio

Dr. Brad Weir is a research scientist at NASA Goddard Space Flight Center and Morgan State University through the GESTAR II cooperative agreement. He is the lead developer of NASA's Goddard Earth Observing System (GEOS) Constituent Data Assimilation System (CoDAS) — a state-of-the-art statistical method for estimating atmospheric trace gas abundances based on satellite observations. His research focuses on developing and applying mathematical and statistical methods to address questions about the physics, chemistry, and biology of the Earth's atmosphere, ocean, and land surface. His work has appeared in Science, the New York Times, the websites of National Geographic and the BBC, the NASA COVID-19 Dashboard, and the NASA/ESA/JAXA trilateral Earth Observing Dashboard.

ORCiD: 0000-0001-6160-0577


Scientist (Senior, 2021-Present)

Global Modeling and Assimilation Office, NASA Goddard Space Flight Center - Greenbelt, MD

November 2013 - Present

Goddard Earth Sciences Technology and Research I & II cooperative agreements:

  • Morgan State University (2021-Present)
  • Universities Space Research Association (2013-2021)

Post-doctoral Research Associate

College of Earth, Ocean, and Atmospheric Sciences, Oregon State University - Corvallis, OR

October 2010 - November 2013

Graduate Research Assistant

Los Alamos National Laboratory - Los Alamos, NM

July 2006 - September 2006


2003 - 2010: Ph.D., Mathematics, University of Arizona, Tucson, AZ

1999 - 2003: B.A., Cum laude, Mathematics, New York University, New York, NY



Balashov, N. V., L. E. Ott, B. Weir, et al. S. Basu, K. J. Davis, N. L. Miles, A. M. Thompson, and R. M. Stauffer. 2023. Flood Impacts on Net Ecosystem Exchange in the Midwestern and Southern United States in 2019 Journal of Geophysical Research: Atmospheres 128 (18): [10.1029/2022jd037697]

Taylor, T. E., C. W. O'Dell, D. Baker, et al. C. Bruegge, A. Chang, L. Chapsky, A. Chatterjee, C. Cheng, F. Chevallier, D. Crisp, L. Dang, B. Drouin, A. Eldering, L. Feng, B. Fisher, D. Fu, M. Gunson, V. Haemmerle, G. R. Keller, M. Kiel, L. Kuai, T. Kurosu, A. Lambert, J. Laughner, R. Lee, J. Liu, L. Mandrake, Y. Marchetti, G. McGarragh, A. Merrelli, R. R. Nelson, G. Osterman, F. Oyafuso, P. I. Palmer, V. H. Payne, R. Rosenberg, P. Somkuti, G. Spiers, C. To, B. Weir, P. O. Wennberg, S. Yu, and J. Zong. 2023. Evaluating the consistency between OCO-2 and OCO-3 XCO<sub>2</sub> estimates derived from the NASA ACOS version 10 retrieval algorithm Atmospheric Measurement Techniques 16 (12): 3173-3209 [10.5194/amt-16-3173-2023]

Wargan, K., B. Weir, G. L. Manney, et al. S. E. Cohn, K. E. Knowland, P. A. Wales, and N. J. Livesey. 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]

Weir, B., T. Oda, L. E. Ott, and G. A. Schmidt. 2022. Assessing progress toward the Paris climate agreement from space Environmental Research Letters 17 (11): 111002 [10.1088/1748-9326/ac998c]

Walley, S., S. Pal, J. F. Campbell, et al. J. Dobler, E. Bell, B. Weir, S. Feng, T. Lauvaux, D. Baker, N. Blume, W. Erxleben, T. Fan, B. Lin, D. McGregor, M. D. Obland, C. O'Dell, and K. J. Davis. 2022. Airborne Lidar Measurements of XCO2 in Synoptically Active Environment and Associated Comparisons with Numerical Simulations Journal of Geophysical Research: Atmospheres 127 (16): e2021JD035664 [10.1029/2021jd035664]

Sweeney, C., A. Chatterjee, S. Wolter, et al. K. McKain, R. Bogue, S. Conley, T. Newberger, L. Hu, L. Ott, B. Poulter, L. Schiferl, B. Weir, Z. Zhang, and C. E. Miller. 2022. Using atmospheric trace gas vertical profiles to evaluate model fluxes: a case study of Arctic-CAP observations and GEOS simulations for the ABoVE domain Atmospheric Chemistry and Physics 22 (9): 6347-6364 [10.5194/acp-22-6347-2022]

Schuh, A. E., B. Byrne, A. R. Jacobson, et al. S. M. Crowell, F. Deng, D. F. Baker, M. S. Johnson, S. Philip, and B. Weir. 2022. On the role of atmospheric model transport uncertainty in estimating the Chinese land carbon sink Nature 603 E13-E14 [10.1038/s41586-021-04258-9]

Peiro, H., S. Crowell, A. Schuh, et al. D. F. Baker, C. O'Dell, A. R. Jacobson, F. Chevallier, J. Liu, A. Eldering, D. Crisp, F. Deng, B. Weir, S. Basu, M. S. Johnson, S. Philip, and I. Baker. 2022. Four years of global carbon cycle observed from the Orbiting Carbon Observatory 2 (OCO-2) version 9 and in situ data and comparison to OCO-2 version 7 Atmospheric Chemistry and Physics 22 (2): 1097-1130 [10.5194/acp-22-1097-2022]

Zhang, L., K. J. Davis, A. E. Schuh, et al. A. R. Jacobson, S. Pal, Y. Y. Cui, D. Baker, S. Crowell, F. Chevallier, M. Remaud, J. Liu, B. Weir, S. Philip, M. S. Johnson, F. Deng, and S. Basu. 2022. Multi‐Season Evaluation of CO2 Weather in OCO‐2 MIP Models Journal of Geophysical Research: Atmospheres 127 (2): e2021JD035457 [10.1029/2021jd035457]

Weir, B., D. Crisp, C. W. O’Dell, et al. S. Basu, A. Chatterjee, J. Kolassa, T. Oda, S. Pawson, B. Poulter, Z. Zhang, P. Ciais, S. J. Davis, Z. Liu, and L. E. Ott. 2021. Regional impacts of COVID-19 on carbon dioxide detected worldwide from space Science Advances 7 (45): eabf9415 [10.1126/sciadv.abf9415]

Davis, K. J., E. V. Browell, S. Feng, et al. T. Lauvaux, M. D. Obland, S. Pal, B. C. Baier, D. F. Baker, I. T. Baker, Z. R. Barkley, K. W. Bowman, Y. Y. Cui, A. S. Denning, J. P. DiGangi, J. T. Dobler, A. Fried, T. Gerken, K. Keller, B. Lin, A. R. Nehrir, C. P. Normile, C. W. O’Dell, L. E. Ott, A. Roiger, A. E. Schuh, C. Sweeney, Y. Wei, B. Weir, M. Xue, and C. A. Williams. 2021. The Atmospheric Carbon and Transport (ACT)-America Mission Bulletin of the American Meteorological Society 102 (9): E1714-E1734 [10.1175/bams-d-20-0300.1]

Weir, B., L. E. Ott, G. J. Collatz, et al. S. R. Kawa, B. Poulter, A. Chatterjee, T. Oda, and S. Pawson. 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]

Campbell, J. F., B. Lin, J. Dobler, et al. S. Pal, K. Davis, M. D. Obland, W. Erxleben, D. McGregor, C. O’Dell, E. Bell, B. Weir, T. Fan, S. Kooi, I. Gordon, A. Corbett, and R. Kochanov. 2020. Field Evaluation of Column CO2 Retrievals from Intensity‐Modulated Continuous‐Wave Differential Absorption Lidar Measurements during the ACT‐America Campaign Earth and Space Science 7 (12): e2019EA000847 [10.1029/2019ea000847]

Wargan, K., B. Weir, G. L. Manney, S. E. Cohn, and N. J. Livesey. 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]

Lee, E., F. Zeng, R. D. Koster, et al. L. E. Ott, S. P. Mahanama, B. Weir, B. Poulter, and T. Oda. 2020. Impact of a Regional US Drought on Land and Atmospheric Carbon Journal of Geophysical Research: Biogeosciences 125 (8): [10.1029/2019jg005599]

Bell, E., C. W. O'Dell, K. J. Davis, et al. J. Campbell, E. Browell, A. Scott Denning, J. Dobler, W. Erxleben, T. Fan, S. Kooi, B. Lin, S. Pal, and B. Weir. 2020. Evaluation of OCO‐2 XCO2 Variability at Local and Synoptic Scales using Lidar and In Situ Observations from the ACT‐America Campaigns Journal of Geophysical Research: Atmospheres 125 (10): [10.1029/2019jd031400]

Wargan, K., N. Kramarova, B. Weir, S. Pawson, and S. M. Davis. 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]

Schuh, A. E., A. R. Jacobson, S. Basu, et al. B. Weir, D. Baker, K. Bowman, F. Chevallier, S. Crowell, K. J. Davis, F. Deng, S. Denning, L. Feng, D. Jones, J. Liu, and P. I. Palmer. 2019. Quantifying the Impact of Atmospheric Transport Uncertainty on CO2 Surface Flux Estimates Global Biogeochemical Cycles 33 484-500 [10.1029/2018gb006086]

Lee, E., F. Zeng, R. D. Koster, et al. B. Weir, L. E. Ott, and B. Poulter. 2018. The impact of spatiotemporal variability in atmospheric CO<sub>2</sub> concentration on global terrestrial carbon fluxes Biogeosciences 15 5635-5652 [10.5194/bg-15-5635-2018]

Eldering, A., P. O. Wennberg, D. Crisp, et al. D. S. Schimel, M. R. Gunson, A. Chatterjee, J. Liu, F. M. Schwandner, Y. Sun, C. W. O’Dell, C. Frankenberg, T. Taylor, B. Fisher, G. B. Osterman, D. Wunch, J. Hakkarainen, J. Tamminen, and B. Weir. 2017. The Orbiting Carbon Observatory-2 early science investigations of regional carbon dioxide fluxes Science 358 (6360): eaam5745 [10.1126/science.aam5745]

Weir, B., R. N. Miller, and Y. H. Spitz. 2013. A potential implicit particle method for high-dimensional systems Nonlinear Processes in Geophysics 20 1047-1060 [10.5194/npg-20-1047-2013]

Weir, B., R. N. Miller, and Y. H. Spitz. 2013. Implicit Estimation of Ecological Model Parameters Bulletin of Mathematical Biology 75 (2): 223-257 [10.1007/s11538-012-9801-6]

Weir, B., Y. Uchiyama, E. M. Lane, J. M. Restrepo, and J. C. McWilliams. 2011. A vortex force analysis of the interaction of rip currents and surface gravity waves Journal of Geophysical Research: Oceans 116 (C5): C05001 [10.1029/2010jc006232]


Weir, B., and L. E. Ott. 2022. OCO-2 GEOS Level 3 monthly, 0.5x0.625 assimilated CO2 V10r <a href="">Product User's Guide (Version 1.0)</a> Goddard Earth Sciences Data and Information Services Center (GES DISC) Greenbelt, MD, USA [10.5067/BGFIODET3HZ8]

Weir, B., and L. E. Ott. 2022. OCO-2 GEOS Level 3 daily, 0.5x0.625 assimilated CO2 V10r <a href="">Product User's Guide (Version 1.0)</a> Goddard Earth Sciences Data and Information Services Center (GES DISC) Greenbelt, MD, USA [10.5067/Y9M4NM9MPCGH]

Kuze, A., Y. Ikehata, N. Kikuchi, et al. F. Kataoka, K. Shiomi, K. Jucks, D. Crisp, B. Weir, and L. Ott. 2021. Covid-19 Impact Monitoring for Climate Environment (Greenhouse Gases) 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS [10.1109/igarss47720.2021.9554328]

Talks, Presentations and Posters


Constituent data assimilation plans of the GMAO at NASA Goddard

April 20, 2023

Mathematical Approaches of Atmospheric Constituents Data Assimilation and Inverse Modeling

Banff International Research Station, Banff, Alberta, Canada

Data assimilation for carbon monitoring

June 11, 2022

WMO GHG/Carbon Monitoring Workshop

World Meteorological Organization, Geneva, Switzerland

The Orbiting Carbon Observatory-2 project: Monitoring atmospheric carbon dioxide

April 22, 2022

Carbon Tracking and Reporting

Energy Conference Network, Houston, TX, USA

The GEOS-Carb reanalysis of atmospheric carbon dioxide

May 5, 2017

GMAO Seminar Series on Earth System Sceince

Global Modeling and Assimilation Office, Greenbelt, MD, USA

Implicit parameter estimation

March 17, 2013

Probabilistic Approaches to Data Assimilation for Earth Systems

Banff International Research Station, Banff, Alberta, Canada

Implicit sampling: theory and implementation

March 7, 2013

International Workshop on Particle Filters for Data Assimilation

Institute for Statistical Mathematics, Tachikawa, Tokyo, Japan

Implicit assimilation for marine ecological models

3, 2012

AGU Fall Meeting 2012, San Francisco, CA, USA

Abstract Id. NG41D-02


Professional Service

2023 - 2025: Secretary, AGU Nonlinear Geophysics

2021: Organizing Committee, 17th International Workshop on Greenhouse Gas Measurements from Space (IWGGMS)