Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2
The Modern-Era Retrospective Analysis for Research and Applications-2 (MERRA2) version of the Goddard Earth Observing System-5 (GEOS-5) atmospheric general circulation model (AGCM) is currently in use in the NASA Global Modeling and Assimilation Office (GMAO) at a wide range of resolutions for a var...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-05-01
|
| Series: | Geoscientific Model Development |
| Online Access: | http://www.geosci-model-dev.net/8/1339/2015/gmd-8-1339-2015.pdf |
| _version_ | 1818519900357918720 |
|---|---|
| author | A. Molod L. Takacs M. Suarez J. Bacmeister |
| author_facet | A. Molod L. Takacs M. Suarez J. Bacmeister |
| author_sort | A. Molod |
| collection | DOAJ |
| description | The Modern-Era Retrospective Analysis for Research and Applications-2
(MERRA2) version of the Goddard Earth Observing System-5 (GEOS-5) atmospheric
general circulation model (AGCM) is currently in use in the NASA Global
Modeling and Assimilation Office (GMAO) at a wide range of resolutions for a
variety of applications. Details of the changes in parameterizations
subsequent to the version in the original MERRA reanalysis are presented
here. Results of a series of atmosphere-only sensitivity studies are shown to
demonstrate changes in simulated climate associated with specific changes in
physical parameterizations, and the impact of the newly implemented
resolution-aware behavior on simulations at different resolutions is
demonstrated. The GEOS-5 AGCM presented here is the model used as part of the
GMAO MERRA2 reanalysis, global mesoscale simulations at 10 km resolution
through 1.5 km resolution, the real-time numerical weather prediction
system, and for atmosphere-only, coupled ocean-atmosphere and coupled
atmosphere-chemistry simulations.
<br><br>
The seasonal mean climate of the MERRA2 version of the GEOS-5 AGCM represents
a substantial improvement over the simulated climate of the MERRA version at
all resolutions and for all applications. Fundamental improvements in
simulated climate are associated with the increased re-evaporation of frozen
precipitation and cloud condensate, resulting in a wetter atmosphere.
Improvements in simulated climate are also shown to be attributable to
changes in the background gravity wave drag, and to upgrades in the
relationship between the ocean surface stress and the ocean roughness. The
series of resolution-aware parameters related to the moist physics
was shown to result in improvements
at higher resolutions and result in AGCM simulations that exhibit seamless
behavior across different resolutions and applications. |
| first_indexed | 2024-12-11T01:30:14Z |
| format | Article |
| id | doaj.art-d2b2fe86a36143bb948a96499e6a4faa |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-12-11T01:30:14Z |
| publishDate | 2015-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-d2b2fe86a36143bb948a96499e6a4faa2022-12-22T01:25:23ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032015-05-01851339135610.5194/gmd-8-1339-2015Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2A. Molod0L. Takacs1M. Suarez2J. Bacmeister3University of Maryland College Park, College Park, MD, USAScience Systems and Applications, Inc., Lanham, MD, USANASA Goddard Space Flight Center, Greenbelt, MD, USANational Center for Atmospheric Research, Boulder, CO, USAThe Modern-Era Retrospective Analysis for Research and Applications-2 (MERRA2) version of the Goddard Earth Observing System-5 (GEOS-5) atmospheric general circulation model (AGCM) is currently in use in the NASA Global Modeling and Assimilation Office (GMAO) at a wide range of resolutions for a variety of applications. Details of the changes in parameterizations subsequent to the version in the original MERRA reanalysis are presented here. Results of a series of atmosphere-only sensitivity studies are shown to demonstrate changes in simulated climate associated with specific changes in physical parameterizations, and the impact of the newly implemented resolution-aware behavior on simulations at different resolutions is demonstrated. The GEOS-5 AGCM presented here is the model used as part of the GMAO MERRA2 reanalysis, global mesoscale simulations at 10 km resolution through 1.5 km resolution, the real-time numerical weather prediction system, and for atmosphere-only, coupled ocean-atmosphere and coupled atmosphere-chemistry simulations. <br><br> The seasonal mean climate of the MERRA2 version of the GEOS-5 AGCM represents a substantial improvement over the simulated climate of the MERRA version at all resolutions and for all applications. Fundamental improvements in simulated climate are associated with the increased re-evaporation of frozen precipitation and cloud condensate, resulting in a wetter atmosphere. Improvements in simulated climate are also shown to be attributable to changes in the background gravity wave drag, and to upgrades in the relationship between the ocean surface stress and the ocean roughness. The series of resolution-aware parameters related to the moist physics was shown to result in improvements at higher resolutions and result in AGCM simulations that exhibit seamless behavior across different resolutions and applications.http://www.geosci-model-dev.net/8/1339/2015/gmd-8-1339-2015.pdf |
| spellingShingle | A. Molod L. Takacs M. Suarez J. Bacmeister Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 Geoscientific Model Development |
| title | Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 |
| title_full | Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 |
| title_fullStr | Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 |
| title_full_unstemmed | Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 |
| title_short | Development of the GEOS-5 atmospheric general circulation model: evolution from MERRA to MERRA2 |
| title_sort | development of the geos 5 atmospheric general circulation model evolution from merra to merra2 |
| url | http://www.geosci-model-dev.net/8/1339/2015/gmd-8-1339-2015.pdf |
| work_keys_str_mv | AT amolod developmentofthegeos5atmosphericgeneralcirculationmodelevolutionfrommerratomerra2 AT ltakacs developmentofthegeos5atmosphericgeneralcirculationmodelevolutionfrommerratomerra2 AT msuarez developmentofthegeos5atmosphericgeneralcirculationmodelevolutionfrommerratomerra2 AT jbacmeister developmentofthegeos5atmosphericgeneralcirculationmodelevolutionfrommerratomerra2 |