Large upper tropospheric ozone enhancements above mid-latitude North America during summer: in situ evidence from the IONS and MOZAIC ozone monitoring network.

Cooper, O.; Stohl, A.; Trainer, M.; Thompson, A.; Witte, J.; Oltmans, S.; Johnson, B.; Merrill, J.; Moody, J.; Morris, G.; Tarasick, D.; Forbes, G.; Nedelec, P.; Fehsenfeld, F.; Meagher, J.; Newchurch, M.; Schmidlin, F.; Turquety, S.; Crawford, J.; Pickering, K.; Cohen, R.; Bertram, T.; Woolridge, P.; Brune, W.