Dynamic Regionalization of the Gulf of Mexico based on normalized radiances (nLw) derived from MODIS-Aqua

A dynamic regionalization of the Gulf of Mexico (GoM) was carried out based on normalized radiances derived from MODIS-Aqua while considering its seasonal variability (Hurricane and Non-hurricane seasons). Daily images with a 1 km resolution from June 2002 to May 2007 were used. To define the dynamic regions, the first Standard Empirical Orthogonal Function (SEOF1) was calculated by combining nLw412 nm and nLw488 nm. The GoM was divided into two large provinces: oceanic and coastal. Within the oceanic province there are three regions with oligotrophic conditions. The coastal province displayed two sub-provinces (the northern and southern Gulf of Mexico) within which eight regions were located. Two of them were classified as transition regions. In general, most regions could be associated with general circulation patterns and/or river discharge influence. When looking at changes in coverage and the number of divisions, this regionalization shows a bi-seasonal modulation governed by hurricane seasons. The approximation presented here allows the dynamic regionalization of the GoM, a zone characterized by small surface gradients on Chl a and SST, including the recognition of smaller structures such as eddies.

► We present a dynamic regionalization of the Gulf of Mexico.
► We define the dynamics regions based on the first Standard Empirical Orthogonal function (SEOF1).
► SEOF1 was calculated combining nLw412 nm and nLw488 nm from MODIS-Aqua.
► This regionalization is adequate for use in areas with little variability in SST and Chl a.