شاخص نوسانات اطلس شمالي و تاثير آن بر اقليم ايران

North Atlantic Oscillation Index and its effect on climate in Iran

Geographical specification in -wide country of Iran produces different climate features. This feature results from natural and unnatural (human) activity of different factors in Iran that cones pond -with other climate phenomenon. One of these climate phenomenon is north Atlantic oscillation index that obtain from difference between normalized monthly data of central pressure Azure high pressure and Island low pressure this research include explanation about behavior of active pressure centers on north Atlantic bused on time series of central pressure Island low (IL) and Azure high pressure (AH) and it effect eon climatic abnormalities in Iran. Using normalized abnormalities of the pressure gradient between centers Azure high pressure and Island low pressure (AH - IL), as a north Atlantic oscillation index (INAO), it mark that strong NAO (AH - IL / gradient higher that normal), associate with precipitation increase and low temperature in winter in most region of Iran the study about weak NAO, show different pattern.