Ridley, B. A., Atlas, E. L., Selkirk, H., Pfister, L., Montzka, D. D., Walega, J. G., … Elkins, J. (2004). Convective transport of reactive constituents to the tropical and mid-latitude tropopause region: I. Observations. Atmospheric Environment, 38, 1259-1274. doi:10.1016/j.atmosenv.2003.11.038