1 joe werne colorado research associates division northwest research associates, inc. 3380 mitchell...
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Joe Werne
Colorado Research Associates Division
NorthWest Research Associates, Inc.
3380 Mitchell Lane
Boulder, CO 80301
werne@cora.nwra.com
303-415-9701 x 207
26 September 2005
Validation Information for DNS Solutions
= Experiment
= Simulation
Universal Symbols
Wind shear: Balloon Comparison
Chen, Kelley, Gibson-Wilde, Werne & Beland, Annales Geophysicae, 2001
Mixing Layers through the Troposphere and Stratosphere
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Ierkic, Woodman & Perillat, Radio Science 25, 941 (1990)
Radar Backscatter
Re ~ 106-107
120 m
U.S. Air Force anemometry data
also, Michael Roggeman, private communication, 2001
Bruce Masson, 1996
β=Φ kC124.0)k( 2n
2nC β
Fort Collins Photo
Colorado Springs, Colorado, 2000 (photo by Tye Parzybok)
Denver Photo
Denver, Colorado, 1953 (photo by Paul E. Branstine)
Estes Park, 1979
Estes Park, Colorado, 1979 (photo by Bob Perney)
Joe’s Back Yard
Lafayette, Colorado, 2002 (photo by Joe Werne)
DNS computed solutions
Kelvin-Helmholtz
Viscous & Thermal Dissipation
CT2 fits from DNS
2nd-order structure-function fits
Werne & Fritts, 2000
Exponent between 2/5 and 2/3
Systematic dependence in x.
CT2 = 3.3 ε-1/3 χ
l0 = 7.4 lK
α=Δ rCT2r
α
2UC
ol
CU2 fits from DNS
α=Δ rCU2r
2nd-order structure-function fits
Werne & Fritts, 2000
α
2UC
ol
Exponent between 2/5 and 2/3
CU2 = 2.1 ε2/3
l0 = 11.3 lK l0 = 8.0 lK
We have also computed structure-function fits for
V and W, but until recently data were not available.
Wroblewski, Cote, Hacker, Crawford, 2002
Comparison with Egrett
2nd-order structure-function fits
Werne & Fritts, 2000
Wroblewski, Cote, Hacker, Crawford, 2002
CV2/CU
2 CW2/CU
2 CU2/CT
2 CW2/CT
2
z, altitude (km)
CU2, CV
2, CW2, CT
2, exponents, inner scale all consistent with measurements.
CU2, CV
2, CW2, CT
2, exponents, inner scale all consistent with measurements.
Peak-to-midlayer ratios
Kelvin-Helmholtz: Balloon Comparison
Chen, Kelley, Gibson-Wilde, Werne & Beland, Annales Geophysicae, 2001
CT2 fits, continuous in time
α
CT2
T Structure Function Fits Werne, Meyer, Bizon & Fritts, 2002
lo
time
z
time
x y
Combine Simulation and Observation for an operational path
Combine Simulation and Observation for an operational path
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Combine Simulation and Observation for an operational path
Combine Simulation and Observation for an operational path
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Combine Simulation and Observation for an operational path
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Combine Simulation and Observation for an operational path
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Combine Simulation and Observation for an operational path
CT2 RiT
Coulman, Vernin & Fuchs, Applied Optics 34 5461 (1995)
Combine Simulation and Observation for an operational path
Conclusions
1. Stratification restricts mixing dynamics to vertically confined regions.
2. Entrainment zones maintain sharp thermal gradients that dominate optical effects.
3. Mixing in the interior of turbulent layers reduces thermal gradients.
4. Mixing zones in wind-shear simulations duplicate morphology exhibited by cloud observations.
5. Potential-temperature profiles, duration, CT2 profiles, and Ri
profiles agree with balloon measurements.
6. Turbulence constants Cθ and C (relating χ and Є to CT2 and CU
2) and CV
2/CU2 and CW
2/CU2 obtained from comparison with the middle of a
simulated shear layer agree with atmospheric measurements, as do the spectral slope and inner scale.
7. Entrainment zones are non-stationary, inhomogeneous, and anisotropic; unfortunately they also have the greatest impact on optical propagation.
8. Dynamic SGS is promising for stable stratification, but systematic dependence on filter width limits generality of method.
9. Improved modeling is required for further progress with LES. This is in progress.
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