Results are presented about the changes in chlorophyll a density, carbon fixation and nutrient levels in the surfacewaters of three transects of the southern South China Sea （SCS）, northern Java Sea （JS） and easte...Results are presented about the changes in chlorophyll a density, carbon fixation and nutrient levels in the surfacewaters of three transects of the southern South China Sea （SCS）, northern Java Sea （JS） and eastern Indian Ocean （IO） duringApril 5-16 of 2011. The in situ Chl a concentration and carbon fixation showed decreasing trends from high to low latitudealong the three transects, while the photosynthetic rate of phytoplankton estimated from 14C incorporation displayed no simplevariation with latitude. Chl a concentration and carbon fixation in the IO water was lower than that in the JS water. Highersalinity and lower contents of dissolved inorganic nitrogen （DIN） and silicate （SiO3^2-） characterized the IO water as comparedto the SCS or JS water, and the PO4^3- content was lower in the IO water than in the SCS or JS water in most cases. Our resultsalso indicate the importance of DIN and SiO3^2- concentrations for the geographical changes in phytoplankton biomass andprimary productivity among the three regions.展开更多
On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huanghai Sea (HS) and northern East Chin...On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huanghai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method. The Kuroshio flows northeastward through eastern part of the investigated region and has the main core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2 x 10(6) m(3)/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4 x 10(6) m(3)/s. The Taiwan Warm Current (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea Coastal Current (HSCC) flows southeastward and enters into the northwestern part of investigated region, and flows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan Warm Current and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea Coastal Current flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and cold water is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 at the northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).展开更多
Early proxy-based studies suggested that there potentially occurred a ＂southern drought/northern flood＂ （SDNF） over East China in the mid-Holocene （from roughly 7000 to 5000 years before present）.In this study,w...Early proxy-based studies suggested that there potentially occurred a ＂southern drought/northern flood＂ （SDNF） over East China in the mid-Holocene （from roughly 7000 to 5000 years before present）.In this study,we used both global and regional atmospheric circulation models to demonstrate that the SDNF-namely,the precipitation increases over North China and decreases over the the lower reaches of the Yangtze River Valley--could have taken place in the mid-Holocene.We found that the SDNF in the mid-Holocene was likely caused by the lower SST in the Pacific.The lowered SST and the higher air temperature over China's Mainland increased the land-sea thermal contrast and,as a result,strengthened the East Asian summer monsoon and enhanced the precipitation over North China.展开更多
基金National Natural Science Foundation of China(41206132,41276162,41130855)Chinese Academy of Sciences Strategic Pilot Science and Technology(XDA11020202,XDA05030403)+2 种基金National Project of Basic Sciences and Technology(2012FY112400,2013FY111200)Chinese Academy of Sciences Knowledge Innovation Program(SQ201115)Natural Science Foundation of Guangdong Province(S2011040000151)
文摘Results are presented about the changes in chlorophyll a density, carbon fixation and nutrient levels in the surfacewaters of three transects of the southern South China Sea （SCS）, northern Java Sea （JS） and eastern Indian Ocean （IO） duringApril 5-16 of 2011. The in situ Chl a concentration and carbon fixation showed decreasing trends from high to low latitudealong the three transects, while the photosynthetic rate of phytoplankton estimated from 14C incorporation displayed no simplevariation with latitude. Chl a concentration and carbon fixation in the IO water was lower than that in the JS water. Highersalinity and lower contents of dissolved inorganic nitrogen （DIN） and silicate （SiO3^2-） characterized the IO water as comparedto the SCS or JS water, and the PO4^3- content was lower in the IO water than in the SCS or JS water in most cases. Our resultsalso indicate the importance of DIN and SiO3^2- concentrations for the geographical changes in phytoplankton biomass andprimary productivity among the three regions.
基金National Natural Science Foundation of China under contract No. 40176007Major State Basic Research Program of China under contract No.G 1999043802.
文摘On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huanghai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method. The Kuroshio flows northeastward through eastern part of the investigated region and has the main core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2 x 10(6) m(3)/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4 x 10(6) m(3)/s. The Taiwan Warm Current (TWC) has much effect on the currents over the continental shelf. The Huanghai Sea Coastal Current (HSCC) flows southeastward and enters into the northwestern part of investigated region, and flows to turn cyclonically, and then it flows northeastward, due to the influences of the Taiwan Warm Current and topography. There is a cyclonic eddy south of Cheju Island where the Huanghai Sea Coastal Current flows to turn cyclonically. It has the feature of high dense and cold water. The uniform and cold water is occurred in the layer from about 30 m level to the bottom between Stations C306 and C311 at the northernmost Section C3. It is a southern part of the Huanghai Sea Cold Water Mass (HSCWM).
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences (Grant XDB03020602)the National Natural Science Foundation of China (Grant No. 41130103)+1 种基金the "Strategic Priority Research Program" of the Chinese Academy of Sciences (Grant No. XDA05120703)the "Introduction of Advanced International Forestry Science and Technology" of the State Forestry Administration (2012-4-79)
文摘Early proxy-based studies suggested that there potentially occurred a ＂southern drought/northern flood＂ （SDNF） over East China in the mid-Holocene （from roughly 7000 to 5000 years before present）.In this study,we used both global and regional atmospheric circulation models to demonstrate that the SDNF-namely,the precipitation increases over North China and decreases over the the lower reaches of the Yangtze River Valley--could have taken place in the mid-Holocene.We found that the SDNF in the mid-Holocene was likely caused by the lower SST in the Pacific.The lowered SST and the higher air temperature over China's Mainland increased the land-sea thermal contrast and,as a result,strengthened the East Asian summer monsoon and enhanced the precipitation over North China.
