Highlights on key polar processes driving the Antarctic surface mass balance
Abstract: Ice sheet mass balance results of the small imbalance between ice flow discharging in the ocean and net snow accumulation on the ice sheet surface, i.e. the surface mass balance (SMB). Past change in ice sheet mass can be assessed using satellite altimetry, gravimetry, or the input-output...
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ftzenodo:oai:zenodo.org:4327066 2023-05-15T13:34:31+02:00 Highlights on key polar processes driving the Antarctic surface mass balance Cécile Agosta Christoph Kittel Charles Amory Xavier Fettweis 2019-12-11 https://zenodo.org/record/4327066 https://doi.org/10.5281/zenodo.4327066 unknown doi:10.5281/zenodo.4327065 https://zenodo.org/record/4327066 https://doi.org/10.5281/zenodo.4327066 oai:zenodo.org:4327066 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode Antarctic Surface mass balance info:eu-repo/semantics/lecture presentation 2019 ftzenodo https://doi.org/10.5281/zenodo.432706610.5281/zenodo.4327065 2023-03-11T04:10:27Z Abstract: Ice sheet mass balance results of the small imbalance between ice flow discharging in the ocean and net snow accumulation on the ice sheet surface, i.e. the surface mass balance (SMB). Past change in ice sheet mass can be assessed using satellite altimetry, gravimetry, or the input-output method, which all request SMB estimates.The input-output method, which consists in separately modeling ice dynamics and SMB, is also the only way to project future trends. Here we use the polar-oriented regional climate model MAR to estimate the Antarctic SMB for the period 1979-2018 using forcing from 7 reanalyses: ERA-5, ERA-Interim, JRA-55, MERRA2, NCEP1, NCEP2, and 20CRv2. We show that spatial patterns of SMB modeled by the reanalyses diverge significantly between each-other, whereas the spread is insignificant after downscaling with MAR. SMB modeled with MAR is markedly closer to observations than the original reanalyses outputs. Divergences in SMB between reanalyses and MAR are driven by divergences in snowfall amounts, which are explained by processes related to clouds and precipitation in the atmosphere (notably cloud-precipitation conversion, precipitation advection and precipitation sublimation) rather than by model resolution. The temporal variability of downscaled SMB is however strongly related to the forcing reanalysis variability. This study emphasis the importance of polar-specific processes and of their implementation in climate models, particularly in view of atmosphere-ice sheet coupling. Conference Object Antarc* Antarctic Ice Sheet Zenodo Antarctic The Antarctic |
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Antarctic Surface mass balance |
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Antarctic Surface mass balance Cécile Agosta Christoph Kittel Charles Amory Xavier Fettweis Highlights on key polar processes driving the Antarctic surface mass balance |
topic_facet |
Antarctic Surface mass balance |
description |
Abstract: Ice sheet mass balance results of the small imbalance between ice flow discharging in the ocean and net snow accumulation on the ice sheet surface, i.e. the surface mass balance (SMB). Past change in ice sheet mass can be assessed using satellite altimetry, gravimetry, or the input-output method, which all request SMB estimates.The input-output method, which consists in separately modeling ice dynamics and SMB, is also the only way to project future trends. Here we use the polar-oriented regional climate model MAR to estimate the Antarctic SMB for the period 1979-2018 using forcing from 7 reanalyses: ERA-5, ERA-Interim, JRA-55, MERRA2, NCEP1, NCEP2, and 20CRv2. We show that spatial patterns of SMB modeled by the reanalyses diverge significantly between each-other, whereas the spread is insignificant after downscaling with MAR. SMB modeled with MAR is markedly closer to observations than the original reanalyses outputs. Divergences in SMB between reanalyses and MAR are driven by divergences in snowfall amounts, which are explained by processes related to clouds and precipitation in the atmosphere (notably cloud-precipitation conversion, precipitation advection and precipitation sublimation) rather than by model resolution. The temporal variability of downscaled SMB is however strongly related to the forcing reanalysis variability. This study emphasis the importance of polar-specific processes and of their implementation in climate models, particularly in view of atmosphere-ice sheet coupling. |
format |
Conference Object |
author |
Cécile Agosta Christoph Kittel Charles Amory Xavier Fettweis |
author_facet |
Cécile Agosta Christoph Kittel Charles Amory Xavier Fettweis |
author_sort |
Cécile Agosta |
title |
Highlights on key polar processes driving the Antarctic surface mass balance |
title_short |
Highlights on key polar processes driving the Antarctic surface mass balance |
title_full |
Highlights on key polar processes driving the Antarctic surface mass balance |
title_fullStr |
Highlights on key polar processes driving the Antarctic surface mass balance |
title_full_unstemmed |
Highlights on key polar processes driving the Antarctic surface mass balance |
title_sort |
highlights on key polar processes driving the antarctic surface mass balance |
publishDate |
2019 |
url |
https://zenodo.org/record/4327066 https://doi.org/10.5281/zenodo.4327066 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
doi:10.5281/zenodo.4327065 https://zenodo.org/record/4327066 https://doi.org/10.5281/zenodo.4327066 oai:zenodo.org:4327066 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by/4.0/legalcode |
op_doi |
https://doi.org/10.5281/zenodo.432706610.5281/zenodo.4327065 |
_version_ |
1766053951064506368 |