Observed Atmospheric Coupling between Barents Sea Ice and the Warm-Arctic Cold-Siberian Anomaly Pattern

Abstract

The decline in Barents Sea ice has been implicated in forcing the “warm-Arctic cold-Siberian” (WACS) anomaly pattern via enhanced turbulent heat flux (THF). This study investigates interannual variability in winter [December–February (DJF)] Barents Sea THF and its relationship to Barents Sea ice and the large-scale atmospheric flow. ERA-Interim and observational data from 1979/80 to 2011/12 are used. The leading pattern (EOF1: 33%) of winter Barents Sea THF variability is relatively weakly correlated (r = 0.30) with Barents Sea ice and appears to be driven primarily by atmospheric variability. The sea ice–related THF variability manifests itself as EOF2 (20%, r = 0.60). THF EOF2 is robust over the entire winter season, but its link to the WACS pattern is not. However, the WACS pattern emerges consistently as the second EOF (20%) of Eurasian surface air temperature (SAT) variability in all winter months. When Eurasia is cold, there are indeed weak reductions in Barents Sea ice, but the associated THF anomalies are on average negative, which is inconsistent with the proposed direct atmospheric response to sea ice variability. Lead–lag correlation analyses on shorter time scales support this conclusion and indicate that atmospheric variability plays an important role in driving observed variability in Barents Sea THF and ice cover, as well as the WACS pattern.

Wind-Driven Atlantic Water Flow as a Direct Mode for Reduced Barents Sea Ice Cover

“…2b). The pattern of sea ice concentration anomalies corresponding to this anomalous atmospheric circulation resembles that of other studies (e.g., Yang et al 2016), which suggests that the northeastern Barents Sea is a hotspot for winter sea ice variability, and, because of the presence of Atlantic water, also associated heat flux anomalies (e.g., Sorokina et al 2016). The choice of one standard deviation in Fig.…”

“…To explore the downstream ocean and ice responses to regional atmospheric forcing, we define a box in the northeastern Barents Sea that covers the Atlantic water pathway through the northeastern Polar Front area where the largest changes in the sea ice cover and oceanto-air heat fluxes are observed both in terms of decadal trends (Yang et al 2016;Sorokina et al 2016) and the February 1993 anomaly (Figs. 2d,f).…”

“…2b), the associated turbulent heat flux anomalies are smaller and therefore of limited importance for the Arctic climate ( Fig. 2f; see also Sorokina et al 2016). We therefore focus our study on the Atlantic water pathway through the Barents Sea.…”

“…The diminishing ice cover and the associated impacts have deservedly received a lot of attention (e.g., Serreze et al 2007;Comiso 2012;Parkinson and Cavalieri 2012). Variable air-sea heat fluxes caused by a changing sea ice cover may act as important drivers of large-scale atmospheric circulation variability (Screen et al 2013;Frankignoul et al 2014;Cohen et al 2014) and have been considered a cause for the midlatitude cold winters in recent years (e.g., Petoukhov and Semenov 2010;Vihma 2014;Cohen et al 2014;Mori et al 2014) and changes to the circulation in the upper troposphere (Schlichtholz 2014); they have been connected to surface temperature in midlatitudes (Schlichtholz 2016), although the causal relationship is complex (Sorokina et al 2016). Changes in the sea ice cover also impact regional marine resources and ecosystems, including species distributions, abundances, and interactions (Fossheim et al 2015); availability of light (Varpe et al 2015); and commercial offshore activity, such as shipping and fossil fuel extraction [e.g., Arctic Climate Impact Assessment (ACIA 2005)].…”

Remarkable link between projected uncertainties of Arctic sea-ice decline and winter Eurasian climate

“…The Siberian high is the key circulation feature of the East Asian winter monsoon that brings cold air masses equatorward via cold surges (Ding, 1994;Chang et al, 2006). In recent decades, one of the most distinct wintertime circulation features is the warm-Arctic-cold-midlatitude temperature pattern Kug et al, 2015;Sorokina et al, 2016). These temperature changes have motivated more research to study whether and how the Arctic changes and the frequency of extreme weather are connected in the present and the future climate [e.g., see the reviews of Cohen et al (2014), Vihma (2014), Barnes and Screen (2015) and Gao et al (2015)].…”