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

知识价值：季节性融雪层、永久冻土分布和温度以及土壤性质是气候变化的关键指标，但在南极洲尚未得到充分利用。PI建议在Anvers岛（64.7°S）和Brabant岛（64.25°S）安装两个环极活动层监测站和永久冻土钻孔，与葡萄牙、西班牙和意大利在阿德莱德岛（67.57°S）、Deception岛（63.0°S）、Livingston岛（62.50°S）、King George岛（62.18°S）和Signy岛（60.70°S）的现有监测站连接起来。此外，他们建议沿着这种纬度/气候梯度检查土壤，以构建南极半岛的碳预算。工作假设是，南极半岛西部的永久冻土分布和温度受到南大洋海冰空间范围的强烈影响，并且研究区域的活动层厚度和永久冻土温度正在以可测量的速率增加。PIs预测，尽管南极半岛和近海岛屿的土壤只占南极无冰地区的20%，但它们将占土壤有机碳的80%以上。持续变暖可能刺激一种正反馈机制，通过这种机制，由于活性层增厚而暴露的土壤有机碳分解，更多的二氧化碳将被释放到大气中。该项目将构建并测试一个机制模型，该模型包括地面温度和气候数据、积雪、与多国PERMANTAR小组合作的数字高程模型、坡角和坡向，以及用于预测WAP沿线永久冻土发生和命运的净辐射。更广泛的影响：该项目将促进六个国家之间的国际研究。该项目与极对极CALM网络、全球陆地永久冻土网络（GTN-P）和SCAR支持的南极永久冻土和冰缘环境（ANTPAS）小组有直接联系，并将确定南极洲气候最敏感地区的纬度梯度。这项研究可以提供信息，帮助更好地了解潜在的快速气候变化。这项研究不仅将为美国主要关注海洋生态系统的地区提供基线陆地数据，而且还将利用Palmer LTER关于海冰动态的广泛数据集。这项研究将培养两名研究生和几名本科生。外展活动将以学童为重点，并将包括？南极冻土科学家的日记？在互联网上，视频会议从现场，和一个？科学家去上学？威斯康星州戴恩县的倡议。

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.