In order to investigate the transport of soil particles and pollutants to the ocean and their concentration distribution in the marine atmosphere, atmospheric concentrations of Al, Si, Fe, S and CI were measured in the Pacific Ocean, the Indian Ocean and the Antarctic Ocean. The marine aerosol samples, collected on board the Antarctic observation ship “Shirase”, were analysed by X-ray fluorescence analysis. The samples were taken every day by the low volume air sampler at the flow rate of 20~30 l/min, during the cruises of “Shirase” from Tokyo to Fremantle in November 1988, from Fremantle to Syowa station in December 1988 and from Syowa station to Sydney in March 1989. As a result, the average concentrations of soil derived elements were 11. 9 ng/m3 for Al, 50.6 ng/m3 for Si, 12.6 ng/m3 for Fe, over the western Pacific Ocean between Tokyo and Fremantle. These values were so low as 1/100 of atmospheric concentration in the land. Especially, over the Indian Ocean and the Antarctic Ocean between Fremantle and Syowa station, concentrations were very low, 6.5 ng/m3 for Al, 13.4 ng/m3 for Si, 3.5 ng/m3 for Fe with average. It is considered that these values are the background concentrations of soil derived elements in the marine atmosphere. The main source of S and Cl in the marine atmosphere is sea salt. Therefore, a strong correlation between concentrations of S and Cl was observed over the Indian Ocean and the Antarctic Ocean. However, over the western Pacific Ocean between Tokyo and Fremantle, a correlation between concentrations of S and CI was not observed. The concentration of S was highly correlated with that of soil derived elements. The western Pacific Ocean was not far from the land such as Asia Continent and Southeast Asia. It is considered that S orignated from oil burning in East Asia and Southeast Asia with soil particles. The marine atmosphere over the western Pacific Ocean is strongly influenced by anthropogenic sources in the land.
ASJC Scopus subject areas
- 化学 (全般)