%0 Journal Article
%T Polysaccharides, Proteins, and Phytoplankton Fragments: Four Chemically Distinct Types of Marine Primary Organic Aerosol Classified by Single Particle Spectromicroscopy
%A Lelia N. Hawkins
%A Lynn M. Russell
%J Advances in Meteorology
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/612132
%X Carbon-containing aerosol particles collected in the Arctic and southeastern Pacific marine boundary layers show distinct chemical signatures of proteins, calcareous phytoplankton, and two types of polysaccharides in Near-Edge Absorption X-ray Fine Structure (NEXAFS) spectromicroscopy. Arctic samples contained mostly supermicron sea salt cuboids with a polysaccharide-like organic coating. Southeastern Pacific samples contained both continental and marine aerosol types; of the 28 analyzed marine particles, 19 were characterized by sharp alkane and inorganic carbonate peaks in NEXAFS spectra and are identified as fragments of calcareous phytoplankton. Submicron spherical particles with spectral similarities to carbohydrate-like marine sediments were also observed in Pacific samples. In both regions, supermicron amide and alkane-containing particles resembling marine proteinaceous material were observed. These four chemical types provide a framework that incorporates several independent reports of previous marine aerosol observations, showing the diversity of the composition and morphology of ocean-derived primary particles. 1. Introduction The transfer of organic components from the ocean surface to marine aerosol through bubble bursting was shown over 40 years ago [1¨C3]. These components, referred to as ¡°marine primary organic aerosol" or marine POA [4], have been observed to contribute to organic mass in remote and coastal marine locations [3, 5¨C8]. In some cases, primary components have been observed to compose greater than 70% of measured submicron OC [6, 7]. The production of submicron particles from bubble bursting remains a key aspect of the global radiation budget because large particle sources are limited to continental and coastal regions [9]; yet the remote marine atmosphere covers more than half of the earth's surface. In remote regions, marine-derived particles have been estimated to account for up to 90% of cloud condensation nuclei (CCN) [10]. Decreases projected for Arctic sea ice extent in response to climate warming may contribute an additional 40¨C200£¿ng£¿m of aerosol organic carbon (OC) by 2100 from a combination of increased surface ocean productivity and increased spatial extent of wave action [11]. This change in OC is significant considering that background concentrations of less than 1£¿ g m are common in the remote MBL [8, 10, 12¨C15]. In ocean surface waters, rising bubbles scavenge organic material that is transferred to the atmosphere as the bubble bursts [1, 16, 17]. Much of this scavenged organic material has been classified as
%U http://www.hindawi.com/journals/amete/2010/612132/