Mineral Aerosol Production, Transport, and Removal During ACE-2: Comparisons of an Event Model to Satellite

摘要

The long-range transport mineral aerosols has climatic implications because of the aerosols' radiative properties. We have incorporated an aerosol microphysical model into the NCAR Model for Atmospheric Transport and Chemistry (MATCH) in order to carry out three-dimensional simulations of dust emission and transport from the Sahara Desert. A detailed source scheme has been implemented which takes into account the surface soil and roughness properties in determining the spatial and temporal variation in dust emissions. The calculated dust fluxes are partitioned across a large number of size bins, and we treat the transport and removal processes on each size bin independently to examine how the aerosol size distribution evolves. We account for dust particle removal by sedimentation, deposition, and wet scavenging processes. The combined model is driven by assimilated meteorological fields and has been applied to a case study of the ACE-2 experiment (June and July, 1997). We constrain dust fields predicted by our model against the remotely sensed and in-situ data available from the experiment time frame. The model is able to reproduce dust optical depths and a plume shape in good agreement with observations made by the AVHRR and TOMS satellite instruments. We present detailed radiative transfer calculations based on our modeled dust fields in order to simulate radiances observed by satellite.