A 3-D MODELING STUDY OF THE SOURCES AND SINKS OF ATMOSPHERIC CARBON-MONOXIDE

A global three-dimensional atmospheric tracer transport model is used to study the sources End sinks of atmospheric carbon monoxide (GO). So urce functions are included for the release of CO from the oxidation o f methane, technological sources, biomass burning, the oxidation of hy drocarbons and the oceans. The removal of CO from the atmosphere is as sumed to be largely due to oxidation through reaction with hydroxyl ra dicals (OH) and removal by soils. To compute CO destruction, a paramet erised OH field, calibrated to reproduce the loss of methyl chloroform , is employed. For the removal of CO by soils, a model is used which a ssumes that the flux of CO into soils is dependent on net primary prod uctivity. To constrain the magnitude of the CO sources and sinks, atmo spheric observations of CO are used. The deduced total CO source is 18 55-2355 Tg. If present estimates of the release of CO from biomass bur ning and oxidation of hydrocarbons are correct then removal by soils c ould potentially be a substantial sink for CO.