Sensitivity to CCN of a Two-Moment Bulk Microphysics Scheme for a Simulated Mesoscale Convective System.

This study examines the sensitivity of simulated cloud microphysical processes including ice-phase processes to background cloud condensation nuclei (CCN) loading with regards to the simulation of a mesoscale convective system.

High-resolution (1-km horizontal grid spacing) simulations using the 3D GEM atmospheric model with the two-moment Milbrandt-Yau (MY2) and the Predicted Particles Properties (P3) bulk microphysics schemes were conducted over the Southern Great Plains during the Midlatitude Continental Convective Clouds Experiment (MC3E).

Results from CCN sensitivity experiments to specific cloud microphysical processes, supplemented by a detailed examination of the microphysical budget, will be presented to address the impacts of CCN loading on the specific microphysics parameterization, including impacts in the simulated storm structure and hydrometeors characteristics throughout the squall line. An examination of the key microphysical processes affected by CCN loading that led to significant differences in the hydrometeors characteristics will be discussed.