Remote sensing of water quality in Tampa Bay: from research to management decision support

Remote sensing of water quality in estuaries has been problematic in the past due to optical complexity of estuarine waters and uncertainties of atmospheric correction. Here, using Tampa Bay (about 1000 km2 with mean bottom depth of 4 m) as a case study, we report our recent progress in algorithm development and application of satellite data products for management decision support. We use data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) to derive validated data products of water column chlorophyll-a concentrations (Chl-a in mg m-3), diffuse attenuation coefficient at 490 nm (Kd490 in m-1), and absorption coefficient of colored dissolved organic matter (CDOM) at 443 nm (ag443 in m-1) for large dynamic ranges. These are derived using customized algorithms and validated using extensive field data collected between 1998 and 2010. The algorithms combine the advantage of both empirical and semi-analytical approaches, and use green and red wavelengths to avoid problems in the blue wavelengths due to imperfect atmospheric correction. The long-term products from 1998 to 2012 are used to develop a satellite-based water quality decision matrix (WQDM) to help make management decisions. Further, time series data are extracted routinely from several pre-defined stations and then provided to the general public on a customized web site through a virtual buoy system (VBS).