The Survey of moisture advection pattern of Iran's Comprehensive precipitations

Transferring the water vapor in the atmosphere directly depend on the conditions of atmospheric circulation, amount and path of humidity changes related to the atmospheric circulation variation. one of the main factors of atmospheric circulation affecting on transferring the moisture is high pressure centers that if placed on the water surface and humidity resources causes the moisture advection in a widely area. However, the role of low pressure systems and cyclones in advection and moisture flux, although not as much as high-pressure systems, but also played a significant role in transmitting and condition of moisture advection. the aim of this study is survey the moisture advection of Iran's precipitations. in this regard, pressure data, specific humidity, u wind and v wind parameters in 500, 700, 850 and 1000 hpa from NCEP/NCAR database were extracted and analyzed. the results showed that the moisture advection of iran's precipitations is related to the moisture advection pattern of low pressure of dual-core of Sudan and east Mediterranean - Europe high pressure, moisture advection pattern of multicore low pressure of central Iran, east Mediterranean and south east of Saudi Arabian, moisture advection pattern of highpressure of north west of Europe- low pressure of Persian gulf, moisture advection pattern of high pressure of Siberia and Kazakhstan- low pressure of south east of Iran and low pressure of Mediterranean. Overly, the results showed that Arabian Sea in low level and Mediterranean Sea in high level had an important role in moisture advection of Iran's precipitations.