Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation
Microtopographic variation that develops among features (troughs, rims, and centers) within polygonal landforms of coastal arctic tundra strongly affects movement of surface water and snow and thereby affects soil water contents (θ) and active layer depth (ALD). Spatial variation in ALD among these...
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ftcdlib:oai:escholarship.org/ark:/13030/qt09x4k422 2023-05-15T13:02:42+02:00 Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation Grant, RF Mekonnen, ZA Riley, WJ Wainwright, HM Graham, D Torn, MS 3161 - 3173 2017-12-01 application/pdf https://escholarship.org/uc/item/09x4k422 unknown eScholarship, University of California qt09x4k422 https://escholarship.org/uc/item/09x4k422 public Journal of Geophysical Research: Biogeosciences, vol 122, iss 12 Geophysics article 2017 ftcdlib 2021-09-06T17:11:25Z Microtopographic variation that develops among features (troughs, rims, and centers) within polygonal landforms of coastal arctic tundra strongly affects movement of surface water and snow and thereby affects soil water contents (θ) and active layer depth (ALD). Spatial variation in ALD among these features may exceed interannual variation in ALD caused by changes in climate and so needs to be represented in projections of changes in arctic ALD. In this study, increases in near-surface θ with decreasing surface elevation among polygon features at the Barrow Experimental Observatory (BEO) were modeled from topographic effects on redistribution of surface water and snow and from lateral water exchange with a subsurface water table during a model run from 1981 to 2015. These increases in θ caused increases in thermal conductivity that in turn caused increases in soil heat fluxes and hence in ALD of up to 15cm with lower versus higher surface elevation which were consistent with increases measured at BEO. The modeled effects of θ caused interannual variation in maximum ALD that compared well with measurements from 1985 to 2015 at the Barrow Circumpolar Active Layer Monitoring (CALM) site (R2=0.61, RMSE=0.03m). For higher polygon features, interannual variation in ALD was more closely associated with annual precipitation than mean annual temperature, indicating that soil wetting from increases in precipitation may hasten permafrost degradation beyond that caused by soil warming from increases in air temperature. This degradation may be more rapid if increases in precipitation cause sustained wetting in higher features. Article in Journal/Newspaper Active layer monitoring Arctic permafrost Tundra University of California: eScholarship Arctic |
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Open Polar |
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University of California: eScholarship |
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ftcdlib |
language |
unknown |
topic |
Geophysics |
spellingShingle |
Geophysics Grant, RF Mekonnen, ZA Riley, WJ Wainwright, HM Graham, D Torn, MS Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
topic_facet |
Geophysics |
description |
Microtopographic variation that develops among features (troughs, rims, and centers) within polygonal landforms of coastal arctic tundra strongly affects movement of surface water and snow and thereby affects soil water contents (θ) and active layer depth (ALD). Spatial variation in ALD among these features may exceed interannual variation in ALD caused by changes in climate and so needs to be represented in projections of changes in arctic ALD. In this study, increases in near-surface θ with decreasing surface elevation among polygon features at the Barrow Experimental Observatory (BEO) were modeled from topographic effects on redistribution of surface water and snow and from lateral water exchange with a subsurface water table during a model run from 1981 to 2015. These increases in θ caused increases in thermal conductivity that in turn caused increases in soil heat fluxes and hence in ALD of up to 15cm with lower versus higher surface elevation which were consistent with increases measured at BEO. The modeled effects of θ caused interannual variation in maximum ALD that compared well with measurements from 1985 to 2015 at the Barrow Circumpolar Active Layer Monitoring (CALM) site (R2=0.61, RMSE=0.03m). For higher polygon features, interannual variation in ALD was more closely associated with annual precipitation than mean annual temperature, indicating that soil wetting from increases in precipitation may hasten permafrost degradation beyond that caused by soil warming from increases in air temperature. This degradation may be more rapid if increases in precipitation cause sustained wetting in higher features. |
format |
Article in Journal/Newspaper |
author |
Grant, RF Mekonnen, ZA Riley, WJ Wainwright, HM Graham, D Torn, MS |
author_facet |
Grant, RF Mekonnen, ZA Riley, WJ Wainwright, HM Graham, D Torn, MS |
author_sort |
Grant, RF |
title |
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
title_short |
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
title_full |
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
title_fullStr |
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
title_full_unstemmed |
Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation |
title_sort |
mathematical modelling of arctic polygonal tundra with ecosys: 1. microtopography determines how active layer depths respond to changes in temperature and precipitation |
publisher |
eScholarship, University of California |
publishDate |
2017 |
url |
https://escholarship.org/uc/item/09x4k422 |
op_coverage |
3161 - 3173 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Active layer monitoring Arctic permafrost Tundra |
genre_facet |
Active layer monitoring Arctic permafrost Tundra |
op_source |
Journal of Geophysical Research: Biogeosciences, vol 122, iss 12 |
op_relation |
qt09x4k422 https://escholarship.org/uc/item/09x4k422 |
op_rights |
public |
_version_ |
1766319484479471616 |