Convective hydration of the stratosphere

Abstract

Strong thunderstorms provide a means for rapidly moving air from the troposphere—the atmospheric layer closest to Earth’s surface—to the stratosphere—the next highest layer of the atmosphere, located approximately 10 miles above the surface. Updrafts within the core of the storm can transport pollutants, water vapor, and ice to the stratosphere on time scales that are shorter than those of other troposphere-stratosphere exchange processes. Modeling (1–3) and observations (4, 5) show that the input of tropospheric air and ice can moisten the normally dry stratosphere and alter its composition and, potentially, its radiative and chemical properties (6). Yet, there are many unanswered questions concerning the transport mechanism. On page 1248 of this issue, O’Neill et al. (7) provide a framework for understanding how some supercell thunderstorms—those that produce above-anvil cirrus plumes—generate an internal hydraulic jump to irreversibly inject air and water from the troposphere to the stratosphere.