Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans
The Southern Ocean cloud cover modeled by the Interim ECMWF Re-Analysis (ERA-Interim) and Modern- Era Retrospective Analysis for Research and Applications (MERRA) reanalyses are compared against Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) obs...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20140012049 2023-05-15T18:25:41+02:00 Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans Booth, James F. Del Genio, Anthony D. Naud, Catherine M. Unclassified, Unlimited, Publicly available March 1, 2014 application/pdf http://hdl.handle.net/2060/20140012049 unknown Document ID: 20140012049 http://hdl.handle.net/2060/20140012049 Copyright, Distribution as joint owner in the copyright CASI Meteorology and Climatology GSFC-E-DAA-TN12411 Journal of Climate; 27; 5; 2109-2124 2014 ftnasantrs 2019-07-21T00:24:50Z The Southern Ocean cloud cover modeled by the Interim ECMWF Re-Analysis (ERA-Interim) and Modern- Era Retrospective Analysis for Research and Applications (MERRA) reanalyses are compared against Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) observations. ERA-Interim monthly mean cloud amounts match the observations within 5%, while MERRA significantly underestimates the cloud amount. For a compositing analysis of clouds in warm season extratropical cyclones, both reanalyses show a low bias in cloud cover. They display a larger bias to the west of the cyclones in the region of subsidence behind the cold fronts. This low bias is larger for MERRA than for ERA-Interim. Both MODIS and MISR retrievals indicate that the clouds in this sector are at a low altitude, often composed of liquid, and of a broken nature. The combined CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) cloud profiles confirm these passive observations, but they also reveal that low-level clouds in other parts of the cyclones are also not properly represented in the reanalyses. The two reanalyses are in fairly good agreement for the dynamic and thermodynamic characteristics of the cyclones, suggesting that the cloud, convection, or boundary layer schemes are the problem instead. An examination of the lower-tropospheric stability distribution in the cyclones from both reanalyses suggests that the parameterization of shallow cumulus clouds may contribute in a large part to the problem. However, the differences in the cloud schemes and in particular in the precipitation processes, which may also contribute, cannot be excluded. Other/Unknown Material Southern Ocean NASA Technical Reports Server (NTRS) Merra ENVELOPE(12.615,12.615,65.816,65.816) Southern Ocean |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
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topic |
Meteorology and Climatology |
spellingShingle |
Meteorology and Climatology Booth, James F. Del Genio, Anthony D. Naud, Catherine M. Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
topic_facet |
Meteorology and Climatology |
description |
The Southern Ocean cloud cover modeled by the Interim ECMWF Re-Analysis (ERA-Interim) and Modern- Era Retrospective Analysis for Research and Applications (MERRA) reanalyses are compared against Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) observations. ERA-Interim monthly mean cloud amounts match the observations within 5%, while MERRA significantly underestimates the cloud amount. For a compositing analysis of clouds in warm season extratropical cyclones, both reanalyses show a low bias in cloud cover. They display a larger bias to the west of the cyclones in the region of subsidence behind the cold fronts. This low bias is larger for MERRA than for ERA-Interim. Both MODIS and MISR retrievals indicate that the clouds in this sector are at a low altitude, often composed of liquid, and of a broken nature. The combined CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) cloud profiles confirm these passive observations, but they also reveal that low-level clouds in other parts of the cyclones are also not properly represented in the reanalyses. The two reanalyses are in fairly good agreement for the dynamic and thermodynamic characteristics of the cyclones, suggesting that the cloud, convection, or boundary layer schemes are the problem instead. An examination of the lower-tropospheric stability distribution in the cyclones from both reanalyses suggests that the parameterization of shallow cumulus clouds may contribute in a large part to the problem. However, the differences in the cloud schemes and in particular in the precipitation processes, which may also contribute, cannot be excluded. |
format |
Other/Unknown Material |
author |
Booth, James F. Del Genio, Anthony D. Naud, Catherine M. |
author_facet |
Booth, James F. Del Genio, Anthony D. Naud, Catherine M. |
author_sort |
Booth, James F. |
title |
Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
title_short |
Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
title_full |
Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
title_fullStr |
Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
title_full_unstemmed |
Evaluation of ERA-interim and MERRA Cloudiness in the Southern Oceans |
title_sort |
evaluation of era-interim and merra cloudiness in the southern oceans |
publishDate |
2014 |
url |
http://hdl.handle.net/2060/20140012049 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(12.615,12.615,65.816,65.816) |
geographic |
Merra Southern Ocean |
geographic_facet |
Merra Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
CASI |
op_relation |
Document ID: 20140012049 http://hdl.handle.net/2060/20140012049 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766207284345569280 |