Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape
Vast carbon stocks stored in permafrost soils of Arctic tundra are under risk of release to the atmosphere under warming climate scenarios. Ice-wedge polygons in the low-gradient polygonal tundra create a complex mosaic of microtopographic features. This microtopography plays a critical role in regu...
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ftcopernicus:oai:publications.copernicus.org:tc49680 2023-05-15T15:15:54+02:00 Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape Kumar, Jitendra Collier, Nathan Bisht, Gautam Mills, Richard T. Thornton, Peter E. Iversen, Colleen M. Romanovsky, Vladimir 2018-09-28 application/pdf https://doi.org/10.5194/tc-10-2241-2016 https://tc.copernicus.org/articles/10/2241/2016/ eng eng doi:10.5194/tc-10-2241-2016 https://tc.copernicus.org/articles/10/2241/2016/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-10-2241-2016 2020-07-20T16:23:59Z Vast carbon stocks stored in permafrost soils of Arctic tundra are under risk of release to the atmosphere under warming climate scenarios. Ice-wedge polygons in the low-gradient polygonal tundra create a complex mosaic of microtopographic features. This microtopography plays a critical role in regulating the fine-scale variability in thermal and hydrological regimes in the polygonal tundra landscape underlain by continuous permafrost. Modeling of thermal regimes of this sensitive ecosystem is essential for understanding the landscape behavior under the current as well as changing climate. We present here an end-to-end effort for high-resolution numerical modeling of thermal hydrology at real-world field sites, utilizing the best available data to characterize and parameterize the models. We develop approaches to model the thermal hydrology of polygonal tundra and apply them at four study sites near Barrow, Alaska, spanning across low to transitional to high-centered polygons, representing a broad polygonal tundra landscape. A multiphase subsurface thermal hydrology model (PFLOTRAN) was developed and applied to study the thermal regimes at four sites. Using a high-resolution lidar digital elevation model (DEM), microtopographic features of the landscape were characterized and represented in the high-resolution model mesh. The best available soil data from field observations and literature were utilized to represent the complex heterogeneous subsurface in the numerical model. Simulation results demonstrate the ability of the developed modeling approach to capture – without recourse to model calibration – several aspects of the complex thermal regimes across the sites, and provide insights into the critical role of polygonal tundra microtopography in regulating the thermal dynamics of the carbon-rich permafrost soils. Areas of significant disagreement between model results and observations highlight the importance of field-based observations of soil thermal and hydraulic properties for modeling-based studies of permafrost thermal dynamics, and provide motivation and guidance for future observations that will help address model and data gaps affecting our current understanding of the system. Text Arctic Barrow Ice permafrost Tundra wedge* Alaska Copernicus Publications: E-Journals Arctic The Cryosphere 10 5 2241 2274 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Vast carbon stocks stored in permafrost soils of Arctic tundra are under risk of release to the atmosphere under warming climate scenarios. Ice-wedge polygons in the low-gradient polygonal tundra create a complex mosaic of microtopographic features. This microtopography plays a critical role in regulating the fine-scale variability in thermal and hydrological regimes in the polygonal tundra landscape underlain by continuous permafrost. Modeling of thermal regimes of this sensitive ecosystem is essential for understanding the landscape behavior under the current as well as changing climate. We present here an end-to-end effort for high-resolution numerical modeling of thermal hydrology at real-world field sites, utilizing the best available data to characterize and parameterize the models. We develop approaches to model the thermal hydrology of polygonal tundra and apply them at four study sites near Barrow, Alaska, spanning across low to transitional to high-centered polygons, representing a broad polygonal tundra landscape. A multiphase subsurface thermal hydrology model (PFLOTRAN) was developed and applied to study the thermal regimes at four sites. Using a high-resolution lidar digital elevation model (DEM), microtopographic features of the landscape were characterized and represented in the high-resolution model mesh. The best available soil data from field observations and literature were utilized to represent the complex heterogeneous subsurface in the numerical model. Simulation results demonstrate the ability of the developed modeling approach to capture – without recourse to model calibration – several aspects of the complex thermal regimes across the sites, and provide insights into the critical role of polygonal tundra microtopography in regulating the thermal dynamics of the carbon-rich permafrost soils. Areas of significant disagreement between model results and observations highlight the importance of field-based observations of soil thermal and hydraulic properties for modeling-based studies of permafrost thermal dynamics, and provide motivation and guidance for future observations that will help address model and data gaps affecting our current understanding of the system. |
format |
Text |
author |
Kumar, Jitendra Collier, Nathan Bisht, Gautam Mills, Richard T. Thornton, Peter E. Iversen, Colleen M. Romanovsky, Vladimir |
spellingShingle |
Kumar, Jitendra Collier, Nathan Bisht, Gautam Mills, Richard T. Thornton, Peter E. Iversen, Colleen M. Romanovsky, Vladimir Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
author_facet |
Kumar, Jitendra Collier, Nathan Bisht, Gautam Mills, Richard T. Thornton, Peter E. Iversen, Colleen M. Romanovsky, Vladimir |
author_sort |
Kumar, Jitendra |
title |
Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
title_short |
Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
title_full |
Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
title_fullStr |
Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
title_full_unstemmed |
Modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
title_sort |
modeling the spatiotemporal variability in subsurface thermal regimes across a low-relief polygonal tundra landscape |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-10-2241-2016 https://tc.copernicus.org/articles/10/2241/2016/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Barrow Ice permafrost Tundra wedge* Alaska |
genre_facet |
Arctic Barrow Ice permafrost Tundra wedge* Alaska |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-10-2241-2016 https://tc.copernicus.org/articles/10/2241/2016/ |
op_doi |
https://doi.org/10.5194/tc-10-2241-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
5 |
container_start_page |
2241 |
op_container_end_page |
2274 |
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1766346233854558208 |