A numerical study of the orographic effect of the Taebak mountains on the increase of the downslope wind speed near Gangnung area

태백산맥의 지형적인 효과와 관련된 강릉 지역의 강풍 사례에 대한 수치모의 연구

  • 이재규
  • Published : 2003.12.01


A numerical simulation for 11 February 1996 has been done to grasp main mechanisms of the occurrence of strong downslope winds near Gangnung area. The simulation performed by using ARPS (Advanced Regional Prediction System) showed that enhanced surface winds were not related with a reflection of vertically propagating gravity waves. Froude numbers were about 1.0, 0.4 and 0.6 for the atmosphere above Daekwanryoung and above a place located 220km upstream, and above another place located 230km downstream from the Taebak mountains, respectively. This suggested that as a subcritical flow ascended the upslope side of the Taebak mountains, Froude numbers would tend to increase according to the increase in wind speed, and near the crest the flow would become supercritical and continue to accelerate as it went down the downslope side until it was adapted back to the ambient subcritical conditions in a turbulent hydraulic jump. Simulated Froude numbers corroborated the hydraulic jump nature of the strong downslope wind. In addition, the inversion was found near the mountain top height upstream of the mountains, and it was favorable for the occurrence of strong downslope winds.


Hydraulic jump;Downslope wind;Froude number;Orographic effect;Subcritical flow;Supercritical flow;Inversion layer;Numerical simulation


  1. Klemp, J. B. and D. K. Lilly, 1975, The dynamic of wave-induced downslope wind, J. Atmos. Sci., 32, 320-339.<0320:TDOWID>2.0.CO;2
  2. 박순태, 2001, 동계 동부지역 강풍에 대한 연구(태백, 소백산맥 풍하측 강풍에 관하여), (대기)한국기상학회보, 11(3), 169-172.
  3. Whiteman, C. D., 2000, Mountain meteorology, Oxford University Press, New York, 355pp.
  4. Gryning, S. E. and E. Batchvarova, 1990, Simple model of daytime boundary layer height, The 9th Symposium on Turbulence and Diffusion, Amer. Meteor. Soc., 379-382pp.
  5. Orlanski, I., 1976, A simple boundary condition for unbounded hyperbolic flows, J. Comput. phys., 21, 251-269.
  6. 유정아, 백종진, 1999, 고립된 산악위에서의 이차원 성층화된 흐름의 흐름체계, 한국기상학회지, 35(3), 384-394.
  7. Moeng, C.H., 1984, A large eddy simulation model for the study of planetary boundary- layer turbulence, J. Atmos. Sci., 41, 2052-2062.<2052:ALESMF>2.0.CO;2
  8. Saito, K. and M. Ikawa, 1991, A numerical study of the local downslope wind "Yamaji- kaze" in Japan, J. Meteor. Soc. Japan, 69, 31-56.
  9. Tao, W. K. and J. Simpson, 1993, Goddard cumulus ensemble model, Part I: Model description, Terrestrial, Atmospheric and Oceanic Sciences, 4, 35-72.
  10. Holton, J. R., 1992, An Introduction to Dynamic Meteorology, 3rd ed., Academic Press, New York, 511pp.
  11. Long, R. R., 1953, A laboratory model resembling the "Bishopwave" phenomenon, Bull. Amer. Meteor. Soc., 34, 205-211.
  12. Miller, P. P. and D. R. Durran, 1991, On the sensitivity of downslope windstorms to the asymmetry of the mountain profile, J. Atmos. Sci., 48, 1457-1473.<1457:OTSODW>2.0.CO;2
  13. Durran, D. R., 1986, Another look at downslope windstorm. Part I: The development of analogs to supercritical flow in an infinitely deep, continuously stratified fluid, J. Atoms. Sci., 43, 2527-2543.<2527:ALADWP>2.0.CO;2
  14. Hoinka, K. P., 1985, A comparison of numerical simulations of hydrostatic flow over mountains with Observations, Mon. Wea. Rev., 113, 719-735.<0719:ACONSO>2.0.CO;2
  15. Klemp, J. B. and R. B. Wilhelmson, 1978, The simulation of three-dimensional convective storm dynamics, J. Atmos. Sci., 35, 1070-1096.<1070:TSOTDC>2.0.CO;2
  16. Lilly, D. K. and J. B. Klemp, 1979, The effects of the terrain shape on nonlinear hydrostatic mountain waves, J. Fluid Mech., 95, 241-261.
  17. Xue, M., K. K. Droegemeier, V. Wong, A. Shapiro and K. Brewster, 1995, ARPS version 4.0 user's guide, Center for Analysis and Prediction of Storms, University of Oklahoma, 380pp.
  18. Crank, J. and P. Nicolson, 1947, A practical method for numerical evaluation of solutions of partial differential equations of the heat- conduction type, Proceedings of the Cambridge Philosophical Society, 43, 50-67.
  19. Nieuwstadt, F. T. W. and H. Tennekes, 1981, A rate equation for the nocturnal boundary- layer height, J. Atmos. Sci., 38, 1418-1429.
  20. Deardorff, J. W., 1972, Numerical investigation of neutral and unstable planetary boundary layers, J. Atmos. Sci., 29, 91-115.<0091:NIONAU>2.0.CO;2
  21. Atkinson, B. W., 1981, Meso-Scale Atmospheric Circulation, Academic Press, New York, 496pp.
  22. Durran, D. R., 1990, Mountain waves and downslope winds, In: Blumen, W. (ed.), Atmospheric processes over complex terrain, Amer. Meteor. Soc., Boston, Massachusetts, Meteor. Monogr., 23(45), 59-81.
  23. Businger, J. A., J. C. Wyngaard, Y. Izumi and E. F. Bradley, 1971, Flux-profile relationships in the atmospheric surface layer, J. Atmos. Sci., 28, 181-189.<0181:FPRITA>2.0.CO;2

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