Seasonal and Decadal Variation of Weather and Climate Extremes in the Arctic

Decadal mean temperatures show a warming over the past 60 years at individual stations in Alaska and the frequency of extremes (defined as the upper and lower percentiles) show corresponding decadal variations for some, but not all stations. The ratio of highest-percentile to lowest-percentile temperature occurrences has increased in the past decade, especially in the colder half of the year. Occurrences of precipitation extremes show more varied trends over the past 60 years, although there are indications that heavy precipitation events track the decadal mean precipitation amounts and that the frequencies of heavy precipitation vary inversely with the occurrence of extended dry periods. We will present the spatial and seasonal distributions of the variations of extremes of temperature and precipitation in the context of changing climatic means in Alaska.