Abstract: An artificial aircraft precipitation enhancement operation in Heilongjiang province on May 24,2016 was analyzed using the conventional data from the Meteorological Information Comprehensive Analysis and Processing System (MICPS),the cloud model products from the Global/Regional Assimilation and Prediction System developed by Chinese Academy of Meteorological Sciences (GRAPES_CAMS) and satellite retrieval products,and based on the Cloud Precipitation Accurate Analysis System over the Northeast China (CPAS_NE) platform.The results show that due to the effects of a cold vortex at high levels and a low pressure at the surface,the operation target area is characterized by thick clouds and a super-cooled layer that has a certain amount of super-cooled water.Meanwhile,the radar echoes show that there is a large area of flaky stratiform cloud,which means a good catalytic capacity for aircraft precipitation.It is the best time to increase precipitation when clouds develop very deep and the vertically cumulative liquid water content is large.The physical testing of the catalytic effects on the target area and the contrast area indicates that the operation has an obvious influence on precipitation at the surface and makes the radar echoes vary small.Due to the satellite products,it can be found that the temperature of blackbody brightness in the target area decreases quickly,and cloud top temperature and height decrease.This means the catalytic effect of the artificial precipitation operation is good.After the aircraft precipitation operation,the thickness of supercool liquid layer reduces,the effective radius decreases.These changes imply that the catalyst consumes supercool liquid water and the large cloud particles become raindrops.In other words,the cloud water has been effectively converted into the rain water which indirectly validated the aircraft precipitation enhancement operation.

Key words: Artificial precipitation enhancement, Operation effect, Satellite retrieval, Radar echo, Physical test