A Numerical Simulation of Multiple Vortices

  • R. Rotunno
Part of the Topics in Atmospheric and Oceanographic Sciences book series (TATM)

Abstract

It often occurs that tornadoes contain smaller subsidiary vortices which revolve about the tornado, which in turn, rotate in the same sense as the tornado (see FUJITA, 1970; FORBES, 1978). This phenomenon goes by various names (“suction vortices”, “satellite vortices”, and “secondary vortices”), however, for this work we follow CHURCH et al. (1979) and refer to the multiple vortex phenomenon (MVP). So, when we speak of the MVP we refer to that type of “suction vortex” which FUJITA (1976) has termed the “orbiting vortex”. That the MVP may be more than a minor detail of the tornadic flow is suggested by damage surveys which indicate the most intense destruction of life and property is associated with cycloidal paths which FUJITA has termed “suction swaths”. As with the tornado, very little is known about the internal circulation of the MVP. Photogrametric and ground survey data are inconclusive on such important questions as to i) what maximum wind speed is achieved by the tornado and ii) the relation between this and the MVP. MVs are clearly visible in photographs but it is extremely difficult to infer actual flow patterns.

Keywords

Vortex Convection Radar Vorticity Cyclone 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. AGEE, E. M., J. T. SNOW and P. R. CLARE 1976 Multiple vortex features in the tornado cyclone and the occurrence of tornado families. Mon. Wea. Rev., 104, 552–563CrossRefADSGoogle Scholar
  2. BROOKS, E. M. 1949 The tornado cyclone. Weatherwise, 2, 32–33CrossRefGoogle Scholar
  3. BROWNING, K. A. 1964 Airflow and precipitation trajectories within severe local storms which travel to the right of the mean wind. J. Atmos. Sci., 21, 634–639CrossRefADSGoogle Scholar
  4. BROWNING, K. A. 1965 Some inferences about the updraft within a severe local storm. J. Atmos. Sci., 30, 533–545MathSciNetGoogle Scholar
  5. BROWNING, K. A. 1977 The structure and mechanisms of hailstorms. MeteorMonogr., 20, 533–545Google Scholar
  6. BROWNING, K. A. and F. LUDLAM 1962 Airflow in convective storms. Quart. J. Roy. Meteor. Soc., 88, 117–135CrossRefADSGoogle Scholar
  7. BRANDES, E. A. 197 8 Mesocyclone evolution and tornadogenesis: some observations. Mon. Wea. Rev., 106, 995–1011CrossRefADSGoogle Scholar
  8. CHURCH, C. R., J. T. SNOW, G. L. BAKER, and E. M. AGEE 1979 Characteristics of tornado-like vortices as a function of swirl ratio: a laboratory investigation. J. Atmos. Sci., 36, 1755–1776CrossRefADSGoogle Scholar
  9. DAVIES-JONES, R. P. 1973 The dependence of core radius on swirl ratio in a tornado simulation. J. Atmos. Sci., 30, 1427–1430CrossRefADSGoogle Scholar
  10. , and E. KESSLER, 1974: Tornadoes. Chapter 16, Weather and Climate Modification, ed. by W. N. HESS, John Wiley, N.Y., 552–595Google Scholar
  11. FORBES, G. S. 1978 Three scales of motion associated with tornadoes. Final Report to the U.S. Nuclear Regulatory Commission (NUREG/CR-0363) RB, 359 ppGoogle Scholar
  12. FUJITA, T. T. 1970 The Lubbock tornadoes: a study of suction spots. Weatherwise, 23, 160–173CrossRefGoogle Scholar
  13. FUJITA, T. T. 1976 History of suction vortices. Proc. of the Symposium on Tornadoes, Texas Tech Univ., 2 8–88Google Scholar
  14. KUO, H.-L. 1971 Axisymmetric flows in the boundary layer of a maintained vortex. J. Atmos. Sci., 28, 20–41CrossRefADSGoogle Scholar
  15. LAMB, H. 1932 Hydrodynamics, Dover Publications, 738 ppGoogle Scholar
  16. LEWELLEN, W. S. 1971 A review of confined vortex flows. NASA Rep. CR-1772, 219 ppGoogle Scholar
  17. LEWELLEN, W. S. 1976 Theoretical models of the tornado vortex. Proc. of the Symposium on Tornadoes, Texas Tech Univ., 107–144Google Scholar
  18. ROTUNNO, R. 1977 Numerical simulation of a laboratory vortex. J. Atmos. Sci., 34, 1942–1956CrossRefADSGoogle Scholar
  19. ROTUNNO, R. 1978 A note on the stability of a cylindrical vortex sheet. J. Fluid Mech., 87, 761–771CrossRefMATHADSMathSciNetGoogle Scholar
  20. ROTUNNO, R. 1979 A study on tornado-like vortex dynamics. J. Atmos. Sci., 36, 140–155CrossRefADSGoogle Scholar
  21. ROTUNNO, R. 1981 A numerical model pertaining to the multiple vortex phenomenon. Final Report to U.S. Nuclear Regulatory Commission (NUREG/CR-1840), 51 ppGoogle Scholar
  22. SNOW, J. T. 1978 On inertial instability as related to the multiple vortex phenomenon. J. Atmos. Sci ., 35, 1660–1671CrossRefADSGoogle Scholar
  23. STOUT, G. E., and F. A. HUFF 1953 Radar records Illinois tornadogenesis. Bull. Amer. Meteor. Soc., 34, 281–284Google Scholar
  24. TAYLOR, G. I. 1915 Eddy motion in the atmosphere. Phil. Trans, Roy. Soc. London, A215, 1–120Google Scholar
  25. WARD, N. B. 1972 The explanation of certain features of tornado dynamics using a laboratory model. J. Atmos. Sci., 49, 1194– 1204CrossRefADSGoogle Scholar
  26. WILLIAMS, G. P. 1969 Numerical integration of the three-dimensional Navier-Stokes equations for incompressible flow. J. Fluid Mech., 37, 727–750CrossRefMATHADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1982

Authors and Affiliations

  • R. Rotunno

There are no affiliations available

Personalised recommendations