Sea Ice Loss and Arctic Cyclone Activity from 1979 to 2014

Abstract

Extensive summer sea ice loss has occurred within the Beaufort, Chukchi, East Siberian, and Laptev Seas over the last decade. Associated anomalies in sensible and latent heat fluxes in autumn have increased Arctic atmospheric precipitable water and air temperatures, with the potential to impact autumn and winter cyclone activity. To examine if a connection exists between recent Arctic sea ice loss and cyclone activity, several cyclone metrics from 60° to 90°N are analyzed. Results show that following years with less September sea ice, there is a subsequent increase in moisture availability, regional baroclinicity, and changes in vertical stability that favor cyclogenesis. However, tracking of individual cyclones indicates no coherent increase in cyclone frequency or intensity associated with sea ice loss. Furthermore, no robust northward progression of extreme cyclones is observed.

Trends in cyclones in the high‐latitude North Atlantic during 1979–2016

“…Koyama et al . () examined the possible connection between the recent Arctic sea ice loss and pan‐Arctic cyclone activity. They found changes in baroclinicity suggesting an increased potential for cyclogenesis in years with low sea ice extent.…”

“…However, when tracking individual cyclones, Koyama et al . () did not observe a coherent increase in either cyclone frequency or intensity associated with sea ice loss.…”

“…Following Simmonds and Lim () and Koyama et al . () we use the atmospheric layer encompassed by the 300 and 700 hPa pressure levels. The vertical wind shear d v /dz is related to the horizontal temperature gradient via the thermal wind equation (Wallace and Hobbs, ).…”

“…Further, as Shepherd () writes, “we have much less confidence in the atmospheric circulation aspects of climate change [compared to the thermodynamic aspect], which are primarily controlled by dynamics and exert a strong control on regional climate”. Regarding cyclones being an important component of atmospheric dynamics, several studies have addressed the question of how cyclone activity has changed and will change in the future Arctic (Rinke et al ., ; Zhang et al ., ; Sepp and Jaagus, ; Li et al ., ; Koyama et al ., ; Zahn et al ., )…”

Evidence for Predictive Skill of High‐Latitude Climate Due to Midsummer Sea Ice Extent Anomalies

“…The purpose of this paper is to analyze the observed lead/lag relationships between variations in (1) Arctic SIE and (2) Arctic atmospheric temperatures and high‐latitude circulation. Previous studies have focused on the linkages between large‐scale climate and sea ice anomalies either at the end of summer melt season (e.g., September; Francis et al, ; Honda et al, ; Koyama et al, ; Serreze et al, ) or averaged over the entire summer (Kay & Gettelman, ; Knudsen et al, ). In contrast to those studies, we demonstrate that the continuous (i.e., not reemerging) lagged linkages between sea ice anomalies and high‐latitude climate are most robust in association with midsummer (July) SIE.…”