Five Year Mean Surface Chlorophyll Estimates in the Northern Gulf of Mexico for 2005 through 2009

These images were created by combining the mean surface chlorophyll estimates to produce seasonal representations for winter, spring, summer and fall. Winter includes the months of January, February and March; spring includes the months of April, May and June; summer includes the months of July, August and September; fall includes the months of October, November and December. Estimates of surface chlorophyll concentration were originally obtained from the Naval Research Laboratory at the Stennis Space Center (NRL/SSC). NRL/SSC processed MODIS-Aqua satellite imagery covering the Gulf of Mexico, for a 5-year time period from January 2005 through December 2009. The Gulf of Mexico was divided into three regions, western, central and eastern. For purposes of this image, the three regions were joined in ArcMAP 10. The surface chlorophyll estimates were determined using the OC3 algorithm for MODIS (O'Reilly et al., 2000). These estimates were then reclassified into phytoplankton productivity categories in accordance with the Coastal and Marine Ecological Classification Standard (CMECS). There are three CMECS categories under this parameter: oligotrophic (< 5 ug/L), mesotrophic (5 - < 50 ug/L), and eutrophic (> 50 ug/L). The mean surface concentrations for the northern Gulf of Mexico only fall into two of the three categories, oligotrophic (shown as blue) and mesotrophic (shown as green).