Water column pCO(2) and air-sea CO2 fluxes were studied during an 18-month period (May 1994-September 1995) in a coastal embayment affected by upwelling, located in the northwestern Iberian Peninsula (Ria de Vigo and adjacent shelf). Overall, the region acted as a net annual atmospheric CO, sink, with magnitude ranging from 0.54 mgC m(-2) d(-1) in the Ria estuary to 22 mgC m(-2) d(-1) offshore. During moderate upwelling and upwelling relaxation conditions the sampling area was a sink for atmospheric CO2. By contrast, during winter conditions and during intense upwelling the flux reversed towards the atmosphere. The relative influence of physical and biological processes on pCO(2) was evaluated using two different approaches: firstly, statistical analysis... |