World-scale monthly mapping of the C0 2 ocean-atmosphere gas-transfer coefficient

Abstract

Monthly maps of the ocean—atmosphere CO₂ gas-transfer coefficient are derived from meteorological winds for 1982. The seasonal variations are of the order of a factor 2, mostly in the Northern Hemisphere. A strong meridional pattern is observed: the exchange coefficient is larger at high latitudes than in tropical areas. However, the zonal variations within a latitudinal band (generally a westward enhancement) can be as large as the meridional ones. The representativity of the winds is a major concern: interannual variations of the order of 30 % are documented by an analysis of four years of the monthly transfer coefficient derived from meteorological winds in the Atlantic ocean. In the future, these maps will be obtainable on a routine basis from satellite data. As an example, a map derived for August 1978 from Seasat altimeter winds is compared with the present ones.