Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate th...Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate the chemical and radiative impacts of an assumed 2 ppmv increase in H20. The chemical effects of this H20 increase lead to an overall decrease of the total column ozone (TCO) by ~1% in the tropics and by a maximum of 12% at southern high latitudes. At northern high latitudes, the TCO is increased by only up to 5% due to stronger transport in the Arctic. A 2-ppmv H2O increase in the model's radiation scheme causes a cooling of the tropical stratosphere of no more than 2 K, but a cooling of more than 4 K at high latitudes. Consequently, the TCO is increased by about 2%-6%. Increasing stratospheric H2O, therefore, cools the stratosphere both directly and indirectly, except in the polar regions where the temperature responds differently due to feedbacks between ozone and H2O changes. The combined chemical and radiative effects of increasing H2O may give rise to more cooling in the tropics and middle latitudes but less cooling in the polar stratosphere. The combined effects of H2O increases on ozone tend to offset each other, except in the Arctic stratosphere where both the radiative and chemical impacts give rise to increased ozone. The chemical and radiative effects of increasing H2O cause dynamical responses in the stratosphere with an evident hemispheric asymmetry. In terms of ozone recovery, increasing the stratospheric H2O is likely to accelerate the recovery in the northern high latitudes and delay it in the southern high latitudes. The modeled ozone recovery is more significant between 2000 ~2050 than between 2050~2100, driven mainly by the larger relative change in chlorine in the earlier period.展开更多
The Arctic has experienced several extreme springtime stratospheric ozone depletion events over the past four decades,particularly in 1997,2011 and 2020.However,the impact of this stratospheric ozone depletion on the ...The Arctic has experienced several extreme springtime stratospheric ozone depletion events over the past four decades,particularly in 1997,2011 and 2020.However,the impact of this stratospheric ozone depletion on the climate system remains poorly understood.Here we show that the stratospheric ozone depletion causes significant reductions in the sea ice concentration(SIC)and the sea ice thickness(SIT)over the Kara Sea,Laptev Sea and East Siberian Sea from spring to summer.This is partially caused by enhanced ice transport from Barents-Kara Sea and East Siberian Sea to the Fram Strait,which is induced by a strengthened and longer lived polar vortex associated with stratospheric ozone depletion.Additionally,cloud longwave radiation and surface albedo feedbacks enhance the melting of Arctic sea ice,particularly along the coast of the Eurasian continent.This study highlights the need for realistic representation of stratosphere-troposphere interactions in order to accurately predict Arctic sea ice loss.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40575019, 40730949)the U.K. Natural Environ-ment Research Council (NERC)
文摘Using a detailed, fully coupled chemistry climate model (CCM), the effect of increasing stratospheric H20 on ozone and temperature is investigated. Different CCM time-slice runs have been performed to investigate the chemical and radiative impacts of an assumed 2 ppmv increase in H20. The chemical effects of this H20 increase lead to an overall decrease of the total column ozone (TCO) by ~1% in the tropics and by a maximum of 12% at southern high latitudes. At northern high latitudes, the TCO is increased by only up to 5% due to stronger transport in the Arctic. A 2-ppmv H2O increase in the model's radiation scheme causes a cooling of the tropical stratosphere of no more than 2 K, but a cooling of more than 4 K at high latitudes. Consequently, the TCO is increased by about 2%-6%. Increasing stratospheric H2O, therefore, cools the stratosphere both directly and indirectly, except in the polar regions where the temperature responds differently due to feedbacks between ozone and H2O changes. The combined chemical and radiative effects of increasing H2O may give rise to more cooling in the tropics and middle latitudes but less cooling in the polar stratosphere. The combined effects of H2O increases on ozone tend to offset each other, except in the Arctic stratosphere where both the radiative and chemical impacts give rise to increased ozone. The chemical and radiative effects of increasing H2O cause dynamical responses in the stratosphere with an evident hemispheric asymmetry. In terms of ozone recovery, increasing the stratospheric H2O is likely to accelerate the recovery in the northern high latitudes and delay it in the southern high latitudes. The modeled ozone recovery is more significant between 2000 ~2050 than between 2050~2100, driven mainly by the larger relative change in chlorine in the earlier period.
基金supported by Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2021SP312)the National Natural Science Foundation of China(4207506242130601,and 41922044)+3 种基金the National Key Research&Development Program of China(2018YFC1506003)the Fundamental Research Funds for the Central Universities,China(lzujbky-2021ey04)Young Doctoral Funds for Gansu Provincial Education Department(2021QB-009)supported by Supercomputing Center of Lanzhou University。
文摘The Arctic has experienced several extreme springtime stratospheric ozone depletion events over the past four decades,particularly in 1997,2011 and 2020.However,the impact of this stratospheric ozone depletion on the climate system remains poorly understood.Here we show that the stratospheric ozone depletion causes significant reductions in the sea ice concentration(SIC)and the sea ice thickness(SIT)over the Kara Sea,Laptev Sea and East Siberian Sea from spring to summer.This is partially caused by enhanced ice transport from Barents-Kara Sea and East Siberian Sea to the Fram Strait,which is induced by a strengthened and longer lived polar vortex associated with stratospheric ozone depletion.Additionally,cloud longwave radiation and surface albedo feedbacks enhance the melting of Arctic sea ice,particularly along the coast of the Eurasian continent.This study highlights the need for realistic representation of stratosphere-troposphere interactions in order to accurately predict Arctic sea ice loss.