Fractionation of inorganic nitrates in winter Arctic troposphere: Coarse aerosol particles containing inorganic nitrates

Abstract

Abstract. Atmospheric aerosol particles and acidic gases were collected at Ny-Alesund, Norwegian high Arctic, in winter (December -March) of 1994/1995, 1995/1996 and 1996/1997 to understand the sink processes of atmospheric inorganic nitrate and reactive nitrogen oxides. At•nospheric inorganic nitrates were mostly present as particulate NO3-in the coarse mode defined as diameter >2.3 jim) of which major constituents were sea-salt compounds such as Na + and C1-. The number fraction of coarse aerosol particles containing NO3-increased in aged oceanic air masses. The internal mixing between sea-salt particles and inorganic nitrates revealed by individual particle analysis implies that uptake of gaseous HNO3 and/or formation of particulate NO3' through heterogeneous processes occurs on sea-salt particles. A simple uptake model was used to estimate the production rate of particulate NO3-due to these processes. Model calculations showed that the formation of particulate NO3-was mainly due to the uptake of gaseous HNO3 on sea-salt particles in winter Arctic. However, the heterogeneous formation from N:Os and NO3 also makes an important contribution to the formation of particulate NO3-under no and/or weak solar radiation in winter Arctic (polar night). Thus the heterogeneous formation of NO3-on sea-salt particles may play an important role as a sink of reactive nitrogen oxide in winter Arctic.

Nitrate dry deposition in Svalbard

“…However, earlier studies suggest that nitrate in the Ny-Å lesund area is likely associated with sea salt particles with a larger diameter than what is captured by the DMPS (Hara et al, 1999;Teinila¨et al, 2003Teinila¨et al, , 2004. For the period investigated in this study there were no continuous measurements of particulate size distributions in the supermicron size in Ny-Å lesund or at the Zeppelin Station.…”

“…Hence, even adapting the model to fit the submicron v d ðpÀNO 3 Þ previous reported in literature (Petroff and Zhang, 2010 and references there in) would not change this relationship. Taking earlier literature v d estimations (Cadle et al, 1985;Bergin et al, 1995;Nilsson and Rannik, 2001;Zhang et al, 2009) and d p of p-NO 3 in the Arctic (Bergin et al, 1995;Hara et al, 1999;Ianniello et al, 2002;Teinila¨et al, 2003;Teinila¨et al, 2004) into account, the modelled results from the LND run seem to best represent the actual p-NO 3 deposition in the Ny-Å lesund area and will be the one used for further discussion in this work.…”

“…The snow cover itself creates an adhesive surface where a thin layer of non-frozen water is present on the surface of each snow crystal, the Quasi Liquid Layer (Kvlividz et al, 1970). Since the snow pack is also a highly permeable material with a constant exchange of air with the atmosphere (Sturm and Johnson, 1991;Albert and Hardy, 1995;Colbeck, 1997;Albert et al, 2002), the process of dry deposition occurs not only at the surface but also within the top few centimetres of the snow pack (Harder et al, 1996).…”

Microbial Cell Retention in a Melting High Arctic Snowpack, Svalbard

“…The same pattern of higher final concentrations can also be seen for NO 3 -. It is known that atmospheric NO 3 -within the Arctic can occur in association with aerosols (Hara et al, 1999;Teinilä et al, 2003) and with bacteria (Hill et al, 2007). If particles and bacteria remain in the snowpack rather than following the meltwater, as our results suggest, an elevated concentration of associated chemicals (such as NO 3 -) might be expected in the remaining snow.…”

The MESSy aerosol submodel MADE3 (v2.0b): description and a box model test

“…A number of measurements suggest that aerosol NO 3 may primarily partition to the coarse mode both under clean marine conditions and when marine aerosol is affected by anthropogenic pollution (Kerminen et al, 1997;Hara et al, 1999;Yeatman et al, 2001;Cavalli et al, 2004;Nolte et al, 2008). However, in the assessment of the ship emissions' effects on climate by Peters et al ( , 2013, NO 3 formation was not included at all, and the low-sulfur shipping fuel studies by Lauer et al (2009) and Righi et al (2011) did not include interactions of condensable gases with coarse mode particles (except for water vapour).…”