Ozone and Water Vapor Injected into the Stratosphere from Two Isolated Thunderstorms

Abstract

The local ozone concentration and water vapor overburden were measured from a WB-57F aircraft near thunderstorms that reached or penetrated the tropopause. Two storms were studied extensively: one that penetrated 800 m above the tropopause and another that reached to about the tropopause level. In both cases, water vapor overburdens above and downwind averaged some 40% higher than those upwind of the storms. The water vapor overburdens directly above the higher storm were about 2.4 times that of those background measurements upwind and at the same levels; directly above the weaker storm the water vapor was about 1.8 times as great as the background measurements. The spatial distribution of ozone around the two storms was similar to that of the water vapor: downwind concentrations exceeded those upwind at all levels. An excess in ozone of about 25% was observed in circumnavigations above the storm tops when compared with fair-weather values at the same levels away from the storm. Ozone concentrations directly above the higher storm, however, were observed to be about 40% more than those concentrations away from the storm, while those directly above the weaker storm were about 20% less than in undisturbed air. It thus appears that thunderstorms do inject substantial amounts of water vapor into the stratosphere and that growing, electrically active storms also generate ozone at their tops.