A sensitivity analysis of an irradiance spectral attenuation model is performed by varying three atmospheric parameters: total ozone, visibility and total precipitable water. The incident solar spectral irradiance over the sea surface is calculated at the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) bands for remote sensing applications. The effects of these atmospheric parameters over some remote sensing reflectance ratios usually used for mapping chlorophyll a concentration from the space are also assessed. The results have shown that visibility is the most important parameter which exerts influence on modeled spectral irradiance but its effect on the remote sensing ratios is smaller than that from total ozone. The total precipitable water did not alter both modeled spectral irradiances and remote sensing ratios for solar zenith angles smaller than 60º. No significant differences were found when solar zenith angles varied from 0 and 60º, even when we used extremely high values of atmospheric parameters. For remote sensing reflectance band ratios 490/510, 490/555 and 510/555 under solar zenith angles smaller than 60º, average values of these atmospheric parameters tested here are enough to model irradiance band ratios.
irradiance; ocean color; model; atmosphere; SeaWiFS
