Estimating the interannual variability of the air-sea CO2 flux in the EastEquatorial Pacific

Measurements of the carbon dioxide partial pressure in the surface layer of the equatorial Pacific ocean around 100 degrees W resulting from 14 cruise s are compared to the sea surface temperature (SST) variability. A method i s derived to interpolate the CO2 measurements from 1991 to 1995 using SST s atellite measurements. By combining them with the exchange coefficient dedu ced from the wind speed provided by two satellite borne instruments (ERS1 s catterometer and SSM/I microwave radiometer) we deduce the air-sea CO2 flux . When averaged over four full years (1991-1994) and 2.5 10(5) km(2) this f lux amounts to an evasion from the ocean of 1.3 mole m(-2) year(-1). (C) 19 99 Elsevier Science Ltd. All rights reserved.