Anthropogenic Carbon, CFC-12 and SF6 in the Tropical Atlantic.

• Applicant: Professor Dr. Douglas W.R. Wallace
• Subject Area: Oceanography
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 42594921

The tropical Atlantic is a potentially important area for uptake and storage of anthropogenic CO2 (Cant). The tropical upwelling areas are also important for the global and regional climate, biological carbon production, air-sea CO2 exchange, and for regulation of the sea surface temperature. However, there is a noticeable gap in the inorganic carbon data coverage for the tropical and equatorial Atlantic, and direct measurements of upwelling and vertical velocities are difficult due to the low velocities involved. In a recent manuscript we have shown that time-series multiple regression (eMLR) based estimates of Cant derived from inorganic carbon data in the sub-tropical Atlantic are highly correlated with TTD-based estimates derived from tracers. Further more tracer measurements provide an efficient way of indirectly assessing upwelling rates. We propose to collect data of the transient tracers SF6 and CFC-12 in upwelling areas of the tropical Atlantic. We will use recently collected carbon and tracer data (M68) from the Tropical Atlantic together with historical data to estimate Cant using both the eMLR and TTD approaches. The tropical correlation of these Cant estimates will be examined. The newly acquired tracer data will be used to estimate upwelling rates in the tropics.

• DFG Programme: Research Grants