Mapping Coastal Hypoxia in the Northern Gulf of Mexico with Ocean Color Imagery

摘要

We combine satellite ocean color imagery and hydrodynamic modeling to estimate the areal extent of coastal hypoxia in the northern Gulf of Mexico. First, we created a 10-year satellite ocean color climatology for the northern Gulf of Mexico. Next, we extracted optical properties at hypoxic locations, to define expected optical conditions of hypoxic waters. Then, for a new image, the observed satellite-derived optical properties are compared to the expected conditions and coupled with a model-derived stratification index in a four- tiered testing approach, to provide a spatial estimate of possible hypoxic areas. The premise is that correspondence to optical properties observed in past hypoxic events can be used to 'predict' where hypoxia is most likely to occur in a new image Satellite ocean color imagery can be used to augment ship surveys and delineate areas of expected hypoxic conditions in near-real time, providing coastal managers with a new monitoring tool.