Interannual variability of equatorial Pacific CO2 fluxes estimated from temperature and salinity data

Based on atmospheric data and models, the tropical CO2 source anomaly reach es up to 2 Gte yr(-1) but the respective contributions of the terrestrial b iosphere and the oceans to this flux are difficult to quantify. Here we pre sent a new method for estimating CO2 fluxes from oceanic observations based on the surprisingly good predictive skill of temperature and salinity for surface dissolved inorganic carbon. Using historical temperature and salini ty data, we reconstruct the basin scale CO2 flux to the atmosphere in the e quatorial Pacific from 1982 to 1993. We find that interannual anomalies do not exceed 0.4 +/-0.2 GtC yr(-1) which suggests that up to 80% of the tropi cal CO2 source anomaly is due to the terrestrial biosphere.