Ronald Gelaro1, Will McCarty1, Max J. Suárez1,2, Ricardo Todling1, Andrea Molod1, Lawrence L. Takacs1,3, Cynthia A. Randles1,4, Anton Darmenov1, Michael G. Bosilovich1, Rolf H. Reichle1, Krzysztof Wargan1,3, Lawrence Coy1,3, Richard I. Cullather5,1, Clara Draper1,2, Santha Akella1,3, Virginie Buchard1,2, Austin Conaty1,3, Arlindo da Silva1, W Gu1,3, Gi-Kong Kim1, Randal D. Koster1, Robert A. Lucchesi1,3, D. Merkova1,3, J. E. Nielsen1,3, Gary Partyka1,3, Steven Pawson1, William M. Putman1, Michele M. Rienecker1, Siegfried D. Schubert1,3, Meta Sienkiewicz1,3, Bin Zhao1,6
1Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
2Universities Space Research Association, Columbia, Maryland
3Science Systems and Applications, Inc., Lanham, Maryland
4Morgan State University, Baltimore, Maryland
5Earth System Science Interdisciplinary Center, University of Maryland, College Park, College Park, Maryland
6Science Applications International Corporation, Beltsville, Maryland
Tóm tắt
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).
