大气对流层顶位温与高度的变化分析

 利用1948~2006年共59 a的NCEP/NCAR温度场、气压场、位势高度场的逐日资料,对全球对流层顶的位温及其高度进行计算,并对其结果进行了分析.结果表明:①对流层顶位温的变化在310~380 K,其中副热带位温最高,而两极位温最低.大陆上空对流层顶位温的空间尺度较小,海洋上空为较大的空间尺度.②1948~2006年的59 a里对流层顶位温,总体上呈现出大陆区域位温下降,海洋区域位温上升的变化趋势,且在6~8月青藏高原及其以东的大陆区域和南极洲对流层顶位温下降趋势明显,12月至次年2月在30°S附近南印度洋和南太平洋海域对流层顶位温上升趋势明显.③全球对流层顶高度在10~17 km范围内,两极最低.两半球的高度升高与降低均同步.两半球存在准半年的位相差异.热带对流层顶多呈现上升趋势,极地对流层顶则多呈现下降趋势.与位温相同的是,陆地上的对流层顶高度下降,海洋上的对流层顶高度上升.

The changes analysis of global potential temperature and height at tropopause

Using the daily global data sets of temperature,pressure and geopotential height from 1948 to 2006,the global potential temperature and geopotential height at tropopause are calculated.The results show that the global potential temperature varys from 310 K to 380 K,maximal temperature occurs in subtropic and minimal appears in polar region.The spatial scale of potential temperature over land is small-scale and that over oceans is large-scale.From 1948 to 2006,tropopause potential temperature generally decre...