Comparison of precipitation projections of CMIP5 and CMIP6 global climate models over Yulin, China

Abstract

This study compared precipitation projections of CMIP5 and 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 finally selected and subsequently downscaled to GPCC resolution using linear scaling method to assess spatiotemporal changes in precipitation in the basin. 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 precipitation in Yulin. This study revealed changes in precipitation in the range of −14.0 to 0.0% and −22.0 to 0.2% during 2021−2060 for RCP4.5 and SSP245 scenarios, respectively. The precipitation was projected to decrease more during 2061–2100 for both the scenarios. The highest decrease of −29.7 to −22.0% was projected by MRI-ESM-2-0 for SSP2-45, while −28.0 to −20.0% by MIROC5 for RCP4.5. For RCP8.5 and SSP5-85 scenarios, precipitation was projected to decrease in the range of −17.0 to −2.0% and −32.0 to 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 RCP85 for this period. A further decrease in precipitation was projected by all GCMs during 2061−2100 for both RCP8.5 and SSP5-85 scenarios. The highest decrease was projected by MIROC5 (−40.2 to −29.0%) for RCP8.5 and IPSL-CM6A-LR (−40.2 to −26.0%) for SSP5-85. Overall, the results revealed a higher decrease in precipitation in Yulin City by CMIP6 GCMs compared to that projected by their corresponding GCMs of CMIP5 for both scenarios. This study can be of significance in the planning and mitigation of climate change as it gives insight into the expected changes in precipitation and the possibility of the choices of the best performing GCMs.