Short-term changes in the partial pressure of CO2 in eastern tropical Atlantic surface seawater and in atmospheric CO2 mole fraction

Autor: Oudot, Claude, Andrié, Chantal
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Tellus B; Vol 41, No 5 (1989)
ISSN: 0280-6509
1600-0889
Popis: Continuous monitoring of oceanic and atmospheric CO2 during periods of 8 to 12 days in two particular locations of the tropical Atlantic was carried out during June-August 1986. At the first location (convergence zone; about 5°N, 20°W), the ocean surface was generally slightly undersaturated with respect to the atmosphere, whereas at the second one (Guinea Dome; 12°N, 22° W), the ocean surface was an important source zone of CO2 for the atmosphere. The results of PCO2 in surface seawater, after correction of the temperature effect, show a decrease between morning and evening related to photosynthetic activity. Over a 3-day period, the CO2 concentration in the air above the ocean may vary up to ±0.6 ppm d-1 at the same location, whereas the wind direction hardly changes. The net CO2 flux changes considerably during a short period (8 to 12 days) in the same place, as does the gas transfer coefficient across the sea surface through the variation of the wind speed: the variability is about 80–90%. The net CO2 flux calculated from mean data is lower (about 30%) than the net CO2 flux calculated from data taken over short time intervals. In the Guinea Dome area in summer, the net CO2 flux can be as high (1.8 mmol m-2 d-1) as in the equatorial area.DOI: 10.1111/j.1600-0889.1989.tb00140.x
Databáze: OpenAIRE