Community Aerosol and Radiation Model for Atmospheres

CARMA is a flexible three-dimensional microphysical model developed over the past 25 years, and has been applied to a wide variety of problems ranging from cloud physics to aerosols on Earth as well as other planets. The model originated from a one dimensional stratospheric aerosol code developed at the NASA Ames Research Center (by Owen B. Toon and Richard P. Turco) that included both gas phase sulfur chemistry and aerosol microphysics. Following up earlier work by E. Jensen and G. E. Thomas of the University of Colorado, IAP has adapted CARMA to the special conditions of the polar summer mesopause to study ice microphysics related to noctilucent clouds and polar mesosphere summer echoes. Currently, IAP uses the Eulerian model in a 1- and 2-dimensional version to study basic microphysical processes such as the nucleation of mesospheric ice particles, the development of the ice particle size distribution (see above figure), or the effect of inertia gravity waves on the development of the ice clouds.

In collaboration with the Department of Meteorology of the University of Stockholm, IAP has further recently adopted the CARMA model for simulations of meteor smoke particles and their distribution in the Earth’s atmosphere.

CARMA modelling

Size distribution of NLC particles as calculated by CARMA