Molecular Distributions and Compound-Specific Stable Carbon Isotopic Compositions of Plant Wax n -Alkanes in Marine Aerosols along a North–South Transect in the Arctic–Northwest Pacific Region

• Published in: Atmosphere
• Main Authors: Jung-Hyun Kim, Jiyeon Park, Sol-Bin Kim, Kyung-Hoon Shin, Sookwan Kim, Yeontae Gim
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: marine aerosol; n -alkanes; compound-specific carbon isotopes; Arctic Ocean; northwest Pacific Ocean; Meteorology. Climatology; QC851-999; Arctic; Pacific
• Online Access: https://doi.org/10.3390/atmos11050499; https://doaj.org/article/04c26fd3078545c1ba15b4802a82a78e

A geographical source of n -alkanes in marine aerosols was assessed along a North–South transect in the Arctic–Northwest Pacific region. Marine aerosol samples were collected during the ARA08 cruise with the R/V Araon between 28 August and 28 September 2017. We investigated molecular distributions of n -alkanes (homologous series of C 16 to C 34 ) and compound-specific stable carbon isotopes (δ 13 C) of n -C 27 , n -C 29 , and n -C 31 . Unresolved complex mixtures (UCM) showed a latitudinal trend from the Arctic Ocean to the northwest Pacific Ocean, highlighting an increasing influence of the plume of polluted air exported from East Asian countries. The anthropogenic input was further evidenced by high U/R ratios (>5) and low CPI 17–23 (0.6–1.4). The occurrence of high molecular weight (HMW) n -alkanes with high CPI 27–31 (>3) indicated the biogenic input of terrestrial higher plant leaf waxes in all studied samples. The δ 13 C of HMW n -alkanes was influenced by both the relative contributions from the C 3 /C 4 plant sources and from fossil fuel combustions. The back-trajectory analyses provided evidence that changes in molecular distributions and δ 13 C of n -alkanes were due to the long-range atmospheric transport of anthropogenic and biogenic organic materials from North American and East Asian countries to the Arctic Ocean and the remote northwest Pacific Ocean, respectively.