Retrieval of Aerosol Properties over Land and over Sea

Aerosols affect, among others, climate [1], air quality [2], health [3], and electro-optical observations. Examples of the latter are the effect of aerosols on the retrievals of surface properties from satellite observations, or the degradation of electro-optical systems used, e.g., for military purposes. Both effects are due to the extinction of radiation at wavelengths from the UV, through the visible to the IR due to scattering and absorption. These processes affect the earth radiation budget through its influence on both incoming and out-going radiation. Aerosols have been identified as an important factor in the regulation of the Earth’ climate. The incoming solar radiation is scattered by aerosols, which induces a negative (cooling) effect on the atmospheric radiation balance. The magnitude of aerosol cooling is a major uncertainty in climate models [4], and may be similar to that of the warming effect of common greenhouse gases. Certain types of aerosols also absorb radiation. This property has often been used to identify aerosols by satellite remote sensing and providing an aerosol index. However, the absorption of aerosols that are most important for climate, e.g., ammonium sulphate and ammonium nitrate that are mainly produced due to anthropogenic activity, is negligible. One of the goals of the research presented here is to discriminate between different aerosol types.