A case study on the cyclonic eddy generated by the tropical cyclone looping over the northern South China Sea (NSCS) is presented, using TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature (SST) data. Thre...A case study on the cyclonic eddy generated by the tropical cyclone looping over the northern South China Sea (NSCS) is presented, using TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature (SST) data. Three cases relating to the tropical cyclone events (Typhoon Kai-Tak in July 2000, Tropical Storm Russ in June 1994 and Tropical Storm Maria in August-September 2000) over the NSCS have been analyzed. For each looping tropical cyclone case, the cyclonic eddy with an obvious sea level depression appears in the sea area where the tropical cyclone takes a loop form, and lasts for about 2 weeks with a slight variation in location. The cold core with the SST difference greater than 2℃against its surrounding areas is also observed by the satellite-derived SST data.展开更多
Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia...Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia pacifica in the Xiamen Bay were determined by the presence of nauplii in the laboratory. The number of viable eggs var/ed temporally and spatially. The maximum number (9.2×10^4m^-2) of viable eggs was in summer. In spring the average abundance of viable eggs was 5.6×10^4 m^-2. The abundances of viable eggs in fall and winter were similar, respectively 2.7×10^4 and 3.3×10^4m^-2, which were the lowest in the year. The numbers of viable eggs inside the stations of the Xiamen Bay were higher than those outside the stations. The viable eggs were found at all depths (0-10 cm),although not in every station. The maximum number did not necessarily occur in the uppermost centimeter of the sediments but often occurred several centimeters below the water-sediment interface. The accumulation of viable eggs in the seabed of a subtropical bay constitutes a potential source of recruitment of nauplii into the pelagic population.展开更多
Heavy minerals with a size range of 0.125￣0.250 mm in the surficial sediment of Minjiang Estuary are studied. Thirty-four heavy min- erals have been identified, with an average content of 1.92%. Major minerals includ...Heavy minerals with a size range of 0.125￣0.250 mm in the surficial sediment of Minjiang Estuary are studied. Thirty-four heavy min- erals have been identified, with an average content of 1.92%. Major minerals include magnetite, epidote, hematite, hornblende, il- menite, and zircon mica. These types are the same as those in the 0.063￣0.125 mm range; however, the average content is lower, which reveals that the heavy minerals in Minjiang Estuary are mainly enriched in the very-fine sand fraction. According to the content and distribution characteristics of the major heavy minerals, Minjiang Estuary can be divided into 4 mineral assemblage zones. In each zone the assemblage of heavy minerals is greatly affected by the hydrodynamic condition and the sedimentary environment. Heavy mineral types also show that detrital matters in Minjiang Estuary are originated from the weathering and erosion of the bedrock in the Minjiang River drainage area.展开更多
Chemical forms of phosphorus in the sediments of the Daya Bay, the Zhujiang River estuary , and the Xiamen Bay are measured with extraction solutions of MgCl2, NaOH, and HC1. Their availabilities to Chlorella sp. and ...Chemical forms of phosphorus in the sediments of the Daya Bay, the Zhujiang River estuary , and the Xiamen Bay are measured with extraction solutions of MgCl2, NaOH, and HC1. Their availabilities to Chlorella sp. and Isochrysis galbana are estimated by using sediments as the sole source of P in the bioassays. The results show that the contents of total phosphorus (TP) in these sediments are 449.3, 650.1 and 643.9 mg/kg, respectively. The contents of non-apatite inorganic P (NAIP) extracted with MgCl2 and NaOH from 3 sediments are 168.8, 146.6 and 118.1 mg/kg, respectively, and account for 18.3% -32.6% of TP. The phosphorus extracted with HC1 solution is greater than that extracted with NaOH solution and the lowest extracted P is MgCl2-extractable P. The greatest relative growth rates of Chlorella sp. and Isochrysis galbana cultured with sediments are in the range of 4.3% -26.9%. The increasing biomasses of these algae correspond to NAIP and AAPP (the estimated algal-available particulate P). AAPP accounts for 42.4% -78.2% of NAIP, 21.1 % - 27.1% of total inorganic P, and 11.8% - 20.3% of TP, respectively.展开更多
The composition, assemblage and distribution characteristics of heavy minerals from 63 to 125 μm grain sizes in surface sediment from the Xinghua Bay (17 stations) are studied. The matter source of silt and the relat...The composition, assemblage and distribution characteristics of heavy minerals from 63 to 125 μm grain sizes in surface sediment from the Xinghua Bay (17 stations) are studied. The matter source of silt and the relationship between heavy minerals and sedimentary environment are also discussed. The results show that there are 37 kinds of heavy minerals and the average content of them is 12.08%, which exceeds 6% compared with the Meizhou Bay (5.67%). The dominant minerals are magnetite, hornblende, epidote, ilmenite, hematite, limonite, zircon and so on. Mineral kinds reveal that the sources of silt in this bay are the fluvial input and eroded products of bedrock in circumjacent land and islands of the Xinghua Bay. However, the matter source from outside this bay is less. Four mineral assemblage zones can be divided based on heavy mineral contents and distribution characteristics in the Xinghua Bay, which are not only influenced by matter source, but also controlled by hydrodynamic condition and sedimentary environment in the Xinghua Bay.展开更多
文摘A case study on the cyclonic eddy generated by the tropical cyclone looping over the northern South China Sea (NSCS) is presented, using TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature (SST) data. Three cases relating to the tropical cyclone events (Typhoon Kai-Tak in July 2000, Tropical Storm Russ in June 1994 and Tropical Storm Maria in August-September 2000) over the NSCS have been analyzed. For each looping tropical cyclone case, the cyclonic eddy with an obvious sea level depression appears in the sea area where the tropical cyclone takes a loop form, and lasts for about 2 weeks with a slight variation in location. The cold core with the SST difference greater than 2℃against its surrounding areas is also observed by the satellite-derived SST data.
文摘Many estuarine and coastal planktonic copepods depend on the hatching of benthic resting eggs for recruitment of nauplii to the water column population. The distribution and abundance of viable resting eggs of Acartia pacifica in the Xiamen Bay were determined by the presence of nauplii in the laboratory. The number of viable eggs var/ed temporally and spatially. The maximum number (9.2×10^4m^-2) of viable eggs was in summer. In spring the average abundance of viable eggs was 5.6×10^4 m^-2. The abundances of viable eggs in fall and winter were similar, respectively 2.7×10^4 and 3.3×10^4m^-2, which were the lowest in the year. The numbers of viable eggs inside the stations of the Xiamen Bay were higher than those outside the stations. The viable eggs were found at all depths (0-10 cm),although not in every station. The maximum number did not necessarily occur in the uppermost centimeter of the sediments but often occurred several centimeters below the water-sediment interface. The accumulation of viable eggs in the seabed of a subtropical bay constitutes a potential source of recruitment of nauplii into the pelagic population.
基金suported by the natural science of Fujian(No.D94014)
文摘Heavy minerals with a size range of 0.125￣0.250 mm in the surficial sediment of Minjiang Estuary are studied. Thirty-four heavy min- erals have been identified, with an average content of 1.92%. Major minerals include magnetite, epidote, hematite, hornblende, il- menite, and zircon mica. These types are the same as those in the 0.063￣0.125 mm range; however, the average content is lower, which reveals that the heavy minerals in Minjiang Estuary are mainly enriched in the very-fine sand fraction. According to the content and distribution characteristics of the major heavy minerals, Minjiang Estuary can be divided into 4 mineral assemblage zones. In each zone the assemblage of heavy minerals is greatly affected by the hydrodynamic condition and the sedimentary environment. Heavy mineral types also show that detrital matters in Minjiang Estuary are originated from the weathering and erosion of the bedrock in the Minjiang River drainage area.
文摘Chemical forms of phosphorus in the sediments of the Daya Bay, the Zhujiang River estuary , and the Xiamen Bay are measured with extraction solutions of MgCl2, NaOH, and HC1. Their availabilities to Chlorella sp. and Isochrysis galbana are estimated by using sediments as the sole source of P in the bioassays. The results show that the contents of total phosphorus (TP) in these sediments are 449.3, 650.1 and 643.9 mg/kg, respectively. The contents of non-apatite inorganic P (NAIP) extracted with MgCl2 and NaOH from 3 sediments are 168.8, 146.6 and 118.1 mg/kg, respectively, and account for 18.3% -32.6% of TP. The phosphorus extracted with HC1 solution is greater than that extracted with NaOH solution and the lowest extracted P is MgCl2-extractable P. The greatest relative growth rates of Chlorella sp. and Isochrysis galbana cultured with sediments are in the range of 4.3% -26.9%. The increasing biomasses of these algae correspond to NAIP and AAPP (the estimated algal-available particulate P). AAPP accounts for 42.4% -78.2% of NAIP, 21.1 % - 27.1% of total inorganic P, and 11.8% - 20.3% of TP, respectively.
基金supported by the Natural Science Foundation Project of Fujian Province under contract No.D9910006.
文摘The composition, assemblage and distribution characteristics of heavy minerals from 63 to 125 μm grain sizes in surface sediment from the Xinghua Bay (17 stations) are studied. The matter source of silt and the relationship between heavy minerals and sedimentary environment are also discussed. The results show that there are 37 kinds of heavy minerals and the average content of them is 12.08%, which exceeds 6% compared with the Meizhou Bay (5.67%). The dominant minerals are magnetite, hornblende, epidote, ilmenite, hematite, limonite, zircon and so on. Mineral kinds reveal that the sources of silt in this bay are the fluvial input and eroded products of bedrock in circumjacent land and islands of the Xinghua Bay. However, the matter source from outside this bay is less. Four mineral assemblage zones can be divided based on heavy mineral contents and distribution characteristics in the Xinghua Bay, which are not only influenced by matter source, but also controlled by hydrodynamic condition and sedimentary environment in the Xinghua Bay.
