Equatorial Pacific ocean horizontal velocity, divergence, and upwelling

Upper-ocean horizontal velocity and divergence were estimated from shipboar d observations taken from 1991 1999 in the equatorial Pacific between 170 d egreesW and 95 degreesW. Mean transports were estimated for the zonal curre nts at the mean longitude of the sections, 136 degreesW. Mean meridional cu rrents for the entire longitude range included poleward surface flows reach ing -0.09 m s-(1) in the south and 0.13 m s(-1) in the north as well as equ atorward flow within the thermocline reaching 0.05 m s(-1) in the south and -0.04 m s(-1) in the north near 23 degreesC (85 m). Vertical velocity was diagnosed by integrating horizontal divergence estimated for the entire reg ion down from the surface. Equatorial upwelling velocities peaked at 1.9 (/-0.9) x 10(-5) m s(-1) at 50 m. The upwelling transport in the area bounde d by 3.6 degreesS-5.2 degreesN, 170 degreesW-95 degreesW was 62 (+/-18) x 1 0(6) m(3) s(-1) at 50 m. Strong downwelling was apparent within the North E quatorial Countercurrent. An asymmetry in the meridional flows suggested th at on the order of 10 x 10(6) m(3) s(-1) of thermocline water from the Sout hern Hemisphere was upwelled at the equator and moved into the Northern Hem isphere as surface water. This interhemispheric exchange path could be part of the route for water from the Southern Hemisphere to supply the Indonesi an Throughflow.