The concentrations of total suspended matter (TSM) and the compositions of organic stable carbon isotopes of TSM and bottom sediments were analyzed to study the sources of TSM and sediments and the transportation proc...The concentrations of total suspended matter (TSM) and the compositions of organic stable carbon isotopes of TSM and bottom sediments were analyzed to study the sources of TSM and sediments and the transportation processes. For this study, 284 TSM samples and 64 sediment ones taken from 67 stations along 7 transects and in 5 layers were collected in the southern Yellow Sea on the cruise in May, 1998. The main sediment transportation pattern in the southern Yellow Sea was obtained by analyzing the distribution characteristics of TSM concentration and particulate organic carbon δ^13C values. It was confirmed from the pattern that the bottom layer plays a more important role than the surface one in the transportation processes of terrigenous material to the central deep-water area of the southern Yellow Sea. The Yellow Sea circulation is an important control factor in determining the sediment transportation pattern in the southern Yellow Sea. The carbon isotope signals of sedimentary organic matter confirmed that the main material in sediments with high sedimentation rate in the Shandong subaqueous delta originated from the modern Yellow River.The terrigenous sediments in the deep-water area of the southern Yellow Sea are mainly from the abandoned Yellow River and the modern Yellow River, and a small portion of them are from the modern Yangtze material. The amount of terrigenous material from Korean Peninsula and its influence range are relatively limited. The conclusions derived from TSM and stable carbon isotopes were further confirmed by another independent material source tracer--PAHs.展开更多
Methods were developed to determine the mass ratios of carbon isotopes in trace amounts of aerosol carbon- ate. A Finnigan MAT 252 mass spectrometer fitted with an on-line Kiel device was to determine the C/12C ratio ...Methods were developed to determine the mass ratios of carbon isotopes in trace amounts of aerosol carbon- ate. A Finnigan MAT 252 mass spectrometer fitted with an on-line Kiel device was to determine the C/12C ratio in CO2 13 produced from the carbonate. A study using these methods was conducted to characterize the carbonate carbon isotopes in aerosol samples collected in Xi’an on dusty and normal days during March and April 2002. Results of the study demonstrate that insights into the origin of the dust can be deduced from its isotopic composition. That is, the δ C of 13 carbonate for dust storm samples ranged from ?1.4‰ to ?4.2‰, and this is consistent with sandy materials in dust source regions upwind. In contrast, for non-dusty days δ13C ranged from ?7.5% to ?9.3‰, which is more similar to fine particles emitted from local surface soils. Comparisons of dust storm aerosols with surface soils from source regions and with aerosol samples collected downwind indicate that the δ C values did not change appreciably during long- 13 range transport. Therefore, carbon isotopes have the poten- tial for distinguishing among source materials, and this ap- proach provides a powerful new tool for identifying dust provenance.展开更多
文摘The concentrations of total suspended matter (TSM) and the compositions of organic stable carbon isotopes of TSM and bottom sediments were analyzed to study the sources of TSM and sediments and the transportation processes. For this study, 284 TSM samples and 64 sediment ones taken from 67 stations along 7 transects and in 5 layers were collected in the southern Yellow Sea on the cruise in May, 1998. The main sediment transportation pattern in the southern Yellow Sea was obtained by analyzing the distribution characteristics of TSM concentration and particulate organic carbon δ^13C values. It was confirmed from the pattern that the bottom layer plays a more important role than the surface one in the transportation processes of terrigenous material to the central deep-water area of the southern Yellow Sea. The Yellow Sea circulation is an important control factor in determining the sediment transportation pattern in the southern Yellow Sea. The carbon isotope signals of sedimentary organic matter confirmed that the main material in sediments with high sedimentation rate in the Shandong subaqueous delta originated from the modern Yellow River.The terrigenous sediments in the deep-water area of the southern Yellow Sea are mainly from the abandoned Yellow River and the modern Yellow River, and a small portion of them are from the modern Yangtze material. The amount of terrigenous material from Korean Peninsula and its influence range are relatively limited. The conclusions derived from TSM and stable carbon isotopes were further confirmed by another independent material source tracer--PAHs.
文摘Methods were developed to determine the mass ratios of carbon isotopes in trace amounts of aerosol carbon- ate. A Finnigan MAT 252 mass spectrometer fitted with an on-line Kiel device was to determine the C/12C ratio in CO2 13 produced from the carbonate. A study using these methods was conducted to characterize the carbonate carbon isotopes in aerosol samples collected in Xi’an on dusty and normal days during March and April 2002. Results of the study demonstrate that insights into the origin of the dust can be deduced from its isotopic composition. That is, the δ C of 13 carbonate for dust storm samples ranged from ?1.4‰ to ?4.2‰, and this is consistent with sandy materials in dust source regions upwind. In contrast, for non-dusty days δ13C ranged from ?7.5% to ?9.3‰, which is more similar to fine particles emitted from local surface soils. Comparisons of dust storm aerosols with surface soils from source regions and with aerosol samples collected downwind indicate that the δ C values did not change appreciably during long- 13 range transport. Therefore, carbon isotopes have the poten- tial for distinguishing among source materials, and this ap- proach provides a powerful new tool for identifying dust provenance.
