RECENT CLIMATE AND CRYOSPHERIC CHANGE IN NORTHWEST GREENLAND

Northwest (NW) Greenland temperatures have increased by 3^oC since 1990, with most of the warming occurring in fall and winter. According to remote sensing data, the NW Greenland ice sheet (GIS) and coastal ice caps are responding with ice mass loss and margin retreat, but the cryosphere’s response to previous climate variability is poorly constrained in this region. To improve projections of future ice loss and sea-level rise in a warming climate, we are developing records of Holocene climate change and cryospheric response in NW Greenland from lake sediment cores, ice cores, glacial geologic data, and instrumental weather data. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 21 m) from the coastal region of the GIS (2Barrel site; 76.9317^o N, 63.1467^o W, 1685 m el.) and the summit of North Ice Cap (76.938^o N, 67.671^o W, 1273 m el.) in 2011, 2012 and 2014. Here we show that the 2Barrel ice core spanning 1990-2010 records a 25% increase in mean annual snow accumulation, and is positively correlated with ERA-Interim reanalysis precipitation (r = 0.52, p<0.01) and instrumental precipitation from Thule (r = 0.43 p<0.05). The 2Barrel annual methanesulfonate (MSA) and sea-salt sodium concentrations are strongly correlated with spring (r = -0.58, p<0.01) and fall (r = 0.73, p<0.001) sea-ice concentrations, respectively, in northern Baffin Bay. Dust and MSA concentrations are significantly correlated with summertime Thule temperature and with the Atlantic Multidecadal Oscillation. Our results show that a deep ice core collected from this dynamic and climate-sensitive region of NW Greenland would produce a valuable record of late Holocene climate and sea ice extent.