Authors: Dmitry Streletskiy*, George Washington University
Topics: Cryosphere, Polar Regions, Climatology and Meteorology
Keywords: permafrost, arctic, global, GTN-P
Session Type: Paper
Start / End Time: 3:20 PM / 5:00 PM
Room: Regent, Marriott, River Tower Elevators, 4th Floor
Presentation File: No File Uploaded
Permafrost is defined as soil, rock, and any other subsurface earth material that exists at or below 0°C continuously for two or more consecutive years. On top of permafrost is the active layer, which thaws during the summer and freezes again the following winter. The Global Terrestrial Network for Permafrost (GTN-P) provides systematic long-term measurements of permafrost temperature and active layer thickness (ALT), and generates essential baseline information for the assessment of climate change impacts in polar and high mountain regions. The GTN-P data show that permafrost temperature has generally increased across the entire permafrost domain. The greatest increases are found in the High Arctic and are pronounced in regions with cold permafrost such as Russia and North America. In the Subarctic, where permafrost temperatures are relatively high and within 2°C of the freezing point, less change was observed. In Alpine permafrost areas most measurement sites also show significant warming since 2009. In Antarctica, permafrost temperature showed various trends, depending on regional changes in atmospheric temperature and snow accumulation. ALT exhibits large interannual variability, but has generally increased in the majority of regions, especially in European Arctic where several sites experienced permafrost degradation. In several locations thaw penetration into the ice-rich layer rather than ALT thickening was observed under warming climatic conditions. The results reveal further need for improved geographic coverage of the observational network, further refining of monitoring standards and integration of other ecosystem and climatic variables in order to better assess changes in permafrost system at global scales.