Conditional Instability and Shear for Six Hurricanes over the Atlantic Ocean
TLDR
One hundred and thirty dropwindsondes deployed within 500 km radius of the eye of six North Atlantic hurricanes were used to determine the magnitudes and trends in convective available potential energy, and 10-1500m and 0-6-km shear of the horizontal wind as a function of radius, quadrant, and hurricane intensity as discussed by the authors.Abstract:
One hundred and thirty Omega dropwindsondes deployed within 500-km radius of the eye of six North Atlantic hurricanes are used to determine the magnitudes and trends in convective available potential energy, and 10–1500-m and 0–6-km shear of the horizontal wind as a function of radius, quadrant, and hurricane intensity. The moist convective instability found at large radii (400–500 km) decreases to near neutral stability by 75 km from the eyewall. Vertical shears increase as radius decreases, but maximum shear values are only one-half of those found over land. Scatter for both the conditional instability and the shear is influenced chiefly by hurricane intensity, but proximity to reflectivity features does modulate the pattern. The ratio of the conditional instability to the shear (bulk Richardson number) indicates that supercell formation is favored within 250 km of the circulation center, but helicity values are below the threshold to support strong waterspouts. The difference between these oce...read more
Citations
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References
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The Dependence of Numerically Simulated Convective Storms on Vertical Wind Shear and Buoyancy
TL;DR: In this paper, the effects of vertical wind shear and buoyancy on convective storm structure and evolution were investigated with the use of a three-dimensional numerical cloud model, by varying the magnitude of buoyant energy and one-directional vertical shear over a wide range of environmental conditions associated with severe storms.
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Richard Rotunno,Kerry Emanuel +1 more
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TL;DR: In this paper, the authors describe the two different kinds of downdraft air frequently observed to the rear of some low-latitude squall lines at low levels, and the lowest layer is hypothesized to be the product of convective-scale saturated downdavs and the drier air is the result of mesoscale unsaturated downdvings as described by Zipser.
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