The EPOCS cruise designated EP2-86-OC began on 21 May (Day 141) 1986 aboard the NOAA Research Vessel (R/V) Oceanographer. The ship departed from Balboa, Panama and headed southwest to the equator at 97° W. The cruise track continued west along the equator, diverting for mooring work along 110° W and 140° W. The cruise continued northwest from the equator at 143° W, ending in Honolulu, Hawaii on 20 June (Day 171). CTD and oxygen measurements for this track are reported in Lynch et al. (1988). Chlorofluorocarbon (CFC) measurements are reported by Wisegarver et al. (1993).
The mean atmospheric fugacity, f(CO2)air, for this equatorial track was 334.7 ±1.1 µatm. Surface seawater values, f(CO2)sw, ranged between ~410 µatm and 430 µatm along the equator from 90° W to 112° W. Concentration dropped sharply (to ~370 µatm) when the ship diverted north into fresher, warmer waters to the north of 3° N. The f(CO2)sw rose to ~420 µatm as the cruise track returned to the equator, but dropped to ~360 µatm as the ship moved away from the equator near 143° W, 6° N. Concentrations continued low (~350 µatm) into Hawaii. The mean percent standard deviation of the standard gases on this leg was <1%.
Seven points were anomalously low on this track. They are flagged in the data files.