International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2572

Full Length Research Paper

The role of the subtropical jet stream in cyclogenesis over the Central Mediterranean Sea: A case study of February 1974

Elham Mobarak Hassan1*, Majid Azadi2, Amir Hussain Meshkatee3 and Majid Mazraee Farahani4
1Department of Meteorology, Basic Sciences, Science and Research branch, Islamic Azad University, Tehran branch, Iran. 2Faculty of Atmospheric Science and Meteorological Research Center, Tehran, Iran. 3Department of Meteorology, Science and Research Branch, Islamic Azad University, Tehran, Iran. 4Faculty of Institute of Geophysics University, Tehran, Iran.
Email: [email protected]

  •  Accepted: 11 May 2011
  •  Published: 18 June 2011


The Mediterranean Sea is recognized as one of the most important locations for cyclogenesis. In the course of this study, the role of subtropical jet stream in the formation of a deep cyclone over the central part of the Mediterranean Sea during 21 to 23, February 1974, was studied. The analysis based on NCEP data showed that there was a strong link between the presence of a subtropical jet along the African coast of Mediterranean Sea with the core speed of 60 to 70 ms-1 and its associated secondary circulation with the formation of that cyclone. Analysis also showed that there were strong positive vorticity advection at 500 hpa and divergence in horizontal wind field at 200 hpa surfaces that led to the occurrence of ascending motion maxima at the time of the formation of the cyclone. 


Key words: Cyclogenesis, subtropical jet, divergence, positive vorticty advection (PVA).


Abbreviations: SJT, Subtropical jet; PJ, polar jet; PVA, positive vorticity advention.