Analysis and forecasting of heat waves in selected cities in Northwest of Iran

Heat waves are one of the most important weather disasters, and their destructive environmental effects require knowledge and forecast. The purpose of this study is to forecast the future conditions of heat waves in Ardabil, Tabriz and Urmia during the years 2020-2050 using SDSM downscaler and Baldy index. For this purpose, the maximum daily temperature data of selected cities from 1961 to 2005 after preparation were entered into SDSM software and analyzed with CanESM2 model with 2٫6, 8٫5and RCP 4٫8 scenarios and with the output of the model, the maximum temperature trend of the three stations during the next 30 years was investigated and their heat waves were Forecasted using the Baldy index. According to the results of the error measurement of the model, the simulations performed had acceptable accuracy. Due to the fact that each of the cities showed the least error in one scenario, so the heat wave prediction of each station was done using the least error scenario. Based on the results the average maximum temperature will decrease from late winter to late spring compared to the base period and will increase slightly in mid-summer. In general, we will see a decrease in the average maximum temperature in Ardabil and an increasing trend of the mentioned parameter in Tabriz and Urmia cities during the years 2020-2050. Also, the study of the predicted heat waves in the next thirty years showed that one-day waves in Ardabil and Urmia will be a slight increase and in Tabriz will be almost without trend. Two-day heat waves will decrease in Tabriz and Urmia and will increase in Ardabil. The trend of three-day heat waves in Ardabil and Urmia will be decreasing and increasing in Tabrizthe highest continuity of heat waves was four days, which was forecast in Urmia. The highest frequency of two- and three-day heat waves in all three cities will be in the cold seasons of the year.