摘要
利用1958—2001年44年的ECMWF再分析值资料,采用Euler算法的Wei诊断模型,计算估计了全球平流层与对流层之间穿越对流层顶的质量通量(cross-tropopause flux,即CTF),并对其时空变化特征进行了分析。结果表明:(1)全球CTF的空间分布呈纬向型,且基本与全球经向环流相配合,其中对流层顶断裂带中向下的通量形势较复杂,南半球通量交换的空间变化较均匀,北半球有多峰结构的空间变化,东亚在全球的CTF中有重要作用。(2)南北半球热带对流层顶纬向平均向上的净通量极值分别在5°S为0.873×10-4kg.m-2.s-1和10°N为0.155×10-3kg.m-2.s-1;极地对流层顶向上和向下的通量极值对应在62.5°S为0.510×10-3kg.m-2.s-1,75°S是-0.365×10-3kg.m-2.s-1,55°N为0.257×10-3kg.m-2.s-1,75°N是-0.234×10-3kg.m-2.s-1,两极向上的通量极值在87.5°S为0.355×10-3kg.m-2.s-1,90°N为0.300×10-3kg.m-2.s-1;对流层顶断裂带中向下的净通量极值在35°S是-0.416×10-3kg.m-2.s-1,35°N为-0.333×10-3kg.m-2.s-1。(3)全球的净通量变化出现非对称性的季节波动,南半球和北半球净通量的季节与年际变化趋势完全相反,全球极地对流层顶控制区域的半球年平均质量交换量为-3.55×108Tg.a-1。(4)全球平均的CTF有显著的QBO特征,南北半球的年代际变化明显,特别是20世纪70年代中期至80年代中期出现了质量通量振幅的异常突变现象。
Using the 44-year（19582001） datasets of pressure and temperature at tropopause,calculating the global cross-tropopause mass flux（CTF） by Wei formula,and analyzing its space changes,seasonal and interannual variations.The results are as follows：（1） The global CTF presents zonality,and mostly cooperate with global general meridional circulation.The downward mass flux is very complicated in the tropopause break.The space variation of STE in Southern Hemisphere is even,and variation of Northern hemisphere has many peak values.The CTF over Eastern Asia plays an important role in the global CTF.（2） The upward peak values of tropical tropopause zonal mean mass flux are 0.873×10^-4kg·m^-6·s^-1 in 5°S and 0.155×10^-3kg·m^-2·s^-1 in 10°N,and the downward peak values in arctic tropopause are 0.510×10^-3kg·m^-2·s^-1 in 62.5°S,-0.365×10^-3kg·m^-2·s^-1 in 75°S and 0.257×10^-3kg·m^-2·s^-1 in 55°N,-0.234×10^-3kg·m^-2·s^-1 in 75°N;the upward peak values over the two poles are 0.355×10-3kg m-2·s-1 in 87.5°S and 0.300×10^-3kg·m^-2·s^-1 in 90°N;and the net mass flux in tropopause break are-0.416×10^-3kg·m^-2·s^-1 in 35°S and -0.333×10^-3kg·m^-2·s^-1 in 35°N.（3） The seasonal and annual variations of net mass flux between Southern and Northern hemispheres are complete contrary,and global net mass flux shows unsymmetrical seasonal wave. The annual means STE of mass in the Arctic tropopause is-3.55×10^17kg·a^-1.（4） Global average CTF present remarkable characteristic of QBO,annual evolution of CTF is very obvious over Southern and Northern Hemispheres,in particular,the catastrophe of mass flux amplitude appears during the middle of 1970′s to the middle of 1980′s.
出处
《高原气象》
CSCD
北大核心
2007年第5期910-920,共11页
Plateau Meteorology
基金
中国气象局气候变化专项项目(CCSF2007-46)
中国气象局成都高原气象研究所开放实验室基金课题(LPM2007007)
国家自然科学基金项目(4033034
40675021)共同资助
