Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics
Recent observations indicate that many marineâ€terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to longâ€term trends in climate forcing. In this study, we describe a simple twoâ€stage model that accurately emulates the response to external forci...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Geophysical Union
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1029/2018JF004709 |
id |
ftcaltechauth:oai:authors.library.caltech.edu:68s3b-jy606 |
---|---|
record_format |
openpolar |
spelling |
ftcaltechauth:oai:authors.library.caltech.edu:68s3b-jy606 2024-10-13T14:01:33+00:00 Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne 2018-09 https://doi.org/10.1029/2018JF004709 unknown American Geophysical Union https://doi.org/10.31223/osf.io/7jthq https://doi.org/10.1029/2018JF004709 eprintid:90398 info:eu-repo/semantics/openAccess Other Journal of Geophysical Research. Earth Surface, 123(9), 2205-2227, (2018-09) glaciers climate ice sheet stochastic stability ice stream info:eu-repo/semantics/article 2018 ftcaltechauth https://doi.org/10.1029/2018JF00470910.31223/osf.io/7jthq 2024-09-25T18:46:39Z Recent observations indicate that many marineâ€terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to longâ€term trends in climate forcing. In this study, we describe a simple twoâ€stage model that accurately emulates the response to external forcing of marineâ€terminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marineâ€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 marineâ€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. © 2018 American Geophysical Union. Received 9 APR 2018; Accepted 25 JUL 2018; Accepted article online 2 AUG 2018; Published online 19 SEP 2018. Source code and documentation of the twoâ€stage and flowline models used in this study are freely available as public repositories on GitHub: https://github.com/aarobel/. Thanks to Olga Sergienko, Martin Truffer, Jeremy Bassis, and Elisa Mantelli for helpful comments on the manuscript. ... Article in Journal/Newspaper Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf Caltech Authors (California Institute of Technology) Greenland Jeremy ENVELOPE(-68.838,-68.838,-69.402,-69.402) Sergienko ENVELOPE(-29.400,-29.400,-80.633,-80.633) |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
glaciers climate ice sheet stochastic stability ice stream |
spellingShingle |
glaciers climate ice sheet stochastic stability ice stream Robel, Alexander A. Roe, Gerard H. Haseloff, Marianne Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
topic_facet |
glaciers climate ice sheet stochastic stability ice stream |
description |
Recent observations indicate that many marineâ€terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to longâ€term trends in climate forcing. In this study, we describe a simple twoâ€stage model that accurately emulates the response to external forcing of marineâ€terminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marineâ€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 marineâ€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. © 2018 American Geophysical Union. Received 9 APR 2018; Accepted 25 JUL 2018; Accepted article online 2 AUG 2018; Published online 19 SEP 2018. Source code and documentation of the twoâ€stage and flowline models used in this study are freely available as public repositories on GitHub: https://github.com/aarobel/. Thanks to Olga Sergienko, Martin Truffer, Jeremy Bassis, and Elisa Mantelli for helpful comments on the manuscript. ... |
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 Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_short |
Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_full |
Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_fullStr |
Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_full_unstemmed |
Response of Marineâ€Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics |
title_sort |
response of marineâ€terminating glaciers to forcing: time scales, sensitivities, instabilities, and stochastic dynamics |
publisher |
American Geophysical Union |
publishDate |
2018 |
url |
https://doi.org/10.1029/2018JF004709 |
long_lat |
ENVELOPE(-68.838,-68.838,-69.402,-69.402) ENVELOPE(-29.400,-29.400,-80.633,-80.633) |
geographic |
Greenland Jeremy Sergienko |
geographic_facet |
Greenland Jeremy Sergienko |
genre |
Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf |
genre_facet |
Antarc* Antarctica glacier Greenland Ice Sheet Ice Shelf |
op_source |
Journal of Geophysical Research. Earth Surface, 123(9), 2205-2227, (2018-09) |
op_relation |
https://doi.org/10.31223/osf.io/7jthq https://doi.org/10.1029/2018JF004709 eprintid:90398 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1029/2018JF00470910.31223/osf.io/7jthq |
_version_ |
1812811491454222336 |