ANNUAL VARIATIONS OF CLOUD LIQUID WATER IN THE POLAR REGION USING SATELLITE DATA

利用DMSP卫星SSM/I资料研究了柱状液态水和可降水量的季节变化和年际变化。1988年和1989年在Syowa站进行了气象雷达和微波辐射计观测。本文主要分析了1988-1990年的南极卫星资料，并对1987-1995年的资料进行了处理。对1992-1995年的北极资料进行了分析。22 GHz和37 GHz亮温的变化与开阔海区大气可降水量和柱状液态水的变化基本一致。根据SSM/I图像，在Syowa站观测到与低压有关的降水时，在Syowa站近海获得了22 GHz和37 GHz的高亮温区。发现e-…中柱液水含量较高。云带偏多，云带西侧偏低。这一结果与西奥瓦站气象雷达观测到的云带结构特征基本一致。可降水量的变化在2月前后出现一个高峰，而柱状液态水的变化在一年中有两个高峰，分别在2~4月和10~12月左右。1989年的总降水量是1988年的两倍。对比1988年和1989年的SSM/I图像，发现1989年高柱液态水出现的频率高于1988年。特别是在3~5月和10~11月前后出现了较大的差异。在北极资料中发现，一年中有2个不同的可降水量周期。一次是5月至10月，另一次是1月至4月和11月至12月。1993年资料的变化与其他年份的资料有所不同。这可能与北极三年来海冰延伸的面积有关。除1993年外，1992-1995年北极SSM/I的最大柱状液态水为0.2公斤/平方米。较少

Seasonal and annual variations of column liquid water and precipitable water have been investigated using the SSM/I data of DMSP satellite. Meteorological radar and microwave radiometer observations were carried out at Syowa Station in 1988 and 1989. The Antarctic satellite data of 1988-1990 have been analyzed mainly, although the data of 1987-1995 have been dealt with. The Arctic data of 1992-1995 have been analyzed. The variation of 22 GHz and 37 GHz brightness temperature are roughly same as the variation of precipitable water and column liquid water in the atmosphere, respectively over open sea area. Some results of the brightness temperatures are described on behalf of those of column liquid water and precipitable water.High brightness temperature areas of 22 and 37 GHz were admitted near the off coast of Syowa Station according to the SSM/I image, when precipitation associated with low pressure was observed at Syowa Station. It was found that column liquid water was high in the e … More ast of the cloud band but was low in the west of cloud band. This result was similar to the characteristic of band cloud structure observed by meteorological radar at Syowa Station. The variation of precipitable water showed a peak aroung February, but the variation of column liquid water had two peaks in a year which were around February to April and around October to December. Total precipitation of 1989 was twice larger than that of 1988. Comparing the SSM/I images of 1988 and 1989 along the coast, the frequency of the days of high column liquid water was bigger in 1989 than in 1988. Especially, the big difference of both years was found around March to May and around October to November.It was found in the Arctic data that there were 2 periods with different values of precipitable water in a year. One was the period from May to October and others were from January to April and from November to December. The variation of 1993 data showed some difference from the data of other years. It might be related to the area of sea ice extension in three years in the Arctic. Maximum colum liquid water was 0.2 kg/m2 derived from SSM/I in the Arctic in 1992-1995, except 1993. Less