The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics
Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2015-10-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/12/5811/2015/bg-12-5811-2015.pdf |
| _version_ | 1819208120095735808 |
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| author | Y. Yi J. S. Kimball M. A. Rawlins M. Moghaddam E. S. Euskirchen |
| author_facet | Y. Yi J. S. Kimball M. A. Rawlins M. Moghaddam E. S. Euskirchen |
| author_sort | Y. Yi |
| collection | DOAJ |
| description | Northern Hemisphere permafrost affected land
areas contain about twice as much carbon as the global atmosphere. This vast
carbon pool is vulnerable to accelerated losses through mobilization and
decomposition under projected global warming. Satellite data records spanning
the past 3 decades indicate widespread reductions
(~ 0.8–1.3 days decade<sup>−1</sup>) in the mean annual snow cover extent
and frozen-season duration across the pan-Arctic domain, coincident with
regional climate warming trends. How the soil carbon pool responds to these
changes will have a large impact on regional and global climate. Here, we
developed a coupled terrestrial carbon and hydrology model framework with a
detailed 1-D soil heat transfer representation to investigate the sensitivity
of soil organic carbon stocks and soil decomposition to climate warming and
changes in snow cover conditions in the pan-Arctic region over the past 3
decades (1982–2010). Our results indicate widespread soil active layer
deepening across the pan-Arctic, with a mean decadal trend of
6.6 ± 12.0 (SD) cm, corresponding to widespread warming. Warming
promotes vegetation growth and soil heterotrophic respiration particularly
within surface soil layers (≤ 0.2 m). The model simulations also show
that seasonal snow cover has a large impact on soil temperatures, whereby
increases in snow cover promote deeper (≥ 0.5 m) soil layer warming
and soil respiration, while inhibiting soil decomposition from surface (≤
0.2 m) soil layers, especially in colder climate zones (mean annual <i>T</i>
≤ −10 °C). Our results demonstrate the important control of
snow cover on northern soil freeze–thaw and soil carbon decomposition
processes and the necessity of considering both warming and a change in
precipitation and snow cover regimes in characterizing permafrost soil carbon
dynamics. |
| first_indexed | 2024-12-23T05:34:20Z |
| format | Article |
| id | doaj.art-7725321c79d14bae9a1497c31758c62b |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-23T05:34:20Z |
| publishDate | 2015-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-7725321c79d14bae9a1497c31758c62b2022-12-21T17:58:23ZengCopernicus PublicationsBiogeosciences1726-41701726-41892015-10-0112195811582910.5194/bg-12-5811-2015The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamicsY. Yi0J. S. Kimball1M. A. Rawlins2M. Moghaddam3E. S. Euskirchen4Numerical Terradynamic Simulation Group (NTSG), College of Forestry and Conservation, The University of Montana, Missoula, MT 59812, USANumerical Terradynamic Simulation Group (NTSG), College of Forestry and Conservation, The University of Montana, Missoula, MT 59812, USADepartment of Geosciences, University of Massachusetts, Amherst, MA, USADepartment of Electrical Engineering, University of Southern California, Los Angeles, CA, USAInstitute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USANorthern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (~ 0.8–1.3 days decade<sup>−1</sup>) in the mean annual snow cover extent and frozen-season duration across the pan-Arctic domain, coincident with regional climate warming trends. How the soil carbon pool responds to these changes will have a large impact on regional and global climate. Here, we developed a coupled terrestrial carbon and hydrology model framework with a detailed 1-D soil heat transfer representation to investigate the sensitivity of soil organic carbon stocks and soil decomposition to climate warming and changes in snow cover conditions in the pan-Arctic region over the past 3 decades (1982–2010). Our results indicate widespread soil active layer deepening across the pan-Arctic, with a mean decadal trend of 6.6 ± 12.0 (SD) cm, corresponding to widespread warming. Warming promotes vegetation growth and soil heterotrophic respiration particularly within surface soil layers (≤ 0.2 m). The model simulations also show that seasonal snow cover has a large impact on soil temperatures, whereby increases in snow cover promote deeper (≥ 0.5 m) soil layer warming and soil respiration, while inhibiting soil decomposition from surface (≤ 0.2 m) soil layers, especially in colder climate zones (mean annual <i>T</i> ≤ −10 °C). Our results demonstrate the important control of snow cover on northern soil freeze–thaw and soil carbon decomposition processes and the necessity of considering both warming and a change in precipitation and snow cover regimes in characterizing permafrost soil carbon dynamics.http://www.biogeosciences.net/12/5811/2015/bg-12-5811-2015.pdf |
| spellingShingle | Y. Yi J. S. Kimball M. A. Rawlins M. Moghaddam E. S. Euskirchen The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics Biogeosciences |
| title | The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics |
| title_full | The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics |
| title_fullStr | The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics |
| title_full_unstemmed | The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics |
| title_short | The role of snow cover affecting boreal-arctic soil freeze–thaw and carbon dynamics |
| title_sort | role of snow cover affecting boreal arctic soil freeze thaw and carbon dynamics |
| url | http://www.biogeosciences.net/12/5811/2015/bg-12-5811-2015.pdf |
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