Objectives and Questions

Emissions, air quality, and climate in urban areas

SUNVEx will determine organic emissions and chemistry, including of understudied volatile chemical products (VCPs).

1. How well do current emission inventories quantify the flux of anthropogenic VOC emissions over North American cities, including VCPs, mobile sources, cooking, and industrial facilities?
2. How does the relative distribution of VOC emissions vary by city and population density, influencing the ratio of VCP to mobile source emissions?
3. What chemical tracers can be used to source apportion VOCs amongst VCPs, energy-related, cooking, and biogenic sources?
4. What is the composition of gas- and aerosol phase organics in the urban atmosphere, including aromatics, alkanes, terpenes, cycloalkanes, oxygenated VOCs (including water-soluble organics such as alcohols, esters, glycols, and glycol ethers), and organic aerosol?

Determine reactive nitrogen emissions and chemistry in major urban corridor(s).

5. How well do current emission inventories quantify the flux of anthropogenic nitrogen oxides (NOx = NO + NO₂) over North American cities, including from mobile sources, buildings, industrial facilities, and outlying agricultural regions and power generation?
6. How have NOx emissions changed between SUNVEx and previous LA campaigns?

Quantify co-benefits between managing air quality and the carbon cycle.

7. How well do current emission inventories quantify the flux of anthropogenic CO₂ and CH₄ emissions over North American cities, including from mobile sources, buildings, industrial facilities, natural gas infrastructure, and landfills?

Investigate urban meteorology, to better understand extreme heat on urban air quality.

8. How does extreme heat affect urban and coastal meteorology, photochemistry, and ozone and aerosol formation?