Particulate organic nitrates (pON) significantly contribute to the mass of organic aerosol and influence the nitrogen oxides cycle in the atmosphere, but their evolution and lifetime remain uncertain. This study performed simultaneous measurements on the anthropogenically affected surface site and the mountain site on top of the polluted planetary boundary layer (PBL). After aging in the PBL, organic nitrate was converted from primary sources (decreased from 8.7% to 4.3%) to secondary sources (increased from 6.3% to 36.1%), spanning from the surface to the mountain. The evaporation of more volatile inorganic nitrate and the production of secondary organic nitrate during aging in the PBL contributed to the enhanced pON fraction over the top of PBL. The contribution of light absorption by brown carbon increased by 57% at the top of PBL compared to the surface, consistent with the higher fraction of nitrogenous organic aerosols over the mountain. The results provide field evidence that the nitrogenous organic aerosols (OA) may be preserved by adding into secondary OA and significantly contribute to the enhanced importance of brown carbon after aging the vertical transport in the PBL.

颗粒状有机硝酸盐 (pON) 对有机气溶胶的质量有显着影响，并影响大气中的氮氧化物循环，但其演变和寿命仍然不确定。这项研究对受人为影响的地表地点和受污染的行星边界层（PBL）顶部的山地进行了同步测量。在 PBL 中老化后，有机硝酸盐从主要来源（从 8.7% 减少到 4.3%）转化为次要来源（从 6.3% 增加到 36.1%），从地表到山区。 PBL 中老化过程中挥发性较高的无机硝酸盐的蒸发和二次有机硝酸盐的产生导致了 PBL 顶部 pON 分数的增加。与表面相比，PBL 顶部棕色碳的光吸收贡献增加了 57%，这与山上含氮有机气溶胶的较高比例一致。结果提供了现场证据，表明含氮有机气溶胶（OA）可以通过添加到二次OA中来保存，并且在PBL中的垂直传输老化后显着有助于提高棕碳的重要性。