摘要
Cloud microphysical properties including liquid and ice particle number concentration （NC）, liquid water content （LWC）, ice water content （IWC） and effective radius （RE） were retrieved from CloudSat data for a weakly convective and a widespread stratus cloud. Within the mixed-phase cloud layers, liquid-phase fractions needed to be assumed in the data retrieval process, and one existing linear （Pl） and two exponential （P2 and P3） functions, which estimate the liquid-phase fraction as a function of subfreezing temperature （from -20℃ to 0℃）, were tested. The retrieved NC, LWC, IWC and RE using Pl were on average larger than airplane measurements in the same cloud layer, Function P2 performed better than p1 or P3 in retrieving the NCs of cloud droplets in the convective cloud, while function Pl performed better in the stratus cloud. Function P3 performed better in LWC estimation in both convective and stratus clouds. The REs of cloud droplets calculated using the retrieved cloud droplet NC and LWC were closer to the values of in situ observations than those retrieved directly using the Pl function. The retrieved NCs of ice particles in both convective and stratus clouds, on the assumption of liquid-phase fraction during the retrieval of liquid droplet NCs, were closer to those of airplane observations than on the assumption of function P1.
Cloud microphysical properties including liquid and ice particle number concentration （NC）, liquid water content （LWC）, ice water content （IWC） and effective radius （RE） were retrieved from CloudSat data for a weakly convective and a widespread stratus cloud. Within the mixed-phase cloud layers, liquid-phase fractions needed to be assumed in the data retrieval process, and one existing linear （Pl） and two exponential （P2 and P3） functions, which estimate the liquid-phase fraction as a function of subfreezing temperature （from -20℃ to 0℃）, were tested. The retrieved NC, LWC, IWC and RE using Pl were on average larger than airplane measurements in the same cloud layer, Function P2 performed better than p1 or P3 in retrieving the NCs of cloud droplets in the convective cloud, while function Pl performed better in the stratus cloud. Function P3 performed better in LWC estimation in both convective and stratus clouds. The REs of cloud droplets calculated using the retrieved cloud droplet NC and LWC were closer to the values of in situ observations than those retrieved directly using the Pl function. The retrieved NCs of ice particles in both convective and stratus clouds, on the assumption of liquid-phase fraction during the retrieval of liquid droplet NCs, were closer to those of airplane observations than on the assumption of function P1.
基金
funded by the National Natural Science Foundation of China(Grant No.41475035)
the Natural Science Foundation of Jiangsu Province(Grant No.BK20131433)
the Foundations from KLME of NUIST(Grant No.KLME1206)
the Key Laboratory for Aerosol–Cloud–Precipitation of China Meteorological Administration of NUIST(Grant No.KDW1203)
