Variation in the tropopause transition layer over China through analyzing high vertical resolution radiosonde data

摘要

In this work,the meridional variation of the thermal tropopause layer is investigated using high vertical resolution radiosonde measurements over China.A tropopause-based mean method is used to characterize the depth of the tropopause inversion layer (TIL),and a curve-fitting method to profiles of Brunt-Vaisala frequency is applied to identify the transition sharpness of the static stability in the tropopause transition layer (TTL).The eight radiosonde stations are grouped into four latitudinal bands at intervals of 7°.Analyses show that the tropopause at higher latitudes is much more likely to be sharp and have a strong TIL,while that at lower latitudes is dominated by a thick%对流层预被视为中纬度和热带地区大气成分结构的一个关键特征,也是平流层一对流层大气物质交换过程的一个重要环节.本文利用中国东部地区八个站点高分辨率无线电探空资料分析了中国地区热力对流层顶区域精细结构随时间和经度的变化特征.以对流层顶为基准对各个站点温度和浮力频率进行分析,得到对流层顶逆温层有明显的季节变化的稳定性结构,且厚度随着纬度增加而增加.并对浮力频率进行双曲正切拟合,分析对流层顶转换层厚度随纬度的变化特征,发现深厚对流层顶转换层的发生概率随着纬度的增加而降低.