Dicarboxylic and Oxocarboxylic Acids in the Arctic Coastal Ocean (Beaufort Sea-Mackenzie Margin)

• Published in: Global Biogeochemical Cycles
• Main Authors: Sempéré, Richard, Vaïtilingom, Mickael, Charrière, Bruno, Kawamura, Kimitaka, Panagiotopoulos, Christos
• Other Authors: Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD), ANR-11-BS56-0022,SAM,Source d'aérosols marins dans l'atmosphère méditerranéenne(2011), European Project: 1674,ESA
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Arctic Ocean; Mackenzie River; bifunctional carboxylic acids; anthropogenic signatures; organic matter; [SDU]Sciences of the Universe [physics]; Arctic; Beaufort Sea; Global warming; Mackenzie river
• Online Access: https://insu.hal.science/insu-03668091; https://insu.hal.science/insu-03668091/document; https://insu.hal.science/insu-03668091/file/Global%20Biogeochemical%20Cycles%20-%202019%20-%20Semp%20r%20-%20Dicarboxylic%20and%20Oxocarboxylic%20Acids%20in%20the%20Arctic%20Coastal%20Ocean%20Beaufort.pdf; https://doi.org/10.1029/2018GB006165

International audience The distribution of bifunctional carboxylic acids (BCAs) is largely reported as primary or secondary organic aerosols. However, sparse studies describe the distribution of these organic compounds in fluvial and marine environments. In the context of a global warming, we present the first results of a study of the distribution of BCAs in a surface Arctic coastal area near the mouth of the Mackenzie River. These results showed that the Beaufort Sea is an area with elevated BCA content among which glyoxylic acid is predominant, in contrast to low concentrations and predominance of oxalic acid in aerosols reported elsewhere. The carbon fraction of BCAs represents 1.8% to 4.5% of dissolved organic carbon pool in Arctic Ocean. This study reinforces the hypothesis that aquatic biological processes govern the molecular distribution of BCA in marine/river waters, whereas photochemical oxidation reactions regulate their molecular distribution in rain and aerosols. Our results indicate that the Mackenzie River is an important source of BCAs in the Arctic Ocean during July-October period, with a first estimate of 35 × 10 3 tons of BCAs including 12 × 10 3 tons of diacids and 23 × 10 3 tons of oxoacids.