A region centred to the west of Central America around 8–10°N and 88–90°W and about 200 to 400 km wide. Open ocean upwelling causes a domelike configuration of the local well–defined thermocline, bringing nutrients to the photic zone and sustaining increased biological productivity. This cyclonic gyre is located between the North Equatorial Countercurrent (NECC) to the south, the Costa Rica Coastal Current (CRCC) to the east and north, and the extension of the California Current and beginnings of the North Equatorial Current (NEC) to the north and northwest.