[H-CG23] Adaptation to climate change and its social implementation

[HCG23-P02] Detection and Attribution of Greenhouse gases and Anthropogenic Aerosols to Extreme Temperatures over Africa in CanESM5 Large Ensemble

*Paul Ayodele Adigun¹, koji Dairaku¹, Precious Ebiendele¹ (1.Department of Engineering Mechanics and Energy University of Tsukuba)

Keywords:anthropogenic, , continent , , magnitude, , stratospheric, , solar, irradiance

Observational evidence indicates that Africa has seen a major increasing trend in surface air temperature patterns during the last four decades, leading to increased temperature extremes. In this study, we investigate the possible contribution of anthropogenic forcing and greenhouse forcing to the observed increasing trend in extreme temperatures over the African continent using the Canadian Earth System model version 5 (CanESM5) large ensembles. TXx and TNx show an increase of 0.02°C and 0.03 °C per year from 1950 to 2014, respectively. In comparison, TX90p and TN90p show an increase of about 0.18 °C and 0.15 °C per year, respectively. Our results show that aerosol (AER) forcing slows the pace at which the air warms while anthropogenic forcing majorly greenhouse forcing (GHG) is responsible for the observed increase. CO2 forcing changes the four temperature indices similar to GHG, although with a smaller magnitude. CO2 increases TXx and TNx by 0.02-0.04 °C per year and TX90p and TNX90p by 0.1-0.4 °C per year. CO2 forcing has a strong contribution to extreme temperature across africa as compared to volcanoes, stratospheric ozone, and solar irradiance. The two-signal analysis reveals that anthropogenic (ANT) forcing is responsible for the accelerated increase in temperature extreme across the continent. In TX90p, signals from GHGs, AERs, and NATs can be identified and distinguished, GHG signals can be detected in most indices except TX90p over central East Africa (CEAF).