利用HALOE资料分析中层大气中水汽和甲烷的分布特征  

Analysis of H_2O and CH_4 Distribution Characteristics in the Middle Atmosphere Using HALOE Data

作　　者：毕云[1] 陈月娟[1] 许利[1] 邓淑梅[1] 周任君[1] 

机构地区：[1]中国科学技术大学地球和空间科学学院,合肥230026

出　　处：《大气科学》2007年第3期440-448,共9页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金资助项目40505008;40375012

摘　　要：利用1991年12月至2004年5月的HALOE资料,分析了中层大气中微量气体水汽和甲烷的垂直和水平分布特征。垂直分布特征是:水汽混合比在对流层顶和平流层底达到极小值(此极小值区被称为湿层顶),平流层里水汽混合比随高度增加,在平流层上层和中间层低层混合比出现明显的扰动,在中间层顶再次达到极小值,向上混合比又随高度增加。甲烷混合比从100 hPa附近向上混合比一直减少。经向分布特征主要表现为:平流层中下层水汽混合比低值区在热带地区上拱,水汽混合比自低纬向高纬递增;而该气层甲烷混合比则是高值区在热带地区上拱,甲烷混合比自低纬向高纬递减。在低平流层副热带20°S-30°S(20°N-30°N)附近二者混合比水平梯度相对偏大。平流层中上层二者等值线在北半球夏季变成双峰形势,北半球冬季仍是单峰形势。中间层二者都主要表现为冬、夏季分布形势相反。在北半球夏季30°N,平流层中下层水汽和甲烷混合比纬向梯度很小,对流层上层以及中间层二者混合比纬向梯度明显。The HALOE observational data from December 1991 to May 2004 are used to analyze the vertical and horizontal distributions of H2O and CH4 in the middle atmosphere, especially in the upper stratosphere and mesosphere. For a more convenient comparison, the objective analyses are made on the HALOE data and 5°× 5° grid data are obtained （covering 70°S- 70°N, 180°W - 180°E）. The vertical profiles of H2O and CH4 mixing ratio at various latitudes and longitudes as well as in the different years are given, and the latitude-altitude cross section and longitude-altitude cross section of the H2O and CH4 mixing ratio are also presented in this paper. The results show that the H2O mixing ratio decreases from the upper troposphere to the tropopause quickly and reaches a minimum near the tropopause （the minimum is called as ＂hygropause＂） ; and then it increases with height in the lower-middle stratosphere, while it is disturbed significantly in the upper stratosphere and lower mesosphere; it decreases with altitude again and reaches another minimum near the mesopause; the profiles of H2O mixing ratio for the different latitudes, various longitudes and in the different years are similar, except that some difference is exist in mixing ratio amount and the altitudes of the hygropause of different latitudes are not the same. The characteristic of vertical distribution of CH4 shows that it always decreases with height in the middle atmosphere. The profiles for the different latitudes,various longitudes and in the different years are similar, but the mixing ratio values are somewhat different. The meridional distribution shows that the low value zone of H2O mixing ratio bulges upward in the tropical low-middle stratosphere, the H2O mixing ratio increases from low latitudes to high latitudes. In contrast, the high value zone of the CH4 mixing ratio bulges upward in the same place, the CH4 mixing ratio decreases from low latitude to high latitude. Relatively strong horizontal gradients are seen in the subtropical lowe

关 键 词：中层大气 水汽 甲烷 

分 类 号：P421[天文地球—大气科学及气象学]