Parameterization of N<sub>2</sub>O<sub>5</sub> reaction probabilities on the surface of particles containing ammonium, sulfate, and nitrate

Abstract

Abstract.A parameterization was developed for the heterogeneous reaction probability (γ ) of N 2 O 5 as a function of temperature, relative humidity (RH), particle composition, and phase state, for use in advanced air quality models. The reaction probabilities on aqueous NH 4 HSO 4 , (NH 4 ) 2 SO 4 , and NH 4 NO 3 were modeled statistically using data and uncertainty values compiled from seven different laboratory studies. A separate regression model was fit to laboratory data for dry NH 4 HSO 4 and (NH 4 ) 2 SO 4 particles, yielding lower γ values than the corresponding aqueous parameterizations. The regression equations reproduced 80% of the laboratory data within a factor of two and 63% within a factor of 1.5. A fixed value was selected for γ on icecontaining particles based on a review of the literature. The combined parameterization was applied under atmospheric conditions representative of the eastern United States using 3-dimensional fields of temperature, RH, sulfate, nitrate, and ammonium. The resulting spatial distributions of γ were contrasted with three other parameterizations that have been applied in air quality models in the past and with atmospheric observational determinations of γ . Our equations lay the foundation for future research that will parameterize the suppression of γ when inorganic ammoniated particles are mixed or coated with organic material. Our analyses draw attention to a major uncertainty in the available laboratory data at high RH and highlight a critical need for future laboratory measurements of γ at low temperature and high RH to improve model simulations of N 2 O 5 hydrolysis during wintertime conditions.

Review of the global models used within phase 1 of the Chemistry–Climate Model Initiative (CCMI)

“…The look-up table for photolysis rates has been expanded to take account of surface albedo, and a correction to the clear-sky rates is made for clouds following the approach of Chang et al (1987). Hydrolysis of N 2 O 5 in the troposphere has been included, using a monthly varying climatology of sulfate aerosols from a more recent version of the Canadian climate model (von Salzen et al, 2013) and reaction probabilities of Davis et al (2008) assuming ammonium sulfate.…”

Production of N<sub>2</sub>O<sub>5</sub> and ClNO<sub>2</sub> in summer in urban Beijing, China

“…Previous laboratory studies have shown a large variability of γ N 2 O 5 (0.0002-0.3) depending on the physical characteristics of the substrates (e.g., aerosol surfaces, water droplets, and ice and crystal surfaces), environmental conditions (e.g., acidity, relative humidity, and temperature), and chemical composition of aerosol particles (e.g., nitrate, sulfate, black carbon, and organic coating; Sander et al, 2006;Chang et al, 2011;Anttila et al, 2006;Cosman et al, 2008;Thornton and Abbatt, 2005;McNeill et al, 2006). To reveal the effects of each factor on N 2 O 5 /ClNO 2 chemistry, several parameterizations of γ N 2 O 5 and ø have been proposed during the last decade (Riemer et al, 2003;Evans and Jacob, 2005;Anttila et al, 2006;Davis et al, 2008;Riemer et al, 2009;Griffiths et al, 2009). For example, Bertram and Thornton (2009) constructed a parameterization of γ N 2 O 5 as a function of aerosol liquid water, nitrate, and chloride content based on the measurements of laboratory-generated internally mixed chloride-nitrate particles.…”

A parameterization of the heterogeneous hydrolysis of N<sub>2</sub>O<sub>5</sub> for mass-based aerosol models: improvement of particulate nitrate prediction

“…The γ core values can be estimated from previous laboratory experiments (Table 1) of inorganic and primary organic compositions (Davis et al, 2008;Evans and Jacob, 2005, and references therein;). Davis et al (2008) developed a parameterization for N 2 O 5 hydrolysis on ammonium-sulfate-nitrate particles with respect to RH and temperature.…”

“…The γ core values can be estimated from previous laboratory experiments (Table 1) of inorganic and primary organic compositions (Davis et al, 2008;Evans and Jacob, 2005, and references therein;). Davis et al (2008) developed a parameterization for N 2 O 5 hydrolysis on ammonium-sulfate-nitrate particles with respect to RH and temperature. Evans and Jacob (2005) provided the parameterizations for N 2 O 5 hydrolysis on primary organic particles (Thornton et al, 2003), black carbon (Sander et al, 2003), sea salt (Sander et al, 2003), and dust (Bauer et al, 2004); γ core can be derived by a mass-weighted average (Riemer et al, 2003) of each singlecomponent parameterization (Table 1).…”

“…Several laboratory studies reported that γ N 2 O 5 substantially varies with temperature, RH, and particle composition (Mentel et al, 1999;Kane et al, 2001;Hallquist et al, 2003;Chang et al, 2011;Brown and Stutz, 2012;Gaston et al, 2014). Davis et al (2008) developed a parameterization scheme (Davis08) of γ N 2 O 5 for aerosols containing nitrate, sulfate, and ammonium. It was developed on the basis of numerous previous laboratory studies (Badger et al, 2006;Folkers et al, 2003;Hallquist et al, 2003;Folkers, 2002;Kane et al, 2001;Hu and Abbatt, 1997;Mozurkewich and Calvert, 1988) with respect to temperature, RH, and particle compositions.…”