2 research outputs found
Air-sea CO2 fluxes in the Atlantic as measured during the FICARAM cruises
A total of fourteen hydrographic cruises spanning from 2000 to 2008 were conducted
during the spring and autumn seasons between Spain and the Southern Ocean, under
the framework of the Spanish research project FICARAM. The performed underway measurements are processed and analysed to describe the meridional air-sea CO2
fluxes (F CO2) along the Atlantic Ocean. The data was organised into different biogeochemical
oceanographic provinces, according mainly to the thermohaline characteristics.
The obtained spatial and temporal distributions of F CO2 follow the generally expected
patterns and annual trends. The Subtropical regions in both hemispheres alternated the CO2 source and sink nature from autumn to spring, respectively. On the other
hand, Tropical waters and the Patagonian Sea clearly behaved as sinks of atmospheric
CO2 like the waters of the Drake Passage during autumn. The obtained results during
the cruises also revealed significant long-term trends, such as the warming of equatorial
waters (0.11±0.03 Cyr−1) and the decrease of surface salinity (−0.16±0.01 yr−1)
in tropical waters caused by the influence of the Amazon River plume. This reduction
in surface salinity appears to have a direct influence over the CO2 storage rates, fostering
the uptake capacity of atmospheric CO2 (−0.09±0.03 molm−2 yr−1). An analysis
of the biogeochemical forcing on the CO2 fugacity (fCO2) variability performed from
an empirical algorithm highlighted the major role of the Amazon River input in the tropical North Atlantic fluxes. In addition, it has provided a quantitative measure of the
importance of the thermodynamic control of F CO2 at temperate latitudes