Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics
Recent observations indicate that many marine‐terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to long‐term trends in climate forcing. In this study, we describe a simple two‐stage model that accurately emulates the response to external forcing...
Published in: | Journal of Geophysical Research: Earth Surface |
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American Geophysical Union
2018
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ftunivnorthumb:oai:nrl.northumbria.ac.uk:42292 2023-05-15T13:44:52+02:00 Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne 2018-09 text https://nrl.northumbria.ac.uk/id/eprint/42292/ https://doi.org/10.1029/2018JF004709 https://nrl.northumbria.ac.uk/id/eprint/42292/1/Robel_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf en eng American Geophysical Union https://nrl.northumbria.ac.uk/id/eprint/42292/1/Robel_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf Robel, Alexander A., Roe, Gerard H. and Haseloff, Marianne (2018) Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics. Journal of Geophysical Research: Earth Surface, 123 (9). pp. 2205-2227. ISSN 2169-9003 F600 Geology F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Article PeerReviewed 2018 ftunivnorthumb https://doi.org/10.1029/2018JF004709 2022-09-25T06:11:31Z Recent observations indicate that many marine‐terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to long‐term trends in climate forcing. In this study, we describe a simple two‐stage model that accurately emulates the response to external forcing of marine‐terminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marine‐terminating glacier response to forcing. We find that there are two time scales that characterize the stable glacier response to external forcing, a fast time scale of decades to centuries, and a slow time scale of millennia. These two time scales become unstable at different thresholds of bed slope, indicating that there are distinct slow and fast forms of the marine ice sheet instability. We derive simple expressions for the approximate magnitude and transient evolution of the stable glacier response to external forcing, which depend on the equilibrium glacier state and the strength of nonlinearity in forcing processes. The slow response rate of marine‐terminating glaciers indicates that current changes at some glaciers are set to continue and accelerate in coming centuries in response to past climate forcing and that the current extent of change at these glaciers is likely a small fraction of the future committed change caused by past climate forcing. Finally, we find that changing the amplitude of natural fluctuations in some nonlinear forcing processes, such as ice shelf calving, changes the equilibrium glacier state. Article in Journal/Newspaper Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf Northumbria University, Newcastle: Northumbria Research Link (NRL) Greenland Journal of Geophysical Research: Earth Surface 123 9 2205 2227 |
institution |
Open Polar |
collection |
Northumbria University, Newcastle: Northumbria Research Link (NRL) |
op_collection_id |
ftunivnorthumb |
language |
English |
topic |
F600 Geology F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
spellingShingle |
F600 Geology F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
topic_facet |
F600 Geology F700 Ocean Sciences F800 Physical and Terrestrial Geographical and Environmental Sciences |
description |
Recent observations indicate that many marine‐terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to long‐term trends in climate forcing. In this study, we describe a simple two‐stage model that accurately emulates the response to external forcing of marine‐terminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marine‐terminating glacier response to forcing. We find that there are two time scales that characterize the stable glacier response to external forcing, a fast time scale of decades to centuries, and a slow time scale of millennia. These two time scales become unstable at different thresholds of bed slope, indicating that there are distinct slow and fast forms of the marine ice sheet instability. We derive simple expressions for the approximate magnitude and transient evolution of the stable glacier response to external forcing, which depend on the equilibrium glacier state and the strength of nonlinearity in forcing processes. The slow response rate of marine‐terminating glaciers indicates that current changes at some glaciers are set to continue and accelerate in coming centuries in response to past climate forcing and that the current extent of change at these glaciers is likely a small fraction of the future committed change caused by past climate forcing. Finally, we find that changing the amplitude of natural fluctuations in some nonlinear forcing processes, such as ice shelf calving, changes the equilibrium glacier state. |
format |
Article in Journal/Newspaper |
author |
Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne |
author_facet |
Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne |
author_sort |
Robel, Alexander A. |
title |
Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_short |
Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_full |
Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_fullStr |
Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_full_unstemmed |
Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_sort |
response of marine‐terminating glaciers to forcing: time scales, sensitivities, instabilities, and stochastic dynamics |
publisher |
American Geophysical Union |
publishDate |
2018 |
url |
https://nrl.northumbria.ac.uk/id/eprint/42292/ https://doi.org/10.1029/2018JF004709 https://nrl.northumbria.ac.uk/id/eprint/42292/1/Robel_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf |
op_relation |
https://nrl.northumbria.ac.uk/id/eprint/42292/1/Robel_et_al-2018-Journal_of_Geophysical_Research__Earth_Surface.pdf Robel, Alexander A., Roe, Gerard H. and Haseloff, Marianne (2018) Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics. Journal of Geophysical Research: Earth Surface, 123 (9). pp. 2205-2227. ISSN 2169-9003 |
op_doi |
https://doi.org/10.1029/2018JF004709 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
9 |
container_start_page |
2205 |
op_container_end_page |
2227 |
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1766207769497567232 |