As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice E...As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice Extent(SIE).The stage from 1979 to 2006 is characterized by high-frequency(i.e.,seasonal to interannual)temporal variability in SIE and zonal asymmetry in Sea Ice Concentration(SIC),which is primarily under the control of the Amundsen Sea Low(ASL).After 2007,however,sea ice changes exhibit a more spatially homogeneous pattern in SIC and a more temporally long-lasting mode in SIE.Further analysis reveals that sea ice-ocean interaction plays a major role in the low-frequency(i.e.,multiannual)variability of Antarctic sea ice from 2007−22.The related physical process is inferred to manifest as a strong coupling between the surface and the subsurface ocean layers,involving enhanced vertical convection and the downward delivery of the surface anomalies related to ice melting and freezing processes,thus maintaining the SIE anomalies for a longer time.Furthermore,this process mainly occurs in the Amundsen-Bellingshausen Sea(ABS)sector,and the weakened subsurface ocean stratification is the key factor triggering the coupling process in this region.We find that the Circumpolar Deep Water(CDW)over the ABS sector continued to shoal before 2007 and remained stable thereafter.It is speculated that the shoaling of the CDW may be a possible driver leading to the weakening of the subsurface stratification.展开更多
This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),...This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),and the El Niño-Southern Oscillation(ENSO),along with the total sea ice condition during the preceding spring,serve as precursor signals of February sea ice extent(SIE).These climate modes interact,energizing the Pacific-South American pattern(PSA),which deepens and shifts the Amundsen Sea Low(ASL)westward in spring.This pattern generates a dipole sea ice anomaly characterized by an increase in sea ice in the northern Ross Sea but a decrease in ice in the Bellingshausen and northern Weddell Seas.However,as the season transitions into summer,the ASL exerts a pronounced delayed effect,contributing to widespread sea ice loss across West Antarctica.Strong southerly winds on the western flank of the ASL push sea ice away from the inner Ross Sea,exposing coastal waters that absorb solar radiation,thereby accelerating ice melt through positive ice-albedo feedback.Simultaneously,northwesterly winds on the eastern flank transport warm air toward the Bellingshausen and northern Weddell Seas,intensifying ice loss in these regions.Furthermore,the active PSA is accompanied by a tripole sea surface temperature pattern characterized by warming in the Weddell Sea,which promotes continued ice melt.The co-occurrence of an exceptionally positive SAM,a La Niña,and a strong negative IOD during spring 2022,combined with lower-than-normal total spring SIE,ultimately contributed to the record-low Antarctic SIE observed in February 2023.展开更多
Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulatio...Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulation,low power consumption,and unattended operation,introduce challenges to the design and development of motor drives.We present the design of a permanent magnet synchronous motor suitable for this environment,conducting a quantitative analysis on the impacts of cryogenic conditions on lubricant performance,differential thermal contraction of metallic components,and remanent flux density of neodymium iron boron(N52)permanent magnets.We also implement a labyrinth seal structure,combined with silicone sealing rings,to mitigate ice crystal intrusion risks.Finite element analysis and laboratory tests demonstrate a maximum torque output of 25 Nm.This kind of motor is used in the Antarctic 15 cm Near Infrared Telescope at Dome A,Antarctica.Operation data shows a total encoder feedback error of 0.0678"for the telescope control system with 15"s^(−1)tracking speed at−56.79°C.These results comprehensively validate the high reliability and precision of the motor under the extreme conditions of the polar environment.展开更多
Dome A,in Antarctica,offers an exceptional site for ground-based infrared astronomy,with its extremely low atmospheric infrared background noise and excellent seeing conditions.However,deploying near-infrared telescop...Dome A,in Antarctica,offers an exceptional site for ground-based infrared astronomy,with its extremely low atmospheric infrared background noise and excellent seeing conditions.However,deploying near-infrared telescopes in the harsh environment of Antarctica faces the critical challenge of frost accumulation on optical mirrors.While indium tin oxide heating films effectively defrost visible-band Antarctic astronomical telescopes,their thermal radiation at infrared wavelengths introduces significant stray light,severely degrading the signal-to-noise ratio for infrared observations.To address this limitation,we have designed a mechanical snow-removal system capable of efficiently clearing frost from sealing window surfaces at temperatures as low as–80°C.Aperture photometry of target sources,Canopus and HD 2151,revealed that after six days without intervention,floating snow extinction reduced target brightness by up to 3 magnitudes.Following mechanical defrosting,the source flux recovered to stable levels,with measured magnitudes showing rapid initial improvement followed by stabilization.Data analysis indicates that a frost removal strategy operating every 48 h,with each operation consisting of 4–6 cycles,enables efficient removal of frost and snow without introducing additional thermal noise.Future work will focus on optimizing the adaptive control algorithm and exploring novel low-temperature defrosting materials to extend the periods during which Antarctic infrared telescopes can operate unattended.展开更多
Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese A...Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese Antarctic Research Expedition(CHINARE)team reached Dome A,the highest point of the Antarctic ice sheet,marking the beginning of a new era for astro-nomical research from the Antarctic plateau.展开更多
Life in the Antarctic is tough indeed.The extremely cold temperatures,fierce winds and vast stretches of ice make it a challenging environment for most life forms.But all these creatures come here because the Southern...Life in the Antarctic is tough indeed.The extremely cold temperatures,fierce winds and vast stretches of ice make it a challenging environment for most life forms.But all these creatures come here because the Southern Ocean is one of the richest oceans on Earth.When the continent separated from South America and moved south 30 million years ago,strong currents began to move in circles right around it.展开更多
Antarctic krill(Euphausia superba)is a keystone species in the Southern Ocean;however,seasonal variations in reproductive development for krill are complex and remains unknown.A histological investigation with observa...Antarctic krill(Euphausia superba)is a keystone species in the Southern Ocean;however,seasonal variations in reproductive development for krill are complex and remains unknown.A histological investigation with observations of external secondary sex features of krill in the south Scotia Sea region was carried out using a multi-seasonal dataset for detail reproductive descriptions for this commercially important species.The monthly development of secondary sexual characteristics,the thelycum,as well as of oocytes over a period of two years were described.It was observed that krill have diverse reproductive development characteristics within the ovary,and that this function differently between the juvenile,sub-adult,and adult stages.During the summer,adult krill ovaries are large and ripe with oocytes rich in yolk ready for release in late summer.Post spawning,the ovaries resorb,fragment,and regress throughout the autumn and winter.During reproductive diapause period,krill focus on absorbing nutrients.Un-released eggs are reabsorbed by the ovary,the permanent germinal zone is active,and early oocytes begin to develop in preparation for the egg production phase.Krill that are about to spawn have an ovary that fills the space between the digestive gland and muscle.The ovarian development of krill is divided into 10 sexual developmental stages.As a part of this study,data on the carapace thickness with similar development patterns in krill size and carapace width,was investigated for the first time to help understand krill growth and development.展开更多
In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Pe...In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Peninsula in February 1985.Forty years later,in February 2024,China’s fifth research station,Qinling Station,commenced operations on Inexpress-ible Island near Terra Nova Bay.展开更多
The SCAR XIV International Symposium on Antarctic Earth Sciences(ISAES), which has been held every four years, will be held in Punta Arenas, Chile from 18 to 25 August 2025. ISAES aims to provide a comprehensive overv...The SCAR XIV International Symposium on Antarctic Earth Sciences(ISAES), which has been held every four years, will be held in Punta Arenas, Chile from 18 to 25 August 2025. ISAES aims to provide a comprehensive overview of the current state of Antarctic Earth Sciences. The XIV ISAES calls for researchers from around the globe to share their latest research and insights on the Antarctic region's geology, climate, and ecosystems.展开更多
The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical...The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical experiments,the skills of CMIP6 models in simulating the atmospheric responses to Tasman Sea SST are evaluated in this study,with an emphasis on the relationships with AP temperatures.The spatial correlation coefficient and normalized standard deviation are used as the evaluation metrics.Corresponding results suggest that the majority of CMIP6 models can capture the basic spatial distributions of Tasman Sea-related teleconnections across the Southern Hemisphere extratropical region,featuring a Pacific–South America-like pattern.However,the overestimation of atmospheric interannual variability and the underestimation of oceanic interannual variability in CMIP6 models result in a considerable amplification of the atmospheric responses to SST anomalies.The model uncertainty in depicting the relationships between Tasman Sea SSTs and AP surface temperatures,as well as the associated teleconnections,can partially be attributed to variations in grid resolutions among models.Additionally,further analysis of the Antarctic sea ice shows that the Tasman Sea SST may contribute to the interannual variability of the Antarctic dipole in CMIP6.展开更多
Samples for this study were collected from Geologists Island and Prydz Bay in different seasons.Otolith sections were analyzed for elemental composition in the nucleus,juvenile,and edge areas.Elements including Mg,Sr,...Samples for this study were collected from Geologists Island and Prydz Bay in different seasons.Otolith sections were analyzed for elemental composition in the nucleus,juvenile,and edge areas.Elements including Mg,Sr,P,K,Fe,and Zn,normalized to calcium(CMe/CCa),were selected for analysis.To explore population structure,we studied factors influencing population dynamics during life stage,and regional distribution characteristics.For identified individual origins and explored the distribution and migration between regions and migration from hatching to adulthood provide a basis.So as to understand the distribution and migration pattern of Pagothenia borchgrevinki across various life history stages.Results indicated a consistent P.borchgrevinki population spawning across various regions of Southern Ocean,with eggs distributed at the bottom.Coastal slope topography changes and water compensation facilitated egg transportation from the bottom to under sea ice during hatching to juvenile stages.Long-distance migration was facilitated by the Antarctic Circumpolar Current and regional currents during development to adulthood.Multiple spawning grounds and ocean currents contributed to diverse distribution environments during the hatching period.Differences in individual development were important factors during the juvenile period,while ocean currents and autonomous behaviors influenced regional transportation patterns in the post development stages.Therefore,the research holds that differences in distribution environment and behavior during each period led to distinct factors influencing CMe/CCa variations.展开更多
Before you can tie your shoelaces for one of the worlds most remote races,you must first navigate through wild seas,endure(忍受)freezing temperatures and go on a journey that tests more than just your physical enduran...Before you can tie your shoelaces for one of the worlds most remote races,you must first navigate through wild seas,endure(忍受)freezing temperatures and go on a journey that tests more than just your physical endurance.This is no ordinary race;it requires thorough preparation and a strong will.展开更多
Basal melting and calving are the main pathways for mass loss in Antarctic ice shelves.Basal channels,as detailed variations in basal melting,mutually promote basal melting and calving,thereby weakening the stability ...Basal melting and calving are the main pathways for mass loss in Antarctic ice shelves.Basal channels,as detailed variations in basal melting,mutually promote basal melting and calving,thereby weakening the stability of ice shelves.Therefore,it is necessary to calculate and statistically analyze basal melting,basal channels,and calving events across all Antarctic ice shelves and examine the correlation among these three factors.This study utilizes various data sources to calculate the Basal Channel Density(BCD)and average basal melt rate of all Antarctic ice shelves during 2010-2020,as well as the spatial correlation between basal melting,basal channels,and calving.We found that ice shelves along the Amundsen Sea and Bellingshausen Sea have higher basal melt rates and basal channel densities,while other sea areas have lower values.This is mainly influenced by seabed topography and Circumpolar Deep Water.Excluding(CDW)extreme calving events,there is a positive correlation among basal melting,basal channels,and calving in coastal ice shelves across different sea areas,with a correlation coefficient exceeding 0.67.This indicates that basal melting and basal channels are major factors causing ice shelf calving.Our results emphasize the importance of the impact of basal melting,basal channels,and calving on ice shelf stability,and they provide a significant reference for further research on ice shelf-ocean interactions.展开更多
To explore the metabolites of Antarctic marine-derived fungus Penicillium crustosum HDN20-1061 by OSMAC strategy.Methods Multiple medium trials determined fermentation condition and various methods including ODS colum...To explore the metabolites of Antarctic marine-derived fungus Penicillium crustosum HDN20-1061 by OSMAC strategy.Methods Multiple medium trials determined fermentation condition and various methods including ODS column and chromatography and semi-preparative HPLC were employed to separate and purify the extracts of strain HDN20-1061.NMR,MS,ECD and NMR calculations were used to determine the structure of compounds.Results Two new compounds,namely peniphenone F(1)and peniphenone G(2),along with one known compound(3)were isolated from the Penicillium crustosum HDN20-1061.Compound 1 exhibited weak antibacterial activity with an MIC value of 64μM.展开更多
The otolith nucleus captures a fish’s life history during egg and hatching stages,offering insights into species-specific differences in element types and concentrations as well as the endogenous and exogenous factor...The otolith nucleus captures a fish’s life history during egg and hatching stages,offering insights into species-specific differences in element types and concentrations as well as the endogenous and exogenous factors shaping these variations.This study aimed to investigate the variation in the types and concentrations of elements within the otolith nuclei of three Antarctic fish species,including Pagothenia borchgrevinki,Trematomus hansoni,and Trematomus bernacchii,collected from Prydz Bay,East Antarctica.Nine elements,^(23)Na,^(24)Mg,^(29)Si,^(31)P,^(39)K,^(57)Fe,^(66)Zn,^(88)Sr,and^(137)Ba,were selected for analyses because of their concentrations and ecological significance.Ratios of each element to Ca(Me/Ca)were used for analysis,and Me/Ca in the otolith nuclei of these species were analyzed to explore species-specific variations in element types.Significant differences in element composition,except for Fe/Ca and Ba/Ca,were found in different species.Temperature,salinity,reproduction,pelagic larval lifestyle,and diet composition were considered as key endogenous and exogenous factors influencing these differences.Decision tree discriminant analysis,based on the variation of the types and concentrations of elements,was used to identify P.borchgrevinki,T.hansoni,and T.bernacchii with accuracy rates of 86.54%,82.61%,and 73.33%,respectively.Principal component analysis showed overlapping 95%confidence el-lipses for the three species at 79.96%,67.31%,and 56.71%,respectively.As these species belong to the Nototheniidae family and share a similar hatching period,the accuracy of species discrimination is reduced.Considering the high probability of error in distin-guishing species using otolith nucleus elements,we recommend otolith shape should also be considered to improve identification ac-curacy.展开更多
Research on Antarctic microbial diversity has primarily focused on 3 areas:freshwater lake sediments,penguin colonies,and seawater in ice-free regions.There is a scarcity of research on the impact of slopes on microbi...Research on Antarctic microbial diversity has primarily focused on 3 areas:freshwater lake sediments,penguin colonies,and seawater in ice-free regions.There is a scarcity of research on the impact of slopes on microbial community structure,and this study effectively fills this gap.This study focused on the soil in the sparse vegetated tundra on a hillside near the southern coastline of the Antarctic Great Wall Station.The influence of slope position,soil physicochemical properties,and vegetated area on soil bacterial community structure was analyzed.High-throughput sequencing technology was employed to characterize a 16S rRNA gene fragment in soil samples from 5 slope areas and estimate bacterial abundance.Calculation ofα-diversity andβ-diversity indices,and community structure analysis were used to compare the species richness among sampling points,analyze similarities in soil bacterial community structure and composition,and identify the core bacterial population.In the non-vegetated area,the soil on the mountaintop,hillside,and at the foot of the slope showed similar physicochemical properties.In the vegetated area,the soil physicochemical properties were highly similar on the mountaintop,hillside,the foot of the slope,and the foot of the mountain.Weighted Gene Co-expression Network Analysis showed that total organic carbon,pH,and PO_(4)^(3-)-P might affect the structure of bacterial communities at the sampling point by changing the relative abundance of Chthoniobacterales,Sediminibacterium,and Actinobacteria.We hypothesize that slope-driven nutrient transport,amplified by vegetated areas(in the tundra),is a primary driver of bacterial community structure in the Antarctic tundra soil.These results provide insights into the impact of slope on microbial community structure in Antarctica.展开更多
Despite being ubiquitous in oceans and important in marine biogeochemical cycles,planktonic archaea in the Southern Ocean(SO)remain poorly characterized.Although high-throughput sequencing(HTS)approaches based on 16S ...Despite being ubiquitous in oceans and important in marine biogeochemical cycles,planktonic archaea in the Southern Ocean(SO)remain poorly characterized.Although high-throughput sequencing(HTS)approaches based on 16S ribosomal RNA(rRNA)genes have been used widely to study the diversity and composition of microbial community in natural environments,primer-set selection is critical because of amplicon-sequencing bias during metabarcoding.Here,using surface-seawater samples collected from the area between the South Shetland and South Orkney Islands,Antarctica,we compared primer sets Arch349F/Arch806R,515F-Y/926R,and 524F/Arch958R,which target different 16S rRNA gene hypervariable regions to identify the best one for studying planktonic archaeal communities.With much lower number of bacteria-related sequences,primer set 524F/Arch958R showed higher values of archaeal operational taxonomic units(OTUs)as well as alpha-diversity indices,indicating that this primer set was more specific for detecting archaeal species and could be helpful to obtain more comprehensive information on the archaeal community compositions compared to other two primer sets.Compared with primer set Arch349F/Arch806R revealing four phyla(Halobacteriota,Methanobacteriota,Thermoplasmatota,and Thermoproteota)detected in seawater,additional archaeal phyla were observed by 515F-Y/926R(Asgardarchaeota and Nanoarchaeota)and 524F/Arch958R(Micrarchaeota).In spite of the differences in archaeal community compositions observed among the three investigated primer sets,ammonia-oxidizing(e.g.,Nitrososphaeria)and methane-producing(e.g.,Methanobacteria,Methanomicrobia,and Methanosarcinia)archaea were the main groups detected in the surface seawater,indicating the ecological role of planktonic archaea in carbon and nitrogen cycling in the upper waters of the SO.These results underscore the importance of primer-set selection when studying archaeal community diversity and composition in the Antarctic SO.展开更多
Seasonal cycles of phytoplankton blooms are crucial to marine ecosystems and highly sensitive to environmental fluctuations.Rapid climate change has a profound impact on regional environmental conditions,thereby affec...Seasonal cycles of phytoplankton blooms are crucial to marine ecosystems and highly sensitive to environmental fluctuations.Rapid climate change has a profound impact on regional environmental conditions,thereby affecting seasonal blooms at both regional and global scales.The western Antarctic Peninsula(WAP)is one of the most productive regions in the Southern Ocean and has experienced accelerated climate change in recent decades.However,the impact of climate change on bloom dynamics in this region remains uncertain due to regional variability and the complex interplay of environmental factors.Using 26 a(1998−2023)of satellite data,this study examines patterns and trends in bloom seasonal metrics on the southern WAP,and further explores the impact of large-scale climate drivers.A key finding was a clear shift in bloom timing,with earlier and longer blooms observed during 2012−2023.These shifts were associated with reduced spring sea ice extent(SIE),which correlated with warming spring sea surface air temperatures(SAT).Atmospheric teleconnections,particularly the El Niño-Southern Oscillation(ENSO)and Southern Annular Mode(SAM)in spring,were linked to changes in SAT and sea ice dynamics.This study highlights the role of climate drivers in altering bloom dynamics,potentially affecting local marine food webs,and underscores the need for further research to understand Antarctic ecosystem evolution under future climate scenarios.展开更多
This paper evaluates a representation of winter stratospheric circulation in the Antarctic that is based on CRA-40, a 40-year global reanalysis dataset released by the China Meteorological Administration, and compares...This paper evaluates a representation of winter stratospheric circulation in the Antarctic that is based on CRA-40, a 40-year global reanalysis dataset released by the China Meteorological Administration, and compares it with representations based on two other state-of-the-art reanalysis datasets: the fifth-generation atmospheric reanalysis provided by the European Centre for Medium-Range Weather Forecasts(ERA-5) and the Modern-Era Retrospective analysis for Research and Applications, version 2(MERRA-2). In terms of climatology, we find that CRA-40 portrays a stronger and colder polar vortex in the middle and lower stratosphere than ERA-5, but a weaker and warmer one than MERRA-2. However, disagreement among the three reanalyses is confined mainly to the period before1999, and is largely reduced after that time. On the interannual timescale, portrayals of the intensity and area of the 10-hPa polar vortex are quite consistent among the three reanalyses, with correlation coefficients greater than 0.9 between each pair of reanalyses. In addition, the central dates of most sudden stratospheric deceleration(SSD) events at 10 hPa in the three reanalyses differ by less than one day, indicating that CRA-40 is also highly consistent with the other two reanalysis datasets regarding daily evolution. Our analyses suggest that CRA-40 performs comparably to ERA-5 and MERRA-2 in characterizing winter circulation in the Antarctic middle and lower stratosphere.展开更多
Antarctic ice-free areas(<0.4%of the continent)represent Antarctic biodiversity oases,where microbial communities sustain terrestrial ecosystem functions.These habitats-encompassing mineral,ornithogenic soils,biolo...Antarctic ice-free areas(<0.4%of the continent)represent Antarctic biodiversity oases,where microbial communities sustain terrestrial ecosystem functions.These habitats-encompassing mineral,ornithogenic soils,biological soil crusts,and hypolithic/endolithic niches-are shaped by environmental factors such as pH,organic C/N ratios,moisture,elevation,and trace element availability.The diversity of prokaryotes,eukaryotes,and viruses is lower than in other regions,yet the communities exhibit strong endemism,with site-specific uncultivated lineages.Microorganisms persist through cold and stress adaptations,performing organic carbon decomposition,phototrophy,and oxidation of trace gases to drive carbon and nitrogen cycling in various Antarctic soil habitats.Climate change and anthropogenic disturbances are shifting communities toward copiotrophic generalists,altering elementary cycling and feeding back to climate change.Culturation and genomic-based techniques reveal novel microbial taxa with broad biotechnological potentials on bioactive compounds and cryotolerant enzymes.In summary,this review offers a foundation for exploring Antarctic microbial biodiversity,ecosystem resilience,and the development of novel biotechnologies,while also highlighting the urgent need for effective monitoring and preservation strategies to mitigate the impacts of ongoing environmental changes on Antarctic soil ecosystems.展开更多
基金supported by the National Natural Science Foundation China(Grant No.42176222).
文摘As a crucial component of the Earth’s climate system,Antarctic sea ice has demonstrated significant variability over the satellite era.Here,we identify a remarkable decadal transition in the total Antarctic Sea Ice Extent(SIE).The stage from 1979 to 2006 is characterized by high-frequency(i.e.,seasonal to interannual)temporal variability in SIE and zonal asymmetry in Sea Ice Concentration(SIC),which is primarily under the control of the Amundsen Sea Low(ASL).After 2007,however,sea ice changes exhibit a more spatially homogeneous pattern in SIC and a more temporally long-lasting mode in SIE.Further analysis reveals that sea ice-ocean interaction plays a major role in the low-frequency(i.e.,multiannual)variability of Antarctic sea ice from 2007−22.The related physical process is inferred to manifest as a strong coupling between the surface and the subsurface ocean layers,involving enhanced vertical convection and the downward delivery of the surface anomalies related to ice melting and freezing processes,thus maintaining the SIE anomalies for a longer time.Furthermore,this process mainly occurs in the Amundsen-Bellingshausen Sea(ABS)sector,and the weakened subsurface ocean stratification is the key factor triggering the coupling process in this region.We find that the Circumpolar Deep Water(CDW)over the ABS sector continued to shoal before 2007 and remained stable thereafter.It is speculated that the shoaling of the CDW may be a possible driver leading to the weakening of the subsurface stratification.
基金supported by the National Natural Science Foundation of China (Grant Nos.42288101 and 42375045)
文摘This study investigates the influence of major climatic modes on the interannual variability of the annual minimum extent of Antarctic sea ice.It shows that the Southern Annular Mode(SAM),the Indian Ocean Dipole(IOD),and the El Niño-Southern Oscillation(ENSO),along with the total sea ice condition during the preceding spring,serve as precursor signals of February sea ice extent(SIE).These climate modes interact,energizing the Pacific-South American pattern(PSA),which deepens and shifts the Amundsen Sea Low(ASL)westward in spring.This pattern generates a dipole sea ice anomaly characterized by an increase in sea ice in the northern Ross Sea but a decrease in ice in the Bellingshausen and northern Weddell Seas.However,as the season transitions into summer,the ASL exerts a pronounced delayed effect,contributing to widespread sea ice loss across West Antarctica.Strong southerly winds on the western flank of the ASL push sea ice away from the inner Ross Sea,exposing coastal waters that absorb solar radiation,thereby accelerating ice melt through positive ice-albedo feedback.Simultaneously,northwesterly winds on the eastern flank transport warm air toward the Bellingshausen and northern Weddell Seas,intensifying ice loss in these regions.Furthermore,the active PSA is accompanied by a tripole sea surface temperature pattern characterized by warming in the Weddell Sea,which promotes continued ice melt.The co-occurrence of an exceptionally positive SAM,a La Niña,and a strong negative IOD during spring 2022,combined with lower-than-normal total spring SIE,ultimately contributed to the record-low Antarctic SIE observed in February 2023.
基金supported by the Space Debris Resear-ch Project,China(KJSP2020010102)the NationalKey R&D Program of China(2022YFC2807300).
文摘Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulation,low power consumption,and unattended operation,introduce challenges to the design and development of motor drives.We present the design of a permanent magnet synchronous motor suitable for this environment,conducting a quantitative analysis on the impacts of cryogenic conditions on lubricant performance,differential thermal contraction of metallic components,and remanent flux density of neodymium iron boron(N52)permanent magnets.We also implement a labyrinth seal structure,combined with silicone sealing rings,to mitigate ice crystal intrusion risks.Finite element analysis and laboratory tests demonstrate a maximum torque output of 25 Nm.This kind of motor is used in the Antarctic 15 cm Near Infrared Telescope at Dome A,Antarctica.Operation data shows a total encoder feedback error of 0.0678"for the telescope control system with 15"s^(−1)tracking speed at−56.79°C.These results comprehensively validate the high reliability and precision of the motor under the extreme conditions of the polar environment.
基金supported by the Space Debris Research Project,China(KJSP2020010102)the National Key R&D Program of China(2022YFC2807300)the National Natural Science Foundation of China(12573081)。
文摘Dome A,in Antarctica,offers an exceptional site for ground-based infrared astronomy,with its extremely low atmospheric infrared background noise and excellent seeing conditions.However,deploying near-infrared telescopes in the harsh environment of Antarctica faces the critical challenge of frost accumulation on optical mirrors.While indium tin oxide heating films effectively defrost visible-band Antarctic astronomical telescopes,their thermal radiation at infrared wavelengths introduces significant stray light,severely degrading the signal-to-noise ratio for infrared observations.To address this limitation,we have designed a mechanical snow-removal system capable of efficiently clearing frost from sealing window surfaces at temperatures as low as–80°C.Aperture photometry of target sources,Canopus and HD 2151,revealed that after six days without intervention,floating snow extinction reduced target brightness by up to 3 magnitudes.Following mechanical defrosting,the source flux recovered to stable levels,with measured magnitudes showing rapid initial improvement followed by stabilization.Data analysis indicates that a frost removal strategy operating every 48 h,with each operation consisting of 4–6 cycles,enables efficient removal of frost and snow without introducing additional thermal noise.Future work will focus on optimizing the adaptive control algorithm and exploring novel low-temperature defrosting materials to extend the periods during which Antarctic infrared telescopes can operate unattended.
文摘Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese Antarctic Research Expedition(CHINARE)team reached Dome A,the highest point of the Antarctic ice sheet,marking the beginning of a new era for astro-nomical research from the Antarctic plateau.
文摘Life in the Antarctic is tough indeed.The extremely cold temperatures,fierce winds and vast stretches of ice make it a challenging environment for most life forms.But all these creatures come here because the Southern Ocean is one of the richest oceans on Earth.When the continent separated from South America and moved south 30 million years ago,strong currents began to move in circles right around it.
基金Supported by the Inter-governmental Science and Technology Innovation(STI)Cooperation Special Program of the National Key Research and Development Program of China(No.2023YFE0104500)the NIWA-SHOU-Otago Joint Research Center on Antarctic Marine Science。
文摘Antarctic krill(Euphausia superba)is a keystone species in the Southern Ocean;however,seasonal variations in reproductive development for krill are complex and remains unknown.A histological investigation with observations of external secondary sex features of krill in the south Scotia Sea region was carried out using a multi-seasonal dataset for detail reproductive descriptions for this commercially important species.The monthly development of secondary sexual characteristics,the thelycum,as well as of oocytes over a period of two years were described.It was observed that krill have diverse reproductive development characteristics within the ovary,and that this function differently between the juvenile,sub-adult,and adult stages.During the summer,adult krill ovaries are large and ripe with oocytes rich in yolk ready for release in late summer.Post spawning,the ovaries resorb,fragment,and regress throughout the autumn and winter.During reproductive diapause period,krill focus on absorbing nutrients.Un-released eggs are reabsorbed by the ovary,the permanent germinal zone is active,and early oocytes begin to develop in preparation for the egg production phase.Krill that are about to spawn have an ovary that fills the space between the digestive gland and muscle.The ovarian development of krill is divided into 10 sexual developmental stages.As a part of this study,data on the carapace thickness with similar development patterns in krill size and carapace width,was investigated for the first time to help understand krill growth and development.
文摘In November 1984,China launched its first expedition to the Southern Ocean and the Antarctic continent,culminating in the establishment of its first year-round research station—Great Wall Station—on the Antarctic Peninsula in February 1985.Forty years later,in February 2024,China’s fifth research station,Qinling Station,commenced operations on Inexpress-ible Island near Terra Nova Bay.
文摘The SCAR XIV International Symposium on Antarctic Earth Sciences(ISAES), which has been held every four years, will be held in Punta Arenas, Chile from 18 to 25 August 2025. ISAES aims to provide a comprehensive overview of the current state of Antarctic Earth Sciences. The XIV ISAES calls for researchers from around the globe to share their latest research and insights on the Antarctic region's geology, climate, and ecosystems.
基金jointly supported by the National Natural Science Foundation of China(Grant No.42375027)the Natural Science Foundation of Guangdong Province(Grant No.2023A1515010889)。
文摘The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical experiments,the skills of CMIP6 models in simulating the atmospheric responses to Tasman Sea SST are evaluated in this study,with an emphasis on the relationships with AP temperatures.The spatial correlation coefficient and normalized standard deviation are used as the evaluation metrics.Corresponding results suggest that the majority of CMIP6 models can capture the basic spatial distributions of Tasman Sea-related teleconnections across the Southern Hemisphere extratropical region,featuring a Pacific–South America-like pattern.However,the overestimation of atmospheric interannual variability and the underestimation of oceanic interannual variability in CMIP6 models result in a considerable amplification of the atmospheric responses to SST anomalies.The model uncertainty in depicting the relationships between Tasman Sea SSTs and AP surface temperatures,as well as the associated teleconnections,can partially be attributed to variations in grid resolutions among models.Additionally,further analysis of the Antarctic sea ice shows that the Tasman Sea SST may contribute to the interannual variability of the Antarctic dipole in CMIP6.
基金supported by the Impact and Response of Antarctic Seas to Climate Change(Grant no.IRASCC 2020-2025)from Ministry of Natural Resources of the People’s Republic of China.
文摘Samples for this study were collected from Geologists Island and Prydz Bay in different seasons.Otolith sections were analyzed for elemental composition in the nucleus,juvenile,and edge areas.Elements including Mg,Sr,P,K,Fe,and Zn,normalized to calcium(CMe/CCa),were selected for analysis.To explore population structure,we studied factors influencing population dynamics during life stage,and regional distribution characteristics.For identified individual origins and explored the distribution and migration between regions and migration from hatching to adulthood provide a basis.So as to understand the distribution and migration pattern of Pagothenia borchgrevinki across various life history stages.Results indicated a consistent P.borchgrevinki population spawning across various regions of Southern Ocean,with eggs distributed at the bottom.Coastal slope topography changes and water compensation facilitated egg transportation from the bottom to under sea ice during hatching to juvenile stages.Long-distance migration was facilitated by the Antarctic Circumpolar Current and regional currents during development to adulthood.Multiple spawning grounds and ocean currents contributed to diverse distribution environments during the hatching period.Differences in individual development were important factors during the juvenile period,while ocean currents and autonomous behaviors influenced regional transportation patterns in the post development stages.Therefore,the research holds that differences in distribution environment and behavior during each period led to distinct factors influencing CMe/CCa variations.
文摘Before you can tie your shoelaces for one of the worlds most remote races,you must first navigate through wild seas,endure(忍受)freezing temperatures and go on a journey that tests more than just your physical endurance.This is no ordinary race;it requires thorough preparation and a strong will.
基金The National Natural Science Foundation of China No.42406251the Fundamental Research Funds for the Central Universities under contract No.2042025kf0079 and 2042025kf0080+2 种基金the Postdoctoral Fellowship Program of CPSF under contract No.GZC20241257the Postdoctoral Fellowship Program of CPSF under contract No.GZC20241257the Key Laboratory of Polar Environment Monitoring and Public Governance(Wuhan University),the Ministry of Education Open Fund under contract Nos 202403 and 202405.
文摘Basal melting and calving are the main pathways for mass loss in Antarctic ice shelves.Basal channels,as detailed variations in basal melting,mutually promote basal melting and calving,thereby weakening the stability of ice shelves.Therefore,it is necessary to calculate and statistically analyze basal melting,basal channels,and calving events across all Antarctic ice shelves and examine the correlation among these three factors.This study utilizes various data sources to calculate the Basal Channel Density(BCD)and average basal melt rate of all Antarctic ice shelves during 2010-2020,as well as the spatial correlation between basal melting,basal channels,and calving.We found that ice shelves along the Amundsen Sea and Bellingshausen Sea have higher basal melt rates and basal channel densities,while other sea areas have lower values.This is mainly influenced by seabed topography and Circumpolar Deep Water.Excluding(CDW)extreme calving events,there is a positive correlation among basal melting,basal channels,and calving in coastal ice shelves across different sea areas,with a correlation coefficient exceeding 0.67.This indicates that basal melting and basal channels are major factors causing ice shelf calving.Our results emphasize the importance of the impact of basal melting,basal channels,and calving on ice shelf stability,and they provide a significant reference for further research on ice shelf-ocean interactions.
文摘To explore the metabolites of Antarctic marine-derived fungus Penicillium crustosum HDN20-1061 by OSMAC strategy.Methods Multiple medium trials determined fermentation condition and various methods including ODS column and chromatography and semi-preparative HPLC were employed to separate and purify the extracts of strain HDN20-1061.NMR,MS,ECD and NMR calculations were used to determine the structure of compounds.Results Two new compounds,namely peniphenone F(1)and peniphenone G(2),along with one known compound(3)were isolated from the Penicillium crustosum HDN20-1061.Compound 1 exhibited weak antibacterial activity with an MIC value of 64μM.
基金supported by the Impact and Response of Antarctic Seas to Climate Change(No.IRASCC 2020-2025)from the Ministry of Natural Resources of the Peo-ple’s Republic of China.
文摘The otolith nucleus captures a fish’s life history during egg and hatching stages,offering insights into species-specific differences in element types and concentrations as well as the endogenous and exogenous factors shaping these variations.This study aimed to investigate the variation in the types and concentrations of elements within the otolith nuclei of three Antarctic fish species,including Pagothenia borchgrevinki,Trematomus hansoni,and Trematomus bernacchii,collected from Prydz Bay,East Antarctica.Nine elements,^(23)Na,^(24)Mg,^(29)Si,^(31)P,^(39)K,^(57)Fe,^(66)Zn,^(88)Sr,and^(137)Ba,were selected for analyses because of their concentrations and ecological significance.Ratios of each element to Ca(Me/Ca)were used for analysis,and Me/Ca in the otolith nuclei of these species were analyzed to explore species-specific variations in element types.Significant differences in element composition,except for Fe/Ca and Ba/Ca,were found in different species.Temperature,salinity,reproduction,pelagic larval lifestyle,and diet composition were considered as key endogenous and exogenous factors influencing these differences.Decision tree discriminant analysis,based on the variation of the types and concentrations of elements,was used to identify P.borchgrevinki,T.hansoni,and T.bernacchii with accuracy rates of 86.54%,82.61%,and 73.33%,respectively.Principal component analysis showed overlapping 95%confidence el-lipses for the three species at 79.96%,67.31%,and 56.71%,respectively.As these species belong to the Nototheniidae family and share a similar hatching period,the accuracy of species discrimination is reduced.Considering the high probability of error in distin-guishing species using otolith nucleus elements,we recommend otolith shape should also be considered to improve identification ac-curacy.
基金supported by the National Natural Science Foundation of China(Grant no.32501365)Natural Science Foundation of Shandong Province,China(Grant no.ZR2025QC1456).
文摘Research on Antarctic microbial diversity has primarily focused on 3 areas:freshwater lake sediments,penguin colonies,and seawater in ice-free regions.There is a scarcity of research on the impact of slopes on microbial community structure,and this study effectively fills this gap.This study focused on the soil in the sparse vegetated tundra on a hillside near the southern coastline of the Antarctic Great Wall Station.The influence of slope position,soil physicochemical properties,and vegetated area on soil bacterial community structure was analyzed.High-throughput sequencing technology was employed to characterize a 16S rRNA gene fragment in soil samples from 5 slope areas and estimate bacterial abundance.Calculation ofα-diversity andβ-diversity indices,and community structure analysis were used to compare the species richness among sampling points,analyze similarities in soil bacterial community structure and composition,and identify the core bacterial population.In the non-vegetated area,the soil on the mountaintop,hillside,and at the foot of the slope showed similar physicochemical properties.In the vegetated area,the soil physicochemical properties were highly similar on the mountaintop,hillside,the foot of the slope,and the foot of the mountain.Weighted Gene Co-expression Network Analysis showed that total organic carbon,pH,and PO_(4)^(3-)-P might affect the structure of bacterial communities at the sampling point by changing the relative abundance of Chthoniobacterales,Sediminibacterium,and Actinobacteria.We hypothesize that slope-driven nutrient transport,amplified by vegetated areas(in the tundra),is a primary driver of bacterial community structure in the Antarctic tundra soil.These results provide insights into the impact of slope on microbial community structure in Antarctica.
基金The National Key Research and Development Program of China under contract No.2022YFC2807501.
文摘Despite being ubiquitous in oceans and important in marine biogeochemical cycles,planktonic archaea in the Southern Ocean(SO)remain poorly characterized.Although high-throughput sequencing(HTS)approaches based on 16S ribosomal RNA(rRNA)genes have been used widely to study the diversity and composition of microbial community in natural environments,primer-set selection is critical because of amplicon-sequencing bias during metabarcoding.Here,using surface-seawater samples collected from the area between the South Shetland and South Orkney Islands,Antarctica,we compared primer sets Arch349F/Arch806R,515F-Y/926R,and 524F/Arch958R,which target different 16S rRNA gene hypervariable regions to identify the best one for studying planktonic archaeal communities.With much lower number of bacteria-related sequences,primer set 524F/Arch958R showed higher values of archaeal operational taxonomic units(OTUs)as well as alpha-diversity indices,indicating that this primer set was more specific for detecting archaeal species and could be helpful to obtain more comprehensive information on the archaeal community compositions compared to other two primer sets.Compared with primer set Arch349F/Arch806R revealing four phyla(Halobacteriota,Methanobacteriota,Thermoplasmatota,and Thermoproteota)detected in seawater,additional archaeal phyla were observed by 515F-Y/926R(Asgardarchaeota and Nanoarchaeota)and 524F/Arch958R(Micrarchaeota).In spite of the differences in archaeal community compositions observed among the three investigated primer sets,ammonia-oxidizing(e.g.,Nitrososphaeria)and methane-producing(e.g.,Methanobacteria,Methanomicrobia,and Methanosarcinia)archaea were the main groups detected in the surface seawater,indicating the ecological role of planktonic archaea in carbon and nitrogen cycling in the upper waters of the SO.These results underscore the importance of primer-set selection when studying archaeal community diversity and composition in the Antarctic SO.
基金The National Natural Science Foundation of China under contract Nos 42325602 and 41976164the National Key Research and Development Program of China under contract No.2022YFC2807601.
文摘Seasonal cycles of phytoplankton blooms are crucial to marine ecosystems and highly sensitive to environmental fluctuations.Rapid climate change has a profound impact on regional environmental conditions,thereby affecting seasonal blooms at both regional and global scales.The western Antarctic Peninsula(WAP)is one of the most productive regions in the Southern Ocean and has experienced accelerated climate change in recent decades.However,the impact of climate change on bloom dynamics in this region remains uncertain due to regional variability and the complex interplay of environmental factors.Using 26 a(1998−2023)of satellite data,this study examines patterns and trends in bloom seasonal metrics on the southern WAP,and further explores the impact of large-scale climate drivers.A key finding was a clear shift in bloom timing,with earlier and longer blooms observed during 2012−2023.These shifts were associated with reduced spring sea ice extent(SIE),which correlated with warming spring sea surface air temperatures(SAT).Atmospheric teleconnections,particularly the El Niño-Southern Oscillation(ENSO)and Southern Annular Mode(SAM)in spring,were linked to changes in SAT and sea ice dynamics.This study highlights the role of climate drivers in altering bloom dynamics,potentially affecting local marine food webs,and underscores the need for further research to understand Antarctic ecosystem evolution under future climate scenarios.
基金jointly supported by the NSFC project (42088101, 41975048, 42361144843, 42175069)。
文摘This paper evaluates a representation of winter stratospheric circulation in the Antarctic that is based on CRA-40, a 40-year global reanalysis dataset released by the China Meteorological Administration, and compares it with representations based on two other state-of-the-art reanalysis datasets: the fifth-generation atmospheric reanalysis provided by the European Centre for Medium-Range Weather Forecasts(ERA-5) and the Modern-Era Retrospective analysis for Research and Applications, version 2(MERRA-2). In terms of climatology, we find that CRA-40 portrays a stronger and colder polar vortex in the middle and lower stratosphere than ERA-5, but a weaker and warmer one than MERRA-2. However, disagreement among the three reanalyses is confined mainly to the period before1999, and is largely reduced after that time. On the interannual timescale, portrayals of the intensity and area of the 10-hPa polar vortex are quite consistent among the three reanalyses, with correlation coefficients greater than 0.9 between each pair of reanalyses. In addition, the central dates of most sudden stratospheric deceleration(SSD) events at 10 hPa in the three reanalyses differ by less than one day, indicating that CRA-40 is also highly consistent with the other two reanalysis datasets regarding daily evolution. Our analyses suggest that CRA-40 performs comparably to ERA-5 and MERRA-2 in characterizing winter circulation in the Antarctic middle and lower stratosphere.
基金supported by the Shanghai Frontiers Science Center of Polar Science(Grant no.SOO2024-04)the National Natural Science Foundation of China(Grant no.42476264)Lanzhou University(Grant no.lzuibky-2024-oy01).
文摘Antarctic ice-free areas(<0.4%of the continent)represent Antarctic biodiversity oases,where microbial communities sustain terrestrial ecosystem functions.These habitats-encompassing mineral,ornithogenic soils,biological soil crusts,and hypolithic/endolithic niches-are shaped by environmental factors such as pH,organic C/N ratios,moisture,elevation,and trace element availability.The diversity of prokaryotes,eukaryotes,and viruses is lower than in other regions,yet the communities exhibit strong endemism,with site-specific uncultivated lineages.Microorganisms persist through cold and stress adaptations,performing organic carbon decomposition,phototrophy,and oxidation of trace gases to drive carbon and nitrogen cycling in various Antarctic soil habitats.Climate change and anthropogenic disturbances are shifting communities toward copiotrophic generalists,altering elementary cycling and feeding back to climate change.Culturation and genomic-based techniques reveal novel microbial taxa with broad biotechnological potentials on bioactive compounds and cryotolerant enzymes.In summary,this review offers a foundation for exploring Antarctic microbial biodiversity,ecosystem resilience,and the development of novel biotechnologies,while also highlighting the urgent need for effective monitoring and preservation strategies to mitigate the impacts of ongoing environmental changes on Antarctic soil ecosystems.
