Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence
Ground ice is foundational to the integrity of Arctic ecosystems and infrastructure. However, we lack fine-scale ground ice maps across almost the entire Arctic, chiefly because there is no established method for mapping ice-rich permafrost from space. Here, we assess whether remotely sensed late-se...
Published in: | The Cryosphere |
---|---|
Main Authors: | , |
Format: | Text |
Language: | English |
Published: |
2021
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-15-2041-2021 https://tc.copernicus.org/articles/15/2041/2021/ |
id |
ftcopernicus:oai:publications.copernicus.org:tc90501 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:tc90501 2023-05-15T14:55:34+02:00 Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence Zwieback, Simon Meyer, Franz J. 2021-04-23 application/pdf https://doi.org/10.5194/tc-15-2041-2021 https://tc.copernicus.org/articles/15/2041/2021/ eng eng doi:10.5194/tc-15-2041-2021 https://tc.copernicus.org/articles/15/2041/2021/ eISSN: 1994-0424 Text 2021 ftcopernicus https://doi.org/10.5194/tc-15-2041-2021 2021-04-26T16:22:13Z Ground ice is foundational to the integrity of Arctic ecosystems and infrastructure. However, we lack fine-scale ground ice maps across almost the entire Arctic, chiefly because there is no established method for mapping ice-rich permafrost from space. Here, we assess whether remotely sensed late-season subsidence can be used to identify ice-rich permafrost. The idea is that, towards the end of an exceptionally warm summer, the thaw front can penetrate materials that were previously perennially frozen, triggering increased subsidence if they are ice rich. Focusing on northwestern Alaska, we test the idea by comparing the Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) late-season subsidence observations to permafrost cores and an independently derived ground ice classification. We find that the late-season subsidence in an exceptionally warm summer was 4–8 cm (5th–95th percentiles) in the ice-rich areas, while it was low in ice-poor areas ( − 1 to 2 cm; 5th–95th percentiles). The distributions of the late-season subsidence overlapped by 2 %, demonstrating high sensitivity and specificity for identifying top-of-permafrost excess ground ice. The strengths of late-season subsidence include the ease of automation and its applicability to areas that lack conspicuous manifestations of ground ice, as often occurs on hillslopes. One limitation is that it is not sensitive to excess ground ice below the thaw front and thus the total ice content. Late-season subsidence can enhance the automated mapping of permafrost ground ice, complementing existing (predominantly non-automated) approaches based on largely indirect associations with vegetation and periglacial landforms. Thanks to its suitability for mapping ice-rich permafrost, satellite-observed late-season subsidence can make a vital contribution to anticipating terrain instability in the Arctic and sustainably stewarding its ecosystems. Text Arctic Ice permafrost Alaska Copernicus Publications: E-Journals Arctic The Sentinel ENVELOPE(73.317,73.317,-52.983,-52.983) The Cryosphere 15 4 2041 2055 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Ground ice is foundational to the integrity of Arctic ecosystems and infrastructure. However, we lack fine-scale ground ice maps across almost the entire Arctic, chiefly because there is no established method for mapping ice-rich permafrost from space. Here, we assess whether remotely sensed late-season subsidence can be used to identify ice-rich permafrost. The idea is that, towards the end of an exceptionally warm summer, the thaw front can penetrate materials that were previously perennially frozen, triggering increased subsidence if they are ice rich. Focusing on northwestern Alaska, we test the idea by comparing the Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) late-season subsidence observations to permafrost cores and an independently derived ground ice classification. We find that the late-season subsidence in an exceptionally warm summer was 4–8 cm (5th–95th percentiles) in the ice-rich areas, while it was low in ice-poor areas ( − 1 to 2 cm; 5th–95th percentiles). The distributions of the late-season subsidence overlapped by 2 %, demonstrating high sensitivity and specificity for identifying top-of-permafrost excess ground ice. The strengths of late-season subsidence include the ease of automation and its applicability to areas that lack conspicuous manifestations of ground ice, as often occurs on hillslopes. One limitation is that it is not sensitive to excess ground ice below the thaw front and thus the total ice content. Late-season subsidence can enhance the automated mapping of permafrost ground ice, complementing existing (predominantly non-automated) approaches based on largely indirect associations with vegetation and periglacial landforms. Thanks to its suitability for mapping ice-rich permafrost, satellite-observed late-season subsidence can make a vital contribution to anticipating terrain instability in the Arctic and sustainably stewarding its ecosystems. |
format |
Text |
author |
Zwieback, Simon Meyer, Franz J. |
spellingShingle |
Zwieback, Simon Meyer, Franz J. Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
author_facet |
Zwieback, Simon Meyer, Franz J. |
author_sort |
Zwieback, Simon |
title |
Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
title_short |
Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
title_full |
Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
title_fullStr |
Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
title_full_unstemmed |
Top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
title_sort |
top-of-permafrost ground ice indicated by remotely sensed late-season subsidence |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-2041-2021 https://tc.copernicus.org/articles/15/2041/2021/ |
long_lat |
ENVELOPE(73.317,73.317,-52.983,-52.983) |
geographic |
Arctic The Sentinel |
geographic_facet |
Arctic The Sentinel |
genre |
Arctic Ice permafrost Alaska |
genre_facet |
Arctic Ice permafrost Alaska |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-15-2041-2021 https://tc.copernicus.org/articles/15/2041/2021/ |
op_doi |
https://doi.org/10.5194/tc-15-2041-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
4 |
container_start_page |
2041 |
op_container_end_page |
2055 |
_version_ |
1766327600713564160 |