Detection of red tide using Aqua-Terra MODIS satellite data for Aransas bay, Texas

Abstract

Estimating and detecting red tide is particularly challenging when using remotely sensed observations. Aqua-Terra MODIS provides a high resolution spatio-temporal coverage to detect red tide blooms. Both in-situ and satellite data were analyzed for red tide period and non-red tide period in this study. The red tide period was between September and November, 2011 while the non-red tide period was between December and January, 2011. The MODIS derived chlorophyll a showed a much higher concentration (6.9mg/m3) for red tide bloom period. Analysis was aslo performed on Chromophoric Dissolved Organic Matter with the reflectance of both 412nm and 443nm. A correlation was established for both the bloom period and non bloom period. Terra satellite showed a higher correlation for the bloom period and showed a weaker correlation for non-red tide bloom period. A new indicator called red tide index was developed to estimate the percentage of red tide in this study.