Study of effect of NAO Index on temperature and precipitation of southern coastal region of Caspian Sea in 1977-2009 periods

Subject Areas : Marine Physics

S.  Tabarestani ¹ (Dept. of Meteorology, Faculty of Marine Science and Technology Islamic Azad University, Tehran North Branch)
A.  Asgari ² (Atmospheric science & meteorological research centers Islamic Azad University, Tehran North Branch)

Received: 2013-02-21 Accepted : 2014-01-08 Published : 2014-08-23

Keywords: Precipitation, temperature, Azores High Pressure, southern coastal region of Caspian Sea, Iceland Low Pressure, North Atlantic Oscillation,

Abstract :

The North Atlantic oscillation (NAO) is one of the effective indices in changing atmospheric situation of northern hemisphere .Southern coastal region of Caspian Sea is affected by different atmospheric systems and teleconnections such as NAO because of its special geographical situation. In this research, precipitation and temperature data of southern coastal region of Caspian Sea are examined for 8 synoptic stations in 1977-2009 period. NAO index data are also received from cpc.noaa.gov website. Precipitation and temperature data were examined with their corresponding NAO indices data by correlation test in monthly and yearly time scales. Furthermore, we found that in this region, when NAO index increases, precipitation will increase and temperature will decrease and vice versa. During recent years, NAO index shows negative trend, so we expect decrease of precipitation and increase of temperature in the region.