Relationship Between Large-Scale Circulation and Ice Core Proxy Data from the McCall Glacier, Alaska

Wednesday, 17 December 2014
Elizabeth Cassano, Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, John J Cassano, Univ Colorado, Boulder, CO, United States, Joe McConnell, Desert Research Institute Reno, Reno, NV, United States and Matt Nolan, University of Alaska Fairbanks, Fairbanks, AK, United States
Ice cores have often been used to reconstruct paleoclimate based on proxies contained in the cores. Using an ice core from McCall Glacier, in the eastern Brooks Range of Alaska we identify relationships between ice core proxies and synoptic weather patterns influencing McCall Glacier. The self-organizing map (SOM) algorithm is used to objectively identify the synoptic circulation patterns both at the surface and aloft for this region and relate these patterns to 27 proxies processed from the ice core for the past 60 years when reliable atmospheric reanalysis data are available. Correlation analysis with gridded circulation data at both the surface and aloft and with the frequency of synoptic patterns identified by the climate classification created with the SOM algorithm was performed. Results showed the strongest relationships with Iodine, Nitric Acid, Phosphorus, and two measurements of black carbon while aluminum had the weakest relationship with circulation. In addition, seasonal analysis showed the strongest circulation relationships in spring and summer with the weakest in autumn.