Abstract:
The microwave remote sensing is able to penetrate clouds, and gives a clear view of the ice distributing. The Brightness Temperature (BT) of three water vapor channels (183.3±1, 183.3±3, and 183.3±7 GHz), which is from the Advanced Microwave Sounding UnitB (AMSUB) onboard NOAA series satellites, has high sensitivity to ice contents in convective cloud. With the ice contents enhancing, the BT descends due to the ice dispersion attenuation. Thus, this study is focused on retrievalling the cloud ice concents using the variety of BT. With the simulation experiments, the results confirm that the BT responses of the three water vapor channels initiated at different altitudes, for convective cloud systems, the BT changes caused by ice particles at 183.3±1 GHz are mainly seen above the 300 hPa, about 10 km, while those at 183.3±3 GHz and 183.3±7 GHz are about 8 km and 6.5 km, that is corresponding to the level of 400 hPa and 450 hPa, respectively. The present study derives the retrieved method for the vertical distributions of frozen hydrometeors, and computes the IWP (ice and water path) and the IWTH (ice and water thick) using satellite measurements at the AMSUB water vapor channels. The good correspondence of the retrieved results with the high lightning area are reached by use of the methods. Strong negative lightning mainly happens over the high level ice collection area, while positive and weak negative lightning happen over the middle level. Contrasted with Total Precipitation Water (TPW) from the TRMM/TMI, the average square root error of the retrieved IWP results is about 0.4.