NEW RESULTS FROM THE NORTHGRIP, GREENLAND ICE CORE

New results from the NorthGRIP ice core in northern Greenland will be discussed. Based on gas dating and comparisons to ocean cores, the NorthGRIP ice core extends back about 123,000 years, capturing the latter part of the Eemian. The ice isotope values imply that the Eemian had a stable climate that was 5K warmer than present day, and ended with a slow, steady cooling to glacial conditions over 5,000 years. A new abrupt climate change event at 114,000 years is revealed for the first time, showing that such events occurred before ice sheets had grown substantially and the climate had cooled to full glacial conditions. Comparison of ice isotopes with other Greenland ice cores, GRIP, GISP2, Renland, Camp Century and DYE3, reveals that a strong climate gradient was present in northern Greenland during full glacial times, and that this gradient may have been modulated by the extent of the Laurentide ice sheet. The northern part of the Greenland ice sheet appears to have been stable in height during the Eemain, with heights roughly the same as today, while the southern part of the ice sheet was lower during the Eemain, constraining sea level contributions from Greenland during the Eemian. Finally, the ice melting at the base at NorthGRIP, with an unexpectedly high heat flux for this area. This prevents thinning of ice at depth and leads to a high-resolution record of climate for the end of the last interglacial.