The Optical and Thermal Properties of Asian Dust over Ocean

Abstract

Asian dust storms, which can long range transport and pass through the China Sea, often occur on spring. During this process, dust storm makes some impact on marine ecology and region climate, and the present of Asian dust aerosols over ocean takes some difficult for cloud detection, atmosphere correction of ocean color and sea surface temperature retrieval. Study on Asian dust aerosol properties over ocean is the basis of satellite remote sensing, which is a powerful tool to study dust over ocean. In this paper, the optical and thermal properties of Asian dust aerosol are presented by combining the Moderate Resolution Imaging Spectroradiometer (MODIS) observations and Streamer model simulations. By compare, the reflectance of dust aerosol over ocean at the visible band2, band3 and the near-infrared band6 of MODIS have some significant features, which are different from others, it satisfies Rb3<Rb6<Rb2 for strong dust aerosol over ocean, the weak dust aerosol meets Rb6<Rb2<Rb3, and the dust reflectance is from 0.1 to 0.3. At the thermal atmospheric windows bands which include band29, 31 and 32, for cloud and clear water region, the brightness temperature at band32 is highest and the temperature at band31 is close to band32. However, for dust aerosols, the brightness temperature at band32 is much greater than those at band29, band31, and the brightness temperature difference between band29 and band31 is small and the lower is the difference, the stronger is the dust aerosol. Those Asian dust aerosol characteristics are nice and useful for dust detection, dust retrieval over ocean, and deep study for marine environment and ecology.