The Connection between Alaska and Greenland Ice Cores under Different Climate Regimes

Larger-scale teleconnection patterns exert a strong control on the mean climate state, yet the far-reaching spatial and temporal nature of some of these patterns is not fully understood. The North Atlantic Oscillation (NAO) influences the climate over parts of North America, Greenland, and much of Europe by modulating the strength and location of the Atlantic storm track. The Pacific Decadal Oscillation (PDO) describes the behavior and frequency of El Niño/La Niña events over multi-decadal timescales. The interactions between the PDO and the NAO and their combined influence on the mean climate state are active areas of research. Paleoclimate proxy data provide insight to the behavior of this system prior to the instrumental record. Ice core-derived records provide a history of climatic variability through proxy data such as net annual accumulation, oxygen isotopic composition, annual dust concentration, and glaciochemical fluxes. These properties preserved in ice cores from southeast Alaska and west central Greenland provide new insight to the relationship between these two climate teleconnection patterns that strongly influence Northern Hemisphere climate variability. The Greenland and Alaska records are strongly correlative during some periods and seemingly unrelated during other time periods. This transient behavior likely stems from interactive effects between these teleconnection patterns that may enhance or mitigate their individual climatic influence. These ice core sites are ideally located to preserve the histories of the NAO and PDO patterns and offer a unique opportunity to assess how they have interacted over much longer timescales than are available from the instrumental record.