Distribution of the CO₂ partial pressure in the Atlantic ocean between Iceland and the Antarctic peninsula

Abstract

CO₂ partial pressure of surface water, (pCO₂)_sw, was measured continuously during two cruises in the Atlantic Ocean in November/December 1991 and May 1992. A (pCO₂)_sw profile between Iceland and the Antarctic Peninsula is obtained which demonstrates that along the investigated transect the Atlantic Ocean is largely a potential sink for atmospheric CO₂, especially at high latitudes, where partial pressure differences of -80μatm to -100 μatm are observed. A significant potential source region exists only between the equator and 10°S with a maximum μpCO₂ of 35 μatm. An attempt is made to identify the processes that control the (pCO₂)_sw, distribution pattern. The investigations at latitudes > 40° in both hemispheres were performed during spring and correlations between (pCO₂)_sw and chlorophyll a contents indicate that biological production mainly controls the distribution of (pCO₂)_sw. At lower latitudes, (pCO₂)_sw is mainly related to temperature and salinity, but also an upwelling effect could be identified close to the equator.