Awarded for “The increase in stratospheric water vapor from balloonborne frost-point hygrometer measurements at Washington D.C., and Boulder, Colorado”, by Oltmans, S. J., H. Vömel, D. J. Hofmann, K. H. Rosenlof, and D. Kley, Geophys. Res. Lett., 21, 3453-3456, 2000.