Northern Watershed Change, Modeled Permafrost Temperatures in the Yukon River Watershed

Changes in the terrestrial hydrologic cycle in northern watersheds can be seen through permafrost warming. Furthermore, vegetation shifts occur with climate changes coupled with permafrost degradation. Permafrost warming is resultant from warming air temperatures and the collection of buffers between the atmosphere and the cryosphere: the active layer, snow, and vegetation. Our modeling methods combine a meteorological model with a permafrost temperature model in 1 km2 resolution in the 847,642 km2 Yukon River Watershed. The MicroMet model is a quasi-physically based model developed in 2006 by Liston & Elder to spatially interpolate irregularly spaced point meteorological data using known temperature-elevation, wind-topography, humidity-cloudiness, and radiation-cloud-topography relationships. We call on 1997-2007 data from 104 Integrated Surface Data meteorological stations and 100 grid points in a 5 best models ensemble A1B 2090-2100 projection. The Temperature at the Top of the Permafrost (TTOP) model is a numerical model for estimating the thermal state of permafrost. This model is attributed to Smith & Riseborough, 1996. TTOP relates more readily available near surface temperatures to temperatures at the depth of seasonal variation using user-defined landcover n-factors (to relate air temperature to soil surface temperature) and soil thermal conductivities (to simulate the propagation of heat through the active layer). TTOP simulates warm top of the permafrost temperatures for high soil thermal conductivity, land cover with high n-factor, and a high number of thawing degree-days/ year. Here we compare the present and future thermal stability of permafrost in the Yukon River Watershed.