Remote sensing of spatial-temporal variations of Chlorophyll-a in Galveston Bay, Texas

In order to estimate Chlorophyll-a concentrations at high spatial-temporal resolution accurately over bay systems in the western Gulf of Mexico, a 2-step remote sensing algorithm using observations from the Medium Resolution Imaging Spectrometer (MERIS) is developed. Here, the approach is tested in Galveston Bay. First, atmospheric correction for the MERIS reflectance is performed to improve the quality and consistency of the satellite data. Second, an empirical relationship is generated by calibrating the MERIS reflectance ratio between band 7 and band 9 against Chlorophyll-a concentrations measured in-situ. This has enabled construction of Chlorophyll-a maps covering the entire bay area with 300m resolution. A time series of this research product is then compared with the Niño 3.4 index and river inflows, to analyze the effects of hydroclimate on the variation of Chlorophyll-a concentration in Galveston Bay.