A numerical study of aerosol influence on mixed-phase stratiform clouds through modulation of the liquid phase
Tripoli, G. J.
Eloranta, E. W.
mesheuropmc: complex mixtures | sense organs
arxiv: Physics::Atmospheric and Oceanic Physics
Numerical simulations were carried out in a high-resolution two-dimensional
framework to increase our understanding of aerosol indirect effects in
mixed-phase stratiform clouds. Aerosol characteristics explored include
insoluble particle type, soluble mass fraction, influence of aerosol-induced
freezing point depression and influence of aerosol number concentration.
Simulations were analyzed with a focus on the processes related to liquid
phase microphysics, and ice formation was limited to droplet freezing. Of the
aerosol properties investigated, aerosol insoluble mass type and its
associated freezing efficiency was found to be most relevant to cloud
lifetime. Secondary effects from aerosol soluble mass fraction and number
concentration also alter cloud characteristics and lifetime. These
alterations occur via various mechanisms, including changes to the amount of
nucleated ice, influence on liquid phase precipitation and ice riming rates,
and changes to liquid droplet nucleation and growth rates. Alteration of the aerosol
properties in simulations with identical initial and boundary conditions
results in large variability in simulated cloud thickness and lifetime,
ranging from rapid and complete glaciation of liquid to the production of
long-lived, thick stratiform mixed-phase cloud.