Measurements of atmospheric gaseous elemental mercury (GEM) and GEM fluxes in the seas of Southeast Asia in October-December 2019
- 1Pacific Oceanological Institute of Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russian Federation (pacific@poi.dvo.ru)
- 2Institute of Marine Geology and Geophysics of Vietnam Academy of Science and Technology, Hanoy, Vietnam (nbhuong@imgg.vast.vn)
Measurements of gaseous elemental mercury (GEM) in the marine boundary layer (MBL) and GEM evasion fluxes were carried out during the Russian-Vietnam cruise conducted from the Sea of Japan to the South China Sea from October 25 to December 7, 2019. All GEM measurements were performed using two RA-915M mercury analysers (Lumex LLC, Russia). Atmospheric GEM concentrations were measured at two levels (about 2 m and 20 m above the sea surface) with a time resolution of 30 minutes. GEM fluxes were measured in the South China Sea using a dynamic flux chamber.
GEM concentrations ranged between 0.56 ng/m3 and 25.47 ng/m3, and between 0.39 ng/m3 and 23.95 ng/m3 with medians of 1.38 ng/m3 and 1.45 ng/m3 for 2 m and 20 m measurements, respectively. GEM concentrations were significantly affected by air transport of GEM. Concentration Weighted Trajectory (CWT) analysis showed several source regions potentially influencing GEM concentrations in the ambient air during the cruise: the south of the South China Sea, Vietnam, the southeastern China, the south of Japan and the Korean peninsula. Maximum concentrations (up to 25 ng/m3) were registered in Haiphong (Vietnam).
Hg(0) fluxes measured at 7 stations in the South China Sea ranged from 1.1 ng/m2/h to 2.5 ng/m2/h, with median value of 2.07 ng/m2/h. These values were 1,5 times higher than those that were measured by the same method in the Sea of Japan and the Sea of Okhotsk a month earlier.
This work was supported by the Russian Science Foundation (RSF) (Project № 19-77-10011).
How to cite: Kalinchuk, V., Lopatnikov, E., Astakhov, A., Ivanov, M., Shakirov, R., and Cuong, D. H.: Measurements of atmospheric gaseous elemental mercury (GEM) and GEM fluxes in the seas of Southeast Asia in October-December 2019, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12394, https://doi.org/10.5194/egusphere-egu2020-12394, 2020