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

Abstract

We identify that the projected uncertainty of the pan-Arctic sea-ice concentration (SIC) is strongly coupled with the Eurasian circulation in the boreal winter (December-March; DJFM), based on a singular value decomposition (SVD) analysis of the forced response of 11 CMIP5 models. In the models showing a stronger sea-ice decline, the Polar cell becomes weaker and there is an anomalous increase in the sea level pressure (SLP) along 60 • N, including the Urals-Siberia region and the Iceland low region. There is an accompanying weakening of both the midlatitude westerly winds and the Ferrell cell, where the SVD signals are also related to anomalous sea surface temperature warming in the midlatitude North Atlantic. In the Mediterranean region, the anomalous circulation response shows a decreasing SLP and increasing precipitation. The anomalous SLP responses over the Euro-Atlantic region project on to the negative North Atlantic Oscillation-like pattern. Altogether, pan-Arctic SIC decline could strongly impact the winter Eurasian climate, but we should be cautious about the causality of their linkage.

Evaluating Impacts of Recent Arctic Sea Ice Loss on the Northern Hemisphere Winter Climate Change

“…First, sea ice has a strong control on local climate, and therefore it deserves to be better observed and represented in models. Lastly, climate models suggest a link between uncertainties in future change in pan-Arctic sea ice decline and Eurasian climate (Cheung et al, 2018); this implies potential differences between present and future changes. Second, the SST-driven teleconnections also need further investigation, as Geophysical Research Letters 10.1002/2017GL076502 they appear to reduce the chance of simulating the observed AO-like trend.…”

“…Fourth, our experimental design did not resolve active ocean-atmosphere-sea ice coupling or changes in sea ice thickness (Lang et al, 2017;McCusker et al, 2016), and these issues deserve further consideration in a coordinated manner. Lastly, climate models suggest a link between uncertainties in future change in pan-Arctic sea ice decline and Eurasian climate (Cheung et al, 2018); this implies potential differences between present and future changes. There are still conflicting results between this article and previous studies, which highlights a need for engaging community-wide, larger-scale numerical experiments incorporating the aforementioned issues.…”

Subseasonal mode of cold and wet climate in South China during the cold season: a climatological view

“…The subseasonal cold-air activity is nested in a cyclonic circulation at 500 hPa, which can be verified by diagnostic analysis of LCWA ( Figure 5). Besides the considerable contribution of Arctic circulation, winter climate variations over China can also be affected by movement of the East Asian trough, India-Burma trough, and Urals-Siberia blocking (Cheung et al 2012;Leung and Zhou 2016;Leung, Cheung, and Zhou 2017;Li, Chen, and Zhou 2017), as well as the variability of the Madden-Julian Oscillation, El Niño, and pan-Arctic sea-ice concentration (Jia et al 2001;Zhang et al 2015;Cheung et al 2018;Xu et al 2018b). Our work reveals a possible source of the frequency of cold-wet events in SC, as well as their seasonal phase-locking.…”

“…It has been considered as the dominant regulator of the cold-air activity affecting the climate over Eurasia (e.g. Wu and Wang 2002;Cheung et al 2018). Figure 3 shows the first three leading EOF modes of the ISO components of 500-hPa GPH, accounting for 20.7%, 12.5%, and 9.7% of the total variance, respectively.…”

“…A cold and wet extreme event usually occurs during the cold season, displaying a seasonal phase-locking with enhanced atmospheric ISO activity (Wen et al 2009;Song et al 2015;Ma et al 2018), although it varies with the interannual variations of Arctic sea-ice cover (Wu and Wang 2002;Cheung et al 2018;Ma et al 2018) or tropical sea surface temperature (Xu et al 2018a). The climatological ISO components of SAT and rainfall reflect the seasonal phase-locking characteristics, which provides us with possible clues for the subseasonal forecasting of cold and wet events in China.…”