Editorial Type:
Article
Article Type:
Research Article

The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)

Ronald Gelaro Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Will McCarty Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Max J. Suárez Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Universities Space Research Association, Columbia, Maryland

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Ricardo Todling Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Andrea Molod Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Lawrence Takacs Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Cynthia A. Randles Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Morgan State University, Baltimore, Maryland

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Anton Darmenov Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Michael G. Bosilovich Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Rolf Reichle Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Krzysztof Wargan Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Lawrence Coy Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Richard Cullather Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Earth System Science Interdisciplinary Center, University of Maryland, College Park, College Park, Maryland

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Clara Draper Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Universities Space Research Association, Columbia, Maryland

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Santha Akella Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Virginie Buchard Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Universities Space Research Association, Columbia, Maryland

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Austin Conaty Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Arlindo M. da Silva Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Wei Gu Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Gi-Kong Kim Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Randal Koster Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Robert Lucchesi Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Dagmar Merkova Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Jon Eric Nielsen Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Gary Partyka Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Steven Pawson Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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William Putman Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Michele Rienecker Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland

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Siegfried D. Schubert Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Meta Sienkiewicz Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Systems and Applications, Inc., Lanham, Maryland

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Bin Zhao Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
Science Applications International Corporation, Beltsville, Maryland

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Print Publication:
15 Jul 2017
Collections:
Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2)
DOI:
https://doi.org/10.1175/JCLI-D-16-0758.1
Page(s):
5419–5454
Restricted access

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Abstract

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).

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Current affiliation: ExxonMobil Research and Engineering Company, Annandale, New Jersey.

Current affiliation: I.M. System Group, Inc., Rockville, Maryland.

Corresponding author: Ronald Gelaro, ron.gelaro@nasa.gov

Abstract

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).

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Current affiliation: ExxonMobil Research and Engineering Company, Annandale, New Jersey.

Current affiliation: I.M. System Group, Inc., Rockville, Maryland.

Corresponding author: Ronald Gelaro, ron.gelaro@nasa.gov
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