Characteristics Of Ozone Change And Possible Links With Atmospheric Temperature Trends Over The Tibetan Plateau

Using TOMS and OMI ozone data and ERA-Interim and MERRA-2 atmospheric temperature reanalysis data,the spatial-temporal variations of ozone and atmospheric temperature during 1980—2018 over the Tibetan Plateau were evaluated by linear regression,EOF and IDW methods.The results illustrated that a decreasing trend of total ozone was showed during 1980 — 2018,with the decreasing rate of 0.34DU/a.Meantime,atmospheric temperature at lower stratosphere was cooling(0.01-0.08?/a);on the contrary,it was warming in the upper troposphere(0.01-0.07?/a).Setting the time when total ozone at the lowest value as the turning point,total ozone and atmospheric temperature all showed reversal trends since 2008,especially in spring.The decreasing trends(0.54DU/a)of total ozone before 2008 turned to increasing trends(0.47DU/a).The atmospheric temperature at the lower stratospheric reversed from cooling trends to warming trends,and in the upper troposphere,temperature reversed from warming trends to cooling trends.Based on the ozone data of SBUV(/2)and atmospheric temperature reanalysis data,the differences of ozone and temperature in spring between Lhasa and Gonghe which are the typical areas of the Tibetan Plateau were compared.The reversal trends of ozone and atmospheric temperature in those two areas all occurred in 1999.Since 1999,the increasing rate of ozone in Lhasa was higher than Gonghe,which was 0.59DU/a and 0.37DU/a respectively,especially between 63.9-25.5hPa.At the same time,Lhasa had a higher warming rate than Gonghe in the lower stratosphere and a higher cooling rate in the upper troposphere.Correlation analysis was used to explore the possible links between the changes in total ozone and atmospheric temperature.The correlation coefficient shows that there was a significant correlation between total ozone and atmospheric temperature over the Tibetan Plateau.Total ozone had a positive correlation with the atmospheric temperature in the lower stratosphere,with a correlation coefficient of 0.4-0.9,and a negative correlation with the atmospheric temperature in the upper troposphere,with a correlation coefficient of-0.4--0.9.The regression coefficient was used to explore the response of atmospheric temperature to the changes in total ozone.When total ozone showed an increasing(or decreasing)trends,the atmospheric temperature at lower stratosphere would be warming(or cooling)and in upper troposphere,temperature would be cooling(or warming).Over the Tibetan Plateau,the changes in atmospheric temperature are closely linked with total ozone,therefore,the rapid recovery of total ozone may be one of important factors that result in the reversal of atmospheric temperature.