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Moore, Oklahoma May 20, 2013. Shawnee/. MPEX Mobile Soundings 19 May 2013. CSU 21 UTC. CSU 19 UTC. CSU 23 UTC. WRF OUN 19 UTC. WRF OUN 23 UTC. WRF OUN 00 UTC. Trier et al. MWR 2015. Ensemble-analyzed circulation along dry line: 19 May 2013. Supercells. MICRO-. PHYSICS.
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Moore, Oklahoma May 20, 2013 Shawnee/
MPEX Mobile Soundings 19 May 2013 CSU 21 UTC CSU 19 UTC CSU 23 UTC WRF OUN 19 UTC WRF OUN 23 UTC WRF OUN 00 UTC
Trier et al. MWR 2015 Ensemble-analyzed circulation along dry line: 19 May 2013
MICRO- PHYSICS
Physical processes controlling cell types: • Buoyancy processes: basic updraft/downdraft, (ordinary cells) • Gust front processes: triggering of new cells, upscale growth, (multicells) • Dynamic processes: rotating updraft, dynamic vertical pressure gradient forcing, (supercells)
Physical processes controlling cell types: • Buoyancy processes: basic updraft/downdraft, (ordinary cells) • Gust front processes: triggering of new cells, upscale growth, (multicells) • Dynamic processes: rotating updraft, dynamic vertical pressure gradient forcing, (supercells)
Momentum Eq. Dynamic Pressure Eq. --
Linearise pressure eq. about U(z), V(z) (environmental vertical wind shear) So, since
Vorticity Equation: Vertical Vorticity: tilting stretching
Vortex Tube Circulation:
Theorems for inviscid fluids with conservative external forces (e.g., no baroclinicity, buoyancy) (Helmholtz, 1858) ….Vortex lines (tubes) are material lines that are frozen into the fluid. ….The circulation (strength) of a vortex tube is invariant …The circulation on any curve around a vortex tube is constant along the tube.
Tilting: Linearized about a mean vertical wind shear:
Vertical Momentum Eq. (rewritten) (dynamic) + (buoyancy)
(H = horizontal shearing deformation) So, for a wind profile in pure rotation: So, again, since
Supercell Hodographs: Supercell processes are Galilean invariant!!!
Linearise pressure eq. about U(z), V(z) (environmental vertical wind shear) So, since