TITLE

Doppler Radar Observations of Dust Devils in Texas

AUTHOR(S)
Bluestein, Howard B.; Weiss, Christopher C.; Pazmany, Andrew L.
PUB. DATE
January 2004
SOURCE
Monthly Weather Review;Jan2004, Vol. 132 Issue 1, p209
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Analyses of a dust-devil dataset collected in northwest Texas are presented. The data were collected just above the ground at close range with a mobile, W-band (3-mm wavelength) Doppler radar having an azimuthal (radial) resolution of 3–5 m (30 m) at the range of the dust devils. Most dust devils appeared as quasi-circular rings of relatively high radar reflectivity. Four dust-devil vortices were probed, three of which were cyclonic and one anticyclonic. Documentation was obtained of a pair of adjacent cyclonic vortices rotating cyclonically around each other. Approximate radial profiles of azimuthal and radial wind components and of radar reflectivity are detailed and discussed. The diameters of the core of the dust devils ranged from 30 to 130 m; the latter diameters are much wider than that of typical dust devils in a homogeneous environment. The widest vortex was cyclonic and exhibited evidence of a two-cell structure (i.e., sinking motion near the center and rising motion just outside the radius of maximum wind), a broad, calm eye, and an annulus of maximum vorticity just inside the radius of maximum wind. As the vortex widened, it developed an asymmetry, and some evidence was found that two waves propagated cyclonically around it. The narrowest dust devil had the structure of a Rankine combined vortex, that is, a central core of constant vorticity surrounded by potential flow. Owing to very strong radial shear of the azimuthal wind, the vorticity in the dust-devil cores ranged from 0.5 to 1 s[sup -1] , which is as high as the vorticity in some tornadoes. However, the maximum ground-relative wind speeds in each dust devil were only 6.5–13.5 m s[sup -1] . The location of the highest radar reflectivity was located at or within the radius of maximum wind. In the widest dust devil, the vorticity estimated from the Doppler shear associated with its vortex signature was much less than the smaller-scale vorticity ring estimated from the azimuthal wind profile. It is therefore suggested that the vorticity estimated from the Doppler shear in tornadoes may be underestimated significantly when the tornado vortex exhibits a two-cell structure and that Doppler shear alone may not be a good indicator of vortex intensity.
ACCESSION #
11912148

 

Related Articles

  • A New Parametric Model of Vortex Tangential-Wind Profiles: Development, Testing, and Verification. Wood, Vincent T.; White, Luther W. // Journal of the Atmospheric Sciences;May2011, Vol. 68 Issue 5, p990 

    A new parametric model of vortex tangential-wind profiles is presented that is primarily designed to depict realistic-looking tangential wind profiles such as those in intense atmospheric vortices arising in dust devils, waterspouts, tornadoes, mesocyclones, and tropical cyclones. The profile...

  • The Little Twisters' Impact: Dust Devils on Mars. Carr, James R. // Mercury;Mar/Apr2000, Vol. 29 Issue 2, p11 

    Focuses on the physics of dust devil formation. Dust devil formation on Earth; Dust devil formation on Mars; Reasons dust devil is often considered as an irritant.

  • Validation of the Saharan Dust plume conceptual model using lidar, meteosat and ECMWF data. Karyampudi, V. Mohan; Palm, Stephen P. // Bulletin of the American Meteorological Society;Jun99, Vol. 80 Issue 6, p1045 

    Presents a detailed synoptic analysis of the September 16 to 19, 1994 Saharan dust outbreak over the eastern Atlantic and its origin at over West Africa during the September 12 to 15 period. Satellite-derived optical depths of the incident; Analysis of vertical lidar backscattering cross...

  • NATURAL EXPOSURE.  // Australian Geographic;Oct-Dec99, Issue 56, p20 

    Presents a photograph of a whirlwind taken by John Rickertt in Queensland.

  • BLOWIN' IN THE WIND. COLEMAN, CHERYL // Outdoor Life;Nov2012, Vol. 219 Issue 11, p12 

    A personal narrative is presented which explores the author's experience of getting caught in a dust devil during one of her hunting trips.

  • Dust Devil in Mars.  // News 'n' More;Jun2012, Vol. 5 Issue 6, p22 

    The article focuses on the occurrence of a Martian dust devil on March 14, 2012, which was photographed by a High Resolution Imaging Science Experiment camera on board a National Aeronautics and Space Administration (NASA) spacecraft.

  • Dust Devil Shocker! O'Meara, Stephen James // Odyssey;Nov2007, Vol. 16 Issue 8, p2 

    The article presents information on the dust devils that usually occur in the mid- or southwestern U.S.

  • Weather Whys.  // Lakelander (Whitney, TX);7/15/2015, Vol. 28 Issue 27, p6 

    The article presents questions and answers regarding a dust devil or a swirling wind.

  • Books for the Western library. Tracey, Patricia Cleveland // Journal of the West;Oct99, Vol. 38 Issue 4, p115 

    Reviews the book `Dust Devils,' by Robert Laxalt.

Share

Read the Article

Courtesy of NEW JERSEY STATE LIBRARY

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics