全球平流层-对流层之间臭氧通量的时空演变研究

A study of spatial-temporal evolvement of the global cross-tropopause ozone mass flux

利用1958-2001年的臭氧混合比和ECMWF（Europema Centre for Medium-range Weather Forecast）资料，采用Wei诊断模型定量计算了穿越全球对流层顶的臭氧质量通量．结果表明：（1）臭氧通量场存在纬向型和经向型的空间波列结构，这些空间波列均未能跨越对流层顶断裂带到达热带对流层顶控制区，其中南北两极的极区、地中海-伊朗高原-青藏高原-日本南部-北太平洋和南半球对流层顶断裂带中沿纬圈完整的空间波列最为显著．海洋上空臭氧通量的性质较为均匀一致，大陆上空的空间结构多变．北半球向下与向上的局地平均最大臭氧通量分别是-4μg·m^-2·s^-1和2．5μg·m^-2·s^-1，南半球的对应值为-2．5μg·m^-2·s^-1和1．5μg·m^-2·s^-1．（2）纬向平均的臭氧净通量依赖于纬度变化，北半球与南半球具有显著的非对称特性，总效应是平流层臭氧向对流层输运注入．臭氧通量有着显著的季节变化，可随不同季节在地理分布上发生空间转移现象，而且其控制机制不仅受对流层顶的季节运动影响，也随大气环境的季节调整而发生改变．（3）南北半球臭氧净通量的变化趋势相反，南半球为双峰结构。表现为非对称振幅的季节波动结构．全球臭氧通量振幅的年际变化表现出明显的QBO（Quasi-Biennial Oscillation）特性，年代际演变的结构形态（向下的臭氧净通量）可划分为4个阶段：1960年代是平稳变化期，1970年代为增强期，1980年代是又一个相对平稳期，1990年代为剧烈变化期．向下的臭氧净通量主极大值出现在1977、1990年和1998年，极小值在1993年和1996年．

Using the 44 years （1958 ～ 2001 ） ECMWF data sets and ozone maxing rate at tropopause, the global cross-tropopanse ozone mass flux （CTF） has been calculated by Wei formula. The results are as follows： （ 1 ） The global CTF present zonal and mefidional wave patterns which have not reached to the tropic tropopause controlling area by crossing tropopause break, prominently from the Mediterranean area, through the Iran Plateau, Tibetan Plateau, south of Japan, to the North Pacific and in Southern Hemisphere. The spatial variation of STE is uniform over oceans and complicated over continents. The upward and downward flux peak values are - 4μg·m^-2·s^-1 and 2.5μg·m^-2·s^-1 in the Northern Hemisphere, and - 2.5μg·m^-2·s^-1 and 1.5μg·m^-2·s^-1 in the Southern Hemisphere. （2） The zonal means of ozone flux vary with latitudes, and the flux is unsymmetrical in the Northern and Southern Hemispheres for the general effects transfer from stratosphere to troposphere. The ozone flux which has notable seasonal variations presents the geographical distribution changing with seasons, and it is dominated by seasonal variations of atmospheric environment beside by seasonal change of the tropopause. （3） The seasonal and annual variations of pure ozone flux in Southern Hemisphere have two peak values which show the structure of unsymmetrical seasonal wave, which is completely contrary with Northern Hemisphere. Global average CTF exhibits remarkable characteristic of QBO. Interannual change of STF can be divided into four phases, with a balanced phase in the 1960s, an enhanced phase in the 1970s, another balanced phase in the 1980s and a remarkable variation phase in the 1990s. The downward ozone flux maximums appear in 1977, 1990 and 1998, the minimums in 1993 and 1996, respectively.