On the Precipitation and Precipitation Change in Alaska

Gerd Wendler,Telayna Gordon,Martin Stuefer

doi:10.3390/atmos8120253

Abstract

Alaska observes very large differences in precipitation throughout the state; southeast Alaska experiences consistently wet conditions, while northern Arctic Alaska observes very dry conditions. The maximum mean annual precipitation of 5727 mm is observed in the southeastern panhandle at Little Port Arthur, while the minimum of 92 mm occurs on the North Slope at Kuparuk. Besides explaining these large differences due to geographic and orographic location, we discuss the changes in precipitation with time. Analyzing the 18 first-order National Weather Service stations, we found that the total average precipitation in the state increased by 17% over the last 67 years. The observed changes in precipitation are furthermore discussed as a function of the observed temperature increase of 2.1 °C, the mean temperature change of the 18 stations over the same period. This observed warming of Alaska is about three times the magnitude of the mean global warming and allows the air to hold more water vapor. Furthermore, we discuss the effect of the Pacific Decadal Oscillation (PDO), which has a strong influence on both the temperature and precipitation in Alaska.

Highlights

Introduction and BackgroundClimate observations in Alaska go back to the period when Alaska was part of the Russian Empire.Russians established an observatory in 1827 on Baranof Island, Sitka [1,2,3]
The Pacific Decadal Oscillation (PDO) is a function of the water temperature north of 20 N of the Pacific Ocean, which strongly related to the El Niño Southern Oscillation (ENSO)
While the R2 values of the PDO, temperature, and precipitation relationships calculated in our analysis vary regionally, there are clear relationships that warrant further investigation

Summary

Introduction and Background

In interior Alaska, the area between the Alaska Range and the Brooks Range, wind speeds are low, and the climate is continental, experiencing relatively warm summers, but cold winters. Both the highest and lowest statewide temperatures were observed in the Interior. There are modest temperature changes over the seasons: winters are relatively warm, summers are cool, and precipitation is plentiful. This is especially the case in southeastern Alaska.

Climate Data Analysis

Temperature change

Correlation

Mean annual temperature

Findings

Conclusions