These plots show a comparison of the seasonal cycle in stratospheric water vapor derived
from a long record of balloon-borne frost point hygrometer measurements in Boulder, Colorado
(40 N), with results from our HALOE analyses interpolated to Boulder.  The overall excellent
agreement suggests a high degree of reliability in the satellite data.
 

                                              Balloon water vapor                                                                  

                        HALOE water vapor
 

In these plots the dark solid line denotes the local tropopause, and the dashed line is the
400 K isentrope.   Shaded regions denote water vapor mixing ratios below 3.6 ppmv.