Distributional characteristics of DOC in the central Equatorial Pacific

Abstract

Distributions of dissolved organic carbon (DOC) as determined by high temperature catalytic oxidation (HTCO) method, are reported for 5 stations located from 15°N to 5°S along the transect of 180° in the central Equatorial Pacific. Vertical profiles of DOC suggest that levels of DOC in the photic layer at a given station are dependent on the vertical stability of the water column and meridional currents in the central Equatorial Pacific. Concentrations of DOC determined by the HTCO method in the northern North to Equatorial Pacific and those of total organic carbon (TOC) determined by Wet Chemical Oxidation (WCO) method during the GEOSECS Pacific cruises indicated that DOC determined by both methods, taken together with the levels of DOC in the surface water, showed clear meridional differences in the areas from north of 40°N to the equatorial region in the Pacific: values were low at high latitudes, namely, in productive areas, but high at low latitudes, namely, in oligotrophic areas, even though the values of DOC determined by the two methods were different.