|Title:||Dual Hemisphere Abrupt Climate Change Analysis from Greenland and Antarctic Ice Cores|
|Author:||Jones, T.R., White, J.W., Vaughn, B.H., Popp, T.J., Steig, E.J. and Markle, B.R.|
|Periodical:||American Geophysical Union, Fall Meeting 2012, abstract #PP33A-2064|
During the last glacial period, Greenland ice cores reveal 25 quasi-cyclical abrupt warmings occurring roughly every ~1-3 ka, known as Dansgaard-Oeschger (D-O) events. In some Antarctica ice cores, these events appear as more symmetrical and dampened out-of-phase signals, known as Antarctic Isotope Maxima (AIM) events. D-O and AIM events occurred concurrently with major reorganizations in the global land-ocean-atmosphere system, but it is unclear in which hemisphere the trigger causing the reorganizations resides. We utilize ice core records from a north-south transect of Greenland (NEEM, NGRIP, and GISP2) and West Antarctica (WAIS Divide) to study the speed, timing and magnitude of D-O and AIM events during the last glaciation with temporal resolution of years in both hemispheres. Our data set includes the first dual hemisphere high-resolution Continuous Flow Analysis (CFA) measurements of δD, δ18O and deuterium excess from the NEEM and WAIS Divide ice cores, and traditional mass spec measurements from the GISP2 and NGRIP ice cores. Water isotope data will be combined with chemistry and dust data to form a robust temporal image of past climate forcings and climate change.