Comparison of Precipitation Projections of CMIP5 and CMIP6 Global Climate Models over Yulin, China

Abstract This study compared precipitation projections of Coupled Model Intercomparison Project 5 (CMIP5) and 6 (CMIP6) GCMs over Yulin City, China. The performance of CMIP5 and CMIP6 GCMs in replicating Global Precipitation Climatology Centre (GPCC) precipitation climatology of the city was evaluated using different statistical metrics. The best performing GCMs common to both CMIP5 and CMIP6 were selected and subsequently downscaled to GPCC resolution using linear scaling method to spatiotemporal changes in precipitation. The study revealed BCC.CSM1.1(m), IPSL.CM5A.LR, MRI.CGCM3 and MIROC5 of CMIP5 and their equivalents BCC-CSM2-MR, IPSL-CM6A-LR, MRI.ESM2.0 and MIRCO6 of CMIP6 as the most suitable GCMs for the projection of rainfall in Yulin. Changes in precipitation were in the range of -14.0 − 0.0% and − 22.0 − 0.2% during 2021−2060 for RCP4.5 and SSP2-4.5 respectively. The highest decrease of -29.7 ̶ -22.0% was projected by MRI-ESM-2-0 for SSP2-4.5, while − 28.0 − -20.0% by MIROC5 for RCP4.5. For RCP8.5 and SSP5-8.5, precipitation was projected to decrease in the range of -17.0 ̶ -2.0% and − 32.0 ̶ 0.0%, respectively during 2021 ̶ 2060 by most of the GCMs. An increase in precipitation up to 12.3% was projected only by IPSL-CM5A-LR for RCP8.5 for this period. The highest decrease was projected by MIROC5 (-40.2 − -29.0%) for RCP8.5 and IPSL-CM6A-LR (-40.2 − -26.0%) for SSP5-8.5. Overall, the results revealed a higher decrease in precipitation in Yulin city by CMIP6 GCMs compared to those projected by their corresponding GCMs of CMIP5 for both scenarios.