Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska
An important feature of the Arctic is large spatial heterogeneity in active layer conditions, which is generally poorly represented by global models and can lead to large uncertainties in predicting regional ecosystem responses and climate feedbacks. In this study, we developed a spatially integrate...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-12-145-2018 https://www.the-cryosphere.net/12/145/2018/tc-12-145-2018.pdf https://doaj.org/article/f9cd5bf39bd14b07ae53fcbb0e360bb6 |
id |
fttriple:oai:gotriple.eu:oai:doaj.org/article:f9cd5bf39bd14b07ae53fcbb0e360bb6 |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:oai:doaj.org/article:f9cd5bf39bd14b07ae53fcbb0e360bb6 2023-05-15T13:03:27+02:00 Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska Y. Yi J. S. Kimball R. H. Chen M. Moghaddam R. H. Reichle U. Mishra D. Zona W. C. Oechel 2018-01-01 https://doi.org/10.5194/tc-12-145-2018 https://www.the-cryosphere.net/12/145/2018/tc-12-145-2018.pdf https://doaj.org/article/f9cd5bf39bd14b07ae53fcbb0e360bb6 en eng Copernicus Publications doi:10.5194/tc-12-145-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/145/2018/tc-12-145-2018.pdf https://doaj.org/article/f9cd5bf39bd14b07ae53fcbb0e360bb6 undefined The Cryosphere, Vol 12, Pp 145-161 (2018) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/tc-12-145-2018 2023-01-22T17:51:35Z An important feature of the Arctic is large spatial heterogeneity in active layer conditions, which is generally poorly represented by global models and can lead to large uncertainties in predicting regional ecosystem responses and climate feedbacks. In this study, we developed a spatially integrated modeling and analysis framework combining field observations, local-scale ( ∼ 50 m resolution) active layer thickness (ALT) and soil moisture maps derived from low-frequency (L + P-band) airborne radar measurements, and global satellite environmental observations to investigate the ALT sensitivity to recent climate trends and landscape heterogeneity in Alaska. Modeled ALT results show good correspondence with in situ measurements in higher-permafrost-probability (PP ≥ 70 %) areas (n = 33; R = 0.60; mean bias = 1.58 cm; RMSE = 20.32 cm), but with larger uncertainty in sporadic and discontinuous permafrost areas. The model results also reveal widespread ALT deepening since 2001, with smaller ALT increases in northern Alaska (mean trend = 0.32±1.18 cm yr−1) and much larger increases (> 3 cm yr−1) across interior and southern Alaska. The positive ALT trend coincides with regional warming and a longer snow-free season (R = 0.60 ± 0.32). A spatially integrated analysis of the radar retrievals and model sensitivity simulations demonstrated that uncertainty in the spatial and vertical distribution of soil organic carbon (SOC) was the largest factor affecting modeled ALT accuracy, while soil moisture played a secondary role. Potential improvements in characterizing SOC heterogeneity, including better spatial sampling of soil conditions and advances in remote sensing of SOC and soil moisture, will enable more accurate predictions of active layer conditions and refinement of the modeling framework across a larger domain. Article in Journal/Newspaper Active layer thickness Arctic permafrost The Cryosphere Alaska Unknown Arctic The Cryosphere 12 1 145 161 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo Y. Yi J. S. Kimball R. H. Chen M. Moghaddam R. H. Reichle U. Mishra D. Zona W. C. Oechel Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
topic_facet |
envir geo |
description |
An important feature of the Arctic is large spatial heterogeneity in active layer conditions, which is generally poorly represented by global models and can lead to large uncertainties in predicting regional ecosystem responses and climate feedbacks. In this study, we developed a spatially integrated modeling and analysis framework combining field observations, local-scale ( ∼ 50 m resolution) active layer thickness (ALT) and soil moisture maps derived from low-frequency (L + P-band) airborne radar measurements, and global satellite environmental observations to investigate the ALT sensitivity to recent climate trends and landscape heterogeneity in Alaska. Modeled ALT results show good correspondence with in situ measurements in higher-permafrost-probability (PP ≥ 70 %) areas (n = 33; R = 0.60; mean bias = 1.58 cm; RMSE = 20.32 cm), but with larger uncertainty in sporadic and discontinuous permafrost areas. The model results also reveal widespread ALT deepening since 2001, with smaller ALT increases in northern Alaska (mean trend = 0.32±1.18 cm yr−1) and much larger increases (> 3 cm yr−1) across interior and southern Alaska. The positive ALT trend coincides with regional warming and a longer snow-free season (R = 0.60 ± 0.32). A spatially integrated analysis of the radar retrievals and model sensitivity simulations demonstrated that uncertainty in the spatial and vertical distribution of soil organic carbon (SOC) was the largest factor affecting modeled ALT accuracy, while soil moisture played a secondary role. Potential improvements in characterizing SOC heterogeneity, including better spatial sampling of soil conditions and advances in remote sensing of SOC and soil moisture, will enable more accurate predictions of active layer conditions and refinement of the modeling framework across a larger domain. |
format |
Article in Journal/Newspaper |
author |
Y. Yi J. S. Kimball R. H. Chen M. Moghaddam R. H. Reichle U. Mishra D. Zona W. C. Oechel |
author_facet |
Y. Yi J. S. Kimball R. H. Chen M. Moghaddam R. H. Reichle U. Mishra D. Zona W. C. Oechel |
author_sort |
Y. Yi |
title |
Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
title_short |
Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
title_full |
Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
title_fullStr |
Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
title_full_unstemmed |
Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska |
title_sort |
characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in alaska |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-145-2018 https://www.the-cryosphere.net/12/145/2018/tc-12-145-2018.pdf https://doaj.org/article/f9cd5bf39bd14b07ae53fcbb0e360bb6 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Active layer thickness Arctic permafrost The Cryosphere Alaska |
genre_facet |
Active layer thickness Arctic permafrost The Cryosphere Alaska |
op_source |
The Cryosphere, Vol 12, Pp 145-161 (2018) |
op_relation |
doi:10.5194/tc-12-145-2018 1994-0416 1994-0424 https://www.the-cryosphere.net/12/145/2018/tc-12-145-2018.pdf https://doaj.org/article/f9cd5bf39bd14b07ae53fcbb0e360bb6 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-12-145-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
1 |
container_start_page |
145 |
op_container_end_page |
161 |
_version_ |
1766337024198967296 |