Ergebnisse der CO2-Messungen während der Nordost-Atlantik Expedition 1971

During the Northeast-Atlantic-Expedition of 1971, C02 concentration in the air layer near the ocean surface and C02 partial pressure in the surface water was measured between Lisbon and Weather Ship D as well as between Weather Ship D and Hamburg. These measurements were supplemented by depth profiles of C02 partial pressure in the ocean. The resulting zonal distribution is discussed. An interesting aspect of the C02 concentration values in the air layer above the ocean is their significant correlation with the temperature difference between air and water. The possible meaning of this correlation with the regard to the exchange of C02 between ocean and atmosphere is demonstrated by estimating the C02 flux for a particular case. The annual variation of C02 partial pressure in surface water is discussed for two points on longitude 30° W at which the route of the 1971 expedition intersects the route of the 1969 expedition. It is deduced that in temperate latitudes the annual variation of C02 partial pressure in surface water is related to that of surface-water temperature. Based on this relationship and on the PC02 decrease of 35 ppm measured between April and June it is estimated that the annual variation of C02 partial pressure in surface water for the oceanic area around 50° N 30° W amounts to 60 ppm ± 15 ppm