The NOAA Ship Oceanographer departed Townsville, Australia on 13 July (Day 194) for the TW3-87-OC cruise and steamed northeast to 5° S, 165° E for station work in the Samoan Passage. The ship then continued north along 165° E and into Kwajalein, Micronesia on 27 July (Day 208). Details of the CTD temperature, salinity, and oxygen data are given by Mangum et al. (1991).
The mean atmospheric value for this section was 334.01 ±1.11 µatm. Surface seawater CO2 was largely undersaturated through the Coral Sea but increased rapidly to 353 µatm near 5° S. Water values remained near saturation or supersaturated north to 1° S. Across the equator surface seawater was undersaturated as far north as 2° N, but dropped again quickly to undersaturation from 2° N and north into Kwajalein. The mean percent standard deviation of the standard gases on this leg was 0.32%.