Snow‐borne nanosized particles: Abundance, distribution, composition, and significance in ice nucleation processes. Issue 22 (21st November 2015)

• Record Type: Journal Article
• Authors: Rangel‐Alvarado, Rodrigo Benjamin; Nazarenko, Yevgen; Ariya, Parisa A.
• Is Part Of: Journal of geophysical research. Volume 120:Issue 22(2015:Dec.)
• Page Start: 11, 760
• Page End: 11, 774
• Publication Date: 2015-11-21
• Subjects: nanosized particles -- ice nucleation -- snow; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2015JD023773
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: Physicochemical processes of nucleation constitute a major uncertainty in understanding aerosol‐cloud interactions. To improve the knowledge of the ice nucleation process, we characterized physical, chemical, and biological properties of fresh snow using a suite of state‐of‐the‐art techniques based on mass spectrometry, electron microscopy, chromatography, and optical particle sizing. Samples were collected at two North American Arctic sites, as part of international campaigns (2006 and 2009), and in the city of Montreal, Canada, over the last decade. Particle size distribution analyses, in the range of 3 nm to 10 µm, showed that nanosized particles are the most numerous (38–71%) in fresh snow, with a significant portion (11 to 19%) less than 100 nm in size. Particles with diameters less than 200 nm consistently exhibited relatively high ice‐nucleating properties (on average ranged from −19.6 ± 2.4 to −8.1 ± 2.6°C). Chemical analysis of the nanosized fraction suggests that they contain bioorganic materials, such as amino acids, as well as inorganic compounds with similar characteristics to mineral dust. The implication of nanoparticle ubiquity and abundance in diverse snow ecosystems are discussed in the context of their importance in understanding atmospheric nucleation processes. Key Points: The nanosized fraction of particles dominates in snow Nanosized particles in fresh snow show efficient ice nucleating properties The nanosized fraction of particles contains both inorganic and organic matter