The Large-Scale Climate of Alaska - The Effects of the Pacific Decadal Oscillation on the Climate of Alaska

The climate of the state of Alaska is influenced not only by regional anthropogenic climate change, but also by the effects of large-scale ocean atmosphere systems like the Pacific Decadal Oscillation (PDO). Whereas positive anomalies in the PDO index coincide with warmer (sea surface) temperatures in the Gulf of Alaska and across the state, negative anomalies have the opposite effect. After analyzing the strength and direction of the correlation between the PDO index and the average temperatures in each of the 13 climate divisions of Alaska – both annually, as well as seasonally (DJF, MAM, JJA, and SON) – it becomes apparent, that the PDO affects the southern coastal and Panhandle regions much stronger than the Interior and North Slope. Over the course of a year, the correlations are strongest during the winter months, decrease during the spring and summer, only to increase again in the fall. Since the effects of large-scale circulations such as the PDO are changing under the influence of natural and anthropogenic climate change, reliable predictions on the future of the Alaskan climate are extremely complicated. In the future, further analysis is needed to support policy makers in their efforts to help adept the state’s ecosystems and economies to the changing climate.