Preprints
https://doi.org/10.5194/acp-2022-665
https://doi.org/10.5194/acp-2022-665
 
19 Oct 2022
19 Oct 2022
Status: this preprint is currently under review for the journal ACP.

Summertime fluorescence characteristics of atmospheric water-soluble organic carbon in the marine boundary layer of the western Arctic Ocean

Jinyoung Jung1, Yuzo Miyazaki2, Jin Hur3, Mi Hae Jeon1, Youngju Lee1, Kyoung-Ho Cho1, Hyun Young Chung1,4, Kitae Kim1,4, Jung-Ok Choi1, Catherine Lalande1, Joo-Hong Kim1, Taejin Choi1, Young Jun Yoon1, Eun Jin Yang1, and Sung-Ho Kang1 Jinyoung Jung et al.
  • 1Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea
  • 2Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
  • 3Department of Environment & Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Republic of Korea
  • 4Department of Polar Sciences, University of Science and Technology, Incheon 21990, Republic of Korea

Abstract. Accelerated warming and a decline in sea ice coverage in the summertime Arctic Ocean can significantly affect the emissions of marine organic aerosols and biogenic volatile organic compounds. However, how these changes affect the characteristics of atmospheric water-soluble organic carbon (WSOC), which plays an important role in the climate system, remains unclear. Thus, to improve our understanding of WSOC characteristics, including its summertime fluorescence characteristics, in the rapidly changing Arctic Ocean, we simultaneously measured atmospheric concentrations of ionic species and WSOC, fluorescence excitation–emission matrix coupled with parallel factor (EEM–PARAFAC) analysis of WSOC, and marine biological parameters in surface seawaters of the western Arctic Ocean during the summer of 2016. WSOC was predominantly present as fine-mode aerosols (diameter < 2.5 μm) (median = 92 %) with the mean concentration being higher in the coastal water areas (462 ± 130 ngC m−3) than in the sea ice-covered areas (242 ± 88.4 ngC m−3). Moreover, the WSOC in the fine-mode aerosols was positively correlated with the methanesulfonic acid in the fine-mode aerosol samples collected over the sea ice-covered areas (r = 0.88, p < 0.01, n = 10), suggesting high sea–air gas exchange and emissions of aerosol precursor gases due to sea ice retreat and increasing available solar radiation during the Arctic summer. Two fluorescent components, humic-like C1 and protein-like C2, were identified by the PARAFAC modeling of fine-mode atmospheric WSOC. The two components varied regionally between coastal and sea ice-covered areas, with low and high fluorescence intensities observed over the coastal areas and sea ice-covered areas, respectively. Further, the humification index of WSOC was correlated with the fluorescence intensity ratio of the humic-like C1/protein-like C2 (r = 0.89, p < 0.01) and the WSOC concentration in the fine-mode aerosols (r = 0.66, p < 0.05), with the highest values observed in the coastal areas. Additionally, the WSOC concentration in the fine-mode aerosols was positively correlated with the fluorescence intensity ratio of the humic-like C1/protein-like C2 (r = 0.77, p < 0.01), but was negatively correlated to the biological index (r = −0.69, p < 0.01). Overall, these results suggested that the WSOC in the fine-mode aerosols in the coastal areas showed a higher degree of polycondensation and higher aromaticity compared that in the sea ice-covered areas, where WSOC in the fine-mode aerosols was associated with relatively new, less oxygenated, and biologically-derived secondary organic components. The findings can improve our understanding of the chemical and biological linkages of WSOC at the ocean–sea ice–atmosphere interface.

Jinyoung Jung et al.

Status: open (until 30 Nov 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2022-665', Anonymous Referee #1, 09 Nov 2022 reply
  • RC2: 'Comment on acp-2022-665', Anonymous Referee #2, 15 Nov 2022 reply

Jinyoung Jung et al.

Jinyoung Jung et al.

Viewed

Total article views: 315 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
231 75 9 315 26 2 1
  • HTML: 231
  • PDF: 75
  • XML: 9
  • Total: 315
  • Supplement: 26
  • BibTeX: 2
  • EndNote: 1
Views and downloads (calculated since 19 Oct 2022)
Cumulative views and downloads (calculated since 19 Oct 2022)

Viewed (geographical distribution)

Total article views: 310 (including HTML, PDF, and XML) Thereof 310 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 30 Nov 2022
Download
Short summary
This study examined the summertime fluorescence properties of water-soluble organic carbon (WSOC) in aerosols over the western Arctic Ocean. We found that the WSOC in fine-mode aerosols in coastal areas showed a higher polycondensation degree and aromaticity than in sea ice-covered areas. The fluorescence properties of atmospheric WSOC in the summertime marine Arctic boundary can improve our understanding of the WSOC chemical and biological linkages at the ocean–sea ice–atmosphere interface.
Altmetrics