Dissolved nutrients are essential to marine productivity and ecosystem structures in the Southern Ocean.The spatial distributions of dissolved nutrients in the Cosmonaut Sea were studied during the 37th Chinese Nation...Dissolved nutrients are essential to marine productivity and ecosystem structures in the Southern Ocean.The spatial distributions of dissolved nutrients in the Cosmonaut Sea were studied during the 37th Chinese National Antarctic Research Expedition in 2021.The relative standard deviations of the nitrate(NO_(3)-N),nitrite(NO_(2)-N),ammonium(NH_(4)-N),phosphate(PO_(4)-P),and silicate(SiO_(3)-Si)concentrations found in duplicate samples(n=2)were 1.01%,9.04%,6.45%,0.94%,and0.67%,respectively.The mean NO_(3)-N,NO_(2)-N,NH_(4)-N,PO_(4)-P,and SiO_(3)-Si concentrations in the mixed layer were 26.41±4.13,0.15±0.09,0.51±0.22,1.73±0.23,and 41.48±6.94μmol·L^(−1),respectively,and were higher than the relevant limitationconcentrations.The concentrations were generally bounded horizontally by the Southern Boundary(SB)of the Antarctic Circumpolar Current,the NO_(3)-N,NO_(2)-N,NH_(4)-N,and PO_(4)-P concentrations being higher northeast than southwest of the SB but the SiO_(3)-Si concentrations being higher southwest than northeast,indicating that the SB dominates nutrient distributions in themixed layer.The NO_(3)-N,NH_(4)-N,and PO_(4)-P concentrations gradually increased moving vertically down from the mixed layer to 200 m deep and then remained at 33.73±3.51,0.26±0.13,and 2.28±0.10μmol·L^(−1),respectively,to the bottom.The SiO_(3)-Si concentration increased as depth increased and reached a maximum in the bottom layer.The NO_(2)-N concentrationdecreased rapidly as depth increased and was~0μmol·L^(−1)at>150 m deep.Circumpolar Deep Water upwelling may cause high nutrient concentrations in shallower layers up to the 100 m layer between 62.5°S and 64°S.展开更多
Dissolved oxygen(DO)and apparent oxygen utilization(AOU)are crucial parameters for investigating marine ecosystem evolution and the marine environment.In this study,DO and AOU data were obtained and their spatial dist...Dissolved oxygen(DO)and apparent oxygen utilization(AOU)are crucial parameters for investigating marine ecosystem evolution and the marine environment.In this study,DO and AOU data were obtained and their spatial distribution characteristics were explored in the Cosmonaut Sea and Amundsen Sea in austral summer 2021.The standard deviation range of DO parallel samples was<0.1–3.7μmol·L–1,which met the accuracy requirements of the survey method.The DO concentration decreased sharply with water depth in the photic zone and increased slowly to the bottom.AOU in the surface layer of the two seas was significantly negatively correlated with chlorophyll a(p<0.01),and AOU was significantly lower in the south Cosmonaut Sea than in the north Cosmonaut Sea and Amundsen Sea(p<0.01).In austral summer,AOU was as low as<130μmol·L–1 in the nearshore Cosmonaut Sea with thicker Antarctic Surface Water down to ca.500 m.In early winter,AOU was lower than 50μmol·L–1 in the north Amundsen Sea in subsurface water(75–150 m).The unmodified Circumpolar Deep Water with high AOU(>160μmol·L–1)could surge up to ca.150–200 m in both seas,with stronger intrusion in the Amundsen Sea.The AOU in bottom water was significantly lower(p<0.01)in the Cosmonaut Sea(118.9±11.8μmol·L–1)than the Amundsen Sea(141.7±7.4μmol·L–1),indicating the stable existence of fresh oxygen-rich Antarctic Bottom Water in the Cosmonaut Sea.展开更多
The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to...The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to January 2020,a survey of seabirds was carried out on the board icebreaker R/V Xuelong 2 in the Cosmonaut Sea and the Cooperation Sea.Twenty-three bird species were recorded.Antarctic petrel(Thalassoica antarctica),Antarctic prion(Pachyptila desolata),and Arctic tern(Sterna paradisaea)were the most abundant species.A total of about 37500 birds belonging to 23 species were recorded.Around 23%of the region had no record of birds.A large number of birds was recorded in 39°E-40°E,44°E-46°E and 59°E-60°E.Many areas,such as 33°E-35°E,39°E-41°E,44°E-46°E and 59°E-60°E show a great richness.More than two-thirds of seabirds(71%)were observed in the zone near the ocean front.The prediction of the distributions of the most dominant species Antarctic petrel also showed that the area near the ocean front region had an important ecological significance for seabirds.The results suggest that the distribution of seabirds in the Cosmonaut Sea is highly heterogenous.展开更多
This study used specimens of marine organisms caught by rectangular midwater trawl in the Cosmonaut Sea,Southern Ocean,in austral summer 2019/2020,to determine species composition and spatial distributions of mesopela...This study used specimens of marine organisms caught by rectangular midwater trawl in the Cosmonaut Sea,Southern Ocean,in austral summer 2019/2020,to determine species composition and spatial distributions of mesopelagic fauna in this sea.The data were also used to calculate the length-weight relationships of three common fishes captured during the survey(Electrona antarctica,Bathylagus antarcticus,and Cyclothone microdon).A total of 385 individual organisms with a total weight of 15462.2 g and representing 17 species were collected across the 11 stations visited.The small-sized crown jellyfish Atolla wyvillei(order Coronatae)was the most-dominant species by number(96 individuals),and the zooplankton Cyllopus lucasii(Amphipoda)also showed high abundance(54 individuals).Among fishes,81 individuals of Notolepis coatsorum(Paralepididae)were caught,followed by 71 individuals of E.antarctica(Myctophidae),25 individuals of B.antarcticus(Bathylagidae),and 16 individuals of C.microdon(Gonostomatidae).Clustering analysis divided the mesopelagic community into“west”and“east”groups,and a greater number of individuals were collected in the western part of the sea.The length-weight relationships of the three common fishes revealed positive allometric growth for B.antarcticus(b=3.16),and negative allometric growth for E.antarctica and C.microdon(both b=2.53).Our descriptions of the mesopelagic-zone community structure and biological features of three common fishes provide basic information on the ecology of the Cosmonaut Sea,Southern Ocean,and will be useful for ecosystem-based fisheries management in this region.展开更多
Investigations of the effect of geomagnetic activity influence on the heart rhythm regulation of cosmonauts during the expeditions onboard the Soyuz spacecraft, and the MIR orbital space stations was carried out for v...Investigations of the effect of geomagnetic activity influence on the heart rhythm regulation of cosmonauts during the expeditions onboard the Soyuz spacecraft, and the MIR orbital space stations was carried out for various durations of flight in weightlessness and, under control of groups of cosmonauts who were inspected under flight conditions outside the geomagnetic disturbances and in ground preflight conditions, during disturbances and without them. The four series of analytical researches in which the data about changes of characteristics of heart rate variability are demonstrated for the first time the presence of specific effect of geomagnetic disturbances on the system of vegetative regulation of blood circulation of cosmonauts during the flight. The response of cosmonauts’ heart rhythm on the magnetic storm is depending on the initial functional background and, in particular, on the state of mechanisms of vegetative regulation (the duration of flight and adaptation to it).展开更多
本文通过对南极宇航员海ANT36-C4-05岩心的放射性核素^(210)Pb、AMS^(14)C测年、XRF岩心扫描、多参数物性扫描和主、微量元素的测试分析,重建了该海区中全新世(6500 Cal a BP)以来的古生产力演变及其制约因素。研究结果表明,中全新世以...本文通过对南极宇航员海ANT36-C4-05岩心的放射性核素^(210)Pb、AMS^(14)C测年、XRF岩心扫描、多参数物性扫描和主、微量元素的测试分析,重建了该海区中全新世(6500 Cal a BP)以来的古生产力演变及其制约因素。研究结果表明,中全新世以来宇航员海古生产力波动较强,其演变趋势与南极气温变化基本一致,受海冰范围变化制约较大。在6500~5200 Cal a BP期间宇航员海古生产力随着温度升高和海冰范围减小而快速上升;在5200~3350 Cal a BP期间宇航员海的古生产力处于高值期,波动较小;在3350~2000 Cal a BP期间随着温度降低和海冰范围的扩大,硅质、钙质生产力下降;在2000~0 Cal a BP期间古生产力水平变化复杂,变化程度相较于之前小。同时,中全新世以来宇航员海区沉积记录较好地反映了5500 Cal a BP冷事件、DACP冷事件、MWP暖期和LIA冷事件的气候变化,受冷、暖事件影响导致的古生产力的变化最为明显。展开更多
基金financially supported by National Polar Special Program “Impact and Response of Antarctic Seas to Climate Change” (Grant nos. IRASCC 01-01-02A, IRASCC 02-02)the National Natural Science Foundation of China (NSFC) (Grant no. 41976228)
文摘Dissolved nutrients are essential to marine productivity and ecosystem structures in the Southern Ocean.The spatial distributions of dissolved nutrients in the Cosmonaut Sea were studied during the 37th Chinese National Antarctic Research Expedition in 2021.The relative standard deviations of the nitrate(NO_(3)-N),nitrite(NO_(2)-N),ammonium(NH_(4)-N),phosphate(PO_(4)-P),and silicate(SiO_(3)-Si)concentrations found in duplicate samples(n=2)were 1.01%,9.04%,6.45%,0.94%,and0.67%,respectively.The mean NO_(3)-N,NO_(2)-N,NH_(4)-N,PO_(4)-P,and SiO_(3)-Si concentrations in the mixed layer were 26.41±4.13,0.15±0.09,0.51±0.22,1.73±0.23,and 41.48±6.94μmol·L^(−1),respectively,and were higher than the relevant limitationconcentrations.The concentrations were generally bounded horizontally by the Southern Boundary(SB)of the Antarctic Circumpolar Current,the NO_(3)-N,NO_(2)-N,NH_(4)-N,and PO_(4)-P concentrations being higher northeast than southwest of the SB but the SiO_(3)-Si concentrations being higher southwest than northeast,indicating that the SB dominates nutrient distributions in themixed layer.The NO_(3)-N,NH_(4)-N,and PO_(4)-P concentrations gradually increased moving vertically down from the mixed layer to 200 m deep and then remained at 33.73±3.51,0.26±0.13,and 2.28±0.10μmol·L^(−1),respectively,to the bottom.The SiO_(3)-Si concentration increased as depth increased and reached a maximum in the bottom layer.The NO_(2)-N concentrationdecreased rapidly as depth increased and was~0μmol·L^(−1)at>150 m deep.Circumpolar Deep Water upwelling may cause high nutrient concentrations in shallower layers up to the 100 m layer between 62.5°S and 64°S.
基金supported by the National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”(Grant nos.IRASCC 01-01-02A,IRASCC 02-02)the National Key Research and Development Program of China(Grant no.2022YFE0136500)the National Natural Science Foundation of China(Grant no.41976228).
文摘Dissolved oxygen(DO)and apparent oxygen utilization(AOU)are crucial parameters for investigating marine ecosystem evolution and the marine environment.In this study,DO and AOU data were obtained and their spatial distribution characteristics were explored in the Cosmonaut Sea and Amundsen Sea in austral summer 2021.The standard deviation range of DO parallel samples was<0.1–3.7μmol·L–1,which met the accuracy requirements of the survey method.The DO concentration decreased sharply with water depth in the photic zone and increased slowly to the bottom.AOU in the surface layer of the two seas was significantly negatively correlated with chlorophyll a(p<0.01),and AOU was significantly lower in the south Cosmonaut Sea than in the north Cosmonaut Sea and Amundsen Sea(p<0.01).In austral summer,AOU was as low as<130μmol·L–1 in the nearshore Cosmonaut Sea with thicker Antarctic Surface Water down to ca.500 m.In early winter,AOU was lower than 50μmol·L–1 in the north Amundsen Sea in subsurface water(75–150 m).The unmodified Circumpolar Deep Water with high AOU(>160μmol·L–1)could surge up to ca.150–200 m in both seas,with stronger intrusion in the Amundsen Sea.The AOU in bottom water was significantly lower(p<0.01)in the Cosmonaut Sea(118.9±11.8μmol·L–1)than the Amundsen Sea(141.7±7.4μmol·L–1),indicating the stable existence of fresh oxygen-rich Antarctic Bottom Water in the Cosmonaut Sea.
基金financially supported by National Polar Special Program “Impact and Response of Antarctic Seas to Climate Change” (Grant nos. IRASCC2020-2022-05, IRASCC2020-2022-06)
文摘The Cosmonaut Sea is one of the less studied ecosystems in the Southern Hemisphere.Unlike other seas which were near to coastal regions,however,few studies exist on the top predators in this zone.From December 2019 to January 2020,a survey of seabirds was carried out on the board icebreaker R/V Xuelong 2 in the Cosmonaut Sea and the Cooperation Sea.Twenty-three bird species were recorded.Antarctic petrel(Thalassoica antarctica),Antarctic prion(Pachyptila desolata),and Arctic tern(Sterna paradisaea)were the most abundant species.A total of about 37500 birds belonging to 23 species were recorded.Around 23%of the region had no record of birds.A large number of birds was recorded in 39°E-40°E,44°E-46°E and 59°E-60°E.Many areas,such as 33°E-35°E,39°E-41°E,44°E-46°E and 59°E-60°E show a great richness.More than two-thirds of seabirds(71%)were observed in the zone near the ocean front.The prediction of the distributions of the most dominant species Antarctic petrel also showed that the area near the ocean front region had an important ecological significance for seabirds.The results suggest that the distribution of seabirds in the Cosmonaut Sea is highly heterogenous.
基金financially supported by National Polar Special Program“Impact and Response of Antarctic Seas to Climate Change”(Grant no.IRASCC 01-02-05C).
文摘This study used specimens of marine organisms caught by rectangular midwater trawl in the Cosmonaut Sea,Southern Ocean,in austral summer 2019/2020,to determine species composition and spatial distributions of mesopelagic fauna in this sea.The data were also used to calculate the length-weight relationships of three common fishes captured during the survey(Electrona antarctica,Bathylagus antarcticus,and Cyclothone microdon).A total of 385 individual organisms with a total weight of 15462.2 g and representing 17 species were collected across the 11 stations visited.The small-sized crown jellyfish Atolla wyvillei(order Coronatae)was the most-dominant species by number(96 individuals),and the zooplankton Cyllopus lucasii(Amphipoda)also showed high abundance(54 individuals).Among fishes,81 individuals of Notolepis coatsorum(Paralepididae)were caught,followed by 71 individuals of E.antarctica(Myctophidae),25 individuals of B.antarcticus(Bathylagidae),and 16 individuals of C.microdon(Gonostomatidae).Clustering analysis divided the mesopelagic community into“west”and“east”groups,and a greater number of individuals were collected in the western part of the sea.The length-weight relationships of the three common fishes revealed positive allometric growth for B.antarcticus(b=3.16),and negative allometric growth for E.antarctica and C.microdon(both b=2.53).Our descriptions of the mesopelagic-zone community structure and biological features of three common fishes provide basic information on the ecology of the Cosmonaut Sea,Southern Ocean,and will be useful for ecosystem-based fisheries management in this region.
文摘Investigations of the effect of geomagnetic activity influence on the heart rhythm regulation of cosmonauts during the expeditions onboard the Soyuz spacecraft, and the MIR orbital space stations was carried out for various durations of flight in weightlessness and, under control of groups of cosmonauts who were inspected under flight conditions outside the geomagnetic disturbances and in ground preflight conditions, during disturbances and without them. The four series of analytical researches in which the data about changes of characteristics of heart rate variability are demonstrated for the first time the presence of specific effect of geomagnetic disturbances on the system of vegetative regulation of blood circulation of cosmonauts during the flight. The response of cosmonauts’ heart rhythm on the magnetic storm is depending on the initial functional background and, in particular, on the state of mechanisms of vegetative regulation (the duration of flight and adaptation to it).
文摘本文通过对南极宇航员海ANT36-C4-05岩心的放射性核素^(210)Pb、AMS^(14)C测年、XRF岩心扫描、多参数物性扫描和主、微量元素的测试分析,重建了该海区中全新世(6500 Cal a BP)以来的古生产力演变及其制约因素。研究结果表明,中全新世以来宇航员海古生产力波动较强,其演变趋势与南极气温变化基本一致,受海冰范围变化制约较大。在6500~5200 Cal a BP期间宇航员海古生产力随着温度升高和海冰范围减小而快速上升;在5200~3350 Cal a BP期间宇航员海的古生产力处于高值期,波动较小;在3350~2000 Cal a BP期间随着温度降低和海冰范围的扩大,硅质、钙质生产力下降;在2000~0 Cal a BP期间古生产力水平变化复杂,变化程度相较于之前小。同时,中全新世以来宇航员海区沉积记录较好地反映了5500 Cal a BP冷事件、DACP冷事件、MWP暖期和LIA冷事件的气候变化,受冷、暖事件影响导致的古生产力的变化最为明显。
