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The T-REX experiment

The T-REX experiment. Ralph Burton 1 , Stephen Mobbs 1 , Barbara Brooks 1. Harold Klieforth 2 , Martin Hill 1. 1 IAS 2 Desert Research Institute, Reno NV. 1. Motivation. 2. Rotors: brief overview. 3. T-REX. From. “ Hazardous Mountain Winds and their Visual Indicators ”

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The T-REX experiment

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  1. The T-REX experiment Ralph Burton1, Stephen Mobbs1, Barbara Brooks1 Harold Klieforth2, Martin Hill1 1 IAS 2 Desert Research Institute, Reno NV

  2. 1. Motivation. 2. Rotors: brief overview. 3. T-REX.

  3. From “Hazardous Mountain Winds and their Visual Indicators” Federal Aviation Authority, U.S.Dept. of Transportation, 1988

  4. Accidents not limited to one operating altitude, • or time of year, or specific type of aircraft • In many cases, other aircraft operating in the • vicinity of the accident encountered only weak • turbulence severe wind events can be highly localised, violent, and short-lived

  5. From “Hazardous Mountain Winds and their Visual Indicators”, 1988 Accident rate 40% higher in the 11 mountain states Accident rate less than 3 per 100,000 Accident rate greater than 3 per 100,000

  6. DEM of the U.S. showing regions of elevated terrain

  7. From http://adds.aviationweather.gov

  8. From http://adds.aviationweather.gov

  9. Extensive mountain obscuration For aviation weather reports, see http://adds.aviationweather.gov

  10. Owens (dry) lake • Probably the largest single source of • PM10 dust in the United States • Dust plumes tracked to 3000m AGL, • 100 km north of the lake • Affects visibility and vegetation • in many neighbouring wilderness • areas • Dust storms regularly cause • suspension of operations at • China Lake Naval Weapons Center From Reheis (1997) See geochange.er.usgs.gov/sw/impacts/geology/owens

  11. Sierra wave Project (1950s) W I Looking South from 9800m/32000ft

  12. Sierra Wave Project (1950s) Flight of Feb. 16th 1952 From Holmboe and Klieforth 1957

  13. A: Type 1 rotor B: Type 2 rotor From Kuettner (1959)

  14. Maximum rates of climb Cessna 172: 720 ft/min Ibis aerospace 270: 1791 ft/min Boeing Chinook: 1840 ft/min

  15. Sierra Wave Project (1950s) Flight of Feb. 16th 1952 W=-31ft/s w=+41ft/s From Holmboe and Klieforth 1957

  16. Rotor: -1860ft/min Maximum rates of climb Cessna 172: 720 ft/min Net downward Net downward Ibis aerospace 270: 1791 ft/min Net downward Boeing Chinook: 1840 ft/min

  17. “Type 1” rotor

  18. “Type 2” rotor

  19. “Inversion effects on mountain lee waves” Vosper, QJR 2003 Inversion height Wind constant with height

  20. Regime diagram BLASIUS; idealised ridge H = hill height zi = inversion height; Fi = U/(g’zi)1/2 g’ = g/0 U = background wind

  21. H/Zi > 0.3 Consider u=10 ms-1 surf temp = 200C, Zi = 3600m, then we have U2 ~ 45 gives  ~ 2K

  22. Climatology of wave events Based upon satellite imagery, 1km resolution, 15 minute intervals (visible channel) From Grubišić, T-REX proposal

  23. Oct 29th 2000 GOES -Vis From Doyle and Durran (2004)

  24. Regime diagram “Inversion effects on mountain lee waves” Vosper, QJR 2003 29/10/2000

  25. Doyle and Durran (2004) Coupled Ocean-Atmospheric Mesoscale Prediction System (COAMPS) • Fully 3-d simulation using 5 nested grids, finest resolution x=333m • Fully compressible, nonhydrostatic • Mixing length scheme • Terrain-following coordinates

  26. Doyle and Durran (2004)

  27. Doyle and Durran (2004)

  28. T-REX The biggest field campaign ever mounted to study rotors/gravity waves ARL White Sands Missile Range Scripps Institute of Oceanography Colorado Research Associates Cooperative Research in Environmental Science Desert Research Institute DLR Lawrence Livermore National Laboratory UK Met Office NASA NCAR Naval Research Laboratory NOAA Arizona State University Colorado State University Harvard University University of Houston University of Innsbruck University of Leeds University of New Hampshire North Carolina State University Stanford University University of Utah Yale University

  29. Location of field campaign

  30. Masts currently installed in the Owens Valley (DRI) See www.wrcc.dri.edu/trex

  31. Roll cloud observed over the Owens Valley, April 2004 Photo by James Pinto

  32. Roll cloud over Owens Valley March 24 2004 From Grubišić and Cohn (2004)

  33. T-REX Phase I From Grubišić and Kuettner (2004) From Grubišić and Cohn (2004)

  34. Location of proposed Leeds masts National Forest Service Inyo Valley Dept. of Water Resources Sierra Bureau of Land Management

  35. Lower Sierra station site

  36. Valley station site

  37. Inyo station site

  38. Sonic anemometer Temperature sensors GPS aerial Solar panel Logger box Batteries

  39. T-REX IOP: March – April 2006 • At least 28 10m towers • Wind profilers • Lidars • Radiosondes • NCAR Gulfstream • Univ. of Wyoming King Air • FAAM BAe146 • 50 temperature loggers • 3 x 30m flux towers • Univ. Innsbruck mobile • met system • …

  40. T-REX Phase II Map: V. Grubišić in collaboration with the UCAR Joint Office of Scientific Support

  41. T-REX Phase II Typical flight plans Schematic: V. Grubišić and J. Doyle

  42. Rotors – some key scientific questions Climatology: - frequency,preferred location Dynamics • to establish the conditions required • for the formation of rotors Modelling - Ability of current models to predict the occurrence of rotor events - Model validation

  43. Summary Rotors pose a severe aviation hazard and have been cited as being responsible for several major accidents. Still poorly understood. • Preparations in place for the most comprehensive • field campaign to study rotors/lee waves ever made, • using AWS, lidars, aircraft, flux towers, … • Permissions granted for installation of a further 12 • 10m towers: deployment early 2005 • Phase I completed; some case studies already being • undertaken in the US

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