Effect of single and double moment microphysics schemes and change in
CCN, latent heating rate structure associated with severe convective
system over Korean Peninsula
Abstract
Cloud microphysics plays important role on the storm dynamics. To
investigate the impact of advanced microphysics schemes, using single
and double moment (WSM6/WDM6) schemes, numerical simulations are
conducted for a severe convective system that formed over the Korean
Peninsula. Spatial rainfall distribution and pattern correlation
associated with the convective system are improved in WDM6. During
developing stage of the system, the distribution of total hydrometeors
is larger in WDM6 compared to WSM6. Along with mixing ratio of
hydrometeors (cloud, rain, graupel, snow and ice),number concentration
of cloud and rainwater are also predicted in WDM6. To understand the
differences in vertical representation of cloud hydrometeors between the
schemes, rain number concentration (Nr) from WSM6 is also computed using
particle density to compare with Nr readily available in WDM6.Varied
vertical distribution, and large differences in rain number
concentration, rain particle mass are evident between the schemes.
Inclusion of number concentration of rain and cloud, CCN along with
mixing ratio of different hydrometers have improved the storm morphology
in WDM6. Inorder to investigate the cloud-aerosol interactions,
numerical simulation has been conducted using an increase in
CCN(aerosol) in WDM6 which has shown an improved rainfall distribution
with intense hydrometer distribution. The latent heating (LH) rates of
different phase change processes (condensation, evaporation, freezing,
melting, sublimation and deposition) are also computed using various
transformation rate terms in the microphysics modules. It is inferred
that the change in aerosol has increased the LH of evaporation and
freezing and affected the warming and cooling processes, cloud vertical
distribution and subsequent rainfall.