The application of MODIS 250m data to monitor algal blooms in a southwestern US reservoir system

Philip Tarrant, Arizona State University, ptarran@asu.edu
Susanne Neuer, Arizona State University, susanne.neuer@asu.edu (Presenting)

Monitoring ocean primary production using satellite data is well established in biological oceanography. Daily images from SeaWifs, MODIS and MERIS provide excellent temporal resolution, but the relatively coarse spatial resolution of these sensors makes the default ocean color products unsuitable for smaller inland bodies of water, which represent complex optical scenarios. The ability to identify trends that precede cyanobacterial blooms or harmful algal blooms in lakes and reservoirs would provide those agencies responsible for monitoring water quality the opportunity to plan a response. We utilized the two MODIS 250 meter bands (centered on 645nm and 856nm) to produce primary production estimates for Roosevelt Lake, a 9698 ha reservoir in central Arizona. Using the relationship between field and satellite data we created a lake specific algorithm capable of estimating chlorophyll concentrations to within ± 25%. We hope that by using this algorithm we will be able to identify the trends preceding cyanobacterial blooms. One goal of this work has been to develop a simple process that can be used regularly by agency personnel as part of their overall water monitoring program.