The impact of aerosols on ice- and mixed-phase processes in deep convective clouds
remains highly uncertain, and the wide range of interacting microphysical processes
is still poorly understood. To understand these processes, we analyse diagnostic output
of all individual microphysical process rates for two bulk microphysics schemes in
the Weather and Research Forecasting model (WRF). We investigate the response of individual
processes to changes in aerosol conditions and the propagation of perturbations through
the microphysics all the way to the macrophysical development of the convective clouds.
We perform simulations for two different cases of idealised supercells using two double-moment
bulk microphysics schemes and a bin microphysics scheme. The simulations cover a comprehensive
range of values for cloud droplet number concentration (CDNC) and cloud condensation
nuclei (CCN) concentration as a proxy for aerosol effects on convective clouds. We
have developed a new cloud tracking algorithm to analyse the morphology and time evolution
of individually tracked convective cells in the simulations and their response to
the aerosol perturbations.This analysis confirms an expected decrease in warm rain
formation processes due to autoconversion and accretion for more polluted conditions.
There is no evidence of a significant increase in the total amount of latent heat,
as changes to the individual components of the integrated latent heating in the cloud
compensate each other. The latent heating from freezing and riming processes is shifted
to a higher altitude in the cloud, but there is no significant change to the integrated
latent heat from freezing. Different choices in the treatment of deposition and sublimation
processes between the microphysics schemes lead to strong differences including feedbacks
onto condensation and evaporation. These changes in the microphysical processes explain
some of the response in cloud mass and the altitude of the cloud centre of gravity.
However, there remain some contrasts in the development of the bulk cloud parameters
between the microphysics schemes and the two simulated cases.