Quantifying Nitrous Acid Formation Mechanisms Using Measured Vertical Profiles During the CalNex 2010 Campaign and 1D Column Modeling

Autor: James Flynn, Jochen Stutz, Shaddy Ahmed, Rebecca A. Washenfelder, Katie Tuite, Sébastien Dusanter, O. Pikelnaya, Louisa K. Emmons, Stephen M. Griffith, Si-Wan Kim, Cora J. Young, Philip S. Stevens, Catalina Tsai, Patrick R. Veres, Jennie L. Thomas, James M. Roberts
Přispěvatelé: Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), University of California [Los Angeles] (UCLA), University of California-University of California, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), National Oceanic and Atmospheric Administration (NOAA), Indiana University [Bloomington], Indiana University System, National Central University [Taiwan] (NCU), Centre for Energy and Environment (CERI EE), Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), University of Houston, Atmospheric Chemistry Observations and Modeling Laboratory (ACOML), National Center for Atmospheric Research [Boulder] (NCAR), Yonsei University, York University [Toronto], University of California (UC)-University of California (UC), Centre for Energy and Environment (CERI EE - IMT Nord Europe), Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Nord Europe)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of Geophysical Research: Atmospheres
Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2021, 126 (13), pp.e2021JD034689. ⟨10.1029/2021JD034689⟩
Journal of Geophysical Research: Atmospheres, 2021, 126 (13), pp.e2021JD034689. ⟨10.1029/2021JD034689⟩
ISSN: 2169-897X
2169-8996
Popis: International audience; Nitrous acid (HONO) is an important radical precursor that can impact secondary pollutant levels, especially in urban environments. Due to uncertainties in its heterogeneous formation mechanisms, models often under predict HONO concentrations. A number of heterogeneous sources at the ground have been proposed but there is no consensus about which play a significant role in the urban boundary layer. We present a new one-dimensional chemistry and transport model which performs surface chemistry based on molecular collisions and chemical conversion, allowing us to add detailed HONO formation chemistry at the ground. We conducted model runs for the 2010 CalNex campaign, finding good agreement with observations for key species such as O3, NOx, and HOx. With the ground sources implemented, the model captures the diurnal and vertical profile of the HONO observations. Primary HOx production from HONO photolysis is 2–3 times more important than O3 or HCHO photolysis at mid-day, below 10 m. The HONO concentration, and its contribution to HOx, decreases quickly with altitude. Heterogeneous chemistry at the ground provided a HONO source of 2.5 × 1011 molecules cm−2 s−1 during the day and 5 × 1010 molecules cm−2 s−1 at night. The night time source was dominated by NO2 hydrolysis. During the day, photolysis of surface HNO3/nitrate contributed 45%–60% and photo-enhanced conversion of NO2 contributed 20%–45%. Sensitivity studies addressing the uncertainties in both photolytic mechanisms show that, while the relative contribution of either source can vary, HNO3/nitrate is required to produce a surface HONO source that is strong enough to explain observations.
Databáze: OpenAIRE
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