Atmospheric mercury (Hg(0)) concentrations and Hg(0) fluxes in the Sea of Japan and the Okhotsk Sea in fall 2019

2020 ◽  
Author(s):  
Evgeny Lopatnikov ◽  
Viktor Kalinchuk ◽  
Anatoly Astakhov ◽  
Yang Gang ◽  
Jianjun Zou
Keyword(s):  
Sea Of Japan ◽  
Yellow Sea ◽  
Sea Of Okhotsk ◽  
The Yellow Sea ◽  
The Sea Of Japan ◽  
Air Masses ◽  
The Sea Of Okhotsk ◽  
Kurile Islands ◽  
The Pacific ◽  
The Pacific Ocean

<p>Continuous measurements of gaseous elemental mercury (Hg(0)) in the marine boundary layer (MBL) and Hg(0) fluxes were conducted in the Sea of Japan and the Sea of Okhotsk from September 7 to October 17, 2019. All Hg(0) measurements were carried out using two RA-915M mercury analysers (Lumex LLC, Russia). Hg(0) concentrations in the air were measured at two levels (about 2 m and 20 m above the sea surface) with a time resolution of 30 minutes. Hg(0) fluxes were measured at five sample stations using a dynamic flux chamber.</p><p>During the cruise Hg(0) concentrations varied in the range from 0,47 ng/m<sup>3</sup> to 1,55 ng/m<sup>3</sup>, and from 0,31 ng/m<sup>3</sup> to 2,71 ng/m<sup>3</sup> with medians of 0,92 ng/m<sup>3</sup> for 2 m and 20 m, respectively. Atmospheric Hg(0) concentrations in measurements sites were strongly depended on the regions from where air masses came to the study areas. As a result of the Concentration Weighted Trajectory (CWT) analysis we established 2 regions that influenced the Hg(0) concentrations during the cruise: the Northeast China with the Yellow Sea region and the Kurile Islands sector of the Pacific Ocean. The arrival of air masses from China and the Yellow Sea region caused an increase in Hg(0) concentrations in the air in the Sea of Japan and the Sea of Okhotsk. Elevated concentrations were also observed In the Sea of Okhotsk during the periods air masses came from the Kurile Islands sector of the Pacific Ocean.</p><p>Hg(0) fluxes were measured at 3 stations in the Sea of Japan and at 2 stations in the Sea of Okhotsk. The values ranged from 0,57 ng/m<sup>2</sup>/h to 1,55 ng/m<sup>2</sup>/h, with median value of 1,32 ng/m<sup>2</sup>/h. A positive relationships between Hg(0) flux and air and water temperature were observed.</p><p>This work was supported by the Russian Science Foundation (RSF) (Project № 19-77-10011) and by the National Natural Science Foundation of China (Projects №: 41876065, 41420104005, U1606401) and National Program on Global Change and Air-Sea Interaction (Project № GASI-GEOGE-04).</p>

scholarly journals 137Cs concentration in surface waters of Far Eastern seas: Results of expeditionary research in 2018

2020 ◽  
Vol 5 (3) ◽  
pp. 55-63
Author(s):  
O. N. Miroshnichenko ◽  
A. A. Paraskiv
Keyword(s):  
Sea Of Japan ◽  
Surface Waters ◽  
Bering Sea ◽  
Sea Of Okhotsk ◽  
The Sea Of Japan ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Far Eastern ◽  
Far Eastern Seas ◽  
The Bering Sea

Based on the results of expeditionary research carried out during the 82nd cruise of the RV “Akademik M. A. Lavrentyev” (01.06.2018–20.07.2018), the assessment of current levels of concentration activity of technogenic radionuclide 137Cs in surface waters of Far Eastern seas is given. The studies were carried out in the northwestern part of the Sea of Japan, the southern part of the Sea of Okhotsk, the coastal waters of the Pacific Ocean near the Kamchatka Peninsula, and the western part of the Bering Sea. Activity of 137Cs in seawater samples was determined by sorption method using two series-connected adsorbers with subsequent measurement of 137Cs content via its gamma-emitting daughter radionuclide 137mBa. Sorption efficiency was assessed by the difference in activity on the first and second adsorbers. A comparative analysis of contamination levels of water areas studied was made. It was revealed that 137Cs volumetric activity in surface water of the Sea of Japan varied from (2.9 ± 0.1) to (5.1 ± 0.3) Bq·m−3, in the Sea of Okhotsk – from (1.8 ± 0.1) to (2.3 ± 0.1) Bq·m−3, and in the Bering Sea – from (1.7 ± 0.1) to (3.1 ± 0.1) Bq·m−3. The maximum 137Cs concentrations were registered in the Sea of Japan, which might be due to its isolation from other water areas and presence of secondary sources of radionuclide intake. In general, contamination of adjacent water areas is insignificant, and fluctuations in concentrations occur within technogenic isotopes global background in the marginal seas of the Pacific Ocean.

scholarly journals Long-term ocean acidification trends in coastal waters around Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe
Keyword(s):  
Pacific Ocean ◽  
Ocean Acidification ◽  
Sea Of Japan ◽  
Ocean Current ◽  
The Sea Of Japan ◽  
Marginal Seas ◽  
The Pacific ◽  
Activity Measurements ◽  
The Pacific Ocean

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.

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