By Thibaut Dauhut, Jean-Pierre Chaboreau, Peter Haynes, and Todd Lane
The tallest thunderstorms contain regions of upward motion that temporarily penetrate into the lower stratosphere. These overshooting updrafts have been the subject of much discussion with regards to their role in transporting water vapour into the stratosphere from below and helping to determine its composition.
In this study a very high-resolution simulation of a Hector thunderstorm – a large regularly occurring storm near Darwin – is analysed and the hydrating properties of the overshoots are examined.
The study refines our understanding of the processes leading to stratospheric moistening, demonstrating that only the deepest overshoots had a hydrating effect on the stratosphere, with many non-hydrating updrafts present. The entire hydration process lasts only a few minutes during the rapid evolution and decay of the overshoots.
Parts of this work were completed when Thibaut visited The University of Melbourne for three months over the summer of 2015-2016. During that time he managed to arrange a trip to Darwin to view the Hector thunderstorms first hand.
- Paper: Dauhut, T., J. Chaboureau, P.H. Haynes, and T.P. Lane, 2018: The Mechanisms Leading to a Stratospheric Hydration by Overshooting Convection. J. Atmos. Sci.,75,4383–4398, https://doi.org/10.1175/JAS-D-18-0176.1