A complex system of deep zonal currents in the central equatorial Pacific persisted during 16 months of current measurements spanning the 1982–1983 EI Niño episode. At least three extra equatorialcurrents appear to be permanent: the north and south intermediate countercurrents, with eastward velocity cores at 600 m depth, located 1.5–2.0° from the equator; and the south equatorial intermediate current, with a westward core at 900 m depth three or more degrees south of the equator. On the equator, the deep jets were nearly stationary during the period of these measurements. Comparison with earlier measurements shows that over longer periods the jets neither propagate uniformly nor stay in place.
Firing, Eric. 1987. "Deep zonal currents in the central equatorial Pacific." Journal of Marine Research 45, (4). https://elischolar.library.yale.edu/journal_of_marine_research/1869