云雷达联合微波辐射计反演混合性降水层云液态水含量的方法研究  

Retrieval of liquid water content profiles in mixed and rainy stratus clouds by combing cloud radar and microwave radiometer

作　　者：谢晓林[1,2,3] 刘黎平[1] 

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]四川省气象探测数据中心,成都610072 [3]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072

出　　处：《暴雨灾害》2016年第1期1-9,共9页Torrential Rain and Disasters

基　　金：973项目(2012CB417202);公益性行业(气象)科研专项(GYHY201306004);"第三次青藏高原大气科学试验-边界层-对流层综合观测"(GYHY201406001)

摘　　要：单独利用云雷达反演液态含水量（LWC）廓线,由于降水粒子与冰相粒子的影响,反演结果误差较大。单独利用微波辐射计反演LWC廓线,由于无法得到云的垂直结构,结果也不理想。在云雷达联合微波辐射计反演暖云LWC廓线方法的基础上,根据回波强度区分云滴粒子与降水粒子,根据温度区分云滴粒子与冰相粒子,建立粒子分布模型,提出了利用云雷达回波强度数据与微波辐射计液态水路径数据（LWP）联合反演混合性降水层云LWC廓线的算法,基于2014年6月6日与7日两次混合性层云降水个例,联合反演LWC廓线,分析了该联合反演算法的稳定性和合理性,结论如下：（1）与直接用单一Z-LWC经验关系的方法相比,根据联合反演算法,剔除回波强度中的冰相粒子信息,区分云滴粒子和降水粒子,并采用不同Z-LWC经验关系的方法更加合理。（2）影响联合反演算法的7个参数（非降水粒子Z-LWC经验关系的系数a1与b1等）中,降水粒子Z-LWC经验关系系数a2与b2的改变对联合反演算法结果影响稍大,偏差在20%～30%左右,而其他参数的改变对结果的影响很小,偏差小于5%,联合反演算法的稳定性较好。（3）联合反演得到的LWC廓线与微波辐射计输出的LWC廓线相比,廓线分布更为合理。Because of the influence of precipitation and ice particles, the error in liquid water content （LWC） retrieval is big when exclusively using cloud radar data. The error of LWC resulted from microwave radiometer is also big due to not having information on vertical cloud structure. On the basis of retrieving LWC profile for warm clouds by combing cloud radar and microwave radiometer, and incorporating the relationships between echo intensity and precipitation particles, and between temperature and ice particles, a particle distribution model is established, and a method to retrieve LWC in mixed rainy stratus clouds by combing the echo intensity of cloud radar and the liquid water path （LWP） of microwave radiometer is put forward. The stability and rationality of the algorithm are analyzed based on precipitation data on June 6, 2014 and June 7, 2014. The conclusion is as follows. （1） Compared to the method that uses a single Z-LWC relationship to retrieve LWC profile, this algorithm is more reasonable, because it rejects the influence by ice particles to the echo intensity, and uses cloud and precipitation particles separately to retrieve LWC profiles. （2） In the 7 parameters that affect the result of this algorithm, a2 and b2 in the Z-LWC rela- tionship for precipitation have greater impact （20-30%） than the others （less than 5%）. This shows a good stability of this algorithm. （3） Compared to LWC profiles from microwave radiometer alone, the LWC profiles retrieved from this algorithm are more reasonable.

关 键 词：云雷达 微波辐射计 液态水含量 液态水路径 

分 类 号：P412.25[天文地球—大气科学及气象学]