Assessment of chlorophyll variability along the Louisiana coast using multi-satellite data

作者：D'Sa Eurico J^*

来源：GIScience and Remote Sensing, 2014, 51(2): 139-157.

DOI：10.1080/15481603.2014.895578

• Gulf of Mexico
• wavelet analysis
• Mississippi River
• ocean color
• QuikSCAT winds
• hypoxia
• SeaWiFS
• chlorophyll

Variability in surface chlorophyll (Chl) concentrations derived from the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) were examined in conjunction with river discharge, QuikSCAT satellite-derived winds, and sea surface height (SSH) anomaly data along the Louisiana coast, USA. Surface Chl distributions exhibited rapid response to strong northerly winds following a frontal passage. A comparison of time series (1998-2010) river discharge and monthly Chl data indicated Chl variability to be well correlated to seasonal river discharge only for locations near the two river deltas, while offshore, enhancements in Chl during fall-winter was likely due to cross-shelf transport or mixing associated with strong northerly wind stress. Variance in Chl examined using wavelet analysis applied to nearly 10years (1998-2007) of SeaWiFS data indicated patterns of significant Chl variability due to combined enhanced wind and river discharge, offshore flows associated with Ekman transport and coastal wind convergence, and the effect of Hurricane Rita in 2005. Instances of significant Chl variance were also observed to occur during years of large hypoxic zone size suggesting potential linkages to hypoxia. SSH anomaly imagery indicated the presence of warm-core eddies that were responsible for the offshore dispersal of elevated Chl observed in the monthly SeaWiFS imagery. Overall, the use of multi-satellite data better described the forcing and patterns of Chl distributions along the river-dominated Louisiana coast and shelf.

• 出版日期2014-3-4