Ice core-derived histories of North Pacific climate variability

The Pacific Decadal Oscillation (PDO) describes a multi-decadal horseshoe-like pattern in sea surface temperatures (SSTs) of the North Pacific. Observational records are limited in length and thus fail to fully capture the low frequency, multi-decadal nature of the PDO. Paleo-proxies offer the opportunity to explore the long-term behavior of North Pacific climate variability and place its behavior within the longer context of Earth's climate history. Annually resolved accumulation and isotopic records are investigated from an ice core retrieved from southeast Alaska which is ideally located to capture multi-decadal variability in this system over the last millennium. As a terrestrial proxy, the ice core preserves the atmospheric response to the multi-decadal oceanic phenomenon. More specifically, the ice core records reveal long-term shifts in the strength and position of the Aleutian Low which is modulated by the phase of the PDO. These persistent shifts in the Aleutian Low's position also influence the downstream wave patterns over North America. This southeast Alaska ice core record will be utilized along with several PDO and North Pacific paleo-reconstructions to better elucidate the past behavior of the North Pacific climate system.