An Examination of the Convective Moistening of Lower Stratosphere Using Satellite Data

Abstract:

We test the hypothesis that deep convections moisten the lower stratosphere by using satellite data. The water vapor measurements of the EOS-MLS and ACE-FTS are examined and stratified according to the ISCCP deep convection indices. Moreover, trajectory models are used to aid the identification of deep convection impacted water vapor samples. It is found that the convection impacted samples are significantly moister than the nonimpact samples at the lowermost stratospheric layer right above the tropopause, but a dryer tendency is also noticed right above the moistened layer. On the other hand, a substantial fraction of high concentration samples in the datasets cannot be attributed to the moistening effect. Implications of the results are discussed.