NASA - National Aeronautics and Space Administration

Petropavlovskikh, I., E. Ray, S. M. Davis, K. Rosenlof, G. L. Manney, R. E. Shetter, S. R. Hall, K. Ullmann, L. fister, J. Hair, M. A. Fenn, M. Avery, and A. M. Thompson (2010), Low-ozone bubbles observed in the tropical tropopause layer during the TC4 campaign in 2007, J. Geophys. Res., 115, D00J16, doi:10.1029/2009JD012804.