Modelling dust aerosol during ACE ASIA
A size resolved dust emission scheme has been incorporated
into the GLOMAP-bin model following the sandblasting-saltation
parameterization of Alfaro and Gomes (2001). The modelled dust flux is dependant up on wind speed, soil moisture, soil texture, snow and vegetation cover. The scheme has been used to examine dust-sulfate interactions downwind from E. Asia over the ACE-Asia campaign (spring, 2001).
Figure 1. Modelled (purple) and observed (red) mass concentration of dust (ug/m3) for ACE Asia flights in a dust storm event. The average aerosol size distribution (cm-3) simulated with (black solid) and without dust (black dashed), and measured by the DMA (blue) and OPC (red) instrument is shown for each flight.
Figure 2 shows the mass concentration of dust and the aerosol size distribution simulated and observed downwind from E. Asia in several ACE-Asia flights. The model predicts horizontal and vertical concentrations of dust in good agreement with aircraft observations during a dust storm event. Moreover, the modeled dust size distribution agrees well with aircraft OPC measurements (figure 1).
Surprisingly, GLOMAP suggests that even such a large dust storm had only a small
impact on the mass concentration and size distribution of sub-micrometer sulfate.
