1 Joe Werne Colorado Research Associates Division NorthWest Research Associates, Inc. 3380 Mitchell...

1

Joe Werne

Colorado Research Associates Division

NorthWest Research Associates, Inc.

3380 Mitchell Lane

Boulder, CO 80301

[email protected]

303-415-9701 x 207

26 September 2005

Validation Information for DNS Solutions

mailto:[email protected]

= 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



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



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

CT2 RiT



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.

1 Joe Werne Colorado Research Associates Division NorthWest Research Associates, Inc. 3380 Mitchell...

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