Studies on ice core records of dicarboxylic acids, ω-oxocarboxylic acids, pyruvic acid, α-dicarbonyls and fatty acids from southern Alaska since 1665 AD : A link to climate change in the Northern Hemisphere

• Main Author: Pokhrel, Ambarish
• Other Authors: 河村, 公隆, 吉川, 久幸, 関, 宰, 宮崎, 雄三, 白岩, 孝行, 鈴木, 德行
• Format: Other/Unknown Material
• Language: English
• Published: Hokkaido University
• Subjects: Fid; Pacific; ice core; Alaska
• Online Access: http://hdl.handle.net/2115/59331; https://doi.org/10.14943/doctoral.k11786

Alaskan ice core (180 m long, 343 years) has been analyzed for a homologousseries of normal (C2 - C11), branched chain (iC4 - iC6), unsaturated (maleic, fumaric,methylmaleic and phthalic), multifunctional dicarboxylic (malic, oxomalonic and 4-oxopimelic), ω-oxocarboxylic acids (ωC2 - ωC9), pyruvic acid, glyoxal andmethylglyoxal using gas chromatography (GC/FID) and GC/mass spectrometry(GC/MS) to understand historical changes in water soluble organic aerosols.Similarly, homologous series of straight chain fatty acids (C12:0 - C30:0) has beendetected by using GC/FID and GC/MS system.Predominance of oxalic acid was found followed by adipic and succinic acid.Molecular distributions of ω-oxocarboxylic acids are characterized by thepredominance of 9-oxononanoic, followed by 4-oxobutanoic and glyoxylic acids.Historical concentrations of diacids, oxoacids and α-dicarbonyls are formed by theoxidation of precursor compounds emitted from biogenic and biomass burningactivities and which are controlled under climate oscillations and similarmeteorological parameters. Historical trends of monoterpene and isoprene SOAtracers showed significant concentrations since the 1660s, which are associated withambient atmospheric temperature and controlled by Aleutine Low.Molecular distributions of fatty acids are characterized by even carbon numberpredominance with a peak at palmitic (C16:0) followed by oleic (C18:1) and myristicacid (C14:0). The historical trends of short-chain fatty acids, together with correlationanalysis with inorganic ions and organic tracers suggest that short-chain fatty acids(except for C12:0 and C15:0) were mainly derived from sea surface micro layers. Incontrast, long-chain fatty acids (C20:0 - C30:0) are originated from terrestrial higherplants, soil organic matter and dusts, which are also linked with GreenlandTemperature Anomaly (GTA). Hence, this study suggests that Alaskan fatty acids arestrongly influenced by Pacific Decadal Oscillation/North Pacific Gyre Oscillationand/or extra tropical North Pacific ...