Influence of temperature fluctuations on equilibrium ice sheet volume
Forecasting the future sea level relies on accurate modeling of the response of the Greenland and Antarctic ice sheets to changing temperatures. The surface mass balance (SMB) of the Greenland Ice Sheet (GrIS) has a nonlinear response to warming. Cold and warm anomalies of equal size do not cancel o...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:0902de3461944e25ae7a4c7c37308ee8 2023-05-15T13:36:06+02:00 Influence of temperature fluctuations on equilibrium ice sheet volume T. B. Mikkelsen A. Grinsted P. Ditlevsen 2018-01-01 https://doi.org/10.5194/tc-12-39-2018 https://www.the-cryosphere.net/12/39/2018/tc-12-39-2018.pdf https://doaj.org/article/0902de3461944e25ae7a4c7c37308ee8 en eng Copernicus Publications doi:10.5194/tc-12-39-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/39/2018/tc-12-39-2018.pdf https://doaj.org/article/0902de3461944e25ae7a4c7c37308ee8 undefined The Cryosphere, Vol 12, Pp 39-47 (2018) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/tc-12-39-2018 2023-01-22T18:19:22Z Forecasting the future sea level relies on accurate modeling of the response of the Greenland and Antarctic ice sheets to changing temperatures. The surface mass balance (SMB) of the Greenland Ice Sheet (GrIS) has a nonlinear response to warming. Cold and warm anomalies of equal size do not cancel out and it is therefore important to consider the effect of interannual fluctuations in temperature. We find that the steady-state volume of an ice sheet is biased toward larger size if interannual temperature fluctuations are not taken into account in numerical modeling of the ice sheet. We illustrate this in a simple ice sheet model and find that the equilibrium ice volume is approximately 1 m SLE (meters sea level equivalent) smaller when the simple model is forced with fluctuating temperatures as opposed to a stable climate. It is therefore important to consider the effect of interannual temperature fluctuations when designing long experiments such as paleo-spin-ups. We show how the magnitude of the potential bias can be quantified statistically. For recent simulations of the Greenland Ice Sheet, we estimate the bias to be 30 Gt yr−1 (24–59 Gt yr−1, 95 % credibility) for a warming of 3 °C above preindustrial values, or 13 % (10–25, 95 % credibility) of the present-day rate of ice loss. Models of the Greenland Ice Sheet show a collapse threshold beyond which the ice sheet becomes unsustainable. The proximity of the threshold will be underestimated if temperature fluctuations are not taken into account. We estimate the bias to be 0.12 °C (0.10–0.18 °C, 95 % credibility) for a recent estimate of the threshold. In light of our findings it is important to gauge the extent to which this increased variability will influence the mass balance of the ice sheets. Article in Journal/Newspaper Antarc* Antarctic Greenland Ice Sheet The Cryosphere Unknown Antarctic Greenland The Cryosphere 12 1 39 47 |
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geo envir T. B. Mikkelsen A. Grinsted P. Ditlevsen Influence of temperature fluctuations on equilibrium ice sheet volume |
topic_facet |
geo envir |
description |
Forecasting the future sea level relies on accurate modeling of the response of the Greenland and Antarctic ice sheets to changing temperatures. The surface mass balance (SMB) of the Greenland Ice Sheet (GrIS) has a nonlinear response to warming. Cold and warm anomalies of equal size do not cancel out and it is therefore important to consider the effect of interannual fluctuations in temperature. We find that the steady-state volume of an ice sheet is biased toward larger size if interannual temperature fluctuations are not taken into account in numerical modeling of the ice sheet. We illustrate this in a simple ice sheet model and find that the equilibrium ice volume is approximately 1 m SLE (meters sea level equivalent) smaller when the simple model is forced with fluctuating temperatures as opposed to a stable climate. It is therefore important to consider the effect of interannual temperature fluctuations when designing long experiments such as paleo-spin-ups. We show how the magnitude of the potential bias can be quantified statistically. For recent simulations of the Greenland Ice Sheet, we estimate the bias to be 30 Gt yr−1 (24–59 Gt yr−1, 95 % credibility) for a warming of 3 °C above preindustrial values, or 13 % (10–25, 95 % credibility) of the present-day rate of ice loss. Models of the Greenland Ice Sheet show a collapse threshold beyond which the ice sheet becomes unsustainable. The proximity of the threshold will be underestimated if temperature fluctuations are not taken into account. We estimate the bias to be 0.12 °C (0.10–0.18 °C, 95 % credibility) for a recent estimate of the threshold. In light of our findings it is important to gauge the extent to which this increased variability will influence the mass balance of the ice sheets. |
format |
Article in Journal/Newspaper |
author |
T. B. Mikkelsen A. Grinsted P. Ditlevsen |
author_facet |
T. B. Mikkelsen A. Grinsted P. Ditlevsen |
author_sort |
T. B. Mikkelsen |
title |
Influence of temperature fluctuations on equilibrium ice sheet volume |
title_short |
Influence of temperature fluctuations on equilibrium ice sheet volume |
title_full |
Influence of temperature fluctuations on equilibrium ice sheet volume |
title_fullStr |
Influence of temperature fluctuations on equilibrium ice sheet volume |
title_full_unstemmed |
Influence of temperature fluctuations on equilibrium ice sheet volume |
title_sort |
influence of temperature fluctuations on equilibrium ice sheet volume |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-39-2018 https://www.the-cryosphere.net/12/39/2018/tc-12-39-2018.pdf https://doaj.org/article/0902de3461944e25ae7a4c7c37308ee8 |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic Greenland Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 12, Pp 39-47 (2018) |
op_relation |
doi:10.5194/tc-12-39-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/39/2018/tc-12-39-2018.pdf https://doaj.org/article/0902de3461944e25ae7a4c7c37308ee8 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-12-39-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
1 |
container_start_page |
39 |
op_container_end_page |
47 |
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1766074216534245376 |