Performance Tests of the Asian Dust Aerosol Model 2 (ADAM 2)

Abstract

The Asian Dust Aerosol Model 2 (ADAM2) was developed to enhance the ability to deliver timely and quality sand and dust storm forecasts to all Asian countries that might be affected by such storms. The ADAM2 model, modified from the operational ADAM/ADAM1 model used by the Korea Meteorological Administration, utilizes statistically-derived threshold wind speeds with the use of 3 hourly reporting WMO surface data in the whole Asian domain (60-160E, 10-60N) for the period of 1998 to 2006. This also uses the parameterized emission reduction factors due to the vegetation in the Asian dust source region with the use of a Normalized Difference Vegetation Index (NDVI) obtained from Spot/Vegetation product of Maximum Value Composite Syntheses for the same period. Both the threshold wind speeds and the emission reduction factors due to the vegetation vary with time and surface soil types (Gobi, Sand, Loess, and mixed soil). A performance test of the ADAM2 model was conducted with observed PM10 concentrations at some monitoring sites in the source region and the downstream region of Korea for the whole months of May and December in 2007. It was found that the ADAM2 model was able to simulate quite well most of Asian dust-storm occurrences in the source region and dust events observed in Korea. The model simulates quite well the starting and ending times of the dust storms in the source region within 10% margin of error with the observed surface PM₁₀ concentration. In the downstream region of Korea, the starting and ending times of dust events were well-simulated; however, the surface PM10 concentration was slightly overestimated for some dust events. Nevertheless, there is great potential for the ADAM2 model to be used as an operational Asian dust forecast model for Asia.