Journal article

The Mechanisms Leading to a Stratospheric Hydration by Overshooting Convection

Thibaut Dauhut, Jean-Pierre Chaboureau, Peter H Haynes, Todd P Lane

Journal of the Atmospheric Sciences | American Meteorological Society | Published : 2018

Abstract

Overshoots are convective air parcels that rise beyond their level of neutral buoyancy. A giga-large-eddy simulation (100-m cubic resolution) of ''Hector the Convector,'' a deep convective system that regularly forms in northern Australia, is analyzed to identify overshoots and quantify the effect of hydration of the stratosphere. In the simulation, 1507 individual overshoots were identified, and 46 of them were tracked over more than 10 min. Hydration of the stratosphere occurs through a sequence of mechanisms: overshoot penetration into the stratosphere, followed by entrainment of stratospheric air and then by efficient turbulent mixing between the air in the overshoot and the entrained wa..

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University of Melbourne Researchers

Grants

Awarded by StratoClim project - European Union Seventh Framework Programme


Awarded by Australian Research Council's Centres of Excellence scheme


Awarded by GENCI


Funding Acknowledgements

This research was supported by the StratoClim project funded by the European Union Seventh Framework Programme under Grant Agreement 603557 and the Idex Teasao project. Todd Lane is supported by the Australian Research Council's Centres of Excellence scheme (CE170100023). Computer resources were allocated by GENCI through Projects 90569 and 100231 (Grand Challenge Turing). Thibaut Dauhut would like to thank Patrick Mascart, who contributed to the early stage of this study via interesting discussions on the processes at play in the overshoots.