10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Sensitivity of Ice Cloud Formation and Precipitation Initiation to Global Distribution and Abundance of Ice Nucleating Particles in E3SM
KAI ZHANG, Xiaohong Liu, Hui Wan, Pacific Northwest National Laboratory
Abstract Number: 1532 Working Group: Unraveling the Many Facets of Ice Nucleating Particles and Their Interactions with Clouds
Abstract Ice nucleating particles (INP) in the atmosphere affect ice cloud formation and can potentially initiate precipitation. However, ice cloud often doesn’t appear near regions with largest INP concentrations, because the distribution of supersaturation (that is dependent on water vapor and temperature) and temperature are also important factors. In this study, we evaluated the global distribution and abundance of INP in the Energy Exascale Earth System Model (E3SM) and identified several important regions based on the co-occurrence of INP, supersaturation, and low temperature. We performed simulations with perturbed INP concentrations and investigated the competition between different ice nucleation mechanisms. Impact of spatial variability in vertical velocity and water vapor inside the GCM-grid on ice nucleation is represented in the model using the predicted statistical distribution of updraft velocity and water vapor. Results show the perturbed INP concentrations have various impact on ice cloud formation and precipitation initiation in different regions. The impact on cloud radiative forcing will also be discussed.