The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2).
Ronald Gelaro, Will McCarty, Max J Su��rez, Ricardo Todling, Andrea Molod, Lawrence Takacs, Cynthia Randles, Anton Darmenov, Michael G Bosilovich, Rolf Reichle, Krzysztof Wargan, Lawrence Coy, Richard Cullather, Clara Draper, Santha Akella, Virginie Buchard, Austin Conaty, Arlindo da Silva, Wei Gu, Gi-Kong Kim, Randal Koster, Robert Lucchesi, Dagmar Merkova, Jon Eric Nielsen, Gary Partyka, Steven Pawson, William Putman, Michele Rienecker, Siegfried D Schubert, Meta Sienkiewicz, Bin Zhao
Author Information
Ronald Gelaro: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Will McCarty: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Max J Su��rez: Universities Space Research Association, Columbia, MD.
Ricardo Todling: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Andrea Molod: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Lawrence Takacs: Science Systems and Applications, Inc., Lanham, MD.
Cynthia Randles: Morgan State University, Baltimore, MD.
Anton Darmenov: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Michael G Bosilovich: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Rolf Reichle: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Krzysztof Wargan: Science Systems and Applications, Inc., Lanham, MD.
Lawrence Coy: Science Systems and Applications, Inc., Lanham, MD.
Richard Cullather: Earth System Science Interdisciplinary Center, College Park, MD.
Clara Draper: Universities Space Research Association, Columbia, MD.
Santha Akella: Science Systems and Applications, Inc., Lanham, MD.
Virginie Buchard: Universities Space Research Association, Columbia, MD.
Austin Conaty: Science Systems and Applications, Inc., Lanham, MD.
Arlindo da Silva: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Wei Gu: Science Systems and Applications, Inc., Lanham, MD.
Gi-Kong Kim: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Randal Koster: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Robert Lucchesi: Science Systems and Applications, Inc., Lanham, MD.
Dagmar Merkova: Science Systems and Applications, Inc., Lanham, MD.
Jon Eric Nielsen: Science Systems and Applications, Inc., Lanham, MD.
Gary Partyka: Science Systems and Applications, Inc., Lanham, MD.
Steven Pawson: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
William Putman: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Michele Rienecker: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Siegfried D Schubert: Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD.
Meta Sienkiewicz: Science Systems and Applications, Inc., Lanham, MD.
Bin Zhao: Science Applications International Corporation, Beltsville, MD.
The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) is the latest atmospheric reanalysis of the modern satellite era produced by NASA's Global Modeling and Assimilation Office (GMAO). MERRA-2 assimilates observation types not available to its predecessor, MERRA, and includes updates to the Goddard Earth Observing System (GEOS) model and analysis scheme so as to provide a viable ongoing climate analysis beyond MERRA's terminus. While addressing known limitations of MERRA, MERRA-2 is also intended to be a development milestone for a future integrated Earth system analysis (IESA) currently under development at GMAO. This paper provides an overview of the MERRA-2 system and various performance metrics. Among the advances in MERRA-2 relevant to IESA are the assimilation of aerosol observations, several improvements to the representation of the stratosphere including ozone, and improved representations of cryospheric processes. Other improvements in the quality of MERRA-2 compared with MERRA include the reduction of some spurious trends and jumps related to changes in the observing system, and reduced biases and imbalances in aspects of the water cycle. Remaining deficiencies are also identified. Production of MERRA-2 began in June 2014 in four processing streams, and converged to a single near-real time stream in mid 2015. MERRA-2 products are accessible online through the NASA Goddard Earth Sciences Data Information Services Center (GES DISC).
