Features and variability of the Cuban Countercurrent in the Yucatan Basin, Caribbean Sea

The Cuban Countercurrent (CCC), along with the Yucatan Current, forms part of the Yucatan Basin circulation system, but it has not been well described and its connection to the system of currents in the Caribbean Sea has not been studied. Based on altimetry data (1993–2009) and the MERCATOR three-dimensional assimilation model (2007–2009), the CCC was observed flowing ~1000 km from the eastern Yucatan Channel to Jamaica and to have a width of ~150 km. Off southern Cuba, the mean velocity was 0.20 m s–1 at the surface and 0.05 m s–1 at 1000 m depth. The CCC transported ~3.5 Sv when it passed through the Yucatan Channel towards the Caribbean Sea, where ~1.6 Sv was recorded south of Cuba. During its annual cycle, the CCC weakened from December to February (0–250 m) and in the summer its magnitude intensified slightly, reaching 0.35 m s–1 in August, due to the increase in water temperature of the Atlantic warm pool. Consequently, the sea level rose in the center of the Yucatan Basin and the pressure gradient increased along the Cuban coast, producing an increase in zonal velocity (0.1 m s–1) and transport (2–3 Sv; r = 0.90). Its connection to the Caribbean current system demonstrated the importance of its study.