MASINGAR, a global tropospheric aerosol chemical transport model coupled with MRI/JMA98 GCM: Model description

Abstract

This paper presents the first description of a new three-dimensional aerosol chemical transport model, called the Model of Aerosol Species IN the Global AtmospheRe (MASINGAR), which has been developed to study the distributions of atmospheric aerosols and related trace species. MASINGAR is an on-line chemical transport model (CTM) coupled with the MRI/JMA98 GCM. MASINGAR includes nss-sulfate, carbonaceous, mineral dust, and sea-salt aerosols, and accounts for advective transport, subgrid-scale eddy diffusive and convective transport, surface emission, and dry/wet depositions, as well as chemical reactions. The advective transport is calculated using the semi-Lagrangian transport scheme. Parameterization of convective transport is based on the convective mass flux derived by the Arakawa-Schubert scheme. The space and time resolutions of the model are variable, with a standard spatial resolution of T42 (2.8° × 2.8°) and 30 vertical layers (up to 0.8hPa) with a 20-minute time step. In addition, the model has a built-in, four-dimensional data assimilation (FDDA) system with a nudging scheme incorporating an assimilated meteorological field, which enables the model to realistically simulate a specific period and a short-period forecast of aerosols. The model simulation of mineral dust aerosol in April 2002 suggests that MASINGAR simulates the synoptic scale aerosol events.