Assessing Anthropogenic Emissions of Volatile Organic Compounds using Satellite Retrievals of Formaldehyde

We evaluate several volatile organic compound (VOC) emission inventories in the Los Angeles Basin with the California Nexus of Air Quality and Climate Change (CalNex) 2010 field campaign data and mesoscale model simulations. In addition, we investigated the role of VOC emissions in the production of O3 and formaldehyde (HCHO). HCHO is a chemical species that is measured from space. Finer HCHO temporal and spatial scales than present retrievals will be available with future geostationary and polar-orbiting satellites. Our modeled O3 and HCHO using either US EPA National Emission Inventory (NEI) 2005 VOC or top-down anthropogenic VOC emissions agree with the observations in Pasadena for both weekdays and weekends. All of our simulations are based on the Fuel-based Inventory for motor-Vehicle Emissions (FIVE) NOx and CO emissions in 2010. The model simulated O3 and HCHO utilizing the NEI 2011 VOC emissions (the most up-to-date EPA inventory) are lower than the observations. Causes for the discrepancies between the observations and model simulations using different VOC emission inventories will be investigated. Our optimized model HCHO simulations and results mimic the enhanced HCHO retrievals from future geostationary and allow us to examine the effectiveness of the future HCHO satellite data for understanding and predicting tropospheric O3 and its precursors.