School of Atmospheric Sciences,Nanjing University
In order to evaluate the effect of cloud seeding operation for rain suppression during the opening ceremony of the Nanjing 2014 Youth Olympics Games, the WRF model was used to simulate the precipitation processes and cloud seeding operation. The present work is the first part of the study. Firstly, the effects of precipitation simulation using eight microphysics schemes were evaluated through comparison with the observation. Furthermore, we chose Thompson and Milbrandt-Yau microphysics schemes to analyze the cloud structures and precipitation formation mechanisms. Results show that the cloud structures and precipitation mechanisms simulated by the two microphysics schemes are consistent. The precipitation affecting the Nanjing Olympic Sports Center on the day of the opening ceremony is generated by the weak mixed convective-stratiform cloud system, and the precipitation processes are dominated by ice-phased microphysical processes. The melting of snow is the main source of rainwater, contributing 72% in Thompson microphysics scheme and 60% in Milbrandt-Yau microphysics scheme, and the evaporation is the main sink term, which consumes 94% of the rainwater in Thompson microphysics scheme and 95.6% in Milbrandt-Yau microphysics scheme.