Increase of Caribbean Water Incursion into the Gulf of Mexico: The Need in Biochemistry Studies of a New Characterization of the Upper Waters of the central Gulf of México

Circulation in the central Gulf of Mexico’s (GoM) is dominated by the Loop Current (LC) and its associated eddies. The dynamics of the Loop Current and the detached Loop Current eddies dominate the Gulf of Mexico's surface circulation and transport Caribbean water into the gulf. At least three near-surface water masses are affected by mesoscale processes that modulate the biogeochemical cycles. In this work, base on 25-years (1993-2017) of daily satellite data calculated from the absolute dynamic topography and oceanic current monthly climatologies, it is shown 1) that there is an annual intrusion of the Caribbean water with an inward incursion that starts in spring, peaks in the summer; and 2) after 2003, larger volumes of CW have invaded the western GoM. From a biogeochemical perspective, the surface waters of the deep GoM are considered oligotrophic as they are relatively isolated from the more eutrophic waters of the coast and continental shelves. Prior studies have presented different classifications of water masses where the greater emphasis was on deep waters and not on the surface waters (σ_θ < 26 kg·m^-3). We presents the need to use a new reclassification of water masses in the GoM, based on thermohaline properties and dissolved oxygen (DO) concentration using data from a total of five summer and winter cruises carried out primarily in the central GoM.