The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss
In recent decades, the Arctic climate has experienced substantial climactic change, including significant decreases in both sea ice extent and Greenland Ice Sheet (GrIS) surface mass balance. These trends are overlain by substantial interannual variability in atmospheric circulation driven by large-...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20180008754 2023-05-15T15:03:36+02:00 The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss Cullather, Richard Andrews, Lauren C. Molod, Andrea M. Unclassified, Unlimited, Publicly available December 10, 2018 application/pdf http://hdl.handle.net/2060/20180008754 unknown Document ID: 20180008754 http://hdl.handle.net/2060/20180008754 Copyright, Public use permitted CASI Meteorology and Climatology GSFC-E-DAA-TN64421 AGU 2018 Fall Meeting; 10-14 Dec. 2018; Washington, D.C.; United States 2018 ftnasantrs 2019-07-20T23:07:40Z In recent decades, the Arctic climate has experienced substantial climactic change, including significant decreases in both sea ice extent and Greenland Ice Sheet (GrIS) surface mass balance. These trends are overlain by substantial interannual variability in atmospheric circulation driven by large-scale atmospheric teleconnection patterns. In addition, there is evidence to suggest that the removal of Arctic sea ice can alter local atmospheric circulation through increased air temperature, clouds, and water vapor, which may contribute to increased surface melting on the GrIS. Here, we seek to characterize how these processes are linked to Greenland Ice Sheet surface mass loss and constrain how the representation of these forcings can impact the prediction of meltwater runoff within the NASA Goddard Earth Observing System Model (GEOS) seasonal-to-subseasonal forecasting system (S2S v2.1). To do this, we use a combination of the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) reanalysis product, retrospective seasonal forecasts from the GEOS S2S v2.1, and independent GEOS simulations. Results from MERRA-2 reanalysis indicate that the negative phase of the North Atlantic Oscillation (NAO) results in warm surface air temperatures and reduced precipitation across Greenland, both of which act to enhance summer ice surface mass losses. When compared with MERRA-2, retrospective forecasts from the GEOS S2S v2.1 system effectively reproduce the pattern of summer GrIS surface mass loss and demonstrate reasonable skill in predicting the magnitude of meltwater runoff at leads of 1 to 3 months. However, during periods with a strong negative NAO, ice sheet surface mass balance is substantially underestimated. This pattern is also associated with an underprediction of the Greenland Blocking Index height and over prediction of sea ice extent, suggesting that both local and non-local forcings may play a role in the reduced prediction skill during these periods. Using both retrospective forecasts and independent simulations, we characterize the relative importance of local and non-local mechanisms in driving summer GrIS Other/Unknown Material Arctic Greenland Ice Sheet North Atlantic North Atlantic oscillation Sea ice NASA Technical Reports Server (NTRS) Arctic Greenland 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 |
spellingShingle |
Meteorology and Climatology Cullather, Richard Andrews, Lauren C. Molod, Andrea M. The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
topic_facet |
Meteorology and Climatology |
description |
In recent decades, the Arctic climate has experienced substantial climactic change, including significant decreases in both sea ice extent and Greenland Ice Sheet (GrIS) surface mass balance. These trends are overlain by substantial interannual variability in atmospheric circulation driven by large-scale atmospheric teleconnection patterns. In addition, there is evidence to suggest that the removal of Arctic sea ice can alter local atmospheric circulation through increased air temperature, clouds, and water vapor, which may contribute to increased surface melting on the GrIS. Here, we seek to characterize how these processes are linked to Greenland Ice Sheet surface mass loss and constrain how the representation of these forcings can impact the prediction of meltwater runoff within the NASA Goddard Earth Observing System Model (GEOS) seasonal-to-subseasonal forecasting system (S2S v2.1). To do this, we use a combination of the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) reanalysis product, retrospective seasonal forecasts from the GEOS S2S v2.1, and independent GEOS simulations. Results from MERRA-2 reanalysis indicate that the negative phase of the North Atlantic Oscillation (NAO) results in warm surface air temperatures and reduced precipitation across Greenland, both of which act to enhance summer ice surface mass losses. When compared with MERRA-2, retrospective forecasts from the GEOS S2S v2.1 system effectively reproduce the pattern of summer GrIS surface mass loss and demonstrate reasonable skill in predicting the magnitude of meltwater runoff at leads of 1 to 3 months. However, during periods with a strong negative NAO, ice sheet surface mass balance is substantially underestimated. This pattern is also associated with an underprediction of the Greenland Blocking Index height and over prediction of sea ice extent, suggesting that both local and non-local forcings may play a role in the reduced prediction skill during these periods. Using both retrospective forecasts and independent simulations, we characterize the relative importance of local and non-local mechanisms in driving summer GrIS |
format |
Other/Unknown Material |
author |
Cullather, Richard Andrews, Lauren C. Molod, Andrea M. |
author_facet |
Cullather, Richard Andrews, Lauren C. Molod, Andrea M. |
author_sort |
Cullather, Richard |
title |
The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
title_short |
The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
title_full |
The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
title_fullStr |
The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
title_full_unstemmed |
The Role of Atmospheric Teleconnections and Local Forcings in Predicting Greenland Ice Sheet Surface Mass Loss |
title_sort |
role of atmospheric teleconnections and local forcings in predicting greenland ice sheet surface mass loss |
publishDate |
2018 |
url |
http://hdl.handle.net/2060/20180008754 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(12.615,12.615,65.816,65.816) |
geographic |
Arctic Greenland Merra |
geographic_facet |
Arctic Greenland Merra |
genre |
Arctic Greenland Ice Sheet North Atlantic North Atlantic oscillation Sea ice |
genre_facet |
Arctic Greenland Ice Sheet North Atlantic North Atlantic oscillation Sea ice |
op_source |
CASI |
op_relation |
Document ID: 20180008754 http://hdl.handle.net/2060/20180008754 |
op_rights |
Copyright, Public use permitted |
_version_ |
1766335468152029184 |