M. Torre Jorgenson Bruce K. Wylie Shawn J. Nield Kristofer D. Johnson Andrew O. Finley Neal J. Pastick 2015 <p>High-latitude regions are experiencing rapid and extensive changes in ecosystem composition and function as&nbsp;the result of increases in average air temperature. Increasing air temperatures have led to widespread thawing&nbsp;and degradation of permafrost, which in turn has affected ecosystems, socioeconomics, and the carbon cycle of&nbsp;high latitudes. Here we overcome complex interactions among surface and subsurface conditions to map nearsurface&nbsp;permafrost through decision and regression tree approaches that statistically and spatially extend field&nbsp;observations using remotely sensed imagery, climatic data, and thematic maps of a wide range of surface and&nbsp;subsurface biophysical characteristics. The data fusion approach generated medium-resolution (30-m pixels)&nbsp;maps of near-surface (within 1 m) permafrost, active-layer thickness, and associated uncertainty estimates&nbsp;throughout mainland Alaska. Our calibrated models (overall test accuracy of ~85%) were used to quantify changes&nbsp;in permafrost distribution under varying future climate scenarios assuming no other changes in biophysical&nbsp;factors. Models indicate that near-surface permafrost underlies 38% of mainland Alaska and that near-surface&nbsp;permafrost will disappear on 16 to 24% of the landscape by the end of the 21st Century. Simulations suggest&nbsp;that near-surface permafrost degradation is more probable in central regions of Alaska than more northerly regions.&nbsp;Taken together, these results have obvious implications for potential remobilization of frozen soil carbon&nbsp;pools under warmer temperatures. Additionally, warmer and drier conditions may increase fire activity and&nbsp;severity, which may exacerbate rates of permafrost thaw and carbon remobilization relative to climate alone.&nbsp;The mapping of permafrost distribution across Alaska is important for land-use planning, environmental assessments,&nbsp;and a wide-array of geophysical studies.</p> application/pdf 10.1016/j.rse.2015.07.019 en Elsevier Distribution of near-surface permafrost in Alaska: estimates of present and future conditions article