Monitoring of Iran Monthly Temperature Trend based on database output European Centre for Medium-Range Weather Forecasts (ECMWF) ERA Interim Version

The role of temperature and the importance of its transformation has led to a serious attention to this climate over the last few decades. The rising temperature in some regions of Iran and its possible implications have led to serious concerns for researchers and planners. The aim of this study is to determine the spatial transformation of Iran's temperature over the past four decades. In order to evaluate this trend, the ERA Interim European Centre for Medium-Range Weather Forecasts (ECMWF) database was used during the 1979-2015 period with a spatial resolution of 12566 × 125/0 ° arc per month with 9966 cells. Non-parametric Mann-Kendall and Sen's Slope methods were used to reveal the temperature trend. The results showed that four months of February, March, May and October experienced a one-way (incremental) temperature trend. The highest average of the country's seasonal increase was due to the winter season and its minimum was fall season. In all months of the year, the regions of the country that were between 30 to 35 degrees north have experienced the most significant incremental trend. The cold and temperate regions of the country have been experiencing higher temperatures than other areas. Also, the negative trend of south-east and south (Bushehr coastal areas) of Iran is due to four reasons: 1. Mineralization of the climate of the area; 2. Increased airborne weather conditions; 3. Precipitation vapor; and 4. Clouds and range of temperature changes. The maximum average temperature gradient of the country was at 11.1 ° C in February, and its minimum level was as high as 0.002 ° C in November. In general, Iran's winters are getting warmer, and this will be considered a serious threat to the country's flood victims.