A reassessment of the budget of formic and acetic acids in the boundary layer at Dumont d'Urville (coastal Antarctica): The role of penguin emissions on the budget of several oxygenated volatile organic compounds

Abstract

[1] Initiated in 1997, the year-round study of formic and acetic acids was maintained until 2011 at the coastal Antarctic site of Dumont d'Urville. The records show that formic and acetic acids are rather abundant in summer with typical mixing ratios of 200 pptv and 700 pptv, respectively. With the aim to constrain their budget, investigations of their potential marine precursors like short-chain alkenes and acetaldehyde were initiated in 2011. Acetic acid levels in December 2010 were four times higher than those observed over summers back to 1997. These unusually high levels were accompanied by unusually high levels of ammonia, and by an enrichment of oxalate in aerosols. These observations suggest that the guano decomposition in the large penguin colonies present at the site was particularly strong under weather conditions encountered in spring 2010 (important snow storms followed by sunny days with mild temperatures). Although being dependent on environmental conditions, this process greatly impacts the local atmospheric budget of acetic acid, acetaldehyde, and acetone during the entire summer season. Present at levels as high as 500 pptv, acetaldehyde may represent the major precursor of acetic acid, alkene-ozone reactions remaining insignificant sources. Far less influenced by penguin emissions, the budget of formic acid remains not fully understood even if alkene-ozone reactions contribute significantly.

Measurements of OH and RO<sub>2</sub> radicals at Dome C, East Antarctica

“…Measurements of acetaldehyde are sparse in Antarctic regions. As discussed by Legrand et al (2012), at the coastal site of DDU an acetaldehyde background mixing ratio close to 80 pptv can be assumed, though this value may be highly variable over the Southern ocean (5 to 50 pptv). Hamer et al (2007) reported a mixing ratio of CH 3 CHO of 60 pptv at the SP.…”

“…For CH 3 COCH 3 a typical mixing ratio of 130 ± 30 pptv was used on the basis of observations made at the SP (Hamer et al, 2007). For CH 3 COOH, Legrand et al (2012) measured 60-70 pptv at Dome C between November and February.…”

Water-soluble organic carbon in snow and ice deposited at Alpine, Greenland, and Antarctic sites: a critical review of available data and their atmospheric relevance

“…Since the recoveries are, however, not zero, OC determinations obtained with a UV method are only referred to as DOC if a sample filtration through a quartz fibre filter was applied prior to OC measurements. Whereas this procedure was applied by Hagler et al (2007a), all the other studies using UV methods (Federer et al, 2008;Twickler et al, 1986;Preunkert et al, 2011;Legrand et al, 2007aLegrand et al, , 2013 do not remove insoluble particles prior OC analysis.…”

High summertime aerosol organic functional group concentrations from marine and seabird sources at Ross Island, Antarctica, during AWARE

“…Sugar, levoglucosan, phenols and anthropogenic persistent organic compounds were measured in ambient aerosols at Mario Zucchelli Station and Concordia Station Barbaro et al, 2016Barbaro et al, , 2017Barbaro et al, , 2015a. Carboxylic acids with low molecular weights were also measured at Mario Zucchelli Station, Concordia Station, and Dumont d'Urville (Barbaro et al, 2017;Legrand et al, 2012).…”