EXTENDING THE RECONSTRUCTION OF SURFACE AIR TEMPERATURE USING TREE RINGS FROM THE GULF OF ALASKA

Previous dendroclimatic reconstructions for the Gulf of Alaska (GOA) date to 800 CE and primarily record warm season temperatures. These records have identified a warm interval centered on 950 CE and subsequent cooling considered to be intervals of the Little Ice Age and the contemporary warming of the last hundred years.

Efforts to extend this record are underway using sub fossil wood recently exposed in the wake of retreating glaciers. Using samples collected from Muir Inlet of Glacier Bay, Alaska in the summer of 2014 and previously compiled chronologies from the surrounding area, this project intends to add more tree ring series to the present chronologies to better reconstruct the 2000 year history of surface air temperature variability throughout the GOA. Preliminary results display long period cooling likely associated with Milankovich forcing recognized in other high latitude proxy temperature records and consistent with glacier records from the region. Warm intervals rivaling contemporary warming are evident prior to the recent century and cooling around 600 CE precedes a strong glacial expansion. Overall, the reconstruction is more similar to recent multi proxy reconstructions for western continental North America than for the higher Arctic records which have included the GOA tree-ring temperature records in the past.