Downscaling climate parameters in Fars province, using models of the fifth report and RCP scenarios

Abstract

Climate change is responsible for many extreme weather events on the Earth, including sea level rising, drastic shifts in temperature and precipitation regimes, and changes in flood and drought frequency. In the present study, based on IPCC's latest report, outputs of three GCMs, the EC-EARTH, the HadGEM2-ES and the MIROC5 were downscaled by the LARS-WG model and under RCP4.5 and RCP8.5 scenarios. Also, variations in precipitation, maximum and minimum temperatures for the time series 2021–2040, 2041–2060 and 2061–2080 have been projected and the precipitation extreme values in Gumbel distribution were evaluated. For this purpose, the climate records obtained from Shiraz, Lar and Abadeh synoptic stations in Fars province were used to establish the baseline period (1985–2010). The results of all the stations show that Changes in maximum and minimum temperatures under RCP4.5 and RCP8.5 scenarios have increased. The increase in minimum temperature for the baseline period compared to the upcoming period 2021–2040 under the selected scenarios were 1.43 and 1.65C, respectively. The increase in precipitation for the baseline period compared to the upcoming period (2021–2040) under the two scenarios were up to 2.93 and 1.95, respectively. Furthermore, longer return periods are accompanied by higher amounts of probable maximum precipitation under RCP4.5 and RCP8.5, where extreme precipitation is showing higher level of rise under the latter scenario.