Analysis of Jet Stream Frequencies Associated with Super Heavy Rainfalls of Iran

Document Type : Original Article

Authors

1 Professor in climatology, Isfahan University, Isfahan, Iran

2 Assistant Professor in climatology, Kurdistan University, Sanandaj, Iran

Abstract

In this study, the frequency and location of jet streams associated with heavy rainfalls have been analyzed using environmental to circulation approach. Based on the threshold of the upper 99 percent, 125 days of the super and overall heavy rainfall was selected from the IRIMO data base (including 1437 synoptic, climatic, and rain gage stations). Jet stream frequencies and their locations have been detected from 0˚ to 120˚ E and 0˚ to 80˚ N in five levels (250, 300, 400, 500 and 600 hPa level) at 00:00, 06:00 and 12:00 UTC. The results of this study have shown that jet streams at 00:00 have a remarkable frequency at all levels with the exception of the 250 hPa level. Generally, jet streams are mostly extended from 250 to 600 hPa levels that have provided baroclinic conditions for Iran’s super heavy rainfalls. In this study, the northern half of Saudi Arabia was a major location where jet streams occur or are visible.

Keywords

References

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Iran-Water Resources Research
Volume 7, Issue 2
July 2011
Pages 80-91

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History

  • Receive Date: 16 November 2009
  • Accept Date: 15 March 2011

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