Abstract
Abstract. Historic records of α-dicarbonyls (glyoxal, methylglyoxal), carboxylic acids (C6–C12 dicarboxylic acids, pinic acid, p-hydroxybenzoic acid, phthalic acid, 4-methylphthalic acid), and ions (oxalate, formate, calcium) were determined with annual resolution in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. Chemical analysis of the organic compounds was conducted using ultra-high-performance liquid chromatography (UHPLC) coupled to electrospray ionization high-resolution mass spectrometry (ESI-HRMS) for dicarbonyls and long-chain carboxylic acids and ion chromatography for short-chain carboxylates. Long-term records of the carboxylic acids and dicarbonyls, as well as their source apportionment, are reported for western Europe. This is the first study comprising long-term trends of dicarbonyls and long-chain dicarboxylic acids (C6–C12) in Alpine precipitation. Source assignment of the organic species present in the ice core was performed using principal component analysis. Our results suggest biomass burning, anthropogenic emissions, and transport of mineral dust to be the main parameters influencing the concentration of organic compounds. Ice core records of several highly correlated compounds (e.g., p-hydroxybenzoic acid, pinic acid, pimelic, and suberic acids) can be related to the forest fire history in southern Switzerland. P-hydroxybenzoic acid was found to be the best organic fire tracer in the study area, revealing the highest correlation with the burned area from fires. Historical records of methylglyoxal, phthalic acid, and dicarboxylic acids adipic acid, sebacic acid, and dodecanedioic acid are comparable with that of anthropogenic emissions of volatile organic compounds (VOCs). The small organic acids, oxalic acid and formic acid, are both highly correlated with calcium, suggesting their records to be affected by changing mineral dust transport to the drilling site.
Highlights
To place recent environmental and climatic changes in a longer-term context, and to disentangle anthropogenic and natural sources of air pollution, information on past atmospheric conditions is necessary
The most abundant organic compound detected in the ice core was formate with an average concentration of 64 ng g−1, followed by oxalate, adipic acid, glyoxal, and pinic acid, with 15.9, 0.52, 0.38, and 0.22 ng g−1, respectively
Long-term measurements of organic trace components such as mono- and dicarboxylic acids and α-dicarbonyls have been reported in an Alpine ice core from upper Grenzgletscher, Switzerland, covering the period 1942–1993
Summary
To place recent environmental and climatic changes in a longer-term context, and to disentangle anthropogenic and natural sources of air pollution, information on past atmospheric conditions is necessary. Müller-Tautges et al.: Historic records of organic compounds from an Alpine glacier et al, 2002; Eichler et al, 2000a; van de Velde et al, 2000; Barbante et al, 2004; Schwikowski et al, 2004; Gabrielli et al, 2005) This was mainly assigned to enhanced anthropogenic emissions of the respective precursors, e.g., enhanced anthropogenic SO2 emissions, resulting in high sulfate concentrations archived in ice. In contrast to the well-established analysis of inorganic species, organic compounds have been analyzed in ice cores to a much smaller extent (Legrand et al, 2013). Short dicarboxylates (C2–C5) were analyzed in distinct sections of Alpine firn and ice cores from Col du Dôme and Colle Gnifetti They were attributed to secondary formation from vegetation emissions (Legrand et al, 2007). Source apportionment of the investigated organic species was performed to evaluate the influence of biogenic emissions, forest fires, as well as anthropogenic emissions on past aerosol composition in western Europe
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
