Among all CO source/sink terms, the loss due to CO reaction with OH and the emission from biomass burning appear to be main causes for seasonal fluctuation.
Improved representation of boreal fire emissions for the ICARTT period S. Turquety, D. J. Jacob, J. A. Logan, R. M. Yevich, R. C. Hudman, F. Y. Leung,
Global Distributions of Carbon Monoxide Total Column: A Statistical Analysis from MOPITT Data
