研究人员在遥远的大西洋对流层使用飞机和地面观测HONO，研究展示了混合海洋气溶胶发生再氧化的证据，其效率随着相对湿度的增加而增加，随着pNO3-浓度的降低而降低。从而在很大程度上调和了在多个实验室和现场研究中发现的再氧化光解速率常数的巨大差异。从气溶胶中主动释放HONO对污染环境和清洁环境中的OH和臭氧等大气氧化剂具有重要意义。
据悉，硝酸盐颗粒物(pNO3-)长期以来一直被认为是氮氧化物(一氧化氮和二氧化氮)的永久汇，可以去除对空气质量至关重要并影响全球大气自清洁能力的气体污染物。有证据表明pNO3-的光解作用可以将HONO和氮氧化物循环回气相，对对流层臭氧和OH预算具有潜在的重要影响;然而，“再氧化”光解速率常数上存在着实质性的差异。
附：英文原文
Title: Extensive field evidence for the release of HONO from the photolysis of nitrate aerosols
Author: Simone T. Andersen, Lucy J. Carpenter, Chris Reed, James D. Lee, Rosie Chance, Tomás Sherwen, Adam R. Vaughan, Jordan Stewart, Pete M. Edwards, William J. Bloss, Roberto Sommariva, Leigh R. Crilley, Graeme J. Nott, Luis Neves, Katie Read, Dwayne E. Heard, Paul W. Seakins, Lisa K. Whalley, Graham A. Boustead, Lauren T. Fleming, Daniel Stone, Khanneh Wadinga Fomba
Issue&Volume: 2023-01-18
Abstract: Particulate nitrate (pNO3-) has long been considered a permanent sink for NOx (NO and NO2), removing a gaseous pollutant that is central to air quality and that influences the global self-cleansing capacity of the atmosphere. Evidence is emerging that photolysis of pNO3- can recycle HONO and NOx back to the gas phase with potentially important implications for tropospheric ozone and OH budgets; however, there are substantial discrepancies in “renoxification” photolysis rate constants. Using aircraft and ground-based HONO observations in the remote Atlantic troposphere, we show evidence for renoxification occurring on mixed marine aerosols with an efficiency that increases with relative humidity and decreases with the concentration of pNO3-, thus largely reconciling the very large discrepancies in renoxification photolysis rate constants found across multiple laboratory and field studies. Active release of HONO from aerosol has important implications for atmospheric oxidants such as OH and O3 in both polluted and clean environments.
DOI: add6266
Source: https://www.science.org/doi/10.1126/sciadv.add6266