We describe observations of tropical stratospheric water vapor q that show clear evidence of large‐scale upward advection of the signal from annual fluctuations in the effective “entry mixing ratio” qE of air entering the tropical stratosphere. In other words, air is “marked,” on emergence above the highest cloud tops, like...
Measurements of stratospheric water vapor by the Microwave Limb Sounder aboard the Upper Atmosphere Research Satellite show that in the tropical lower stratosphere, low‐frequency variations are closely related to the annual cycle in tropical tropopause temperatures. Tropical stratospheric air appears to retain information about the tropopause conditions it encountered for...