Surface water carbon dioxide in the waters associated with the subtropical convergence, east of New Zealand

The spatial variations of sea surface carbon dioxide partial pressure in the water masses associated with the subtropical convergence (STC) east of New Zealand in October 1993 are described. The area is a CO2 sink in the austral spring. Dramatic changes in PCOsw2 were observed across the STC—a change of 48 μatm over the Chatham Rise and 80 μatm at the Southland Front, from subantarctic surface water to subtropical water. The effect of biological activity is estimated to be greater in magnitude and opposite in direction to the temperature effect. Instantaneous air–sea fluxes are calculated.