Siberia experienced intense heat waves in 2020,and this unusual warming may have caused more wildfires and losses of permafrost than normal,both of which can be devastating to ecosystems.Based on observational data,th...Siberia experienced intense heat waves in 2020,and this unusual warming may have caused more wildfires and losses of permafrost than normal,both of which can be devastating to ecosystems.Based on observational data,this paper shows that there was an intense warming trend over Siberia(60°–75°N,70°–130°E)in June during 1979–2020.The linear trend of the June surface air temperature is 0.90℃/10 yr over Siberia,which is much larger than the area with the same latitudes(60°–75°N,0°–360°,trend of 0.46℃/10 yr).The warming over Siberia extends from the surface to about 300 h Pa.Increased geopotential height in the mid-to-upper troposphere plays an important role in shaping the Siberian warming,which favors more shortwave radiation reaching the surface and further heating the overlying atmosphere via upward turbulent heat flux and longwave radiation.The Siberian warming is closely related to Arctic sea-ice decline,especially the sea ice over northern Barents Sea and Kara Sea.Numerical experiments carried out using and atmospheric general circulation model(IAP-AGCM4.1)confirmed the contribution of the Arctic sea-ice decline to the Siberian warming and the related changes in circulations and surface fluxes.展开更多
基金supported by the National Key R&D Pro-gram of China[grant number 2017YFE0111800]the National Natural Science Foundation of China[grant numbers 41790472 and 41822502]。
文摘Siberia experienced intense heat waves in 2020,and this unusual warming may have caused more wildfires and losses of permafrost than normal,both of which can be devastating to ecosystems.Based on observational data,this paper shows that there was an intense warming trend over Siberia(60°–75°N,70°–130°E)in June during 1979–2020.The linear trend of the June surface air temperature is 0.90℃/10 yr over Siberia,which is much larger than the area with the same latitudes(60°–75°N,0°–360°,trend of 0.46℃/10 yr).The warming over Siberia extends from the surface to about 300 h Pa.Increased geopotential height in the mid-to-upper troposphere plays an important role in shaping the Siberian warming,which favors more shortwave radiation reaching the surface and further heating the overlying atmosphere via upward turbulent heat flux and longwave radiation.The Siberian warming is closely related to Arctic sea-ice decline,especially the sea ice over northern Barents Sea and Kara Sea.Numerical experiments carried out using and atmospheric general circulation model(IAP-AGCM4.1)confirmed the contribution of the Arctic sea-ice decline to the Siberian warming and the related changes in circulations and surface fluxes.
