Revisiting climatic features in the Alaskan Arctic using newly collected data

Abstract

Climatic features in the Alaskan Arctic have typically been analyzed using data from the limited National Weather Service stations. However, the increasing availability of in situ data in this area allows a more comprehensive understanding of recent changes. This study used newly collected data from 41 stations to investigate climatic features and recent changes in the Alaskan Arctic from the mid-1940s to 2018. We found that the mean annual air temperature (MAAT) ranged from –11.0 to –6.4 ∘C, annual amplitude of air temperature (AAAT) ranged from 16 to 22 ∘C, annual precipitation ranged from 85 to 300 mm, and annual mean snow depth ranged from 13.5 to 34.5 cm during 2007–2012. Compared with data since the late 1980s, MAAT increased by $\sim $ 2 ∘C near the coastline whereas AAAT did not significantly change. Changes in annual precipitation were complex among stations but showed a considerable increase in precipitation, snowfall, and snow depth during the cold months. The number of snow cover days declined, whereas the number of snowfall days increased at both Barrow and Kuparuk. This increase in snowfall events may be attributed to the declining sea ice concentration, which may enhance hydrological cycles. The observed bulk density of fresh snow was around 40–80 kg/m3 and declined from the mid-1980s to the late-1990s, then increased until the end of the study period. This expanded in situ dataset provides a more comprehensive understanding of climatic conditions in the Alaskan Arctic and confirms rapid changes during recent decades. This study may also serve to validate and benchmark high-resolution climate models.