Abstract
The study utilized the Moderate Resolution Imaging Spectroradiometer (MODIS) red-channel reflectance with a spatial resolution of 250 m to estimate suspended sediment concentration (SSC) in the Mobile Bay estuary, Alabama. Based on monthly in situ sampling, a new algorithm was developed using an exponential regression model. The concentration of inorganic suspended sediments (ISS) in Mobile Bay and Mississippi Sound was concerned and mapped by applying the new algorithm. The ISS maps during a cold front passage have revealed how the resuspension and transport of sediments respond to the variable wind forcing in this micro-tidal system. Particle tracking based on a three-dimensional hydrodynamic model was utilized to explain what was observed from the satellite imagery. It has been found that the rapid disappearance of the surface ISS after a cold front passage was mainly caused by settling of sediments rather than flushing out of the estuary. The study demonstrates that a combination of ISS mapped from the MODIS band-1 reflectance and three-dimensional numerical modelling is an effective tool to analyse sediment dynamics in the Mobile Bay estuary and other similar estuaries.
Acknowledgements
We thank the anonymous reviewers for their constructive comments on the manuscript. This study was supported partially by the National Science Foundation (NSF, Grant No. 0652859), the Alabama Center for Estuarine Studies (ACES), the Louisiana Sea Grant (LASG) and NASA HBCU NCC13-03011. Any opinions, findings and conclusions or recommendations expressed in this article are those of the authors and do not necessarily reflect the views of NSF, ACES, LASG or NASA.