Abstract
The carbon dioxide (CO2) flux estimation between the atmosphere and the ocean is very im
portant in carbon cycling and climate change research. Generally the carbon dioxide flux is pro
portional to the difference of gas concentration (or partial pressure) and to the gas exchange
coefficient. In this research, theCO2 exchange coefficient is investigated basedon whitecapmodel
assuming thatCO2transfer velocity is proportional to whitecap coverage, which is related to wind
friction velocity.Weestimate the gas exchange coefficient using the relationship between wind
friction velocity and wave age. The gas exchange coefficient and its distribution, seasonal and
annual variation in the North Pacific were estimated based on the modified whitecap model by
using the observations of the scatterometer on the European Remote Sensing (ERS) satellites, the
Special Sensor Microwave / Imager (SSM/I) on the operational spacecraft of the Defense Meteo
rological Space Program (DMSP) and the Advanced Very High Resolution Radiometer (AVHRR)
on the National Oceanic andAtmospheric Administration satellites. The global meanCO2 ex
change coefficient is close to the result derived from ,4C data and the global mean value has
shown an increase trend during the period 1991 - 1992.
