Analysis of trends in temperature parameters in Iran

Today, climate change and its anomalies, one of the important issues raised in the world. Detection of changes on temperature and precipitation as the most important climatic elements, is used as primary evidence of climate change in many parts of the world. This paper investigates the temperature trend of Iran of annual, monthly and seasonal scales. For this purpose minimum, average and maximum temperature data of 38 synoptic stations, over the period of 50 years (1960-2010) with good distribution, were obtained from Iran meteorological organization.  Then the temperature trend parameters were investigated (studied) by Mann Kendall nonparametric test. The results showed that the general temperature trend is increased in most of the stations for different time scales; however this intensity of increase decreases from the minimum to maximum temperature. On monthly, in June and July, and on seasonal, in summer, the increase of temperatures are higher than other time. Although the most frequency positive trend of the maximum and average temperature observed in the winter, but for a few of the stations was significant. While in warm seasons especially in the summer, the frequency of station with positive significantly trend is higher. In terms of spatial, the stations that located in the Alborz Mountains, South West and South East of IRAN have experienced higher temperatures than other areas of the country and in some station such as SHAREKORD, URIMA, KHORRAMABABD AND BANDAR ABASS trend of temperature in different scale is mostly decreasing.