Yin Xiaohong, Tang Feng, Huang Zhijiong, Liao Songdi, Sha Qinge, Cheng Peng, Lu Menghua, Li Zhen, Yu Fei, Xu Yuanqian, Shao Min, Zheng Junyu
Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China.
Institute of Mass Spectrometry and Atmospheric Environment, Jinan University, Guangzhou 510632, China.
Sci Total Environ. 2023 Nov 15;899:165737. doi: 10.1016/j.scitotenv.2023.165737. Epub 2023 Jul 24.
Nitrous acid (HONO) plays an important role in the budget of hydroxyl radical (OH) in the atmosphere. However, current chemical transport models (CTMs) typically underestimate ambient concentrations of HONO due to a dearth of high resolution primary HONO emission inventories. To address this issue, we have established a highly resolved bottom-up HONO emission inventory for CTMs in Guangdong province, utilizing the best available domestic measured emission factors and newly obtained activity data. Our results indicate that emissions from various sources in 2020, including soil, on-road traffic, non-road traffic, biomass burning, and stationary combustion, were estimated at 21.5, 10.0, 8.2, 2.5, and 0.7 kt, respectively. Notably, the HONO emissions structure differed between the Pearl River Delta (PRD) and the non-PRD regions. Specifically, traffic sources were the dominant contributors (62 %) to HONO emissions in the PRD, whereas soil sources accounted for the majority (65 %) of those in the non-PRD. Among on-road traffic sources, diesel vehicles played a significant role, contributing 99.7 %. Comparisons with previous methods suggest that HONO emissions from diesel vehicles are underestimated by approximately 2.5 times. Higher HONO emissions, dominated by soil emissions, were observed in summer months, particularly in August. Furthermore, diesel vehicle emissions were pronounced at night, likely contributing to the nighttime accumulation of HONO and the morning peak of OH. The emission inventories developed in this study can be directly applied to widely used CTMs, such as CMAQ, CAMx, WRF-Chem, and NAQPMS, to support the simulation of OH formation and secondary air pollution.
亚硝酸（HONO）在大气中羟基自由基（OH）的收支中起着重要作用。然而，由于缺乏高分辨率的一次HONO排放清单，当前的化学传输模型（CTMs）通常低估了HONO的环境浓度。为了解决这个问题，我们利用国内现有的最佳实测排放因子和新获得的活动数据，建立了广东省CTMs的高分辨率自下而上的HONO排放清单。我们的结果表明，2020年来自各种源的排放，包括土壤、道路移动源、非道路移动源、生物质燃烧和固定燃烧，估计分别为21.5、10.0、8.2、2.5和0.7千吨。值得注意的是，珠江三角洲（PRD）和非PRD地区的HONO排放结构有所不同。具体而言，交通源是PRD地区HONO排放的主要贡献者（62%），而非PRD地区土壤源占大多数（65%）。在道路移动源中，柴油车辆起着重要作用，贡献了99.7%。与以前的方法比较表明，柴油车辆的HONO排放被低估了约2.5倍。在夏季月份，特别是8月，观察到以土壤排放为主的较高HONO排放。此外，柴油车辆排放夜间明显，可能导致HONO的夜间积累和OH的早晨峰值。本研究中开发的排放清单可直接应用于广泛使用的CTMs，如CMAQ、CAMx、WRF-Chem和NAQPMS，以支持OH形成和二次空气污染的模拟。
