Meteorology and Atmospheric Physics

, Volume 66, Issue 3–4, pp 143–155 | Cite as

A real data simulation of the Adriatic bora and the impact of mountain height on bora trajectories

  • L. Lazić
  • I. Tošić
Article

Summary

This study addresses simulation of the local bora wind and its properties as reflected on typical trajectories. Trajectory calculations are implemented in the Eta Model. The Eta Model has a vertical coordinate which permits a step-like representation of mountains and quasi-horizontal coordinate surfaces, the so-called eta coordinate. A realistic real data simulation of a bora wind case in achieved using the model with a 28 km horizontal resolution and 16 layers in the vertical. Numerical experiments with different mountain heights and shapes in the bora wind region are performed. These are motivated by observational indications and theoretically based expectations that a certain intermediate mountain elevation is required for generation of downslope windstorms with bora wind properties. Three-dimensional trajectories over various mountains mimicing real mountains but differing primarily in elevation are calculated and analysed. The maximum bora wind speed is predicted as expected through three-dimensional channels in the step mountain representations. The results illustrate and are in agreement with the observational evidence that mountain barriers of the elevation of about 1000 m are a necessary requirement for the occurrence of the bora-type downslope windstorms.

Keywords

Vertical Coordinate Trajectory Calculation Typical Trajectory Coordinate Surface Wind Region 

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References

  1. Arakawa, S., 1976: Numerical experiments on the local strong winds: Bora and fohn. In: Yoshino, M. (ed.),Local Wind Bora. Tokyo: University of Tokyo Press, 289 pp.Google Scholar
  2. Chen, W. D., Smith, R. B., 1987: Blocking and deflection of airflow by the Alps.Mon. Wea. Rev.,115, 2578–2597.Google Scholar
  3. Glasnović, D., Jurčec, V., 1990: Determination of upstream bora layer depth.Meteorol. Atmos. Phys.,43, 137–144.Google Scholar
  4. Janjić, Z. I., 1990: Physical package for the step-mountain, eta coordinate model.Mon. Wea. Rev.,118, 1429–1443.Google Scholar
  5. Janjić, Z. I. 1994: The step-mountain eta coordinate model: Further developments of the convection, viscous sublayer and turbulence closure schemes.Mon. Wea. Rev.,122, 927–945.Google Scholar
  6. Jurčec, V., 1989: Severe Adriatic bora storms in relation to synoptic developments.Papers of Meteorological Society of Croatia,24, 11–20.Google Scholar
  7. Klemp, J. B., Durran, D. R., 1987: Numerical modeling of bora winds.Meteorol. Atmos. Phys.,36, 215–227.Google Scholar
  8. Mesinger, F., 1984: A blocking technique for the representation of mountains in atmospheric model.Riv. Met. Aeronautica,44, 195–202.Google Scholar
  9. Mesinger, F., Janjić, Z. I., Ničković, S., Gavrilov, D., Deaven, D. G., 1988: The step-mountain coordinate: model description and performance for cases of Alpine lee cyclogenesis and for a case of an Appalachian redevelopment.Mon. Wea. Rev.,116, 1493–1518.Google Scholar
  10. Petersen, R. A., Uccellini, L. W., 1979: The computation of isentropic atmospheric trajectories using a Discrere Model formulation.Mon. Wea Rev.,107, 566–574.Google Scholar
  11. Smith, R. B., 1985: On severe downslope winds.J. Atmos. Sci.,42, 2597–2603.Google Scholar
  12. Smith, R. B., 1987: Areal observations of Yugoslavian bora.J. Atmos. Sci.,44, 269–297.Google Scholar
  13. Smith, R. B., Sun, J., 1987: Generalized hydraulic solutions pertaining to severe downslope wind.J. Atmos. Sci.,44, 2934–2939.Google Scholar
  14. Yoshino, M., 1976:Local Wind Bora, Tokyo: University of Tokyo Press, 289 pp.Google Scholar

Copyright information

© Springer-Verlag 1998

Authors and Affiliations

  • L. Lazić
    • 1
  • I. Tošić
    • 1
  1. 1.Department of MeterologyUniversity of BelgradeBelgradeYugoslavia

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