The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the ACEAsia campaign from Gosan, Jeju Island, Korea; Sapporo, Japan, and Chichi-jima Island in the western North Pacific, as well as on the NOAA R/V Ronald H. Brown. Total extracts were analyzed by GC-MS to determine both polar and aliphatic compounds. Total particles, organic matter and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean.Secondary oxidation products increase with increasing transport distance and time. The ACEAsia aerosols are comprised not only of desert dust, but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuels use in urban areas.

The presence of saccharides is being reported for aerosols taken in urban, rural, and marine locales. The commonly found primary saccharides are alpha- and beta-glucose, alpha- and beta-fructose, sucrose, and mycose with lesser amounts of other monosaccharides. Saccharide polyols are also found in some airsheds and consist mainly of sorbitol, xylitol, mannitol, erythritol, and glycerol. In temperate climate areas these compounds increase from negligible concentrations in winter aerosols (usually dominated by levoglucosan and related anhydrosaccharides from biomass burning) to a maximum in late spring-summer, followed by a decrease to winter. The composition of the saccharide mixtures suggests soil and associated microbiota as the source. Saccharide analyses of soils confirmed these compositions. Therefore, we propose resuspension of soil (also unpaved road dust) from agricultural activities as a major component of aerosol particles and the saccharides are the source specific tracers. In addition, the saccharides as well as the anhydrosaccharide derivatives from biomass burning are completely water soluble and thus contribute significantly to the total water-soluble mass of aerosols.

[1] Aerosol sampling for major oxygenated organic compounds (dicarboxylic acids, fatty acids, and levoglucosan) was conducted from 15 March to 19 April 2001 on board the National Oceanic and Atmospheric Administration R/V Ronald H. Brown over the western North Pacific, the East China Sea, and the Sea of Japan, as part of the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) campaign. During the cruise, aerosol particles were collected on quartz fiber filters using a high-volume air sampler. Diacids were also collected using an annular denuder sampling system to assess their gas-particle partitioning. Concentrations of total diacids, total fatty acids, and levoglucosan were found to be higher off the coasts of East Asia than in the remote Pacific. Contributions of these organic compounds to total organic carbon and total organic matter (OM) were calculated to be 9.8 ± 2.3% and 19.0 ± 4.8%, respectively, assuming OM to be organic carbon  1.6. Diacid concentrations were highly correlated with nss-SO 4 2À and NO 3 À , which originate from anthropogenic sources over East Asia. The temporal variations and chain-length distributions of fatty acids suggest that atmospheric transport of terrestrial organic materials is important off the coast of the continent. C 2 À C 5 diacids were present predominantly in the particulate phase. The relative abundances of C 2 À C 5 diacids stayed almost unchanged throughout the cruise, suggesting that deposition is more important than chemical decomposition as a sink of diacids and that they are relatively stable end products in the atmosphere.

Atmospheric particles were collected for one year (2001)(2002) at a site Gosan on Jeju Island, South Korea. The samples were analyzed for water-soluble dicarboxylic acids and related compounds using a capillary GC and GC/MS. Total carbon and nitrogen contents, as well as their stable isotopic ratios, were also determined using elemental analyzer (EA) and EA/IR/MS, respectively. Elemental and isotopic analyses were also performed after the HCl vapor treatment of aerosol samples. The results demonstrate that calcium carbonate of dust origin was not a significant component, except for a few dust event samples. Carbonates most likely reacted with acidic species (such as H 2 SO 4 , HNO 3 and organic acids) in the atmosphere during a long-range transport, and did not contribute to the total aerosol carbon, except for few strong dust episodes that occurred in spring. This study also demonstrates that nitrate and ammonium largely contribute to aerosol nitrogen and organic nitrogen is minor component in the Asian aerosols. Acidic aerosols enriched with sulfate likely adsorb NH 3 gas that is emitted from soils in Asia whereas mineral dust particles containing carbonate may adsorb HNO 3 and volatile organic acids.Homologous series of dicarboxylic acids (C 2 -C 12 ) including unsaturated structures as well as ketocarboxylic acids (C 2 -C 9 ) were detected in the aerosol samples with oxalic (C 2 ) acid being the most abundant species followed by malonic (C 3 ) or succinic (C 4 ) acids. Total concentrations of diacids (130-2070 ng m -3 ) are one or two orders of magnitude greater than those reported for remote marine aerosols in the North Pacific, but are equivalent to those reported for urban aerosols. Very high concentrations of dusts (up to 880 µg m -3 ) and watersoluble dicarboxylic acids were often observed in early spring. However, their correlation (r=0.27) is not strong throughout the campaign. Although both mineral dusts and diacids are derived from the Asian continent, they originate from different sources and source regions.Diacids are probably emitted from urban sources in East Asia and produced by secondary photochemical oxidation of their precursors, whereas dusts are derived from the arid interior regions. This study provides evidence for photochemical production of water-soluble organic acids in East Asia and the western North Pacific rim.3