Impacts of Global Warming on Humidity Amounts of Precipitation Systems
Abstract:
To conduct this research, in first step the precipitation data of four synoptic stations (Kermanshah, Khorram Abad , Sanandaj and Hamedan) in the western Iran during the period 1979-1979 in cold months of January, February, March, October, November and December were obtained from the Meteorological Organization of Republic of Islamic Iran (IRIMO) and based on the ninety-fifth percentile threshold,, the heaviest 24-hour rainfall of each station in each month was identified.
Further for the days when heavy rains occurred, the specific humidity cell data and the daily temperature for four times (18-12-06-00) from the reanalysis ERA5 data over a period of 30 years ( 1979-1979) European Center of Mid-Latitude Weather Forecast (ECMWF) with spatial resolution of 0.25 * ° 0.25 ° arc were received . Non-parametric Mann-Kendall and age Sen’s Slope Estimator Nonparametric tests were used to analyze the trend and Pearson correlation coefficient and linear parametric regression methods were used to analyze the relationships. The results show that the specific humidity trend of rainfall systems in western Iran (except March at 700 hPa) in January, February, March, October, November and December at both 850 and 700 hPa levels was positive and incremental, although it was not significant at the 95% confidence level.
There is a positive linear relationship between the temperature trend of precipitation systems and their specific humidity (except October at 850 hPa) from January to March and November to December at 850 and 700 hPa, which Can affect the intensity of rainfalls, type and speed of horizontal movement of precipitation systems in the future.

Abstract:
To conduct this research, in first step the precipitation data of four synoptic stations (Kermanshah, Khorram Abad , Sanandaj and Hamedan) in the western Iran during the period 1979-1979 in cold months of January, February, March, October, November and December were obtained from the Meteorological Organization of Republic of Islamic Iran (IRIMO) and based on the ninety-fifth percentile threshold,, the heaviest 24-hour rainfall of each station in each month was identified.
Further for the days when heavy rains occurred, the specific humidity cell data and the daily temperature for four times (18-12-06-00) from the reanalysis ERA5 data over a period of 30 years ( 1979-1979) European Center of Mid-Latitude Weather Forecast (ECMWF) with spatial resolution of 0.25 * ° 0.25 ° arc were received . Non-parametric Mann-Kendall and age Sen’s Slope Estimator Nonparametric tests were used to analyze the trend and Pearson correlation coefficient and linear parametric regression methods were used to analyze the relationships. The results show that the specific humidity trend of rainfall systems in western Iran (except March at 700 hPa) in January, February, March, October, November and December at both 850 and 700 hPa levels was positive and incremental, although it was not significant at the 95% confidence level.
There is a positive linear relationship between the temperature trend of precipitation systems and their specific humidity (except October at 850 hPa) from January to March and November to December at 850 and 700 hPa, which Can affect the intensity of rainfalls, type and speed of horizontal movement of precipitation systems in the future.