Coordinatin of subtropical-pressure centers in flood-rains of the south and south-easthern Iran. Case study: The rainfall of july 1976

Subject Areas : Geopolitic

محمد  Saligheh ¹ (ندارد)

Received: 2015-01-17 Accepted : 2015-01-17 Published : 2004-04-20

Keywords: Pressure centers coordination, summery rainfalls, convergency, Precipitation,

Abstract :

Iran's southern half's climatic have especially features, is its summery rainfalls amongwhich the long–term rain of July 1976 has had a unique specialty as studied till now.In this period, there was coordination between the atmospheric cycles of low latitudes(seasonal spring) and mid latitudes (tropic adjoined-high pressure recycling).Thepresent study shows that the coordination of these pressure systems resulted in stringthing and intensifying the moisture penetrate from eastern side towards the site ofstudy. The coordination between these two systems in the south of Himalayas createda sort of convergency, therefore eastern and western flows of polar edge of seasonalcell have moved with higher speed. This velocity increasing make the system able tosend more moisture to Iran's south and southern east region. Moreover, the rainfallneeds elevating factors. These factor are created at a time when elevating conditionsare provided by atmosphere middle levels. Researches shows that when tropicaladjoined-high pressures transfer to higher levels, the opportunity for local sweepingselevating, will increase and precipitation will occur.