气候变暖背景下全球对流层顶高度和温度的分布特征及变化趋势

Global Distribution Characteristics and Variation Tendency of Tropopause Height and Temperature Under the Background of Climate Warming

利用1979年1月—2014年6月ERA-Interim和NCEP再分析月平均资料,计算并分析全球对流层顶高度、温度等物理量的时空变化特征。结果表明:(1)对流层顶高度和温度的空间分布有很强的纬度依赖性,中高纬度地区对流层顶高度和温度变化随纬度变化分布较明显;(2)近36 a来,全球对流层顶高度整体升高(气压下降约1~2 h Pa·(10 a)^(-1)),而对流层顶温度降低(温度下降约0.1℃·(10 a)^(-1));(3)不同季节对流层顶的高度和温度场都有一定的空间结构变化,两者之间存在季节变化的协调性,且北半球较南半球的变化更复杂;(4)通过ERA-Interim资料和NCEP资料的对比,发现基于NCEP资料得到的对流层顶高度比ERA-Interim资料约高1 km,而2种资料的对流层顶温度在赤道、副热带地区比较接近,都稳定在192~200 K之间,但南、北半球中高纬度温度分布明显不同;(5)除北半球中高纬度北美洲和欧洲局部地区外,对流层顶高度的升高与对流层顶温度的下降存在明显的正相关,尤其是热带地区和南半球高纬地区,相关系数超过0.8。

Based on the monthly average data of ERA-Interim and NCEP reanalysis from January 1979 to June 2014,the tropopause height and temperature were estimated,and their temporal and spatial distribution and variation tendency were analyzed. Results are as follows：（1） The spatial distributions of tropopause height and temperature were greatly controlled by the changes of latitude,especially the changes of tropopause height and temperature in middle and high latitudes with latitude were obvious.（2） The global tropopause height generally rised during 1979-2014,and the pressure of tropopause dropped about 1-2 h Pa per 10-year,while the tropopause temperature decreased with falling rate about 0. 1 ℃ per 10-year.（3） The tropopause height and temperature had obvious seasonal changes,there was seasonal coordination between the height and temperature of tropopause,and the change in the northern hemisphere was more complex than that in the southern hemisphere.（4） The tropopause height from NCEP reanalysis data was about 1 km higher than that from ERA-Iterim data on the whole,while the tropopause temperatures from two kinds of data in the subtropics to equator were close,which was stable from 192 K to 200 K,but the distribution of tropopause temperature in middle and high latitudes of the southern hemisphere and northern hemisphere was significantly different.（5） In addition to the local region in the northern hemisphere,the increase of tropopause height was obviously positive related with the drop of tropopause temperature,especially their correlation coefficients were over 0. 8 in the tropics and high latitudes of the southern hemisphere.