Abstract

It was evident from observations in the recent past that atmospheric variables are changing at regional scale and may continue to impact the regional weather in the coming future. An 8-member ensemble from the HighResMIP experiment is used to analyze projected changes in temperature, atmospheric pressure, precipitation, and surface wind over Iran during 2015–2050 period. A considerable increase of temperature between 2 and 2.5 °C by 2050 with respect to the baseline period (1979–2014) is expected with a higher rate towards southwestern and southeastern of Iran. From the seasonal analysis, an increase of~4 °C (2 °C) by 2050 would be maintained in summer (winter) season over the country. Furthermore, a reduction in atmospheric pressure between 0.2 and 1 hPa by 2050 with respect to the baseline period towards the northwestern region of the country is foresaw; however, no consistent changes are expected in the remain regions where lack of coherence between models is recognized. Besides, precipitation changes are expected to be signifcant towards the northwestern Iran region with values between 0.1 and 0.3 mm day−1 by 2050 with respect to the baseline period, contrary to the results obtained in the eastern region with changes between−0.1 and 0.1 mm day−1 towards the Lut and the Kavir deserts. Additionally, an interesting behavior was noticeable in all the models selected with a reduction in precipitation of 0.3 mm day−1 between June and September which announce temperature increases principally in boreal summer, thus can exacerbate extensive droughts in diferent regions of Iran. Finally, surface wind speed and direction behavior were assessed, showing an increase of surface wind speed between 0.05 and 0.1 ms−1, but no signifcant trends were observed in the majority of the country similar to expected changes in wind direction