Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature?
With progressing global warming, snowfall in Antarctica is expected to increase, which could counteract or even temporarily overcompensate ice-sheet mass losses through increased ice discharge, calving and melting. For sea-level projections it is therefore vital to understand the processes determini...
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ftcopernicus:oai:publications.copernicus.org:tcd108477 2023-05-15T13:38:41+02:00 Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? Nicola, Lena Notz, Dirk Winkelmann, Ricarda 2023-01-02 application/pdf https://doi.org/10.5194/tc-2022-254 https://tc.copernicus.org/preprints/tc-2022-254/ eng eng doi:10.5194/tc-2022-254 https://tc.copernicus.org/preprints/tc-2022-254/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-2022-254 2023-01-09T17:22:43Z With progressing global warming, snowfall in Antarctica is expected to increase, which could counteract or even temporarily overcompensate ice-sheet mass losses through increased ice discharge, calving and melting. For sea-level projections it is therefore vital to understand the processes determining snowfall changes in Antarctica. Here we revisit the relationship between Antarctic temperature changes and precipitation changes, identifying and explaining regional differences and deviations from the theoretical approach based on the Clausius-Clapeyron relationship. Analysing the latest estimates from global (CMIP6) and regional (RACMO2.3) model projections, we find an average increase of 5.5 % in annual precipitation over Antarctica per degree of warming, with a minimum sensitivity of 2 % K -1 near Siple Coast, and a maximum sensitivity > 10 % K -1 at the East Antarctic Plateau region. This large range can be explained by the prevailing climatic conditions, with local temperatures determining the Clausius-Clapeyron sensitivity that is counteracted in some regions by the prevalence of the coastal wind regime. We compare different approaches of deriving the sensitivity factor, which in some cases can lead to sensitivity changes of up to 7 % for the same model. Importantly, local sensitivity-factors are found to be strongly dependent on the warming level, suggesting that some ice-sheet models which base their precipitation estimates on parameterizations derived from these sensitivity factors might overestimate warming-induced snowfall changes, particularly in high-emission scenarios. This would have consequences for Antarctic sea-level projections for this century and beyond. Text Antarc* Antarctic Antarctica Ice Sheet Copernicus Publications: E-Journals Antarctic Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) Siple Coast ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
With progressing global warming, snowfall in Antarctica is expected to increase, which could counteract or even temporarily overcompensate ice-sheet mass losses through increased ice discharge, calving and melting. For sea-level projections it is therefore vital to understand the processes determining snowfall changes in Antarctica. Here we revisit the relationship between Antarctic temperature changes and precipitation changes, identifying and explaining regional differences and deviations from the theoretical approach based on the Clausius-Clapeyron relationship. Analysing the latest estimates from global (CMIP6) and regional (RACMO2.3) model projections, we find an average increase of 5.5 % in annual precipitation over Antarctica per degree of warming, with a minimum sensitivity of 2 % K -1 near Siple Coast, and a maximum sensitivity > 10 % K -1 at the East Antarctic Plateau region. This large range can be explained by the prevailing climatic conditions, with local temperatures determining the Clausius-Clapeyron sensitivity that is counteracted in some regions by the prevalence of the coastal wind regime. We compare different approaches of deriving the sensitivity factor, which in some cases can lead to sensitivity changes of up to 7 % for the same model. Importantly, local sensitivity-factors are found to be strongly dependent on the warming level, suggesting that some ice-sheet models which base their precipitation estimates on parameterizations derived from these sensitivity factors might overestimate warming-induced snowfall changes, particularly in high-emission scenarios. This would have consequences for Antarctic sea-level projections for this century and beyond. |
format |
Text |
author |
Nicola, Lena Notz, Dirk Winkelmann, Ricarda |
spellingShingle |
Nicola, Lena Notz, Dirk Winkelmann, Ricarda Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
author_facet |
Nicola, Lena Notz, Dirk Winkelmann, Ricarda |
author_sort |
Nicola, Lena |
title |
Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
title_short |
Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
title_full |
Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
title_fullStr |
Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
title_full_unstemmed |
Revisiting temperature sensitivity: How does Antarctic precipitation change with temperature? |
title_sort |
revisiting temperature sensitivity: how does antarctic precipitation change with temperature? |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-2022-254 https://tc.copernicus.org/preprints/tc-2022-254/ |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) ENVELOPE(-155.000,-155.000,-82.000,-82.000) |
geographic |
Antarctic Siple Siple Coast |
geographic_facet |
Antarctic Siple Siple Coast |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2022-254 https://tc.copernicus.org/preprints/tc-2022-254/ |
op_doi |
https://doi.org/10.5194/tc-2022-254 |
_version_ |
1766109772718800896 |