Evaluation and behavior of the aerosol #epsilon# Angstroem coefficient fro mspectral solar irradiance measurements in the Gulf of Cadiz (Huelva, Spain) to assess ocean color atmospheric correction

摘要

An operational data base is being developed under Spanish project for the calibration/validation of hte ocean color satellite sensori n the regional area of the Gulf of Cadiz. A total characterization of optical aerosol properties: aerosol optical thickness (AOT), particle size distribution and radiative aerosol parameters, etc., is being carried out in order to develop and validate operational atmospheric correction algorithms. Auxiliary data as ozone measurements, pressure and wind speed is also available. Here we present a work applied to the SeaWIFS color ocean sensor in order to address atmospheric correction. Determination and spectral behavior of the Angstroem #alpha# turbidity parameter and the #elpsilon# coefficient have been analysed using hte aerosol parameters, mainly the aerosol optical depth. Thsi coefficient is the key parameter in the current worldwide SeaWIFS atmospheric correction algorithm. However this algorithm presents great discrepancies in the estiamtes of pigment concentration in coastal zones (water case 1). As part of calibration/valiation procedures, special algorithms are needed adapted for regional coastal zone applicatiosn, hence insitu aerosol measurements are required.