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Meteorology and Atmospheric Physics

, Volume 127, Issue 6, pp 649–658 | Cite as

The onset of a severe summer bora episode near Oštarijska Vrata Pass in the Northern Adriatic

  • Tanja TrošićEmail author
Original Paper
  • 119 Downloads

Abstract

A severe bora episode which lasted from 22 to 25 July 2012 has been selected for the 3D numerical model analysis of the start of the bora near the Oštarijska Pass in the Northern Adriatic of Croatia. The 10-m wind analysis shows that the gap flow turns and rotates in the central part of the Vir Sea at the start of bora. The MM5 model validation shows that the modelled wind matches well the automatic stations measurements and the validation of the vertical profiles shows that the model adequately captured the basic thermodynamic and flow structure during the bora episode. The vertical cross sections show the turning of the horizontal wind in the first 500–800 m over a relatively small area over the Vir Sea. The analysis implies that the wind turning can be attributed to the impact of the Etesian windflow, the frontal passage and the positions of the outer islands and coastal area. The analysis of the horizontal vorticity of the surface wind shows vorticity banners downwind of the gap with high vorticity values, up to 4 × 10−5 s−1, in the central part of the Vir Sea. A secondary northeastern vorticity maximum is developed due to the orography of the coastal area and the rotational windflow.

Keywords

Wind Speed Vorticity Turbulent Kinetic Energy Vertical Cross Section Hydraulic Jump 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

The author is thankful to the Meteorological and hydrological service of Croatia for the automatic stations measurements and the information about the measurement data. The PSU/NCAR MM5 model was used and the FNL NCEP/NCAR analysis was used for the boundary and initial conditions for the model. The author thanks three anonymous reviewers for constructive comments which have improved the paper.

References

  1. Belušić D, Klaić ZB (2006) Mesoscale dynamics, structure and predictability of a severe Adriatic bora case. Meteorol Z 15:157–168CrossRefGoogle Scholar
  2. Belušić D, Žagar M, Grisogono B (2007) Numerical simulation of pulsations in the bora wind. Q J Roy Meteorol Soc 133:1371–1388CrossRefGoogle Scholar
  3. Bitan A, Saaroni H (1992) The horizontal and vertical extension of the Persian Gulf trough. Int J Climatol 12:733–747CrossRefGoogle Scholar
  4. Brzović N (1999) Factors affecting the Adriatic cyclone and associated windstorms. Contrib Atmos Phys 72:51–65Google Scholar
  5. Enger L, Grisogono B (1998) The response of bora type flow to sea-surface temperature. Q J Roy Meteorol Soc 124:1227–1244CrossRefGoogle Scholar
  6. Gohm A, Mayr GJ (2005) Numerical and observational case-study of a deep Adriatic bora. Q J Roy Meteorol Soc 131:1363–1392CrossRefGoogle Scholar
  7. Gohm A, Mayr GJ, Fix A, Giez A (2008) On the onset of bora and the formation of rotors and jumps near a mountain gap. Q J Roy Meteorol Soc 134:21–46CrossRefGoogle Scholar
  8. Grell GA, Dudhia J, Stauffer DR (1995) A description of the fifth-generation Penn State/NCAR mesoscale model (MM5). NCAR Technical Note, NCAR/TN-398 + STRGoogle Scholar
  9. Grisogono B, Belušić D (2009) A review of recent advances in understanding the meso- and microscale properties of the severe Bora wind. Tellus A 61:1–16CrossRefGoogle Scholar
  10. Grubišić V (2004) Bora-driven potential vorticity banners over the Adriatic. Q J Roy Meteorol Soc 130:2571–2603CrossRefGoogle Scholar
  11. Horvath K, Ivatek-Šahdan S, Ivančan-Picek B, Grubišić V (2009) Evolution and structure of severe cyclonic Bora: contrast between the northern and southern Adriatic. Wea Forecasting 24:946–964CrossRefGoogle Scholar
  12. Ivančan-Picek B, Tutiš V (1996) Severe Adriatic Bora on 28 December 1992. Tellus 48A:357–367CrossRefGoogle Scholar
  13. Jurčec V (1981) On mesoscale characteristics of bora conditions in Yugoslavia. Pure Appl Geophys 119:640–657Google Scholar
  14. Jurčec V (1988) The Adriatic frontal bora type. Rasprave-Papers 23:13–25Google Scholar
  15. Jurčec V (1989) Severe Adriatic Bora storms in relation to synoptic developments. Rasprave-Papers 24:11–20Google Scholar
  16. Klarin M, Kraljev D (2002) Meteorological conditions in the Zadar sea-area and their influence on sailing. Jadranska Meteorol 47(6):31–36Google Scholar
  17. Kotroni V, Lagouvardos K, Lalas D (2001) The effect of the island of Crete on the Etesian winds over the Aegean Sea. Q J Roy Meteorol Soc 127:1917–1937CrossRefGoogle Scholar
  18. Kuzmić M, Janeković I, Ivančan-Picek B, Trošić T, Tomažić I (2005) Severe northeastern Adriatic bura events and circulation in greater Kvarner region. Croat Meteorol J 40:320–323Google Scholar
  19. Pan F, Smith RB (1999) Gap winds and wakes: SAR observations and numerical simulations. J Atmos Sci 56:905–923CrossRefGoogle Scholar
  20. Smith RB (1987) Aerial observation of the Yugoslavian bora. J Atmos Sci 44:269–297CrossRefGoogle Scholar
  21. Trošić T, Trošić Ž (2010) Numerical simulation and observational analysis of the bora of Pag’s ribs. Bound Layer Meteorol 134:353–366CrossRefGoogle Scholar
  22. Trošić T, Šinik N, Trošić Ž (2006) Available potential energy of the daily coastal circulation at Zadar (Croatia). Meteorol Atmos Phys 93:211–220CrossRefGoogle Scholar
  23. Večenaj Ž, Belušić D, Grubišić V, Grisogono B (2012) Along-coast features of the bora related turbulence. Bound Layer Meteorol 143:527–545CrossRefGoogle Scholar
  24. Vučetić V (1985) On local and mesoscale characteristic of bora. Papers 20:11–20Google Scholar
  25. Vučetić V (1991) Statistical analysis of severe Adriatic bora. Croat Meteorol J 28:19–36Google Scholar
  26. Wieringa J (1980) Representativness of wind observations at airports. Bull Amer Met Soc 61:962–971CrossRefGoogle Scholar
  27. Yoshino MM (1976) Local wind bora. University of Tokyo Press, TokyoGoogle Scholar
  28. Ziv B, Saaroni H, Alpert P (2004) The factors governing the summer regime of the eastern Mediterranean. Int J Climatol 24:1859–1871CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Wien 2015

Authors and Affiliations

  1. 1.Meteorological and Hydrological ServiceZagrebCroatia

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