Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska
In the past three decades, an abrupt, pan-Arctic acceleration of ice wedge melting has transformed tundra landscapes, spurring the formation of hummock-like features known as high-centered polygons (HCPs). This rapid geomorphic transition profoundly alters regional hydrology and influences surface e...
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Online Access: | http://www.osti.gov/servlets/purl/1607283 https://www.osti.gov/biblio/1607283 https://doi.org/10.1029/2019JF005349 |
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ftosti:oai:osti.gov:1607283 2023-10-01T03:53:43+02:00 Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska Abolt, Charles J. Young, Michael H. Atchley, Adam L. Harp, Dylan R. Coon, Ethan T. 2023-08-30 application/pdf http://www.osti.gov/servlets/purl/1607283 https://www.osti.gov/biblio/1607283 https://doi.org/10.1029/2019JF005349 unknown http://www.osti.gov/servlets/purl/1607283 https://www.osti.gov/biblio/1607283 https://doi.org/10.1029/2019JF005349 doi:10.1029/2019JF005349 54 ENVIRONMENTAL SCIENCES 2023 ftosti https://doi.org/10.1029/2019JF005349 2023-09-02T22:50:56Z In the past three decades, an abrupt, pan-Arctic acceleration of ice wedge melting has transformed tundra landscapes, spurring the formation of hummock-like features known as high-centered polygons (HCPs). This rapid geomorphic transition profoundly alters regional hydrology and influences surface emissions of CO 2 and CH 4 . In Arctic Alaska, most recent instances of ice wedge degradation have arrested within 15–20 years of inception, stabilizing HCP microtopography. However, feedbacks between ground surface deformation and permafrost stability are incompletely understood, limiting our capacity to predict trajectories of landscape evolution in a still warmer future. In this work, we use field data from a site near Prudhoe Bay, Alaska, to develop a modeling-based framework for assessing the strength of positive (i.e., exacerbating) feedbacks on ice wedge degradation, focusing on the importance of heterogeneity in surface drainage and microtopographic conditions. Our simulations suggest that, when troughs are narrow, positive feedbacks on ice wedge melting (associated with thermokarst pool formation) are relatively weak. Positive feedbacks are markedly stronger beneath wide troughs, such as those that form above older, larger ice wedges. Seasonal thaw abruptly accelerates once a talik begins to form beneath wide and deep thermokarst pools. Once a talik initiates, winter severity and snowpack thickness increase in importance as predictors of thaw intensity in summer. Our results indicate that meter-scale heterogeneity in polygonal microtopography potentially exerts strong, nonlinear controls on thermokarst trajectories. These findings are useful for predicting future thermokarst dynamics and for interpreting the results from coarser-resolution land surface models operating at greater spatial and temporal scales. Other/Unknown Material Arctic Ice permafrost Prudhoe Bay Thermokarst Tundra wedge* Alaska SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Arctic Talik ENVELOPE(146.601,146.601,59.667,59.667) Journal of Geophysical Research: Earth Surface 125 3 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Abolt, Charles J. Young, Michael H. Atchley, Adam L. Harp, Dylan R. Coon, Ethan T. Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
In the past three decades, an abrupt, pan-Arctic acceleration of ice wedge melting has transformed tundra landscapes, spurring the formation of hummock-like features known as high-centered polygons (HCPs). This rapid geomorphic transition profoundly alters regional hydrology and influences surface emissions of CO 2 and CH 4 . In Arctic Alaska, most recent instances of ice wedge degradation have arrested within 15–20 years of inception, stabilizing HCP microtopography. However, feedbacks between ground surface deformation and permafrost stability are incompletely understood, limiting our capacity to predict trajectories of landscape evolution in a still warmer future. In this work, we use field data from a site near Prudhoe Bay, Alaska, to develop a modeling-based framework for assessing the strength of positive (i.e., exacerbating) feedbacks on ice wedge degradation, focusing on the importance of heterogeneity in surface drainage and microtopographic conditions. Our simulations suggest that, when troughs are narrow, positive feedbacks on ice wedge melting (associated with thermokarst pool formation) are relatively weak. Positive feedbacks are markedly stronger beneath wide troughs, such as those that form above older, larger ice wedges. Seasonal thaw abruptly accelerates once a talik begins to form beneath wide and deep thermokarst pools. Once a talik initiates, winter severity and snowpack thickness increase in importance as predictors of thaw intensity in summer. Our results indicate that meter-scale heterogeneity in polygonal microtopography potentially exerts strong, nonlinear controls on thermokarst trajectories. These findings are useful for predicting future thermokarst dynamics and for interpreting the results from coarser-resolution land surface models operating at greater spatial and temporal scales. |
author |
Abolt, Charles J. Young, Michael H. Atchley, Adam L. Harp, Dylan R. Coon, Ethan T. |
author_facet |
Abolt, Charles J. Young, Michael H. Atchley, Adam L. Harp, Dylan R. Coon, Ethan T. |
author_sort |
Abolt, Charles J. |
title |
Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
title_short |
Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
title_full |
Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
title_fullStr |
Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
title_full_unstemmed |
Feedbacks Between Surface Deformation and Permafrost Degradation in Ice Wedge Polygons, Arctic Coastal Plain, Alaska |
title_sort |
feedbacks between surface deformation and permafrost degradation in ice wedge polygons, arctic coastal plain, alaska |
publishDate |
2023 |
url |
http://www.osti.gov/servlets/purl/1607283 https://www.osti.gov/biblio/1607283 https://doi.org/10.1029/2019JF005349 |
long_lat |
ENVELOPE(146.601,146.601,59.667,59.667) |
geographic |
Arctic Talik |
geographic_facet |
Arctic Talik |
genre |
Arctic Ice permafrost Prudhoe Bay Thermokarst Tundra wedge* Alaska |
genre_facet |
Arctic Ice permafrost Prudhoe Bay Thermokarst Tundra wedge* Alaska |
op_relation |
http://www.osti.gov/servlets/purl/1607283 https://www.osti.gov/biblio/1607283 https://doi.org/10.1029/2019JF005349 doi:10.1029/2019JF005349 |
op_doi |
https://doi.org/10.1029/2019JF005349 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
125 |
container_issue |
3 |
_version_ |
1778520525209862144 |