The soil particle size dependent emission parameterization for an Asian dust (Yellow Sand) observed.pdf

Atmospheric Environment 37 (2003) 4625–4636 ARTICLE IN PRESS AE International – Asia*Correspondin E-mail addre 1352-2310/$ - see doi:10.1016/j.atmThe soil particle size dependent emission parameterization for an Asian dust (Yellow Sand) observed in Korea in April 2002 Hee-Jin In, Soon-Ung Park* School of Earth and Environmental Sciences, Seoul National University, San 56-1 Shilim-Dong, Kwanak-Ku, Seoul 151-742, South Korea Received 3 April 2003; received in revised form 24 July 2003; accepted 30 July 2003Abstract Intense Asian dust (Yellow Sand) events have been observed in Korea on 21–23 March and 7–9 April 2002. During these periods the observed PM10 concentrations were over 1000mgm
3 at most monitoring sites in South Korea. The operational meteorological model of the Regional Data Assimilation and Prediction System of the Korea Meteorological Administration and the aerosol transport model with the improved particle size distribution parameterization developed at Seoul National University were used to simulate the intense Yellow Sand event observed on 7–9 April 2002. The comparison with the observational data shows that the present model system could reasonably simulate the evolutionary features of Yellow Sand over South Korea including the starting and ending time of the event, the particle size spectrum and the PM10 concentration. It was found that the dominant particle diameter in the mass concentration ranged from 3.67 to 10mm during this dust event. A promising dust emission model depending on the particle size distribution constructed by the sum of several log-normal distributions of particle sizes of different soil types has been developed and found to yield better spectral-mass concentration in the size range of larger than 10mm. This result suggests that size distributions of Asian dust (Yellow Sand) are consistent with those found in the USA, Central Asia and the Sahara desert. However, the accuracy of the model requires more detailed soil particle dist