A circulation based perspective on the impacts of the 1976 Pacific Climate Shift on Alaskan weather
Abstract
As has been noted in previous work, the North Pacific region experienced a climate shift in 1976. In this presentation we focus on atmospheric circulation differences before and after this shift in the western Arctic to understand long term trends in Alaskan surface air temperature. The method of self-organizing maps (SOMs) is applied to NCEP/NCAR Reanalysis data to identify synoptic weather patterns and document changes in large-scale circulation, as indicated by changes in the frequency of occurrence of these synoptic weather patterns, over Alaska and the surrounding regions. In addition, temperatures at several locations in Alaska are analyzed for the time periods before and after the climate shift. Initial analysis has shown for locations south of the Brooks Range there was a step change increase in temperature at the time of the climate shift but that temperatures had been getting cooler before and after that step change. We utilize the SOM based synoptic weather pattern analysis to determine what portion of these temperature changes can be attributed to changes in circulation associated with the climate shift.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMGC42A..07C
- Keywords:
-
- 1637 GLOBAL CHANGE / Regional climate change;
- 3349 ATMOSPHERIC PROCESSES / Polar meteorology;
- 3364 ATMOSPHERIC PROCESSES / Synoptic-scale meteorology