A dual dynamic chamber system based on IBBCEAS for measuring fluxes of nitrous acid in agricultural fields in the North China Plain

High resolution vertical distribution and sources of HONO and NO<sub>2</sub> in the nocturnal boundary layer in urban Beijing, China

“…2c). In addition, the IBBCEAS instrument was also compared with the long optical path absorption photometer (LOPAP) and the stripping coil ion chromatography (SC-IC) in our previous studies (Tang et al, 2019;Duan et al, 2018), which also showed good correlations for HONO measurements (LOPAP: R 2 = 0.894, SC-IC: R 2 = 0.98).…”

High-resolution vertical distribution and sources of HONO and NO<sub>2</sub> in the nocturnal boundary layer in urban Beijing, China

“…A total of 25 %-60 % of daytime OH production was accounted for due to HONO photolysis, according to previous reports (Lu et al, 2012;Ma et al, 2017;Tong et al, 2016;Su et al, 2008b;Huang et al, 2017;Spataro et al, 2013). OH initiates daytime photochemistry and promotes the formation of secondary products (including ozone, O 3 , and peroxyacetyl nitrate, PAN) and secondary aerosols (Alicke et al, 2002;Tang et al, 2015;Kleffmann, 2007;An et al, 2012). In addition, HONO as a nitrosating agent forms carcinogenic nitrosamines (Hanst et al, 1977;Pitts et al, 1978), and its health effects have attracted increasing amounts of concern (Sleiman et al, 2010;Bartolomei et al, 2015;Gómez Alvarez et al, 2014).…”

“…Despite the importance of HONO, the details of the formation processes of HONO in the atmosphere have been debated for decades. New state-of-the-art science instruments have observed much higher daytime HONO concentrations than simulated values from atmospheric chemical models in both rural and urban areas, implying missing HONO sources (Li et al, 2012(Li et al, , 2014Wang et al, 2017;Oswald et al, 2015;Wong et al, 2012;Karamchandani et al, 2015;Kleffmann, 2007;Mendez et al, 2017;Michoud et al, 2014Michoud et al, , 2015Tang et al, 2015;Vogel et al, 2003;Sörgel et al, 2011). Several homogeneous reaction mechanisms for HONO have been proposed, but the latter have been considered irrelevant under actual atmospheric conditions, including photolysis of ortho-substituted nitroaromatics (Bejan et al, 2006) and the reaction of photoexcited NO 2 with H 2 O (Li et al, 2008).…”

Exploration of the atmospheric chemistry of nitrous acid in a coastal city of southeastern China: Results from measurements across four seasons

“…The atmospheric concentrations of both HONO and NO2 were determined using IBBCEAS, which has previously been widely applied to such measurements (Tang et al, 2019;Duan et al, 2018;Min et al, 2016). Multiple reflections in the resonator cavity enhance the length of the effective absorption path, thereby enhancing the detection sensitivity of the instrument.…”

“…Commonly accepted HONO sources include direct emission from motor vehicles (Chang et al, 2016;Kirchstetter et al, 1996;Kramer et al, 2020;Xu et al, 2015) or soil (Su et al, 2011;Tang et al, 2019;Oswald et al, 2013), the homogeneous conversion of NO by OH (Seinfeld and Pandis, 1998;Kleffmann, 2007), and the heterogeneous reaction of NO2 on humid surfaces (Alicke, 2002;Finlayson-Pitts et al, 2003). Other heterogeneous daytime sources, such as photosensitive reduction of NO2 on organic surfaces (Stemmler et al, 2006) and the photolysis of particulate nitrate by ultraviolet (UV) light (Kasibhatla et al, 2018;Romer et al, 2018;Ye et al, 2017;Scharko et al, 2014), have been identified by previous laboratory measurements and field studies.…”