Correlation Between Active Layer Thermal Regime and air Temperature
Abstract
Inter-annual variations of the active layer thickness have been monitored on a hemispheric scale over the last decade to achieve a better perception of the influence of the ongoing climate change on the thermal regime. The thermal regime at the surface represents the main boundary condition for the subsurface thermal regimes. Therefore, the surface characteristics are the main factor influencing the heat flux. This has consequences for modelling mountain permafrost distribution since area with different surface characteristics will react completely different on climate change effects, because of altered feedback mechanisms. Thermal regimes underneath coarse, blocky material is known to be up to several degrees cooler than adjacent soils but the processes that are involved are not yet fully understood. New data from a permafrost site in the Swiss Alps suggest that a specific air temperature of approximately 6°C acts as a limit controlling the pattern of heat fluxes across the surface boundary and might reveal some of the explanations for why discontinuous mountain permafrost can subsist below the zero degree mean annual air temperature.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSM.C34A..03H
- Keywords:
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- 1823 Frozen ground;
- 1863 Snow and ice (1827)