Atmospheric Turbulence Research at WVU

This material is based upon work supported by the National Science Foundation.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Lewellen, D. C., W. S. Lewellen.  "Near-Surface Intensification of Tornado Vortices".  J. Atmos. Sci., 64:2176-2194, 2007.
PDF Version (2260k)

Lewellen, D. C., W. S. Lewellen.  "Near-Surface Vortex Intensification Through Corner Flow Collapse".  J. Atmos. Sci., 64:2195-2209, 2007.
PDF Version (1760k)

Lewellen, D. C., W. S. Lewellen.  "On the Limits to Near-Surface Intensification of Tornado Vortices". In Preprints, 23rd Conference on Severe Local Storms, paper 13.5, 5pp., St. Louis, MO, Nov. 6--10, 2006.  Amer. Meteor. Soc.  
PDF Version (359k)

Gong, B., D. C. Lewellen, W. S. Lewellen.  "Effects of Fine-Scale Debris on Different Tornado Corner Flows". In Preprints, 23rd Conference on Severe Local Storms, paper P10.3, 5pp., St. Louis, MO, Nov. 6--10, 2006.  Amer. Meteor. Soc.
PDF Version (1009k)

Lewellen, D. C., B. Gong, W. S. Lewellen.  "Effects of Debris on Near-Surface Tornado Dynamics".  In Preprints, 22th Conference on Severe Local Storms, paper 15.5, 5pp., Hyannis, MA, Oct. 4-8, 2004.  Amer. Meteor. Soc.
PDF Version (410k)

Xia, J., W. S. Lewellen. and D.C. Lewellen,  "Influence of Mach Number on Tornado Corner Flow Dynamics",  J. Atmos. Sci., 60:2820-2825, 2003
PDF Version (260k)

D. C. Lewellen, W. S. Lewellen, and J. Xia. "The Influence of a Local Swirl Ratio on Tornado Intensification near the Surface",  J. Atmos. Sci., 57:527-544, 2000.
PDF Version (635k)

Lewellen, D.C., and W. S. Lewellen,  "Near-Surface Intensification During Unsteady Tornado Evolution", paper for presentation at the AMS 21st Conference on Severe Local Storms.
PDF Version (199k)

Lewellen, W.S., J. Xia and D.C. Lewellen, "Transonic Velocities in Tornadoes?",  paper for presentation at the AMS 21st Conference on Severe Local Storms.
PDF Version (205k)

Lewellen, W.S., J. Xia and D.C. Lewellen, "Nonaxisymmetric, Unsteady Tornadic Corner Flows",  paper for presentation at the AMS 20th Conference on Severe Local Storms, Orlando, FL, Sept. 2000.
HTML Version
PDF Version (336k)
Compressed Postscript Version (259k)

D. C. Lewellen,  W. S. Lewellen, and J. Xia,  "Importance of Surface Layer Inflow to Tornado Vortex Intensity", paper for presentation at the AMS 19th Conference on Severe Local Storms, Minneapolis, MN, Sept. 1998.
PDF Version (212k)
Compressed Postscript Version (538k)

Lewellen W. S.,  D.C. Lewellen and R.I. Sykes,  "Large-Eddy Simulation of a Tornado's Interaction with the Surface",  J. Atmos. Sci. , 54:581-605, 1997.
PDF Version (3596k)

Simulated medium swirl "F4" tornado translating at 15m/s into a field of 1mm "sand" showing growth of debris cloud(16M mpeg file)

• Alternate view with initial closeup(14M mpeg file)
• Wireframe isosurfaces of constant perturbation pressure and debris loading showing weakening of the tornado vortex with the growth of the debris cloud(10M mpeg file)

Videos and Slides presented at the AMS 22nd Conference on Severe Local Storms, Hyannis, MA, Oct. 2004

• Presentation Slides (1M pdf file)
• Translating Tornado with Debris(5M mpeg file)

Videos presented at the AMS 20th Conference on Severe Local Storms, Orlando, FL, Sept. 2000

• Time varying corner flow, vertical slice (3M mpeg file)
• Time varying corner flow (5M mpeg file)

Other Videos

• Dynamic pressure, medium swirl (4M mpeg file)
• Dynamic pressure, high swirl (5M mpeg file)
• High swirl with central downflow (2M mpeg file)
• Medium swirl (2M mpeg file)

Low Swirl Results

• U, 250m x 250m domain
• V, 250m x 250m domain
• W, 250m x 250m domain
• Dynamic pressure, 150m domain

Medium Swirl Results

Without Translation

• U, 400m x 400m domain
• V, 400m x 400m domain
• W, 400m x 400m domain

With 15 m/s Translation

• W, 1km x 2km domain
• V, 400m x 400m domain
• W, 400m x 400m domain
• W and pressure at 40m height, 200m x 200m domain
• Pressure, 300m domain

High Swirl Results

• V, constant convergence, 600m domain
• W, constant convergence, 600m domain

With central down draft

• U, 600m domain
• V, 600m domain
• W, 600m domain
• W and pressure at 50m height, 200m domain
• Pressure, 300m domain

With central down draft and translation

• V, 600m domain
• W, 600m domain
• W and pressure at 50m height, 200m domain