The Significant Contribution of Polycyclic Aromatic Nitrogen Heterocycles to Light Absorption in the Winter North China Plain

By quantifying the absorption of black carbon (BC), brown (BrC) and lensing effect, we found that BrC dominates total at 450 nm, largest contribution proportion could reach 78.3% during heavy pollution. The average enhancement (Eabs) 530 nm was only 1.38, indicating BC is not coated well here. value Ångstrom exponent (AAE) between 5.3, suggesting a high concentration in Wangdu. CHN+ greatest contributor to light molecules detected MSOC with 12.2–22.4%, which polycyclic aromatic nitrogen heterocycles (PANHs) were dominant compounds. C6H5NO3 its homologous series accounted for 3.0–11.3%, C15H9N series, including one C16H11N three C17H13N compounds, 5.1–12.3%. these PANHs comparable nitro–aromatics, should attract more attention impact climate radiative forcing.