ABSTRACT

The amount of total carbon dioxide estimated from pH and alkalinity was plotted against AOU. Results obtained were compared with those of a phosphate vs. AOU plot previously reported by the present authors. As a result, the following pints were confirmed: 1) The relationship between total carbon dioxide and AOU is given by a straight line with a slope of about 100/270 in an atomic ratio of carbon to oxygen for a group of waters with equal chlorinity and temperature. 2) The atomic ratio of carbon to phosphorus of about 100 to 1 obtained from the comparison of the ratios of ΣCO₂ to AOU and P to AOU coincides with the C to P ratio given by FLEMING for a composite plankton sample. 3) Total carbon dioxide consists of three components; oxidative total carbon dioxide, reserved total carbon dioxide proportional to chlorosity (major portion of reserved total carbon dioxide) and reserved total carbon dioxide independent of chlorosity (minor portion of reserved total carbon dioxide). 4) Chlorosity-independent portion of reserved total carbon dioxide, as well as reserved phosphate, is remarkably more abundant in the Oyashio waters than in the Kuroshio waters.