The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate
Climate change is particularly strong in Greenland primarily as a result of changes in advection of heat and moisture fluxes from lower latitudes. The atmospheric structures involved influence the surface mass balance and their pattern are largely explained by climate oscillations which describe the...
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ftcopernicus:oai:publications.copernicus.org:tcd100263 2023-05-15T16:26:37+02:00 The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate Silva, Tiago Abermann, Jakob Noël, Brice Shahi, Sonika Berg, Willem Jan Schöner, Wolfgang 2022-01-14 application/pdf https://doi.org/10.5194/tc-2021-388 https://tc.copernicus.org/preprints/tc-2021-388/ eng eng doi:10.5194/tc-2021-388 https://tc.copernicus.org/preprints/tc-2021-388/ eISSN: 1994-0424 Text 2022 ftcopernicus https://doi.org/10.5194/tc-2021-388 2022-01-17T17:22:17Z Climate change is particularly strong in Greenland primarily as a result of changes in advection of heat and moisture fluxes from lower latitudes. The atmospheric structures involved influence the surface mass balance and their pattern are largely explained by climate oscillations which describe the internal climate variability. Based on a clustering method, we combine the Greenland Blocking Index and the North Atlantic Oscillation index with the vertically integrated water vapor to analyze inter-seasonal and regional impacts of the North Atlantic influence on the surface energy components over the Greenland Ice Sheet. In comparison to the reference period (1959–1990), the atmosphere has become warmer and moister during recent decades (1991–2020) for contrasting atmospheric circulation patterns. Particularly in the northern regions, increases in tropospheric water vapor enhance incoming longwave radiation and thus contribute to surface warming. Surface warming is most evident in winter, although its magnitude and spatial extent depend on the prevailing atmospheric configuration. Relative to the reference period, increases in sensible heat flux in the summer ablation zone are found irrespective of the atmospheric circulation pattern. Especially in the northern ablation zone, these are explained by the stronger katabatic winds which are partly driven by the larger surface pressure gradients between the ice/snow-covered surface and adjacent seas, and by the larger temperature gradient between near-surface air and the air above. Increases in net shortwave radiation are mainly connected to high-pressure systems. Whereas in the southern part of Greenland the atmosphere has gotten optical thinner, thus allowing more incoming shortwave radiation to reach the surface, in the northern part the incoming shortwave radiation flux has changed little with respect to the reference period, but the surface albedo decreased due to the expansion of the bare ice area. Text Greenland Ice Sheet North Atlantic North Atlantic oscillation Copernicus Publications: E-Journals Greenland |
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Copernicus Publications: E-Journals |
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language |
English |
description |
Climate change is particularly strong in Greenland primarily as a result of changes in advection of heat and moisture fluxes from lower latitudes. The atmospheric structures involved influence the surface mass balance and their pattern are largely explained by climate oscillations which describe the internal climate variability. Based on a clustering method, we combine the Greenland Blocking Index and the North Atlantic Oscillation index with the vertically integrated water vapor to analyze inter-seasonal and regional impacts of the North Atlantic influence on the surface energy components over the Greenland Ice Sheet. In comparison to the reference period (1959–1990), the atmosphere has become warmer and moister during recent decades (1991–2020) for contrasting atmospheric circulation patterns. Particularly in the northern regions, increases in tropospheric water vapor enhance incoming longwave radiation and thus contribute to surface warming. Surface warming is most evident in winter, although its magnitude and spatial extent depend on the prevailing atmospheric configuration. Relative to the reference period, increases in sensible heat flux in the summer ablation zone are found irrespective of the atmospheric circulation pattern. Especially in the northern ablation zone, these are explained by the stronger katabatic winds which are partly driven by the larger surface pressure gradients between the ice/snow-covered surface and adjacent seas, and by the larger temperature gradient between near-surface air and the air above. Increases in net shortwave radiation are mainly connected to high-pressure systems. Whereas in the southern part of Greenland the atmosphere has gotten optical thinner, thus allowing more incoming shortwave radiation to reach the surface, in the northern part the incoming shortwave radiation flux has changed little with respect to the reference period, but the surface albedo decreased due to the expansion of the bare ice area. |
format |
Text |
author |
Silva, Tiago Abermann, Jakob Noël, Brice Shahi, Sonika Berg, Willem Jan Schöner, Wolfgang |
spellingShingle |
Silva, Tiago Abermann, Jakob Noël, Brice Shahi, Sonika Berg, Willem Jan Schöner, Wolfgang The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
author_facet |
Silva, Tiago Abermann, Jakob Noël, Brice Shahi, Sonika Berg, Willem Jan Schöner, Wolfgang |
author_sort |
Silva, Tiago |
title |
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
title_short |
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
title_full |
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
title_fullStr |
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
title_full_unstemmed |
The impact of climate oscillations on the surface energy budget over the Greenland Ice Sheet in a changing climate |
title_sort |
impact of climate oscillations on the surface energy budget over the greenland ice sheet in a changing climate |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-2021-388 https://tc.copernicus.org/preprints/tc-2021-388/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet North Atlantic North Atlantic oscillation |
genre_facet |
Greenland Ice Sheet North Atlantic North Atlantic oscillation |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2021-388 https://tc.copernicus.org/preprints/tc-2021-388/ |
op_doi |
https://doi.org/10.5194/tc-2021-388 |
_version_ |
1766015550906957824 |