Seasonal to decadal variations of water vapor in the tropical lower stratosphere observed with balloonborne cryogenic frost point hygrometers

H. Vömel, F. Hasebe, M. Shiotani, S.-Y. Ogino, S. Iwasaki, N. Nishi, T. Shibata, K. Shimizu, E. Nishimoto, J. Valverde-Canossa, H. B. Selkirk and S. J. Oltmans