A dynamic and thermodynamic coupling view of the linkages between Eurasian cooling and Arctic warming

Abstract

Investigating the contrast between wintertime warming in the Arctic and cooling in Eurasia is of great importance for understanding regional climate change. In this study, we propose a dynamic and thermodynamic coupling view of the linkages between wintertime Arctic warming and Eurasian cooling since 1979. The key factors are the energy budget at the Earth’s surface, the diabatic heating and baroclinicity of the atmosphere, and subsurface ocean heat. A summertime origin of wintertime Arctic warming suggests a partial driving role of the Arctic in wintertime Eurasian cooling. The reasons for this finding are as follows. First, there is a dipole pattern in the diabatic heating change in winter over the Arctic Ocean corresponding to the anticyclonic circulation that links Eurasian cooling and Arctic warming. Second, the change in diabatic heating of the atmosphere is determined by sensible heat at the Earth’s surface through vertical diffusion. Third, the positive sensible heat change in the eastern Arctic sector in winter originates from the summertime enhanced absorption of solar radiation by the subsurface ocean over the sea ice loss region. Meanwhile, the negative sensible heat change in the western Arctic sector and wide Arctic warming can be explained by the circulation development triggered by the change in the east. Additionally, the background strong baroclinicity of the atmosphere in mid-high latitudes and corresponding two-way Arctic and mid-latitude interactions are necessary for circulation development in winter. Furthermore, the seasonality of the changes indicates that Eurasian cooling occurs only in winter because the diabatic heating change in the Arctic is strongest in winter. Overall, the comprehensive mechanisms from the summertime Earth’s surface and subsurface ocean to the wintertime atmosphere suggest a driving role of the Arctic. Note that the situation in interannual variability is more complex than the overall trend because the persistence of the influence of summertime sea ice is weakly established in terms of interannual variability.

Extratropical Climate Change During Periods Before and After an Arctic Ice‐Free Summer

“…Therefore, shortwave radiation uptake by the Arctic Ocean is not released immediately via longwave radiation and sensible/latent heat, and induces a lagged net energy cycle across seasons (Figure 4). As per the Stefan‐Boltzmann law, longwave feedback synchronized upward and downward longwave radiation with Arctic warming, during each month of the year (Figures 2–4 and Figure S4 in Supporting Information S1; Dai et al., 2019; Pithan & Mauritsen, 2014; Xie et al., 2021). Therefore, downward longwave radiation appears to be the dominant factor that directly induces seasonality in Arctic warming (Figures 2 and 3), especially in clear‐sky situations (Gao et al., 2019; Lu & Cai, 2009).…”

“…The fully active multisphere interactions are crucial for Arctic climate change‐related investigations. For example, multisphere interactions are suggested to be the most relevant to the Arctic and mid‐latitude connections (Blackport et al., 2019; Xie et al., 2021). Thus, comparisons between the two periods before and after an ice‐free summer may be helpful.…”

Responses of vegetation growth to climate change over the Tibetan Plateau from 1982 to 2018

“…Meanwhile, precipitation and VPD serve as the dominant controlling factor for NDVI GS over 19% and 12% of the TP region, respectively, which are mainly located in the southwestern TP, covered by alpine steppe and alpine meadows, and have relatively high elevations (figure 1(b)) and a cold-arid climate (figure S1 (available online at stacks.iop.org/ERC/ 4/045007/mmedia)). Although longwave radiation dominantly impacts NDVI GS over 7% of the TP, mainly located in southern shrub areas, one should note that longwave radiation is highly correlated with air temperature and may serve as the second dominant factor or one of the top driving factors in these areas with air temperature as the dominant impacting factor (Xie et al 2021). In other words, temperature-dominated regions may also bear the substantial impacts of longwave radiation.…”

Relations of Enhanced High‐Latitude Concurrent Blockings With Recent Warm Arctic‐Cold Continent Patterns

“…The subsurface ocean in the Barents Sea absorbs more energy in the summer and then releases it into the atmosphere in the winter, facilitating the observation of a warm Barents Sea and its atmosphere in winter. The subsequent feedback between temperature advection and atmospheric circulation development, similar to the baroclinic wave mechanism, favors WACC (Xie et al., 2022).…”