Editorial Type:
Article
Article Type:
Research Article

Observations of Convective Thermals with Weather Radar

Valery Melnikov Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, and NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma

Search for other papers by Valery Melnikov in
Current site
Google Scholar
PubMed Close
and
Dusan S. Zrnić NOAA/OAR/National Severe Storms Laboratory, Norman, Oklahoma

Search for other papers by Dusan S. Zrnić in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Jul 2017
DOI:
https://doi.org/10.1175/JTECH-D-17-0068.1
Page(s):
1585–1590
Restricted access

Abstract

It is shown that the NEXRAD weather radar with enhanced detectability is capable of observing the evolution of convective thermals. The fields of radar differential reflectivity show that the upper parts of the thermals are observable due to Bragg scatter, whereas scattering from insects dominates in the lower parts. The thermal-top rise rate is between 1.5 and 3.7 m s−1 in the analyzed case. Radar observations of thermals also enable estimations of their maximum heights, horizontal sizes, and the turbulent dissipation rate within each thermal. These attributes characterize the intensity of convection.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JTECH-D-17-0068.s1.

Corresponding author: Valery Melnikov, valery.melnikov@noaa.gov

Abstract

It is shown that the NEXRAD weather radar with enhanced detectability is capable of observing the evolution of convective thermals. The fields of radar differential reflectivity show that the upper parts of the thermals are observable due to Bragg scatter, whereas scattering from insects dominates in the lower parts. The thermal-top rise rate is between 1.5 and 3.7 m s−1 in the analyzed case. Radar observations of thermals also enable estimations of their maximum heights, horizontal sizes, and the turbulent dissipation rate within each thermal. These attributes characterize the intensity of convection.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JTECH-D-17-0068.s1.

Corresponding author: Valery Melnikov, valery.melnikov@noaa.gov
Save
Cover Journal of Atmospheric and Oceanic Technology
Journal of Atmospheric and Oceanic Technology

  • Contreras, R. F., and S. J. Frasier, 2008: High-resolution observations of insects in the atmospheric boundary layer. J. Atmos. Oceanic Technol., 25, 2176–2187, doi:10.1175/2008JTECHA1059.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Crum, T. D., R. B. Stull, and E. W. Eloranta, 1987: Coincident lidar and aircraft observations of entrainment into thermal and mixed layers. J. Appl. Meteor. Climatol., 26, 774–788, doi:10.1175/1520-0450(1987)026<0774:CLAAOO>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Doviak, R. J., and D. S. Zrnić, 2006: Doppler Radar and Weather Observations. 2nd ed. Dover Publications, 562 pp.

  • Drake, V. A., and D. R. Reynolds, 2012: Radar Entomology: Observing Insect Flight and Migration. CABI, 489 pp.

    • Crossref
    • Export Citation

  • Fabry, F., 2015: Radar Meteorology: Principles and Applications. Cambridge University Press, 256 pp.

    • Crossref
    • Export Citation

  • Geerts, B., and Q. Miao, 2005: The use of millimeter Doppler radar echoes to estimate vertical air velocities in the fair-weather convective boundary layer. J. Atmos. Oceanic Technol., 22, 225–246, doi:10.1175/JTECH1699.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Gossard, E. E., 1990: Radar research on the atmospheric boundary layer. Radar in Meteorology: Battan Memorial and 40th Anniversary Radar Meteorology Conference, D. Atlas, Ed., Amer. Meteor. Soc., 477– 527.

    • Crossref
    • Export Citation

  • Gossard, E. E., and R. G. Strauch, 1983: Radar Observations of Clear Air and Clouds. Elsevier, 280 pp.

  • Heinselman, P. L., D. J. Stensrud, R. M. Hluchan, P. L. Spencer, P. C. Burke, and K. L. Elmore, 2009: Radar reflectivity–based estimates of mixed layer depth. J. Atmos. Oceanic Technol., 26, 229–239, doi:10.1175/2008JTECHA1091.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Hooper, W. P., and E. W. Eloranta, 1986: Lidar measurements of wind in the planetary boundary layer: The method, accuracy and results from joint measurements with radiosonde and kytoon. J. Climate Appl. Meteor., 25, 990–1001, doi:10.1175/1520-0450(1986)025<0990:LMOWIT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Knight, C. A., and L. J. Miller, 1998: Early radar echoes from small, warm cumulus: Bragg and hydrometeor scattering. J. Atmos. Sci., 55, 2974–2992, doi:10.1175/1520-0469(1998)055<2974:EREFSW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Knight, C. A., J. Vivekanandan, and S. G. Lasher-Trapp, 2002: First radar echoes and the early ZDR history of Florida cumulus. J. Atmos. Sci., 59, 1454–1472, doi:10.1175/1520-0469(2002)059<1454:FREATE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Melnikov, V. M., and D. S. Zrnić, 2007: Autocorrelation and cross-correlation estimators of polarimetric variables. J. Atmos. Oceanic Technol., 24, 1337–1350, doi:10.1175/JTECH2054.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Melnikov, V. M., and P. T. Schlatter, 2011: Enhancing sensitivity on the polarimetric WSR-88D. 27th Conf. on Interactive Information Processing Systems (IIPS), Seattle, WA, Amer. Meteor. Soc., 14.3. [Available online at https://ams.confex.com/ams/91Annual/webprogram/Paper178856.html.]

  • Melnikov, V. M., R. J. Doviak, D. S. Zrnić, and D. J. Stensrud, 2011: Mapping Bragg scatter with a polarimetric WSR-88D. J. Atmos. Oceanic Technol., 28, 1273–1285, doi:10.1175/JTECH-D-10-05048.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Melnikov, V. M., R. J. Doviak, D. S. Zrnić, and D. J. Stensrud, 2013: Structures of Bragg scatter observed with the polarimetric WSR-88D. J. Atmos. Oceanic Technol., 30, 1253–1258, doi:10.1175/JTECH-D-12-00210.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Rabin, R., and R. J. Doviak, 1989: Meteorological and astronomical influences on radar reflectivity in the convective boundary layer. J. Appl. Meteor., 28, 1226–1235, doi:10.1175/1520-0450(1989)028<1226:MAAIOR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Richardson, L. M., J. G. Cunningham, W. D. Zittel, R. R. Lee, R. L. Ice, V. M. Melnikov, N. P. Hoban, and J. G. Gebauer, 2017: Bragg scatter detection by the WSR-88D. Part I: Algorithm development. J. Atmos. Oceanic Technol., 34, 465–478, doi:10.1175/JTECH-D-16-0030.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Stull, R. B., 1988: An Introduction to Boundary Layer Meteorology. Kluwer Academic, 666 pp.

    • Crossref
    • Export Citation

  • Wilson, J. W., and W. E. Schreiber, 1986: Initiation of convective storms at radar-observed boundary-layer convergence lines. Mon. Wea. Rev., 114, 2516–2536, doi:10.1175/1520-0493(1986)114<2516:IOCSAR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wilson, J. W., T. M. Weckwerth, J. Vivekanandan, R. M. Wakimoto, and R. W. Russell, 1994: Boundary layer clear-air radar echoes: Origin of echoes and accuracy of deriving winds. J. Atmos. Oceanic Technol., 11, 1184–1206, doi:10.1175/1520-0426(1994)011<1184:BLCARE>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Zrnić, D. S., and A. V. Ryzhkov, 1998: Observations of insects and birds with a polarimetric radar. IEEE Trans. Geosci. Remote Sens., 36, 661–668, doi:10.1109/36.662746.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 603 208 78
PDF Downloads 490 85 2