Tropospheric ozone in CMIP6 simulations

Abstract. The evolution of tropospheric ozone from 1850 to 2100 has been studied using data Phase 6 the Coupled Model Intercomparison Project (CMIP6). We evaluate long-term changes coupled atmosphere–ocean chemistry–climate models, focusing on CMIP Historical and ScenarioMIP ssp370 experiments, for which detailed tropospheric-ozone diagnostics were archived. model ensemble evaluated against a suite surface, sonde satellite observations past several decades found reproduce well salient spatial, seasonal decadal variability trends. multi-model mean burden increases 247 ± 36 Tg in value 356 31 period 2005–2014, an increase 44 %. Modelled present-day values agree with previous determinations (ACCENT: 336 27 Tg; Atmospheric Chemistry Climate Project, ACCMIP: 337 23 Tropospheric Ozone Assessment Report, TOAR: 340 34 Tg). In 416 35 by 2100. budget examined over same lumped production (PO3) loss (LO3) diagnostics. Both chemical terms steadily 2100, net (PO3-LO3) reaching maximum around year 2000. residual term, contains contributions stratosphere–troposphere transport reaches minimum time before recovering 21st century, while dry deposition 1850–2100. Differences between are explained variation tropopause height stratospheric burden.