Ozone Production Underestimation Over the Tibetan Plateau: The Role of NOx and OVOCs Modeling Uncertainties

Abstract Chemical production and destruction are key components of the tropospheric ozone (O 3 ) budget, yet significant model spreads exist among various global models in estimating O 3 chemical budgets. Observations in the background atmospheres play a crucial role in validating and evaluating model uncertainties in O 3 chemistry. Here, we conducted comprehensive observations of the O 3 chemical budget at a remote site on the Tibetan Plateau. By comparing the observed O 3 chemical budgets with those simulated by GEOS‐Chem, a global chemical transport model, we identified a 60% underestimation in the O 3 production rate by GEOS‐Chem. Detailed budget analysis of O 3 and radicals revealed that this discrepancy primarily arose from GEOS‐Chem's inadequate representation of nitrogen oxides (NO x ), followed by oxygenated volatile organic compounds (OVOCs). Comparisons with previous studies indicate a widespread model bias in simulating O 3 precursors and their chemical budgets. These findings underscore the challenges in understanding O 3 chemistry linked to our imperfect understanding of the atmospheric fate of NO x and OVOCs.