Seminar - Lioudmila Ametistova - Application Of A Satellite Ocean Color Technique For Monitoring Coastal Waters: Great Barrier Reef Case Study

Wednesday, June 9, 2004, 1.10 - 1.50 pm
Civil Engineering Lecture Room 3

Abstract

Remote sensing is often considered as a means of addressing the limitations of ground-based monitoring networks by obtaining synoptic measurements of optical signals from the targeted water bodies. These optical signals, usually measured as water reflectance, must then be transformed, through appropriate methodologies, into estimates of water coloring substances and consequently, water quality parameters. In optically complex coastal waters, methods to accurately retrieve optical properties remotely are still evolving. Analytical and empirical relationships between apparent and inherent optical water properties are combined to develop a bio-optical model, using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) visible spectral bands. In this study the inverse bio-optical model was incorporated in the remote sensing processing software SEADAS to allow for iterative atmospheric correction and subsequent retrieval of chlorophyll concentration, inorganic sediments load and dissolved organic matter absorption. The vicinity of Hinchinbrook channel, central Great Barrier Reef zone, Australia, was used as a case study, where presence of particulate matter and colored dissolved organic matter imply inadequateness of SeaWiFS standard chlorophyll algorithm. The new algorithm was validated using sea-truth measurements of water-coloring constituents acquired during various seasons throughout 2002-2004. In situ and corresponding remote observations agree within their uncertainty boundaries. The method was then applied to study fluxes of particulate and dissolved organic and inorganic matter following flood events of the adjacent Herbert River during austral summer of 1999.