Impact of Recent Climate Warming on Active-Layer Dynamics, Permafrost, and Soil Properties on the Western Antarctic Peninsula

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Intellectual Merit: The seasonal thaw layer, permafrost distribution and temperature, and soil properties are key indicators of climate change that have been under-utilized in Antarctica. The PI proposes to install two Circumpolar Active Layer Monitoring (CALM-S) stations and permafrost boreholes on Anvers (64.7°S) and Brabant Islands (64.25°S) to link with existing stations maintained by Portugal, Spain, and Italy on Adelaide (67.57°S), Deception (63.0°S), Livingston (62.50°S), King George (62.18°S), and Signy (60.70°S) Islands. In addition, they propose to examine soils along this latitudinal/climatic gradient to construct a carbon budget for the Antarctic Peninsula. The working hypothesis is that permafrost distribution and temperatures on the West Antarctic Peninsula are strongly influenced by the spatial extent of sea ice in the Southern Ocean, and that the active-layer thickness and permafrost temperatures are increasing at a measurable rate in the study areas. The PIs predict that although soils of the Antarctic Peninsula and offshore islands comprise only 20% of the ice-free area of Antarctica, they will account for more than 80% of the soil organic carbon. Continued warming could stimulate a positive feedback mechanism whereby additional CO2 will be released to the atmosphere as soil organic carbon exposed by thickening of the active layer decomposes. The project will construct and test a mechanistic model that includes ground temperature and climate data, snow cover, a digital elevation model in conjunction with the multi-national PERMANTAR group, slope angle and aspect, and net radiation for predicting the occurrence and the fate of permafrost along the WAP.Broader impacts: This project will foster international research among six countries. The project has direct links with the pole-to-pole CALM network, the Global Terrestrial Network for Permafrost (GTN-P), and the SCAR- supported Antarctic Permafrost and Periglacial Environments (ANTPAS) group, and WILL formalize a latitudinal gradient in the most climatically sensitive zone of Antarctica. The research could provide information to help better understand potential rapid climatic changes. The study not only will provide baseline terrestrial data in an area where the focus of U.S. activities has been predominantly on marine ecosystems, but will also take advantage of the extensive Palmer LTER dataset on sea-ice dynamics. The study will train two graduate students and several undergraduates. Outreach activities will focus on school children and will include ?Diary from Antarctic Permafrost Scientists? on the Internet, videoconferencing from the field, and a ?scientist goes to school? initiative for Dane County, WI.