卫星云参数与飞机云物理探测对比研究和飞行方案设计

Comparative Analysis of Satellite Cloud Parameters and Aircraft Cloud Physics Detections and Flight Plan Studies

开展卫星反演云特性参数与飞机观测的对比研究,对于更好地发挥卫星遥感观测在天气、云物理和人工影响天气方面的探测优势具有重要意义。选取2012年9月21日一次层状云降水过程,对比分析FY-2与MODIS反演云参数及飞机观测结果,探索了飞机检验卫星云参数的飞行方案。结果表明:FY-2反演云参数演变趋势与飞机观测结果有较好的一致性;FY-2反演有效粒子半径(Effective Radius,Re)和光学厚度(τ)与MODIS反演的Re和τ间相关性较好,但此个例FY-2反演值普遍小于MODIS反演值;探测区域FY-2反演Re频率分布与飞机观测Re分布有一定差异,FY-2反演Re偏小,MODIS反演Re频率分布与飞机观测结果更为接近;飞机观测计算得到的τ和液水路径值(Liquid WaterPath,LWP)与卫星反演τ和LWP差异较大,FY-2反演值明显偏小。对于Re的检验,飞机最好在Re分布不大均匀的云顶作较长距离平飞观测;对于LWP和τ等垂直积分参量的检验,飞机最好选择在光学厚度较均匀的小区域内螺旋爬升至云顶之上,再自云顶向下至最低高度进行垂直观测。

Carrying out comparative studies of satellite retrieved cloud characteristic parameters and aircraft observations is of great significance to better utilize the advantages of satellite remote sensing observations in the aspects of weather,cloud physics and weather modification.The process of stratiform cloud precipitation on September 21,2012 was selected,and FY-2 satellite retrieved cloud characteristic parameters were compared with those of MODIS and aircraft observations.The aircraft flight plans of assessing satellite retrieved parameters were also explored.The results showed that the evolutionary trend of FY-2 retrieved cloud parameters was in good agreement with aircraft observations.There was a good correlation between parameters retrieved by FY-2 and MODIS,but the inversions of FY-2 was generally smaller than that of MODIS.The frequency distribution of FY-2 retrieval in the detection area was more concentrated,and the frequency distribution of MODIS inversion Re is closer to the aircraft observation result.The difference between τ and Liquid Water Path (LWP) from satellite inversion and those calculated by aircraft observation was large,and the FY-2 inversion value was obviously smaller.For the validation of satellite Re ,it is better to do long-distance horizontal flight observation near the cloud top height.Inhomogeneous Re distribution is expected.For the validation of vertical integral parameters such as τ and LWP,it is better to choose the uniform optical thickness area.The aircraft should climb up to the top of the cloud,and then hover down from the top of the cloud to the lowest height.