A map of the sea-surface geopotential anomaly relative to 10 MPa (1000 dbar) suggests that the subtropical gyre in the South Atlantic contains two high cells centered at about 22S and 32S just off the coast of South America. The two cells mayor may not be connected to each other by a narrow band of high geopotential anomaly along the western boundary. This circulation pattern is associated with a general poleward-deepening trend of the isanosteres below 300 m and a reversed trend in the shallower layer. The reversed trend of the isanosteres is particularly pronounced near 25S. This pattern is similar to those found on various maps of surface or near-surface geopotential anomaly in the western subtropical North Pacific and North Atlantic oceans and appears to be a permanent feature.
Tsuchiya, Mizuki. 1985. "Evidence of a double-cell subtropical gyre in the South Atlantic Ocean." Journal of Marine Research 43, (1). https://elischolar.library.yale.edu/journal_of_marine_research/1764