Evaluation of the accuracy of CMIP۶ models based on Taylor diagram for simulating precipitation in the southern part of the Aras river basin

This study was aimed at evaluating the accuracy of selected models at ۷ synoptic meteorological stations based on Taylor's diagram to simulate precipitation in the southern part of the Aras river basin (Iran) over the past three decades. This study, by examining the the CMIP۶ series models with high horizontal resolution, intends to introduce the superior model in the region for predicting precipitation so that the water resources situation in the studied region can be managed. For this purpose, data from ۴ AOGCM (MPI-ASM۱-۲-HR, CMCC-CM۲-SR۵, BCC-CSM۲-MR and EC-Earth۳-CC) were used by the CMIP۶ series models. The historical period of ۱۹۸۵-۲۰۱۴ was considered. The raw output of the models downscaled by CMhyd software. To select the appropriate downscaling method, three methods were used: Linear Scaling, Power transformation, and Taylor diagram distribution mapping. The performance of the models at each station was evaluated by Taylor's chart. The calculations showed that the top model in all selected stations in the study area is the BCC model and the weakest model for simulation of the southern part of the Aras river basin, the MPI model. The results showed that the raw output of the models had a lot of error and could not be used directly. The results also showed that the Linear Scaling downscaling method has a good ability to optimize the output of GCM models in the study area. Based on the study, the BCC model is reliable for predicting precipitation in the study area.

کلیدواژه ها:

CMhyd ، CMIP۶ ، Aras river basin ، Precipitation ، Simulation