Dialkene‐Induced Radical Cycle Amplification and Reactive Aldehydes Formation: Synergistic Impacts on Ozone Production

Abstract Dialkenes, such as isoprene and 1,3‐butadiene (BD), are highly reactive volatile organic compounds (HRVOCs) that undergo rapid atmospheric oxidation driving radical cycles and secondary pollutant formation. Field measurements in Shanghai, China during spring and summer identified distinct characteristics: anthropogenic BD dominated dialkene levels in spring enhancing formaldehyde (HCHO) formation, whereas biogenic isoprene prevailed in summer correlating with elevated glyoxal (CHOCHO). Box model simulations revealed that dialkene chemistry enhanced RO x cycle rates by over 10% under BD‐dominant and 40% under isoprene‐dominant conditions contributing nearly half of reactive aldehyde formation. Further simulations on O 3 indicate that the reactive aldehydes formed from dialkenes exert an influence nearly equivalent to the direct impact of dialkenes. Varying dialkenes composition and abundance modulate RO x activity and secondary aldehydes formation. Accurate identification of these HRVOCs and their oxidative products is crucial for clarifying primary‐secondary VOC–O 3 interactions and for developing targeted O 3 reduction strategies.