Liu, J., Drummond, J., Jones, D., Cao, Z., Bremer, H., Kar, J., … Gille, J. C. (2006). Large horizontal gradients in atmospheric CO at the synoptic scale as seen by spaceborne measurements of pollution in the troposphere. Journal Of Geophysical Research-Atmospheres, 111, D02306. doi:10.1029/2005JD006076