用GMS-5对东亚地区对流层高层水汽的研究

大气中的水汽是气候变化中至关重要的影响因子,对流层高层的水汽对地气系统的辐射能量平衡尤为重要。卫星观测极大地弥补了常规探空手段对高空低温低湿条件下的水汽探测能力的不足。6．7μm水汽通道是被广泛用于大气水汽反演的卫星通道之一,Soden等（1993）提出一个用该通道亮温反演对流层高层水汽的方法。将这一方法应用于日本GMS-5静止卫星的水汽云图,得到东亚地区中无云区域与水汽云图具有相同时空分辨率的对流层高层水汽分布。反演得到的月平均对流层高层平均相对湿度与NCEP分析资料给出的平均相对湿度具有较好的一致性。根据 1996-2002年的GMS 5水汽通道亮温资料得到东亚地区对流层高层水汽的典型时、空分布形式。随卫星观测记录的延续,反演得到的长时间序列的对流层高层相对湿度资料将为水循环的研究和水汽对气候变化响应和反馈的研究提供有力依据。

RESEARCH ON THE UPPER TROPOSPHERE WATER VAPOR OVER EAST ASIA WITH THE GMS-5

Water vapor is a key factor of the climate change. The water vapor in upper troposphere is more important to global radiative balance. Satellite remote sensing provides a useful way to retrieve the upper troposphere water vapor at the low temperature. One of the most widely used channels to retrieval the water vapor is the 6.7 μm channel.Soden (1993) suggested a scheme by using this channel to obtain upper troposphere relative humidity. In this paper, we apply this method to the water vapor channel data provided by the GMS-5, and get the distribution of the clear sky upper troposphere water vapor over East Asia. A month-average distribution is confirming by the relative humidity distribution given by the NCEP data. Based on the GMS-5 data of 1996-2002, we get an average distribution of the upper troposphere water vapor over East Asia. This product is an aid ant data set for the research on water cycle and the responding of the atmospheric water vapor to climate change.