机载微波辐射计测云中液态水含量(Ⅱ):反演方法  

Measurement of Column Cloud Liquid Water Content by Airborne Upward-Looking Microwave Radiometer (Ⅱ): Retrieval Method

作　　者：江芳[1] 魏重[1] 雷恒池[1] 金德镇[2] 张景红[2] 谷淑芳[2] 

机构地区：[1]中国科学院大气物理研究所,北京100029 [2]吉林省人工影响天气办公室,吉林长春130062

出　　处：《高原气象》2004年第1期33-39,共7页Plateau Meteorology

基　　金：国家自然科学基金项目(40275002);吉林省人工影响天气开放实验室部分基金共同资助

摘　　要：介绍了机载对空微波辐射计探测云中路径积分液态水含量(L)的辐射传输原理和反演方法;根据吉林省长春市的历史探空资料和典型的层状云液水垂直分布模式,得到该地区4～7月各月随高度而变化的反演公式系数的表达式,并给出了反演误差的数值模拟检验结果:在地面反演值对"真值"的统计相对偏差是15%～25%,在6km高度处为5%～10%,表明该方法已具有实用可接受的精度。此外,为减少由于回归样本中云液水廓线的"失真"给反演造成的误差,本文在对探空廓线作诊断建立云液水廓线时,引入了实际目测最低云底高的信息。数值模拟比较表明,该措施行之有效,使对流层中下层几乎所有高度上L反演值的精度提高了5%～20%,观测高度越低,精度提高的越多。The fundamental and method of deducing path-integrated cloud liquid water content (L) by an airborne upward-looking microwave radiometer are introduced in this paper. Based on historic radiosonde data in Changchun city, Jilin province and on the model of vertical distribution of cloud liquid water content for typical stratiformis, the coefficients of retrieval equation are obtained as the functions of height for each month from April to July and the numerical simulation tests of the accuracy of retrieval results are given: The statistical relative deviation of retrieved values of L to the simulated trues on the ground is 15%～25% and that at altitude of 6 km is 5%～10%, that means the retrieval method and implementation of the method are applicable to processing measurements of an airborne radiometer made in China recently. Besides, the information on actual height of the lowest cloud base is used in constructing of cloud liquid water profile by using the radiosonde profiles, that makes an improvement of relative accuracy of retrieved value of L at almost all altitudes by 5%～10% according to numerical simulation comparison. The lower the altitude is, the more the accuracy is improved.

关 键 词：机载微波辐射计 云液态水含量 反演方法 云模型 

分 类 号：P414.2[天文地球—大气科学及气象学]