NITROUS OXIDE FLUXES AT THE AIR-SEA INTERFACE IN GUANABARA BAY

In Surface water concentrations of N2O were measured at 37 stations in Guanabara Bay and fluxes estimated across the air-sea interface. Concentrations averaged 8.2 +/- 2.2 nmol L-1 and 90% of the stations showed supersaturation averaging 33%. N2O fluxes were estimated using a two-film model which is given by the product of the concentration difference across the film and the gas transfer coefficient (k(w)). Two parametrizations of kw were used which provided average fluxes of 0.3 and 3.0 mu g N m(-2) h(-1). Flux measurements using floating chambers (not reported here) seem to agree with the upper limit of these estimates.