The three dimensional structure of the western boundary current east of the Vietnam coast was determined from measurements by Argo profiling floats which deployed near the east of the Vietnam Coast in October 2007. Th...The three dimensional structure of the western boundary current east of the Vietnam coast was determined from measurements by Argo profiling floats which deployed near the east of the Vietnam Coast in October 2007. The trajectories of the Argo floats provided robust evidence that there does exist southward flowing current along the Vietnam coast. The southward current begins at about 15°N, 111°E, flowing along the 1 000 m isobath and extending to 5°N south. The estimated surface and parking depth velocities obtained from the floats suggest that this southward current can extend to 1 000 m depth. The mean surface velocity of the western boundary current is about 49 cm/s, with the maximum speed exceeding 100 cm/s occurring at 11.6°N, 109.5°E in the direction of 245°. The mean parking depth (1 000 m) velocity is 12-16 cm/s with the maximum speed of 36 cm/s occurring at 12.1°N, 109.7°E in the direction of 239°. The water mass analysis suggests that the Kuroshio surface water and NPIW are not apparent in the western boundary current although this time was the favored season for the Kuroshio intrusion into Luzon Strait. The mean geostrophic currents suggest that the Kuroshio intrusion into Luzon Strait during October to December 2007 is very weak, as most of the intruding water was carried eastward at 14°N near the western boundary and little flowed southward along the western boundary, providing an explanation for the absence of Kuroshio surface water and NPIW in the water mass analysis. There is a strong cyclonic circulation in the SSCS during this time, which induces a strong mixing in the western boundary companied by a homogeneous salinity layer between 300 600 m in the salinity vertical distribution. No reversal undercurrent occurred at the intermediate depth along the western boundary east of the Vietnam coast during October to December 200%展开更多
Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociat...Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociation. Inthis method, vacuum method, electro-osmosis and chemical flocculation were used comprehensively to separate soilfrom flush fluid. The experiments of the method of "vacuum + electro-osmosis" for drainage was made. After pretreat-ing the flush fluid, suction pressure was offered by the sand well in the bottom and electro-osmosis was used to drainoff water. The results of the experiment show that the good effect can be obtained in drainage when the electric gradi-ent is greater than 8.3 V/cm and the quantity of sand well is more than 6. In industrial production, it is necessary to in-crease the quantity of sand well, to arrange the electrodes rationally and to set up an intermittent electric circuit. On thebasis of the experiments , the industrial feasible flow was put forward. It may be a helpful attempt to apply consolida-tion technology to the fields of the environmental protection and so on.展开更多
The ^226Ra and ^228Ra activities of Qinghai Lake surface water, groundwater, river water, suspended particles, and bottom sediments were measured in a gamma-ray spectrometer. The sources of ^226Ra and ^228Ra were disc...The ^226Ra and ^228Ra activities of Qinghai Lake surface water, groundwater, river water, suspended particles, and bottom sediments were measured in a gamma-ray spectrometer. The sources of ^226Ra and ^228Ra were discussed according to their distribution characteristics. ^226Ra and ^228Ra activities (dpm/(100 L)) ranged from 14.13±0.22 to 19.22±0.42 and 17.724-0.66 to 30.96:kl.47 in the surface water of the North Bay, respectively, and from 7.88±0.24 to 33.80±0.47 and 15.73±0.74 to 57.31±1.44, respectively, in the South Bay. The surface water near the estuary had a lower salinity and had a higher concentration of radium isotopes than the samples collected further away. The farther offshore the sample, the higher the salinity was, and the lower the radium isotope activity. The distribution of radium activities in the western part of Qinghai Lake is controlled by several factors, including Buha River runoff, desorption from suspended particles derived from the river, groundwater discharge, and a small amount of diffusion from the sediment.展开更多
The paper calculates and analyzes physical and chemical characteristics of total suspended particles (TSP), including mass concentration, absorption coefficient, optical refraction index imaginary unit and chemical ...The paper calculates and analyzes physical and chemical characteristics of total suspended particles (TSP), including mass concentration, absorption coefficient, optical refraction index imaginary unit and chemical composition based on observational data of atmosphere aerosol in Xi'an and Nanjing from 1997 to 1999. Enrichment characteristic of TSP elements and sources of pollution are discussed via statistical treatment of enrichment factor of elements and correlation analysis. The result shows that aerosol particles exist remarkable differences in physical and chemical. The highest enrichment in TSP is Pb, Zn, S and As, which comes from different kinds of pollution.展开更多
Brazil and Colombia have large reserves of coal. Those reserves in Brazil are located predominantly in the south and the main reserves in Colombia are located in the north. Despite the relative ease of exploitation, t...Brazil and Colombia have large reserves of coal. Those reserves in Brazil are located predominantly in the south and the main reserves in Colombia are located in the north. Despite the relative ease of exploitation, these resources have been underestimated as a source of energy. Currently, these countries are developing projects and partnerships aiming to qualify this mineral resource, adding quality to the final product of the processing plants. In this scenario, the processing of Brazilian and Colombian coal in flotation columns appears as a promising alternative, having been successful in mineral systems containing fine particles. The paper aims to study the overall process of column flotation for a specific Brazilian coal and a specific Colombian coal. The material used in this study consists of fine coal from Brazil (Copelmi) and Colombia (Cerrejon). The objective is to recover carbonaceous matter and reduce the ash and contaminants grade. The two coals were floated using a negative bias in a 5 cm diameter conventional flotation column of 5 m high. Flotation parameter investigated included air velocity in the range 0.6 to 1.5 cm/s. For all runs, a constant negative bias of-0.25 cm/s and a pulp concentration of 8% w/w were used. For Cerrej6n coal, 300 g/ton of frother and 907 g/ton of collector was used, whereas for Copelmi coal, 600 g/ton of frother and 1,815 g/ton of collector was employed. The frother was a commercial Aerofroth 65 (AF65), whereas the collector was Kerosene. For the Colombian coal, in general, yield, organic recovery, ash recovery and water recovery decreased with the increasing air rate. However, for Brazilian coal the air rate had no significant effect. For Colombian coal, the highest yield (60% w/w) and organic recovery (69% w/w) were obtained at the lowest air rate (0.6 cm/s).展开更多
Changes in sea surface temperature (SST), seawater oxygen isotope (δ18Osw), and local salinity proxy (δ18Osw-ss ) in the past 155 ka were studied using a sediment core (MD06-3052) from the northern edge of t...Changes in sea surface temperature (SST), seawater oxygen isotope (δ18Osw), and local salinity proxy (δ18Osw-ss ) in the past 155 ka were studied using a sediment core (MD06-3052) from the northern edge of the western Pacific Warm Pool (WPWP), within the flow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ18O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO2 profile showed a close connection between the WPWP and the Antarctic. Values of 818Osw exhibited very similar variations to those of mean ocean δ18Osw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ18O reflect a more saline condition during high local summer insolation (SI) periods. Such correspondence between δ18O and local SI in the WPWP may reflect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their influence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.展开更多
Flow cytometric determinations of the abundance distribution picophytoplankton (i.e. Prochlorococcus spp., orange fluorescence and community structure of Svnechococcus spp. and picoeukaryotes) were used for samples ...Flow cytometric determinations of the abundance distribution picophytoplankton (i.e. Prochlorococcus spp., orange fluorescence and community structure of Svnechococcus spp. and picoeukaryotes) were used for samples taken from the Philippine Sea in the western tropical Pacific Ocean from September to October of 2004. A fluorescence probe was employed to detect Chlorophyll a (Chl a). Abundances of Prochlorococcus spp., orange fluorescence Synechococcus spp. and picoeukaryotes ranged from 0.1 to 58×10^3 cells ml^-1, 0.38 to 17×10^2 cells ml^-1 and 0.42 to 26×10^2 cells ml^-1, respectively. Synechococcus spp. and picoeukaryotes co-occurred in relatively shallow water with the maximum abundance observed at 50 to 70 m depth, while Prochlorococcus spp. only occurred in the 70 to 200 m layer. Prochlorococcus spp. was the dominant picophytoplankton population in terms of abundance and biomass. The cell size and carbon biomass content were estimated for the three picophytoplankton groups. In addition, among the three groups of picophytoplankton, the relative contribution of red fluorescence to the total red fluorescence varied with depth. The fluorescence and light scatter properties of individual cells indicated that in the upper 100 m layer, picoeukaryotes were a major contributor to total red fluorescence, while at the depth below 100 m, Prochlorococcus spp. and Synechococcus spp. made an important contribution to the total red fluorescence.展开更多
The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three...The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8℃ and 7.3℃, respectively. The lowest water temperature occurred in winter from December to March at-2℃ and the highest in June and July at 17.7℃. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identifi ed. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included H olophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and A rctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×10^7 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1–3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass(including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was signifi cantly negatively correlated with salinity.展开更多
Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton...Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton fauna in the pelagial of these lakes,approximately 30%in the littoral zone and10%in small northern thermokarst lakes.Biometric measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.展开更多
This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979-2011.The Argos observations manifest some new phenomena.The climatological annual mean circulation shows ...This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979-2011.The Argos observations manifest some new phenomena.The climatological annual mean circulation shows that the surface current becomes much stronger after turning around in shore in the western Indian Ocean.In the tropical Indian Ocean,the Great Whirl(GW) to the east of Somalia develops quickly in spring(April-May) as the monsoon reverses to move northward,becoming strongest in summer(June-September) and disappearing in autumn(October-November).The west end of the Agulhas retroflection can reach 18°E,and it exhibits a seasonal variation.At approximately 90°E,the Agulhas Return Current combines with the eastward South Atlantic Current and finally joins the Antarctic Circumpolar Current.展开更多
Based on the detailed planktonic foraminifera faunal count and Globigerinoides ruber Mg/Ca ratio analysis of Core MD05-2901,we reconstructed the longest Mg/Ca sea surface temperature(SST) sequence of the upwelling are...Based on the detailed planktonic foraminifera faunal count and Globigerinoides ruber Mg/Ca ratio analysis of Core MD05-2901,we reconstructed the longest Mg/Ca sea surface temperature(SST) sequence of the upwelling area off Vietnam in the western South China Sea(SCS).Ocean environment,especially the SST variation,over the last 450 ka is discussed in this study.SST variation has typical glacial/interglacial alternations from 23.03°C to 29.93°C with a glacial/interglacial difference of 4.8°C on average.SST during the interglacial periods fluctuates significantly,up to 5.6°C,which is larger than the average glacial/interglacial difference.SST variation during the glacial periods is much smaller.Spectrum analysis shows that SST change dominates on the typical Milankovitch cycles,such as 112,40.7 and 23.6 ka.Evident leading of SST variation against the δ 18 O can be observed during the Terminations 1,4,and 5,which is confirmed by their cross-spectrum analysis on these cycles.MD05-2901 is the first core in the South China Sea that has multi-SST records,such as SST Mg/Ca,k' 37 U-SST and planktonic foraminiferal fauna-based SST.SSTs from different methods can be correlated with each other in glacial/interglacial time scale,whereas SST Mg/Ca records abrupt climate change events more clearly.SST Mg/Ca at MD05-2901 since MIS 5 is 0.6°C lower than that of the southern SCS on average,but equivalent to or even 2°C lower than that of the northern SCS during some interglacial period.The SST character of MD05-2901 reflects less influence of latitude,but an important role of the regional upwelling driven by the eastern Asian summer monsoon,and suggests a stronger upwelling during the interglacial periods in the western SCS.展开更多
基金Supported by the Knowledge Innovation Projects of Chinese Academy of Sciences(Nos. KZCX2-YW-214, KZCX2-YW-Q11-02)NSFC (No. 40806010)+1 种基金the National Basic Research Program of China "973 Program" (No.2006CB403600)the CAS Key projects, and by the "Hundreds-Talent Program" project of CAS
文摘The three dimensional structure of the western boundary current east of the Vietnam coast was determined from measurements by Argo profiling floats which deployed near the east of the Vietnam Coast in October 2007. The trajectories of the Argo floats provided robust evidence that there does exist southward flowing current along the Vietnam coast. The southward current begins at about 15°N, 111°E, flowing along the 1 000 m isobath and extending to 5°N south. The estimated surface and parking depth velocities obtained from the floats suggest that this southward current can extend to 1 000 m depth. The mean surface velocity of the western boundary current is about 49 cm/s, with the maximum speed exceeding 100 cm/s occurring at 11.6°N, 109.5°E in the direction of 245°. The mean parking depth (1 000 m) velocity is 12-16 cm/s with the maximum speed of 36 cm/s occurring at 12.1°N, 109.7°E in the direction of 239°. The water mass analysis suggests that the Kuroshio surface water and NPIW are not apparent in the western boundary current although this time was the favored season for the Kuroshio intrusion into Luzon Strait. The mean geostrophic currents suggest that the Kuroshio intrusion into Luzon Strait during October to December 2007 is very weak, as most of the intruding water was carried eastward at 14°N near the western boundary and little flowed southward along the western boundary, providing an explanation for the absence of Kuroshio surface water and NPIW in the water mass analysis. There is a strong cyclonic circulation in the SSCS during this time, which induces a strong mixing in the western boundary companied by a homogeneous salinity layer between 300 600 m in the salinity vertical distribution. No reversal undercurrent occurred at the intermediate depth along the western boundary east of the Vietnam coast during October to December 200%
文摘Because there are plenty of clay particles in the flush fluid of Pingguo Aluminum Mine, the consolidationtechnology in geotechnical engineering was adopted to carry out the disassociation of water and soil disassociation. Inthis method, vacuum method, electro-osmosis and chemical flocculation were used comprehensively to separate soilfrom flush fluid. The experiments of the method of "vacuum + electro-osmosis" for drainage was made. After pretreat-ing the flush fluid, suction pressure was offered by the sand well in the bottom and electro-osmosis was used to drainoff water. The results of the experiment show that the good effect can be obtained in drainage when the electric gradi-ent is greater than 8.3 V/cm and the quantity of sand well is more than 6. In industrial production, it is necessary to in-crease the quantity of sand well, to arrange the electrodes rationally and to set up an intermittent electric circuit. On thebasis of the experiments , the industrial feasible flow was put forward. It may be a helpful attempt to apply consolida-tion technology to the fields of the environmental protection and so on.
基金Supported by the"One Hundred Plan"Project of Chinese Academy of Sciences:Groundwater Discharge and Geochemical Processes of Plateau Inland Lakes(No.Y210101028)the Tracer of Groundwater Discharge by Radioactive Isotope(No.Y360051010)
文摘The ^226Ra and ^228Ra activities of Qinghai Lake surface water, groundwater, river water, suspended particles, and bottom sediments were measured in a gamma-ray spectrometer. The sources of ^226Ra and ^228Ra were discussed according to their distribution characteristics. ^226Ra and ^228Ra activities (dpm/(100 L)) ranged from 14.13±0.22 to 19.22±0.42 and 17.724-0.66 to 30.96:kl.47 in the surface water of the North Bay, respectively, and from 7.88±0.24 to 33.80±0.47 and 15.73±0.74 to 57.31±1.44, respectively, in the South Bay. The surface water near the estuary had a lower salinity and had a higher concentration of radium isotopes than the samples collected further away. The farther offshore the sample, the higher the salinity was, and the lower the radium isotope activity. The distribution of radium activities in the western part of Qinghai Lake is controlled by several factors, including Buha River runoff, desorption from suspended particles derived from the river, groundwater discharge, and a small amount of diffusion from the sediment.
文摘The paper calculates and analyzes physical and chemical characteristics of total suspended particles (TSP), including mass concentration, absorption coefficient, optical refraction index imaginary unit and chemical composition based on observational data of atmosphere aerosol in Xi'an and Nanjing from 1997 to 1999. Enrichment characteristic of TSP elements and sources of pollution are discussed via statistical treatment of enrichment factor of elements and correlation analysis. The result shows that aerosol particles exist remarkable differences in physical and chemical. The highest enrichment in TSP is Pb, Zn, S and As, which comes from different kinds of pollution.
文摘Brazil and Colombia have large reserves of coal. Those reserves in Brazil are located predominantly in the south and the main reserves in Colombia are located in the north. Despite the relative ease of exploitation, these resources have been underestimated as a source of energy. Currently, these countries are developing projects and partnerships aiming to qualify this mineral resource, adding quality to the final product of the processing plants. In this scenario, the processing of Brazilian and Colombian coal in flotation columns appears as a promising alternative, having been successful in mineral systems containing fine particles. The paper aims to study the overall process of column flotation for a specific Brazilian coal and a specific Colombian coal. The material used in this study consists of fine coal from Brazil (Copelmi) and Colombia (Cerrejon). The objective is to recover carbonaceous matter and reduce the ash and contaminants grade. The two coals were floated using a negative bias in a 5 cm diameter conventional flotation column of 5 m high. Flotation parameter investigated included air velocity in the range 0.6 to 1.5 cm/s. For all runs, a constant negative bias of-0.25 cm/s and a pulp concentration of 8% w/w were used. For Cerrej6n coal, 300 g/ton of frother and 907 g/ton of collector was used, whereas for Copelmi coal, 600 g/ton of frother and 1,815 g/ton of collector was employed. The frother was a commercial Aerofroth 65 (AF65), whereas the collector was Kerosene. For the Colombian coal, in general, yield, organic recovery, ash recovery and water recovery decreased with the increasing air rate. However, for Brazilian coal the air rate had no significant effect. For Colombian coal, the highest yield (60% w/w) and organic recovery (69% w/w) were obtained at the lowest air rate (0.6 cm/s).
基金Supported by the National Natural Science Foundation of China(Nos.41230959,41076030,41106042,40906038,41206044)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11030104)the Project of Global Change and Air-Sea Interaction
文摘Changes in sea surface temperature (SST), seawater oxygen isotope (δ18Osw), and local salinity proxy (δ18Osw-ss ) in the past 155 ka were studied using a sediment core (MD06-3052) from the northern edge of the western Pacific Warm Pool (WPWP), within the flow path of the bifurcation of the North Equatorial Current. Our records reveal a lead-lag relationship between paired Mg/Ca-SST and δ18O during Termination II and the last interglacial period. Similarity in SST between our site and the Antarctic temperature proxy and in CO2 profile showed a close connection between the WPWP and the Antarctic. Values of 818Osw exhibited very similar variations to those of mean ocean δ18Osw, owing to the past sea-level changes on glacial-interglacial timescale. Calculated values of δ18O reflect a more saline condition during high local summer insolation (SI) periods. Such correspondence between δ18O and local SI in the WPWP may reflect complex interaction between ENSO and monsoon, which was stimulated by changes in solar irradiance and their influence on the local hydrologic cycle. This then caused a striking reorganization of atmospheric circulation over the WPWP.
基金Supported by National Natural Science Foundation of China (No. 40821004)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-213-3)National Basic Research Program of China (973 Program) (No. 2006CB400604)
文摘Flow cytometric determinations of the abundance distribution picophytoplankton (i.e. Prochlorococcus spp., orange fluorescence and community structure of Svnechococcus spp. and picoeukaryotes) were used for samples taken from the Philippine Sea in the western tropical Pacific Ocean from September to October of 2004. A fluorescence probe was employed to detect Chlorophyll a (Chl a). Abundances of Prochlorococcus spp., orange fluorescence Synechococcus spp. and picoeukaryotes ranged from 0.1 to 58×10^3 cells ml^-1, 0.38 to 17×10^2 cells ml^-1 and 0.42 to 26×10^2 cells ml^-1, respectively. Synechococcus spp. and picoeukaryotes co-occurred in relatively shallow water with the maximum abundance observed at 50 to 70 m depth, while Prochlorococcus spp. only occurred in the 70 to 200 m layer. Prochlorococcus spp. was the dominant picophytoplankton population in terms of abundance and biomass. The cell size and carbon biomass content were estimated for the three picophytoplankton groups. In addition, among the three groups of picophytoplankton, the relative contribution of red fluorescence to the total red fluorescence varied with depth. The fluorescence and light scatter properties of individual cells indicated that in the upper 100 m layer, picoeukaryotes were a major contributor to total red fluorescence, while at the depth below 100 m, Prochlorococcus spp. and Synechococcus spp. made an important contribution to the total red fluorescence.
基金Supported by the China Geological Survey(Resources No.[2002]004)the National Natural Science Foundation of China(No.30371112)+1 种基金the Liaoning Science and Technology Foundation(Nos.002119,20022100)the Special Program for Key Basic Research of Ministry of Science and Technology,China(No.2014FY210700)
文摘The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8℃ and 7.3℃, respectively. The lowest water temperature occurred in winter from December to March at-2℃ and the highest in June and July at 17.7℃. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identifi ed. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included H olophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and A rctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×10^7 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1–3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass(including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was signifi cantly negatively correlated with salinity.
基金Supported by the Projects"Modem state,biodiversity and ecology of the shore zone of Baikal"(VI.51.1.10)(2013-2016)the "Dynamics of natural and natural-human systems to climate change and anthropogenic pressures(for example,Trans-Baikal)"(Ⅷ.79.1.2)(2013-2016)
文摘Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars,1863 dominates among crustaceans.In July,its abundance comprised 64%-98%of the total plankton fauna in the pelagial of these lakes,approximately 30%in the littoral zone and10%in small northern thermokarst lakes.Biometric measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.
基金supported by the National Basic Research Program of China(2010CB950302)the Knowledge Innovation Program of the Chinese Academy of Sciences(SQ201108)the National Natural Science Foundation of China (41176024,41176023,and 41149908)
文摘This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979-2011.The Argos observations manifest some new phenomena.The climatological annual mean circulation shows that the surface current becomes much stronger after turning around in shore in the western Indian Ocean.In the tropical Indian Ocean,the Great Whirl(GW) to the east of Somalia develops quickly in spring(April-May) as the monsoon reverses to move northward,becoming strongest in summer(June-September) and disappearing in autumn(October-November).The west end of the Agulhas retroflection can reach 18°E,and it exhibits a seasonal variation.At approximately 90°E,the Agulhas Return Current combines with the eastward South Atlantic Current and finally joins the Antarctic Circumpolar Current.
基金supported by the CAS Knowledge Innovation Projects (Grant No.KZCX-YW-155-2)National Natural Science Foundation of China (Grant Nos. 40879020 and 41106035)+1 种基金National Basic Research Program of China (Grant No. 2007CB815902)State Key Laboratory of Marine Geology,Tongji University (Grant No. G0901)
文摘Based on the detailed planktonic foraminifera faunal count and Globigerinoides ruber Mg/Ca ratio analysis of Core MD05-2901,we reconstructed the longest Mg/Ca sea surface temperature(SST) sequence of the upwelling area off Vietnam in the western South China Sea(SCS).Ocean environment,especially the SST variation,over the last 450 ka is discussed in this study.SST variation has typical glacial/interglacial alternations from 23.03°C to 29.93°C with a glacial/interglacial difference of 4.8°C on average.SST during the interglacial periods fluctuates significantly,up to 5.6°C,which is larger than the average glacial/interglacial difference.SST variation during the glacial periods is much smaller.Spectrum analysis shows that SST change dominates on the typical Milankovitch cycles,such as 112,40.7 and 23.6 ka.Evident leading of SST variation against the δ 18 O can be observed during the Terminations 1,4,and 5,which is confirmed by their cross-spectrum analysis on these cycles.MD05-2901 is the first core in the South China Sea that has multi-SST records,such as SST Mg/Ca,k' 37 U-SST and planktonic foraminiferal fauna-based SST.SSTs from different methods can be correlated with each other in glacial/interglacial time scale,whereas SST Mg/Ca records abrupt climate change events more clearly.SST Mg/Ca at MD05-2901 since MIS 5 is 0.6°C lower than that of the southern SCS on average,but equivalent to or even 2°C lower than that of the northern SCS during some interglacial period.The SST character of MD05-2901 reflects less influence of latitude,but an important role of the regional upwelling driven by the eastern Asian summer monsoon,and suggests a stronger upwelling during the interglacial periods in the western SCS.