Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments
Satellite‐derived surface soil moisture data are available for the Arctic, but detailed validation is still lacking. Previous studies have shown low correlations between in situ and modeled data. It is hypothesized that soil temperature variations after soil thaw impact MetOp ASCAT satellite‐derived...
Published in: | Journal of Geophysical Research: Earth Surface |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2018
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Online Access: | https://doi.org/10.1029/2018JF004658 https://eplus.uni-salzburg.at/doi/10.1029/2018JF004658 https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-10931 |
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ftunivsalzburg:oai:eplus.uni-salzburg.at:3364773 2024-06-16T07:37:36+00:00 Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments Högström, Elin Heim, Birgit Bartsch, Annett Bergstedt, Helena Pointner, Georg 38.03 38.63 PLUS:IFFB:ZGIS 2018 text/html https://doi.org/10.1029/2018JF004658 https://eplus.uni-salzburg.at/doi/10.1029/2018JF004658 https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-10931 eng eng Wiley vignette : https://eplus.uni-salzburg.at/titlepage/urn/urn:nbn:at:at-ubs:3-10931/128 vignette : https://eplus.uni-salzburg.at/titlepage/doi/10.1029/2018JF004658/128 2169-9003 doi:10.1029/2018JF004658 https://eplus.uni-salzburg.at/doi/10.1029/2018JF004658 urn:nbn:at:at-ubs:3-10931 https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-10931 local:99144889780903331 system:AC15287676 cc-by_4 radar tundra soil moisture C band Arctic Text Article 2018 ftunivsalzburg https://doi.org/10.1029/2018JF004658 2024-05-21T18:37:02Z Satellite‐derived surface soil moisture data are available for the Arctic, but detailed validation is still lacking. Previous studies have shown low correlations between in situ and modeled data. It is hypothesized that soil temperature variations after soil thaw impact MetOp ASCAT satellite‐derived surface soil moisture (SSM) measurements in wet tundra environments, as C band backscatter is sensitive to changes in dielectric properties. We compare in situ measurements of water content within the active layer at four sites across the Arctic in Alaska (Barrow, Sagwon, Toolik) and Siberia (Tiksi), taken in the spring after thawing and in autumn prior to freezing. In addition to the long‐term measurement fields, where sensors are installed deeper in the ground, we designed a monitoring setup for measuring moisture very close to the surface in the Lena River Delta, Siberia. The volumetric water content (VWC) and soil temperature sensors were placed in the moss organic layer in order to account for the limited penetration depth of the radar signal. ASCAT SSM variations are generally very small, in line with the low variability of in situ VWC. Short‐term changes after complete thawing of the upper organic layer, however, seem to be mostly influenced by soil temperature. Correlations between SSM and in situ VWC are generally very low, or even negative. Mean standard deviation matching results in a comparably high root‐mean‐square error (on average 11%) for predictions of VWC. Further investigations and measurement networks are needed to clarify factors causing temporal variation of C band backscatter in tundra regions. Article in Journal/Newspaper Arctic Barrow lena river Tiksi Tundra Alaska Siberia ePLUS - Open Access Publikationsserver der Universität Salzburg Arctic Tiksi ENVELOPE(128.867,128.867,71.633,71.633) Journal of Geophysical Research: Earth Surface 123 12 3190 3205 |
institution |
Open Polar |
collection |
ePLUS - Open Access Publikationsserver der Universität Salzburg |
op_collection_id |
ftunivsalzburg |
language |
English |
topic |
radar tundra soil moisture C band Arctic |
spellingShingle |
radar tundra soil moisture C band Arctic Högström, Elin Heim, Birgit Bartsch, Annett Bergstedt, Helena Pointner, Georg Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
topic_facet |
radar tundra soil moisture C band Arctic |
description |
Satellite‐derived surface soil moisture data are available for the Arctic, but detailed validation is still lacking. Previous studies have shown low correlations between in situ and modeled data. It is hypothesized that soil temperature variations after soil thaw impact MetOp ASCAT satellite‐derived surface soil moisture (SSM) measurements in wet tundra environments, as C band backscatter is sensitive to changes in dielectric properties. We compare in situ measurements of water content within the active layer at four sites across the Arctic in Alaska (Barrow, Sagwon, Toolik) and Siberia (Tiksi), taken in the spring after thawing and in autumn prior to freezing. In addition to the long‐term measurement fields, where sensors are installed deeper in the ground, we designed a monitoring setup for measuring moisture very close to the surface in the Lena River Delta, Siberia. The volumetric water content (VWC) and soil temperature sensors were placed in the moss organic layer in order to account for the limited penetration depth of the radar signal. ASCAT SSM variations are generally very small, in line with the low variability of in situ VWC. Short‐term changes after complete thawing of the upper organic layer, however, seem to be mostly influenced by soil temperature. Correlations between SSM and in situ VWC are generally very low, or even negative. Mean standard deviation matching results in a comparably high root‐mean‐square error (on average 11%) for predictions of VWC. Further investigations and measurement networks are needed to clarify factors causing temporal variation of C band backscatter in tundra regions. |
format |
Article in Journal/Newspaper |
author |
Högström, Elin Heim, Birgit Bartsch, Annett Bergstedt, Helena Pointner, Georg |
author_facet |
Högström, Elin Heim, Birgit Bartsch, Annett Bergstedt, Helena Pointner, Georg |
author_sort |
Högström, Elin |
title |
Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
title_short |
Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
title_full |
Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
title_fullStr |
Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
title_full_unstemmed |
Journal of Geophysical Research. Earth Surface / Evaluation of a MetOp ASCAT‐Derived Surface Soil Moisture Product in Tundra Environments |
title_sort |
journal of geophysical research. earth surface / evaluation of a metop ascat‐derived surface soil moisture product in tundra environments |
publisher |
Wiley |
publishDate |
2018 |
url |
https://doi.org/10.1029/2018JF004658 https://eplus.uni-salzburg.at/doi/10.1029/2018JF004658 https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-10931 |
op_coverage |
38.03 38.63 PLUS:IFFB:ZGIS |
long_lat |
ENVELOPE(128.867,128.867,71.633,71.633) |
geographic |
Arctic Tiksi |
geographic_facet |
Arctic Tiksi |
genre |
Arctic Barrow lena river Tiksi Tundra Alaska Siberia |
genre_facet |
Arctic Barrow lena river Tiksi Tundra Alaska Siberia |
op_relation |
vignette : https://eplus.uni-salzburg.at/titlepage/urn/urn:nbn:at:at-ubs:3-10931/128 vignette : https://eplus.uni-salzburg.at/titlepage/doi/10.1029/2018JF004658/128 2169-9003 doi:10.1029/2018JF004658 https://eplus.uni-salzburg.at/doi/10.1029/2018JF004658 urn:nbn:at:at-ubs:3-10931 https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-10931 local:99144889780903331 system:AC15287676 |
op_rights |
cc-by_4 |
op_doi |
https://doi.org/10.1029/2018JF004658 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
12 |
container_start_page |
3190 |
op_container_end_page |
3205 |
_version_ |
1802004265538945024 |