• Banta, R. M., L. D. Olivier, W. D. Neff, D. H. Levinson, and D. Ruffieux, 1995: Influence of canyon-induced flows on flow and dispersion over adjacent plains. Theor. Appl. Climatol., 52, 2741.

    • Search Google Scholar
    • Export Citation
  • Cramer, P., 1972: Potential temperature analysis for mountainous terrain. J. Appl. Meteor., 11, 4450.

  • Darby, L. S., and R. M. Banta, 2006: The modulation of canyon flows by larger-scale influences. Preprints, 12th Conf Mountain Meteorology, Santa Fe, NM. Amer. Meteor. Soc., 14.4. [Available online at https://ams.confex.com/ams/pdfpapers/114383.pdf.]

  • Lackmann, G. M., and J. E. Overland, 1989: Atmospheric structure and momentum balance during a gap wind event in Shelikof Strait, Alaska. Mon. Wea. Rev., 117, 18171833.

    • Search Google Scholar
    • Export Citation
  • Mass, C. F., S. Businger, M. D. Albright, and Z. A. Tucker, 1995: A windstorm in the lee of a gap in a coastal mountain barrier. Mon. Wea. Rev., 123, 315331.

    • Search Google Scholar
    • Export Citation
  • Mayr, G. J., and Coauthors, 2007: Gap flows: Results from the Mesoscale Alpine Programme. Quart. J. Roy. Meteor. Soc., 133, 881896.

  • Overland, J. E., and B. A. Walter Jr., 1981: Gap winds in the Strait of Juan de Fuca. Mon. Wea. Rev., 109, 22212227.

  • Pamperin, H., and G. Stilke, 1985: Nächtliche Grenzschicht und LLJ im Alpenvorland nahe dem Inntalausgang (Nocturnal boundary layer and low-level jet near the Inn Valley exit). Meteor. Rundsch., 38, 145156.

    • Search Google Scholar
    • Export Citation
  • Poulos, G. S., and S. Zhong, 2008: The observational history of small-scale katabatic winds in mid-latitudes. Geogr. Compass, 2, 17981821.

    • Search Google Scholar
    • Export Citation
  • Sharp, J., and C. F. Mass, 2002: Columbia Gorge gap flow: Insights from observational analysis and ultra-high-resolution simulation. Bull. Amer. Meteor. Soc., 83, 17571762.

    • Search Google Scholar
    • Export Citation
  • Sharp, J., and C. F. Mass, 2004: Columbia Gorge gap winds: Their climatological influence and synoptic evolution. Wea. Forecasting, 19, 970992.

    • Search Google Scholar
    • Export Citation
  • Stilke, G., 1984: Nocturnal boundary layer and low-level jet in the pre-Alpine region near the outlet of the Inn Valley. Proc. 18th Int. Conf. on Alpine Meteorology, Opatija, Germany, ICAM, 68–71.

  • Whiteman, C. D., 1990: Observations of thermally developed wind systems in mountainous terrain. Atmospheric Processes over Complex Terrain, Meteor. Monogr., No. 45. Amer. Meteor. Soc., 5–42.

  • Whiteman, C. D., 2000: Mountain Meteorology: Fundamentals and Applications. Oxford University Press, 355 pp.

  • Wilkerson, T. D., A. B. Marchant, and T. J. Apedaile, 2012: Wind field characterization from the trajectories of small balloons. J. Atmos. Oceanic Technol., 29, 12361249.

    • Search Google Scholar
    • Export Citation
  • Zängl, G., 2004: A reexamination of the valley wind system in the Alpine Inn Valley with numerical simulations. Meteor. Atmos. Phys., 87, 241256.

    • Search Google Scholar
    • Export Citation
  • Zardi, D., and C. D. Whiteman, 2012: Diurnal mountain wind systems. Mountain Weather Research and Forecasting, F. K. Chow, S. F. J. DeWekker, and B. Snyder Eds., Springer, 35–119.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 238 92 3
PDF Downloads 201 71 8

Observations of Thermally Driven Wind Jets at the Exit of Weber Canyon, Utah

View More View Less
  • 1 University of Utah, Salt Lake City, Utah
Restricted access

Abstract

Thermally driven valley-exit jets were investigated at Utah’s Weber Canyon, a main tributary of the Great Salt Lake basin. An intensive measurement campaign during July–September 2010 supplemented longer-term measurements to characterize the wind and temperature structure in the vicinity of the canyon exit. Exit jets at Weber Canyon are most frequent in late summer or early fall. Strong low-level-wind jets formed at the canyon exit on 75 of 90 nights (83%) during the measurement campaign, with the best-developed winds forming during synoptically undisturbed, clear-sky periods. Winds inside the canyon consisted of a weak down-valley flow layer that occupied most of the 1000-m depth of the canyon. The flow was observed to descend, thin, and accelerate at the valley exit, producing winds that were typically 2.5 times as strong but much more shallow than those inside the canyon. Maximum nighttime jet-axis wind speeds of 15–20 m s−1 are typically found about 80–120 m above the ground at the canyon exit on clear undisturbed nights in the late summer and fall. The jets form 1–3 h after sunset, approach a near-steady state during the late night, and continue until 5–6 h after sunrise, although slowly losing speed after sunrise. The jet is a local modification at the canyon exit of the thermally driven down-valley flow. Its continuation after sunrise is thought to be caused by the nighttime buildup and persistence of a cold-air pool in the Morgan Basin at the east end of the canyon. The potential for utilizing the exit jet for wind power generation is discussed.

Current affiliation: Hatch Associates Consultants, Inc., 933 S. Edison St., Salt Lake City, UT 84111.

Corresponding author address: Morgan F. Chrust, Dept. of Atmospheric Sciences, University of Utah, Rm. 819, 135 S 1460 E, Salt Lake City, UT 84112-0110. E-mail: morgan.farley-chrust@utah.edu

Abstract

Thermally driven valley-exit jets were investigated at Utah’s Weber Canyon, a main tributary of the Great Salt Lake basin. An intensive measurement campaign during July–September 2010 supplemented longer-term measurements to characterize the wind and temperature structure in the vicinity of the canyon exit. Exit jets at Weber Canyon are most frequent in late summer or early fall. Strong low-level-wind jets formed at the canyon exit on 75 of 90 nights (83%) during the measurement campaign, with the best-developed winds forming during synoptically undisturbed, clear-sky periods. Winds inside the canyon consisted of a weak down-valley flow layer that occupied most of the 1000-m depth of the canyon. The flow was observed to descend, thin, and accelerate at the valley exit, producing winds that were typically 2.5 times as strong but much more shallow than those inside the canyon. Maximum nighttime jet-axis wind speeds of 15–20 m s−1 are typically found about 80–120 m above the ground at the canyon exit on clear undisturbed nights in the late summer and fall. The jets form 1–3 h after sunset, approach a near-steady state during the late night, and continue until 5–6 h after sunrise, although slowly losing speed after sunrise. The jet is a local modification at the canyon exit of the thermally driven down-valley flow. Its continuation after sunrise is thought to be caused by the nighttime buildup and persistence of a cold-air pool in the Morgan Basin at the east end of the canyon. The potential for utilizing the exit jet for wind power generation is discussed.

Current affiliation: Hatch Associates Consultants, Inc., 933 S. Edison St., Salt Lake City, UT 84111.

Corresponding author address: Morgan F. Chrust, Dept. of Atmospheric Sciences, University of Utah, Rm. 819, 135 S 1460 E, Salt Lake City, UT 84112-0110. E-mail: morgan.farley-chrust@utah.edu
Save