Importance of regional indices of atmospheric circulation for periods of warming and cooling in Svalbard during 1920–2018

Abstract

The Arctic has experienced prominent climate warming, at the beginning of the 20th century and currently. Comparing the driving mechanism during these periods helps to explain the causes of contemporary climate change. Our study explores the impact of regional circulation on Svalbard's surface air temperature (SAT, 2 m above ground). We used air temperature data from Svalbard Airport, Bjørnøya stations, and three regional circulation indices that describe the frequency of cyclonic conditions, zonal circulation, and meridional circulation. The indices were calculated for four circulation areas with differing circulation conditions and, therefore, may have various impacts on long-term changes in SAT. This was checked for the entire study period , and 30-year sub-periods representing the most prominent climatic events: the early 20th-century Arctic warming (ETCAW), contemporary Arctic warming (CAW), and a cold period between them (CAP). In autumn and winter, the deviations in SAT from the long-term average during warm and cold periods were almost twice as large at Svalbard Airport as at Bjørnøya. In these seasons, the ETCAW was significantly warmer than the subsequent cold period, which was not the case for summer and spring. However, long-term trends in the regional circulation indices were more evident in summer and spring than in autumn and winter. Air temperature was the most strongly influenced by meridional circulation over the eastern circulation areas, with the exception of spring, when air temperature variability was more affected by zonal circulation.The recent warming weakened the relationship between SAT and the indices in summer. We attributed the ETCAW in autumn to a southerly advection of sensible heat. During the same historical period, the impact of the indices was much weaker in winter. In winter during the CAP, there was a higher frequency of northern air advection, particularly over the northern part of the Greenland Sea.

The Influence of Atmospheric Circulation on Mean and Extreme Weather Conditions on Kaffiøyra (NW Spitsbergen, Svalbard Archipelago) in the Summer Seasons 1975–2015

“…AC plays a much greater role in shaping weather and climate in the Norwegian Arctic than elsewhere on the globe. Climate model studies have shown that changes in response to climate changes are strongest and quickest in the Arctic (e.g., Turner and Marshall 2011;Przybylak 2016;Łupikasza et al, 2021). A characteristic feature of AC over Spitsbergen is its increased cyclonic activity, conditioned by the island's location near the Arctic front (Niedźwiedź 2013a).…”

“…AC also affects the extent of sea ice in the Arctic (Ding et al, 2017). In addition, changes happening in the Arctic are associated not only with positive feedback mechanisms-"Arctic amplification" (Serreze and Barry 2011)but also with changes in the extent of sea ice (Ding et al, 2017) and the reshaping of the pressure field and atmospheric circulation (Przybylak 2002;Łupikasza et al, 2021).…”

Polish Polar Research

“…In addition, the positive trend in autumn precipitation is one of the highest in Svalbard (Førland et al 2020). Nonetheless, the meteorological data from the PPS have rarely been analyzed in recent studies (e.g., Serreze et al 2015;Nordli et al 2020;Przybylak and Wyszyński 2020;Łupikasza et al 2021).…”