Title: Evidence of Recent Warming in Polar Latitudes from Borehole Temperature
Author: Orsi, A.J. and Severinghaus, J.P.
Periodical: American Geophysical Union, Fall Meeting 2010, abstract #C24A-04
Abstract: Polar regions have been warming significantly for the last 50 years, and not only near the coast. We present here two borehole temperature records: one from WAIS Divide (79°S, 112°W) in the center of West Antarctica, and one from NEEM in North Greenland (77°N, 51°W). Both of these sites have a mean annual temperature of -29°C. Borehole temperature records allow us to put modern measurement in the context of a longer time series. At WAIS Divide, the 300m record takes us back 500 years, before the "Little Ice Age" minimum. The recent part of the record is in complete agreement with climate field reconstructions based on automatic weather station and satellite data, showing that WAIS Divide has warmed by more than 1°C since 1958. At NEEM, there is a 1°C temperature gradient in the firn between 20 and 80m, compared to 0.2°C at WAIS. This is evidence for an even faster rate of warming in recent decades. Significant warming inland is a concern for the stability of the ice sheets and eventually sea level rise.
Year: 2010