Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9758330 | Marine Chemistry | 2005 | 17 Pages |
Abstract
Monthly seawater pH and alkalinity measurements were collected between January 1996 and December 2000 at 10°30â²N, 64°40â²W as part of the CARIACO (CArbon Retention In A Colored Ocean) oceanographic time series. One key objective of CARIACO is to study temporal variability in Total CO2 (TCO2) concentrations and CO2 fugacity (fCO2) at this tropical coastal wind-driven upwelling site. Between 1996 and 2000, the difference between atmospheric and surface ocean CO2 concentrations ranged from about â 64.3 to + 62.3 μatm. Physical and biochemical factors, specifically upwelling, temperature, primary production, and TCO2 concentrations interacted to control temporal variations in fCO2. Air-sea CO2 fluxes were typically depressed (0 to + 10 mmol C mâ 2 dayâ 1) in the first few months of the year during upwelling. Fluxes were higher during June-November (+ 10 to 20 mmol C mâ 2 dayâ 1). Fluxes were generally independent of the slight changes in salinity normally seen at the station, but low positive flux values were seen in the second half of 1999 during a period of anomalously heavy rains and land-derived runoff. During the 5 years of monthly data examined, only two episodes of negative air-sea CO2 flux were observed. These occurred during short but intense upwelling events in March 1997 (â10 mmol C mâ 2 dayâ 1) and March 1998 (â 50 mmol C mâ 2 dayâ 1). Therefore, the Cariaco Basin generally acted as a source of CO2 to the atmosphere in spite of primary productivity in excess of between 300 and 600 g C mâ 2 yearâ 1.
Related Topics
Physical Sciences and Engineering
Chemistry
Chemistry (General)
Authors
Y.M. Astor, M.I. Scranton, F. Muller-Karger, R. Bohrer, J. GarcÃa,