Can Column Formaldehyde Observations Inform Air Quality Monitoring Strategies for Ozone and Related Photochemical...

Area of Science:

• Atmospheric Chemistry
• Air Quality Monitoring
• Remote Sensing

Background:

• Previous studies indicated a correlation between formaldehyde column density (ΩHCHO) and surface ozone.
• This relationship was observed using in situ aircraft, ground-based, and airborne remote sensing data.

Purpose of the Study:

• To investigate the correlation between ΩHCHO and surface ozone during the LISTOS and KORUS-AQ campaigns.
• To assess the utility of ΩHCHO as an indicator for air quality monitoring strategies.

Main Methods:

• Analysis of formaldehyde column density (ΩHCHO) and surface ozone data from field campaigns.
• Statistical analysis of temporal and spatial correlations between ΩHCHO and ozone/oxidants.

Main Results:

• Strong temporal (r² = 0.66) and spatial (r² = 0.73) correlations between ΩHCHO and surface ozone were found in the Long Island Sound region.
• In Seoul, ΩHCHO correlated better with Oₓ (ozone and related oxidants) than surface ozone due to NO₂ titration effects.
• The ΩHCHO-Oₓ relationship showed variability, highlighting the need for long-term evaluation.

Conclusions:

• ΩHCHO shows potential for informing ozone monitoring strategies, particularly spatial averages.
• Challenges exist in using satellite-derived ΩHCHO data due to temporal variability.
• Future precise satellite retrievals of ΩHCHO could aid in assessing the effectiveness of surface air quality monitoring networks.