Sunday, 22 January 2012
Pacific Teleconnection Signals As Recorded in West Central Greenland Ice Cores
Hall E (New Orleans Convention Center )
Climate modes emanating from the Pacific sector have far-reaching effects across the globe. The El Niņo/Southern Oscillation (ENSO) reflects anomalies in the sea surface temperature and pressure fields over the tropical Pacific, but climate implications from these anomalies extend from monsoon regions of Asia to North America and even Europe. The Pacific Decadal Oscillation (PDO) explains sea surface temperature anomalies in the North Pacific sector and influences the long-term behavior of the ENSO cycle as well as the storm track over North America expressed as the Pacific/North American Pattern (PNA). The impacts of these different climate modes have been extensively studied in many regions; however, Greenland remains one region where these signals are not well understood. The potential instability of the Greenland Ice Sheet and its contribution to sea level rise raise concerns about its surface mass balance; thus understanding the climatic influences over Greenland, whether local or global in extent, is crucial. Greenland ice cores provide a history of climatic variables through proxy data such as net annual accumulation, oxygen isotopic composition, annual dust concentration, and glaciochemical fluxes. Results will be presented involving the relationship between the Pacific teleconnection patterns and these properties preserved in three ice cores in west central Greenland. The climate of west central Greenland is heavily influenced by the North Atlantic Oscillation (NAO) which may be masking the modest Pacific signal recorded in the ice cores. Thus, the Pacific teleconnection indices will also be compared to the ice core records with the NAO signal removed in order to gain insight on the influence from the Pacific on the climate of Greenland.