The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model
An accurate historical record of evolving Arctic conditions is integral to furthering our understanding of climate processes and to providing a foundation for predicting future climate scenarios in northern high latitudes. Atmospheric reanalyses are seen as an important source of information on the...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20180008512 2023-05-15T14:36:50+02:00 The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model Cullather, Richard I. Collow, Allison B. Marquardt Bosilovich, Michael G. Unclassified, Unlimited, Publicly available December 10, 2018 application/pdf http://hdl.handle.net/2060/20180008512 unknown Document ID: 20180008512 http://hdl.handle.net/2060/20180008512 Copyright, Public use permitted CASI Meteorology and Climatology Geosciences (General) A13M-1478 GSFC-E-DAA-TN63826 American Geophysical Union (AGU) Fall Meeting; 10-14 Dec. 2018; Washington, D.C.; United States 2018 ftnasantrs 2019-07-20T23:08:01Z An accurate historical record of evolving Arctic conditions is integral to furthering our understanding of climate processes and to providing a foundation for predicting future climate scenarios in northern high latitudes. Atmospheric reanalyses are seen as an important source of information on the recent past for the data-sparse Arctic region. An assessment of near-surface Arctic air temperatures finds significant discrepancies among the various modern reanalyses. An important point is the treatment of surface boundary conditions: specifically, the sea ice cover and sea surface temperatures (SSTs) over the Arctic Ocean. Reanalyses use different methodologies and data sources for SSTs and sea ice concentration boundary forcing. Notably, the Modern Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) both use boundary forcing derived from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) over an extended, overlapping period of time. This allows for an examination of differences between the two systems while both concurrently employ the same fractional sea ice coverage. To further understand these differences, an ensemble of AMIP-style simulations using the MERRA-2 atmospheric model - but without data assimilation - shows considerable differences in Arctic temperatures as compared to reanalyses, particularly in autumn and winter months. Results from the AMIP simulations suggest that the surface representation over sea ice used in the MERRA-2 model provides an intrinsic warm bias and obfuscates Arctic Amplification, an established feature present in observations and reanalyses. An additional ensemble of AMIP-style simulations using the MERRA-2 atmospheric model was performed using boundary conditions derived from the ERA-Interim reanalysis. An in-depth comparison of surface temperatures over the Arctic from the two reanalyses and two AMIP-style ensembles will be presented, along with an assessment of the effects of the varying Arctic temperature time series on the atmospheric general circulation and energy budget. Other/Unknown Material Arctic Arctic Ocean Sea ice NASA Technical Reports Server (NTRS) Arctic Arctic Ocean Merra ENVELOPE(12.615,12.615,65.816,65.816) |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Meteorology and Climatology Geosciences (General) |
spellingShingle |
Meteorology and Climatology Geosciences (General) Cullather, Richard I. Collow, Allison B. Marquardt Bosilovich, Michael G. The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
topic_facet |
Meteorology and Climatology Geosciences (General) |
description |
An accurate historical record of evolving Arctic conditions is integral to furthering our understanding of climate processes and to providing a foundation for predicting future climate scenarios in northern high latitudes. Atmospheric reanalyses are seen as an important source of information on the recent past for the data-sparse Arctic region. An assessment of near-surface Arctic air temperatures finds significant discrepancies among the various modern reanalyses. An important point is the treatment of surface boundary conditions: specifically, the sea ice cover and sea surface temperatures (SSTs) over the Arctic Ocean. Reanalyses use different methodologies and data sources for SSTs and sea ice concentration boundary forcing. Notably, the Modern Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) and the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) both use boundary forcing derived from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) over an extended, overlapping period of time. This allows for an examination of differences between the two systems while both concurrently employ the same fractional sea ice coverage. To further understand these differences, an ensemble of AMIP-style simulations using the MERRA-2 atmospheric model - but without data assimilation - shows considerable differences in Arctic temperatures as compared to reanalyses, particularly in autumn and winter months. Results from the AMIP simulations suggest that the surface representation over sea ice used in the MERRA-2 model provides an intrinsic warm bias and obfuscates Arctic Amplification, an established feature present in observations and reanalyses. An additional ensemble of AMIP-style simulations using the MERRA-2 atmospheric model was performed using boundary conditions derived from the ERA-Interim reanalysis. An in-depth comparison of surface temperatures over the Arctic from the two reanalyses and two AMIP-style ensembles will be presented, along with an assessment of the effects of the varying Arctic temperature time series on the atmospheric general circulation and energy budget. |
format |
Other/Unknown Material |
author |
Cullather, Richard I. Collow, Allison B. Marquardt Bosilovich, Michael G. |
author_facet |
Cullather, Richard I. Collow, Allison B. Marquardt Bosilovich, Michael G. |
author_sort |
Cullather, Richard I. |
title |
The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
title_short |
The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
title_full |
The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
title_fullStr |
The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
title_full_unstemmed |
The Influence of Prescribed Boundary Conditions on Near-Surface Temperature over the Arctic in the MERRA-2 Atmospheric Model |
title_sort |
influence of prescribed boundary conditions on near-surface temperature over the arctic in the merra-2 atmospheric model |
publishDate |
2018 |
url |
http://hdl.handle.net/2060/20180008512 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(12.615,12.615,65.816,65.816) |
geographic |
Arctic Arctic Ocean Merra |
geographic_facet |
Arctic Arctic Ocean Merra |
genre |
Arctic Arctic Ocean Sea ice |
genre_facet |
Arctic Arctic Ocean Sea ice |
op_source |
CASI |
op_relation |
Document ID: 20180008512 http://hdl.handle.net/2060/20180008512 |
op_rights |
Copyright, Public use permitted |
_version_ |
1766309366434103296 |