Microphysics

In atmospheric modeling, "microphysics" largely overlaps with "cloud physics" and concerns the formation, development, and precipitation of clouds. More generally, "microphysics" encompasses panoply of physical processes associated with (i) the conversion of water between vapor, liquid, and ice phases, and (ii) the interaction and transformation of "cloud particles", which include droplets, ice particles, and aerosols. For example: microphysical processes include droplet nucleation on aerosol particles; liquid freezing and vapor solidification; chemical and humidity-based transformations of aerosol particles; the agglomeration of ice particles into snowflakes; collisions and breakup of falling droplets (rain); collision between ice particles and droplets or wholesale freezing of droplets to form hail (e.g. Straka (2009)).

Breeze microphysics is nascent and under active development. Breeze aims to eventually provide a wide range of microphysical models, ranging from simple warm-phase saturation adjustment, to the bulk schemes provided by the Climate Modeling Alliance's CloudMicrophysics.jl, to superdroplet schemes, to spectral bin schemes that include a spectrum of droplet sizes, ice particle shapes and aerosol types.