Improving Air Quality Predictions with ASIA-AQ Observations of VOCs

Accurate air quality models are a key component of efforts to reduce pollution affecting human and ecosystem health.  These models provide forecasts so real-time mitigation efforts can be enacted, as well as providing assessments of potential long-term emissions control measures.  The representation of volatile organics compounds (VOCs) varies greatly among atmospheric chemistry models, both in the lumping of compounds for computational efficiency and due to the great uncertainty in the emissions of hydrocarbons and in their oxidation.  The Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ) during February – March 2024 provided comprehensive observations of atmospheric composition in four urban regions in South Korea, Philippines, Taiwan, and Thailand.  Observations from aircraft provided precise measurements of over 100 specific VOCs by several instruments. Using a variable resolution global model with a 12-km horizontal resolution grid over Asia, MUSICAv0 (Multi-Scale Infrastructure for Chemistry and Aerosols version 0), the sensitivity of ozone to chemical mechanism complexity is being quantified.  The comprehensive suite of VOCs observed allows for detailed evaluation of emissions, both in absolute amounts of specific VOCs as well as relative amounts for identifying different emissions sources (biomass burning, transportation, industry, etc.).  In addition, the model chemical mechanism can be evaluated with source hydrocarbons and oxidation products.  Box model results constrained by observations are also used to evaluate the 3D model estimates of ozone production rates.  This work will lead to improving model predictions of air quality and a framework for identifying emissions control measures.  The contributions of the many members of the ASIA-AQ Science Team are gratefully acknowledged.