Abstract:
Based on the latest version ERA-Interim data of the European Centre for Medium-Range Weather Forecasts (ECMWF) from 1979 to 2011,including the total ozone and different-level ozone data,in light of climate tendency rate and Mann-Kendall test and other methods,we've studied the evolution trends of total ozone and troposphere- stratospheric ozone content in East Asia.The results show that overall the total ozone amount in East Asia presented a downtrend from 1979 to 2011.When the studied period is divided into two phases,phase Ⅰ has an evident downtrend ,and the total ozone of phase Ⅱ(19942011) does not reach the level of phase Ⅰ(19791993),although it has a slight increasing trend.It implies that in East Asian region,the ozone recovery trend is not obvious up to now.From 1979 to 2011,the catastrophic change of total ozone started from 1984,and the time of the significantly decreasing was after 1986.By selecting the 4 levels which respectively represent the troposphere and stratosphere,different levels ozone trend have been investigated.The results indicate that the ozone variation for 4 layers have a descending trend in East Asia.The maximum decrease rate is at 10hPa,and the decrease rate presents the characteristics of fast-slow-fast from low level to high level.