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The Impact of Stable Layers on Downdrafts in Tropical ConvectionWhile the idea that downdraft vertical velocity is influenced by thermodynamic stability may seem obvious, there remains a gap in the scientific literature surrounding the interaction between downdrafts and stable layers. A number of questions remain unanswered. Can a stable layer stop the downward progression of a downdraft or merely slow its velocity? Related to this, can a stable layer stop the injection of low entropy air into the boundary layer? Do downdrafts modify the environment in a way that removes pre-existing stable layers (limiting the influence of the stable layer)? Is it possible for evaporative cooling to generate and maintain a stable layer that is sufficiently strong to stop the downward progression of downdrafts?The present study aims to answer these questions using a combination of high-altitude airborne radar and dropsonde observations, both collected within four tropical cyclones (Gaston, Hermine, Karl, and Matthew) during the 2016 NOAA SHOUT field campaign, as well as idealized simulations of tropical deep convection. This presentation will focus on the potential for a stable layer to halt the downward progression of a downdraft (and the associated low entropy air) with particular attention given to conditions and processes that might enhance or mitigate the influence of the stable layer.
Document ID
20190029621
Acquisition Source
Goddard Space Flight Center
Document Type
Presentation
Authors
Helms, Charles N.
(Universities Space Research Association (USRA) Greenbelt, MD, United States)
Date Acquired
August 26, 2019
Publication Date
July 31, 2019
Subject Category
Meteorology And Climatology
Report/Patent Number
GSFC-E-DAA-TN72152
Meeting Information
Meeting: Conference on Mesoscale Processes
Location: Savannah, GA
Country: United States
Start Date: July 29, 2019
End Date: August 1, 2019
Sponsors: American Meteorological Society (AMS-HQ)
Funding Number(s)
CONTRACT_GRANT: NNH15CO48B
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
NASA Peer Committee
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