Estimation of the Total Dust Column and Dry Deposition Flux over the Yellow Sea,China Based on Shipboard Sun Photometer Measurements:Case Study

The total dust column and the dry deposition flux were calculated based on the optical properties that were measured by a shipboard sun photometer POM-01 MKⅡ in a cloud-free and nonfrontal dust condition on 24 April 2006.The total dust column was calculated by using an integration method of the particle size distribution;the mean value was 1.42±0.30 g m 2.A linear correlation between the total dust column and the aerosol optical depth (AOD) with a linear factor of 2.7 g m 2 over the Sahara was applied to calculate the total dust column in this study;the results were lower than these calculated by the integration method.A reasonable factor of 3.2 g m 2 was achieved by minimizing the standard deviation (SD) of the two methods.The two layers model,which includes the deposition processes of turbulent transfer,Brownian diffusion,impaction and gravitational settling over the sea's surface,was used to calculate the dry deposition flux;the mean value was 5.05±2.49 μg m 2 s 1.A correlation among the total dust column,dry deposition flux,AOD,and effective radius was discussed.The correlation between the total dust column and the AOD was better than that between the total dust column and the effective radius;however,the correlation between the dry deposition flux and the effective radius was better than that between the dry deposition flux and the AOD.

The total dust column and the dry deposition flux were calculated based on the optical properties that were measured by a shipboard sun photometer POM-01 MK II in a cloud-free and nonfrontal dust condition on 24 April 2006. The total dust column was calculated by using an integration method of the particle size distribution; the mean value was 1.42±0.30 g m 2. A linear correlation between the total dust column and the aerosol optical depth （AOD） with a linear factor of 2.7 g m 2 over the Sahara was applied to calculate the total dust column in this study; the results were lower than these calculated by the integration method. A reasonable factor of 3.2 g m^-2 was achieved by minimizing the standard deviation （SD） of the two methods. The two layers model, which includes the deposition processes of turbulent transfer, Brownian diffusion, impaction and gravitational settling over the sea＇s surface, was used to calculate the dry deposition flux; the mean value was 5.05±2.49 μg m^-2 s^-1. A correlation among the total dust column, dry deposition flux, AOD, and effective radius was discussed. The correlation between the total better than that between dust column and the AOD was the total dust column and the effective radius; however, the correlation between the dry deposition flux and the effective radius was better than that between the dry deposition flux and the AOD.