Hydrogen chloride-induced surface disordering on ice

Abstract

Characterizing the interaction of hydrogen chloride (HCl) with polar stratospheric cloud ice particles is essential for understanding the processes responsible for ozone depletion. We studied the interaction of gas-phase HCl with ice between 243 and 186 K by using (i) ellipsometry to monitor the ice surface and (ii) coated-wall flow tube experiments, both with chemical ionization mass spectrometry detection of the gas phase. We show that trace amounts of HCl induce formation of a disordered region, or quasi-liquid layer, at the ice surface at stratospheric temperatures. We also show that surface disordering enhances the chlorine activation reaction of HCl with chlorine nitrate (ClONO 2) and also enhances acetic acid (CH 3COOH) adsorption. These results impact our understanding of the chemistry and physics of ice particles in the atmosphere.chlorine activation ͉ ice chemistry ͉ ozone depletion ͉ stratosphere

The adsorption of peroxynitric acid on ice between 230 K and 253 K

“…The observation of reversible adsorption is in agreement with other data available for weak acids or non-acidic species such as H 2 O 2 (Pouvesle et al, 2010), acetone (Winkler et al, 2002;Peybernes et al, 2004;BartelsRausch et al, 2005), formic acid (von Hessberg et al, 2008) and acetic acid (Sokolov and Abbatt, 2002;Symington et al, 2010). For the strong acids HNO 3 and HCl (McNeill et al, 2006) the peak area was significantly lower in the desorption experiments, showing that the adsorption was not reversible for these strong acids. In summary, the uptake of HO 2 NO 2 to the ice surface can be described as reversible adsorption equilibrium at temperatures from 230 K to 253 K.…”

“…Yet, surface modification of the ice by HNO 3 could be important along the first 2 cm of the CWFT. McNeill et al (2006) have observed increased adsorption of acetic acid to ice when another strong acid, HCl, was dosed to the surface at a concentration that induced surface premelting. McNeill et al (2006) observed this increased adsorption at HCl concentrations near the boundary of the solid ice stability regime of the HCl-water phase diagram.…”

“…McNeill et al (2006) have observed increased adsorption of acetic acid to ice when another strong acid, HCl, was dosed to the surface at a concentration that induced surface premelting. McNeill et al (2006) observed this increased adsorption at HCl concentrations near the boundary of the solid ice stability regime of the HCl-water phase diagram. For partial pressures corresponding more to the center of the ice stability regime in the phase diagram no premelting and no increased uptake of acetic acid was observed.…”

Organics in environmental ices: sources, chemistry, and impacts

“…Comparable results have also been obtained with many other oxygenated VOC species, such as acetaldehyde (Petitjean et al, 2009), formic and acetic acids (Jedlovszky et al, 2008;Symington et al, 2010), and alcohols (Kerbrat et al, 2007;Abbatt et al, 2008). A few studies have also shown that the coadsorption of a VOC with another trace gas onto the ice surface can be described well using a competitive Langmuir adsorption model Kerbrat et al, 2010) in the absence of chemically-induced surface changes (McNeill et al, 2006).…”

Surface Snow, Firn and Ice Core Composition in Polar Areas in Relation to Atmospheric Aerosol and Gas Concentrations: Critical Aspects

“…simultaneous condensation of trace gases and water vapour on the ice surface), and dissolution into the quasi-liquid layer (QLL). The impact of QLL should increase by raising the temperature [60]. Abbatt et al [61] measured an enhanced uptake for benzene and acetone at high temperature.…”