Simulation Study of Cloud Properties Affected by Heterogeneous Nucleation Using the GRAPES_SCM during the TWP-ICE Campaign

This study used the Global/Regional Assimilation and PrEdiction System Single-Column Model (GRAPES_SCM) to simulate monsoon precipitation with deep convective cloud and associated cirrus during the Tropical Warm Pool International Cloud Experiment (TWP-ICE), especially during the active and suppressed monsoon periods. Four cases with different heterogeneous nucleation parameterizations were simulated by using the ensemble method. All simulations clearly separated the active and suppressed monsoon periods, and they reproduced the major characteristics of monsoonal cloud such as the total cloud hydrometeor mixing ratio distribution,and precipitation and radiation properties. The results showed that the number concentration production rate of different heterogeneous nucleation parameterizations varied substantially under the given temperature and water vapor mixing ratio. However, ice formation and precipitation during the monsoon period were affected only slightly by the different heterogeneous nucleation parameterizations. This study also captured clear competition between different ice formation processes.