SeaWiFS level-3 products over land

摘要

Over land, the aerosol remote sensing is based on the observation of Dense Dark Vegetation (DDV) and this concept is applied on SeaWiFS with a spectral index (ARVI) to detect the DDV and the use of the bands at 412 nm, 443 nm and 670 nm to characterize the aerosols. We first extend the possibility to remote sense aerosol over less dark vegetation through a simple modeling of the vegetation reflectance ρ_(DDV) versus the ARVI. A linear relationship exists between ρ_(DDV) and ARVI, regardless of the geometrical conditions, but with a slight seasonal dependence. We then developed a level 3 aerosol product for global studies with 32 by 32 SeaWiFS pixels combined in a macro-pixel in order to include a significant number of DDV pixels Within these macro pixels, we documented the composition of the scene (sea, land and clouds), the mean aerosol products and the spatial dispersion of the aerosol product. This level 3 will be first used to investigate the sensitivity of the aerosol module to the inputs parameters: DDV models, assumptions on the aerosol model, accuracy of the radiometric calibration... Then, we will produce statistics on the aerosols over Europe over the SeaWiFS life time.