Dynamical Contribution To Decadal Changes Of The Arctic Stratospheric Temperature And Ozone

Using ERA-Interim,MERRA-2,JRA-55 reanalysis dataset and CMAM simulation data,polar stratosphere temperature,ozone change equations are used to study decadal changes of monthly Arctic stratosphere dynamic contribution to temperature and ozone in ozone depletion and recovery period and 21st century.We discuss dynamic effects on temperature and ozone under different time scales and emission scenarios.The main conclusions are summarized as follows:(1)Due to different planetary wave activity,the dynamic effects of the ozone depletion period from 1980 to 2000 and the recovery period from 2001 to 2015 contribute different temperature trends of the Arctic stratosphere,in each winter and spring month,temperature trends are changed in former and later period.The result of verification using the extended polar temperature variation equation shows that the dynamic and diabatic heating parts controlling the temperature change in the lower stratosphere can be separated.The accumulated dynamic and diabatic heating effects can be used to characterize the contribution of two-period temperature changes in the lower stratosphere in each month.In the polar region,dynamic effect is the dominant factor in the lower stratospheric winter temperature change(about 70%),diabatic heating is the dominant factor in other seasonal temperature changes.(2)The total column ozone decadal change in Arctic Spring from 1980 to 2015 shows an increasing trend,Arctic total column ozone in March and annual average was significantly reduced from 1980 to 2000,recovery from 2000 to 2015.Cumulative heat flux can be used to characterize the transport of ozone from low latitudes to polar regions in winter.The contribution of the dynamic effect to the total column ozone turned from positive to negative in November and December,the dynamic effect of the winter and spring can explain almost 40%of the Arctic total column ozone change.(3)Analysis of Arctic stratospheric temperature trends from 2001 to 2100 using CMAM model simulations,it was found that dynamic and diabetic contribution are equal.Dynamic contribution is stronger under RCP2.6 than the other two scenarios,dynamic effect dominated the process of warming to cooling period in December;increasing carbon dioxide emissions under RCP8.5 scenario significantly reduces middle and upper stratosphere temperature.RCP8.5 scenrio Arctic ozone recovery intensity of each region was the strongest;Dynamic contribution to Arctic ozone change is about 25-30%;ozone change is still dominated by diabatic factor.There are great differences between Arctic temperature,ozone changes and their dynamic contributions under different scenarios.More accurate model simulations and observations should be used to verify their accuracy in the future.