tropical cyclone intensificationroger/tclecs/...anthes (rev. geophys. 1974): the dynamics and...
TRANSCRIPT
![Page 1: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/1.jpg)
Tropical Cyclone Intensification
![Page 2: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/2.jpg)
CISK (Charney and Eliassen 1964)
Cooperative Intensification Theory (Ooyama 1969).
WISHE (Emanuel 1986 … , Holton and Hakim, 2012)
Vortical deep convection paradigm whose mean field view provides an extended Cooperative Intensification Theory
Theories for tropical cyclone intensification and structure
To appear in The Bruce Morton Memorial Volume of the Australian Meteorological and Oceanographical Society Journal
http://www.meteo.physik.uni-muenchen.de/~roger/Publications/M8.pdf
![Page 3: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/3.jpg)
Schematic cross-section through a hurricane
CirrusCirrus
Eye
Spiral bandsEyewall
![Page 4: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/4.jpg)
r
v
Lowest pressure in the centre
Rotation axis
Pressure gradient force
Centrifugal forceand
Coriolis force2v 1 pfv
r r
Gradient wind balance
Primary (tangential)circulation
Force balance in a vortex
![Page 5: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/5.jpg)
Are the eyewall clouds buoyant?
Eye is the warmest place in the storm
See Smith, Montgomery and Zhu (2005) Dyn. Atmos & Oceans
![Page 6: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/6.jpg)
Have to consider generalized buoyancy!
g
ge
2v fvr
p = constant
pref ref
refe
( )
g
2
ev fv, gr
gz
r
g
ge
2v fvr
p = constant
pref ref
refe
( )
g
2
ev fv, gr
gz
r
![Page 7: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/7.jpg)
A simple example: steady two-dimensional boundary layer on a flat plate at normal incidence to an almost parallel stream U(x).
z
x
U(x) boundary layer
Boundary layers in nonrotating fluids
U(x)
u(x,z) < U(x)
![Page 8: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/8.jpg)
V
Pressuregradient
force
Centrifugal force and Coriolis force reduced by friction
v
Secondary circulation
Frictionally-induced secondary circulation
Boundary layer
V(r)
r
21 p v fvr r
![Page 9: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/9.jpg)
![Page 10: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/10.jpg)
Basic principle: conservation of absolute angular momentum:
r
v
If r decreases, v increases!
Spin up requires radial convergence
Tropical cyclone intensification
212M rv fr
12
Mv frr
M
M
![Page 11: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/11.jpg)
wz
0
wz
0
Boundary layer Level of non-divergence
V
Vertical cross section
Dynamics of vortex spin down
Vt
![Page 12: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/12.jpg)
V
C
A
The secondary, or in-up-out, circulation
Vds dAC A
ds
secondarycirculation
secondarycirculation
![Page 13: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/13.jpg)
![Page 14: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/14.jpg)
15
10
5
0 50 100r km
M conserved
M not conserved, inflow feeds the clouds with moisture
M 1v frr 2
z k
mThermally-forced secondary circulation leads to spin up
Conventional view of intensification: axisymmetric
Is that it?
![Page 15: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/15.jpg)
The basic thought experiment for TC intensification
sea
rV(r,z)
Initial condition
p(z)T(z)q(z)
Axisymmetric vortex
Mean sounding
27oC
Nguyen, Smith and Montgomery calculation, QJRMS, 2008: Idealized numerical model simulations, simple physics, MM5 5 km (1.67 km) resolution in the finest nest, 24 -levels
![Page 16: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/16.jpg)
![Page 17: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/17.jpg)
Vertical velocity\vorticity pattern at 24 h
850 mb ~ 1.5 km 850 mb
Vertical velocity Relative vorticityFrom Nguyen, Smith and Montgomery, QJ, 2008
![Page 18: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/18.jpg)
Movie
![Page 19: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/19.jpg)
From Montgomery, Nguyen & Smith (2009): QJRMS
![Page 20: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/20.jpg)
From Montgomery, Nguyen & Smith (2009): QJRMS
![Page 21: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/21.jpg)
From Montgomery, Nguyen & Smith (2009): QJRMS
![Page 22: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/22.jpg)
Movie Time-height sequence of Absolute Angular Momentum
21M rv fr2
M 1v frr 2
![Page 23: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/23.jpg)
Movie
![Page 24: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/24.jpg)
15
10
5
0 50 100r km
z k
mRevised view : two spin-up mechanisms
M conserved
M 1v frr 2
M reduced by friction, butstrong convergence small r large v
![Page 25: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/25.jpg)
A surprise
The maximum wind speed in the boundary layer canexceed that above the boundary layer.
• An unusual in feature boundary layers in general.
• A special feature of the termination boundary layerof intense vortices.
Anthes (1972):
• Inward increase of V due to large radialdisplacements in the boundary layer with partialconservation of AAM opposes the fictional loss ofAAM to the surface.
![Page 26: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/26.jpg)
Emanuel (JAS 1986) : An air-sea interaction theory for tropical cyclones. Part I: Steady state maintenance.
Wirth & Dunkerton (JAS 2006): A unified perspective on the dynamics of axisymmetric hurricanes and monsoons.
Hakim (JAS 2011): The mean state of axisymmetric hurricanes in statistical equilibrium.
Some steady theories/models
Questions
What would be the requirements for a (globally) steady-state hurricane to exist?
Do the foregoing theories/formulations satisfy such conditions?
![Page 27: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/27.jpg)
Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones.
For a tropical cyclone to achieve a steady state, there would have to be an input of cyclonic relative angular momentum to replenish that lost by friction to the sea surface.
Carrier et al. (JFM 1971): A model of the mature hurricane.
A hurricane could last about 30 days before it used up its angular momentum.
Angular momentum considerations
![Page 28: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/28.jpg)
M satisfies
Absolute angular momentum
Steady flow, no diffusion or eddies:
![Page 29: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/29.jpg)
Continuity
Flux form
![Page 30: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/30.jpg)
Integrate the flux form for the steady state:
Advective flux through r = R
Diffusion at z = 0
Eddy and diffusive flux flux through r = R
0 R0
H
![Page 31: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/31.jpg)
The basic thought experiment for intensification
sea
rV(r,z)
Initial condition
p(z)T(z)q(z)
Axisymmetric vortex
Mean sounding
26oC
Persing, Montgomery, McWilliams, Smith, Atm. Chem. Phys. 2013: Idealized numerical model simulations, simple physics, CM1 3 km horizontal grid spacing, 24 -levels
![Page 32: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/32.jpg)
Evolution in intensity
![Page 33: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/33.jpg)
Azimuthal mean tangential wind component
![Page 34: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/34.jpg)
The overturning circulation
![Page 35: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/35.jpg)
Radius-time plots of v and M at 1.5 km
v M
![Page 36: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/36.jpg)
Radius-time plots of v and M at 12 km
v M
![Page 37: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/37.jpg)
Evolution in intensity at 12 km
cyclone
anticyclone
![Page 38: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/38.jpg)
M surfaces
![Page 39: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/39.jpg)
RAM surfaces
![Page 40: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/40.jpg)
RAM surfaces
![Page 41: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/41.jpg)
M tendencies
![Page 42: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/42.jpg)
M tendencies
![Page 43: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/43.jpg)
Integrated RAM / Integrated RAM(t = 0)
cyclonic
anticyclonic
![Page 44: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/44.jpg)
Integrated KE / Integrated KE(t = 0)
cyclonic
anticyclonic
![Page 45: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/45.jpg)
The Emanuel (1986) steady model
![Page 46: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/46.jpg)
Summary 1: thermodynamic requirements for a steady state
Moisture fluxes
rain
Subsidence, radiative cooling, dry
u
e conserved
![Page 47: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/47.jpg)
Summary 2: dynamic requirements for a steady state
Loss of cyclonic AM Gain of cyclonic AM?
Eddy flux of cyclonic AM
![Page 48: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/48.jpg)
Thank you
See: http://www.meteo.physik.uni-muenchen.de/~roger/Publications/M16.pdf
![Page 49: Tropical Cyclone Intensificationroger/TCLecs/...Anthes (Rev. Geophys. 1974): The dynamics and energetics of mature tropical cyclones. For a tropical cyclone to achieve a steady state,](https://reader034.vdocuments.us/reader034/viewer/2022050110/5f47bd39eb1fe96e31603b39/html5/thumbnails/49.jpg)