Jasna Pittman

Electrification in Hurricanes: Implications for Water Vapor in the Tropical Tropopause Layer

This study explores the relation between lightning frequency associated with hurricanes and water vapor in the Tropical Tropopause Layer (TTL) over the Tropical Americas (Caribbean and Gulf of Mexico) during the 2005 hurricane season. The hypothesis herein is that hurricanes that exhibit increases in lightning frequency are associated with stronger updrafts that can transport more moisture into the TTL. This added moisture can potentially be transported irreversibly into the stratosphere and alter the chemical and radiative properties of this layer of the atmosphere. Several studies predict increases in hurricane intensity, particularly in the Atlantic basin, as a result of increases in sea surface temperature due to global warming. Given that climate forecasts are very sensitive to water vapor concentrations in the TTL and in the stratosphere, it is essential to understand the effect that hurricanes have on TTL moisture.