Gliders observations of mesoscale and submesoscale flow structures in the Gulf of Mexico: over three years of continuous monitoring.

As a component of the The Gulf of Mexico Research Consortium (CIGoM), the Group of Monitoring the Ocean with Gliders (GMOG) has a quasi-continuous near real-time monitoring program in the Western Gulf of Mexico (GoM) since May 2016. Mesoscale and sub-mesoscale flow structures have been observed with high-resolution using a fleet of 7 autonomous underwater gliders type SeaGlider (Kongsberg Inc). GMOG has collected over 100,000 vertical profiles of temperature, salinity, chlorophyll-a (Chla), colored dissolved organic matter (CDOM), backscatter, dissolved oxygen (O₂), and over 2,500 of horizontal velocity from the surface down to 1000m depth, with horizontal and vertical resolutions of [3-5]km and [0.5-2]m, respectively. These observations allowed to characterize the high-resolution vertical structure of: 3 large Loop Current Eddies (LCEs), Olympus, Poseidon, and Revelle (https://www.horizonmarine.com/loop-current-eddies), the Campeche cyclone, intra-thermocline eddies embedded in LCEs, river plumes (Mississippi and Bravo), confluent flows, and LCEs’ peripheries. Loop Current Eddy Poseidon was targeted during 4 consecutive missions unraveling its vertical thermohaline structure from the mesoscale down to the small scale. Glider data have improved our understanding of air-sea and dynamical processes inside LCEs and basin-scale repercussions: winter convective mixing driven by the passage of atmospheric frontal systems (or Northern winds) and mixed-layer deepening, Subtropical UnderWater (SUW) transformation to Gulf Common Water (GCW), heat and salt budget in the GoM, stirring of high Chla and CDOM fresh water plumes wrapping around LCEs, and the role of the sub-mesoscale and small-scale in the LCEs dynamics. Glider data can be freely visualized at the GMOG’s webpage https://gliders.cicese.mx/.