期刊文献+
共找到166篇文章
< 1 2 9 >
每页显示 20 50 100
A conjugate study of the polar ionospheric F2-layer and IRI-2007 at 75 ° magnetic latitude for solar minimum 被引量:1
1
作者 HE Fang ZHANG BeiChen +1 位作者 JoranMoen HUANG DeHong 《Advances in Polar Science》 2011年第3期175-183,共9页
Long-duration conjugate observations by the EISCAT Svalbard Radar (ESR) and the ionosonde at Zhongshan station from the International Polar Year (IPY) during solar minimum conditions are analyzed, with respect to ... Long-duration conjugate observations by the EISCAT Svalbard Radar (ESR) and the ionosonde at Zhongshan station from the International Polar Year (IPY) during solar minimum conditions are analyzed, with respect to variability in the F2-1ayer peak parameters. A comparison between International Reference Ionosphere- 2007 (IRI-2007) and observation data clearly demonstrates good agreement in summer, but greater deviations in winter. The IRI model reproduces the F2 peak parameters dominated by solar photoionization reasonably well, but it does not address the effect of electron precipitation. Hence, the discrepancies become large in the winter auroral ionosphere. 展开更多
关键词 Solar minimum polar ionosphere IRI electron precipitation
在线阅读 下载PDF
Optimization of fluorescence in situ hybridization (FISH) for the identification of two polar coccoid green algae species
2
作者 高小艳 李运广 +2 位作者 李会荣 陈雯莉 罗玮 《Chinese Journal of Polar Science》 2010年第2期167-179,共13页
Standard FISH protocols using fluorochrome-labeled oligonucleotide probes have been successfully applied for in situ detection.However,optimized protocols of FISH for specific eukaryotes in marine environments are oft... Standard FISH protocols using fluorochrome-labeled oligonucleotide probes have been successfully applied for in situ detection.However,optimized protocols of FISH for specific eukaryotes in marine environments are often not developed.This study optimized the conditions of fluorescence in situ hybridization (FISH) by using two polar isolated microalgae.The modified conditions were as follows:(1) 10 mg·mL^(-1) lysozyme solution pretreatment at 37℃for 30 min;(2) the hybridization buffer including 20%formamide;(3) the hybridization condition was 47℃for 6 h.The cells enumerated by FISH were compared with those enumerated by flow cytometry(FCM) and DAPI to confirm the cell loss and hybridization efficiency.The optimized protocol was also successfully applied to Arctic Ocean samples,which were found to be dominated by Micromonas sp.The modified protocol showed a high relative efficiency and could be successfully applied for the detection of specific microbial eukaryotes in environmental samples. 展开更多
关键词 Fluorescence in situ hybridization(FISH) Chlorella vulgaris strain Lw2008/02 Micromonas sp.strain CCMP2099
在线阅读 下载PDF
DBpedia-Based Fuzzy Query Recommenda-tion Algorithm and Its Applications in the Resource-Sharing Platform of Polar Samples
3
作者 Wenfang Cheng Qing’e Wu +2 位作者 Xiao Cheng Jie Zhang Zhuanling Song 《International Journal of Intelligence Science》 2015年第5期196-207,共12页
In order to continuously promote the polar sample resource services in China and effectively guide the users to access such information as needed, a fuzzy algorithm based on DBpedia has been proposed through the analy... In order to continuously promote the polar sample resource services in China and effectively guide the users to access such information as needed, a fuzzy algorithm based on DBpedia has been proposed through the analysis of the characteristics of the query recommendations in search engines, namely, to search similar entry queues by constructing a DBpedia category tree, then use the fuzzy matching algorithm to work out the entry similarity, and then present the example query applications of this algorithm on the resource-sharing platform of polar samples. Comparing the traditional literal character matching method and DBpedia semantic similarity algorithm, the experimental results show that the fuzzy query algorithm based on DBpedia features has a higher search accuracy rate, stronger anti-interference capability, and more flexible algorithm use by virtue of its fuzzy weight adjustment. 展开更多
关键词 Search Engine Fuzzy QUERY Semantic SIMILARITY WIKI
在线阅读 下载PDF
Multiscale processes in polar oceans and their climate and ecological implications
4
作者 Ruibo Lei 《Acta Oceanologica Sinica》 2025年第3期1-2,共2页
The Arctic and Antarctica are important components of the Earth system,and the snow and ice over the polar regions make the interactions between the spheres there extremely sensitive to climate change,with an amplifyi... The Arctic and Antarctica are important components of the Earth system,and the snow and ice over the polar regions make the interactions between the spheres there extremely sensitive to climate change,with an amplifying effect on climate warming.Polar regions are the forefront of global climate and ecosystem changes.More than half of the identified climate tipping elements in our planet occur in the polar regions,with the losses of Arctic sea ice,Greenland ice sheet,permafrost,and western Antarctic ice sheet,being considered as tipping elements with global impacts that have already occurred(McKay et al.,2022).These changes in the polar regions affect the heat and material transfer,water and carbon cycles,as well as biological diversity at a global scale,closely related to global sustainable development.Therefore,polar regions are also considered the limiting factors in achieving the United Nations Sustainable Development Goals(Li et al.,2025). 展开更多
关键词 arctic sea icegreenland ice sheetpermafrostand ice sheet arctic antarctica polar oceans climate tipping elements snow ice climate changewith climate change
在线阅读 下载PDF
Spatiotemporal variations of sea ice kinematics in the Transpolar Drift of the Arctic Ocean in 2019/2020 derived from buoy measurements during MOSAiC
5
作者 LIU Minghao LEI Ruibo +1 位作者 LI Na CHENG Xuhua 《Advances in Polar Science》 2025年第2期137-151,共15页
Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate... Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean. 展开更多
关键词 sea ice motion sea ice deformation Arctic Ocean buoy measurements MOSAIC
在线阅读 下载PDF
New horizons in the exploration of polar biodiversity,ecosystems,and genetic resources
6
作者 JI Mukan LIAO Li +3 位作者 Maggie C.Y.LAU VETTER SHAO Changwei ZHANG Xiying Ben LUISI 《Advances in Polar Science》 2025年第4期265-267,共3页
The polar regions host one of the harshest and most unique ecosystems on Earth.These habitats,encompassing the Arctic and the Antarctic and from deep-marine sediments to glacial ice/ice sheets,represent one of the fin... The polar regions host one of the harshest and most unique ecosystems on Earth.These habitats,encompassing the Arctic and the Antarctic and from deep-marine sediments to glacial ice/ice sheets,represent one of the final frontiers of terrestrial biological exploration.Traditionally viewed as desolate,ice-covered lands,polar regions are now recognized as vibrant,complex,and highly sensitive ecosystems. 展开更多
关键词 terrestrial biological explorationtraditionally BIODIVERSITY deep marine sediments ECOSYSTEMS polar regions ARCTIC ANTARCTIC genetic resources
在线阅读 下载PDF
Research progress on secondary metabolites of polar microorganisms
7
作者 WU Zhouyu ZHAI Wanying CHEN Liangbiao 《Advances in Polar Science》 2025年第4期285-300,共16页
The extreme environment of the polar regions has driven the evolution of unique metabolic mechanisms in microorganisms,resulting in structurally diverse and highly active secondary metabolites.These metabolites are no... The extreme environment of the polar regions has driven the evolution of unique metabolic mechanisms in microorganisms,resulting in structurally diverse and highly active secondary metabolites.These metabolites are not only crucial for microbial adaptation to extreme conditions,but also exhibit significant potential for applications in medicine,agriculture(e.g.,biocontrol),and industry.This review provides a comprehensive overview of 111 secondary metabolites derived from polar microorganisms reported between 2013 and 2025,with a focus on advances in their classification,biological activities,and biosynthetic gene cluster mining techniques.Additionally,it highlights key strategies for advancing future investigations,providing a valuable reference for continued exploration in this promising field.Notably,polar microbial secondary metabolites also hold promising applications in agriculture,particularly in biocontrol,soil health enhancement,and stress-resistant crop development. 展开更多
关键词 polar microorganisms secondary metabolites biosynthetic gene clusters genomics technology bioactivity
在线阅读 下载PDF
Comparison of three 16S rRNA gene primer sets for the study of planktonic archaeal communities in the Antarctic Peninsula region
8
作者 Zuoqi Wang Yinxin Zeng +5 位作者 Miming Zhang Yu Du Wei Han Ting Hu Yongqiang Hu Haitao Ding 《Acta Oceanologica Sinica》 2025年第11期201-214,共14页
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
关键词 primer set 16S rRNA gene planktonic archaeal community Southern Ocean ANTARCTIC
在线阅读 下载PDF
Regulatory mechanisms and adaptive functions of small RNAs in extremophilic microorganisms
9
作者 JIANG Wanning DUAN Zedong +4 位作者 LAI Tingyi ZHANG Siqi YU Yong DING Haitao LIAO Li 《Advances in Polar Science》 2026年第1期35-42,共8页
Small RNAs(sRNAs)are important non-coding RNAs that usually play crucial roles in gene expression at the post-transcriptional level.The sRNAs have mostly been investigated in model microorganisms such as Escherichia c... Small RNAs(sRNAs)are important non-coding RNAs that usually play crucial roles in gene expression at the post-transcriptional level.The sRNAs have mostly been investigated in model microorganisms such as Escherichia coli and some pathogens.Nevertheless,microbial sRNAs from extreme environments such as the polar regions and deep sea have recently been discovered and analyzed for their unique roles in stress response,metabolic regulation and adaptation to extreme environments.These sRNAs fine-tune gene expression during oxidative and radiation stress,and modulate temperature and osmotic pressure responses.Representative sRNAs and their functions in thermophilic,psychrophilic,halophilic and radiation-tolerant bacteria are summarized in this review.Despite challenges in sample collection,RNA isolation,and functional annotation,the study of sRNAs in extreme environments provides opportunities for discovering novel regulatory mechanisms,applying them to biotechnology,and advancing our understanding of evolutionary adaptations.Looking ahead,high-throughput sequencing,synthetic biology,and multi-omics integration will bring new breakthroughs in discovering novel sRNAs and their functions and regulatory mechanisms.Such advancements are poised to enable comprehensive characterization of sRNA-mediated regulatory networks in extremophiles and unlock their biotechnological potential through mechanism-driven applications. 展开更多
关键词 small RNAs extremophilic microorganisms regulatory mechanisms adaptive functions
在线阅读 下载PDF
Recent progress in Chinese polar upper-atmospheric physics research: review of research advances supported by the Chinese Arctic and Antarctic expeditions 被引量:6
10
作者 HE Fang HU Hongqiao +5 位作者 YANG Huigen ZHANG Beichen HUANG Dehong LIU Yonghua HU Zejun LIU Jianjun 《Advances in Polar Science》 2016年第4期219-232,共14页
It has been more than 30 years since the first Chinese Antarctic Expedition took place. Polar upper atmospheric observations started at this time. First began at Great Wall Station and then at Zhongshan Station in Ant... It has been more than 30 years since the first Chinese Antarctic Expedition took place. Polar upper atmospheric observations started at this time. First began at Great Wall Station and then at Zhongshan Station in Antarctica, and later in the Arctic at Yellow River Station, Kjell Henriksen Observatory on Svalbard, and at the China-Iceland Joint Aurora Observatory in Iceland. In this paper, we reviewed the advances in polar upper atmosphere physics (UAP) based on the Chinese national Arctic and Antarctic research over the last five years. These included newly deployed observatories and research instruments in the Arctic and Antarctic; and new research findings, from grotmd-based observations, about polar ionosphere dynamics, aurora and particle precipitation, polar plasma convection, geomagnetic pulsations and space plasma waves, space weather in the polar regions, simulations of the polar ionosphere-magnetosphere. In conclusion, suggestions were made for future polar upper atmosphere physics research in China. 展开更多
关键词 upper-atmospheric physics research advances polar ionosphere AURORA particle precipitation plasmaconvection plasma waves space weather
在线阅读 下载PDF
Sensitivity of the Arctic sea ice concentration forecasts to different atmospheric forcing: a case study 被引量:5
11
作者 YANG Qinghua LIU Jiping +6 位作者 ZHANG Zhanhai SUI Cuijuan XING Jianyong LI Ming LI Chunhua ZHAO Jiechen ZHANG Lin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第12期15-23,共9页
A regional Arctic configuration of the Massachusetts Institute of Technology general circulation model (MIT-gcm) is used as the coupled ice-ocean model for forecasting sea ice conditions in the Arctic Ocean at the N... A regional Arctic configuration of the Massachusetts Institute of Technology general circulation model (MIT-gcm) is used as the coupled ice-ocean model for forecasting sea ice conditions in the Arctic Ocean at the Na-tional Marine Environmental Forecasting Center of China (NMEFC), and the numerical weather prediction from the National Center for Environmental Prediction Global Forecast System (NCEP GFS) is used as the atmospheric forcing. To improve the sea ice forecasting, a recently developed Polar Weather Research and Forecasting model (Polar WRF) model prediction is also tested as the atmospheric forcing. Their forecasting performances are evaluated with two different satellite-derived sea ice concentration products as initializa-tions: (1) the Special Sensor Microwave Imager/Sounder (SSMIS) and (2) the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). Three synoptic cases, which represent the typical atmospheric circulations over the Arctic Ocean in summer 2010, are selected to carry out the Arctic sea ice numerical forecasting experiments. The evaluations suggest that the forecasts of sea ice concentrations using the Polar WRF atmo-spheric forcing show some improvements as compared with that of the NCEP GFS. 展开更多
关键词 Arctic Ocean seaice concentration FORECAST
在线阅读 下载PDF
Dome Argus: Ideal site for deep ice drilling 被引量:5
12
作者 TANG Xueyuan SUN Bo LIYuansheng LI Xin CUI Xiangbin 《Advances in Polar Science》 2012年第1期47-54,共8页
Located on the centre of ice drainage range, the highest Dome Argus (Dome A) of East Antarctic Ice Sheet (EAIS), could be represented as an ideal site for deep ice cores drilling containing oldest paleo-climate re... Located on the centre of ice drainage range, the highest Dome Argus (Dome A) of East Antarctic Ice Sheet (EAIS), could be represented as an ideal site for deep ice cores drilling containing oldest paleo-climate records. To select a suitable drilling site for deep ice core, it needs gather all information pertaining to the local meteorology, ice sheet landforms, ice thickness, subgla- cial topography of bed rocks, ice velocity, internal structures of ice sheet, etc. Based on the International Partnerships in Ice Core Sciences (IPICS), we present recent achievement of glaciological research and its perspective at Dome A in this paper. We system- atically discussed the merits and possible ventures of potential drilling sites around Dome A. Among all the candidates, we find that the Chinese Antarctic Kunlun Station is the best site for and assess further the possibility to obtain a replicate core for carrying out the first deep ice core drilling campaign. We emphasize studying dynamics and evolution of climate change. 展开更多
关键词 East Antarctic Ice Sheet Dome Argus GLACIOLOGY deep ice core
在线阅读 下载PDF
Meteorite classification for building the Chinese Antarctic Meteorite Depository Introduction of the classification of 500 Grove Mountains meteorites 被引量:5
13
作者 XIA Zhipeng ZHANG Jie +4 位作者 MIAO Bingkui OU Ronglin XIE Lanfang YANG Rui JING Yuan 《Advances in Polar Science》 2016年第1期56-63,共8页
Meteorites provide an important window into the origins and evolution of the solar system. Since the first four meteorites were recovered in Grove Mountains, Antarctica, in 1998, a further total of 12665 meteorites ha... Meteorites provide an important window into the origins and evolution of the solar system. Since the first four meteorites were recovered in Grove Mountains, Antarctica, in 1998, a further total of 12665 meteorites have been collected over seven polar seasons in the Grove Mountains. All of these meteorites are owned and managed by the Chinese Antarctic Meteorite Depository (CAMD) at the Polar Research Institute of China (PRIC). In recent years, another 500 Antarctic meteorites have been classified and characterized based on mineralogy and petrology. In this work we examine four samples that have been identified as terrestrial, and a further 496 samples that have been confirmed as meteorites. These meteorites are further divided into different types:488 ordinary chondrites, one eucrite, one ureilite, one CM2 carbonaceous chondrite, one EH4 enstatite chondrite, one mesosiderite and three iron meteorites. The classification of meteorites not only provides an abundance of fundamental scientific data, but is also significant for introducing meteorites and related scientific knowledge to the publics particularly via the website of Chinese Resource-sharing Platform of Polar Samples for scientific research and education. 展开更多
关键词 Antarctic meteorites Grove Mountains CLASSIFICATION Chinese Antarctic Meteorite Depository
在线阅读 下载PDF
Extracellular enzymatic activities of cold-adapted bacteria from polar oceans and effect of temperature and salinity on cell growth 被引量:3
14
作者 曾胤新 俞勇 +1 位作者 陈波 李会荣 《Chinese Journal of Polar Science》 2004年第2期118-128,共11页
The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase,... The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase, gelatinase, agarase, chitinase or cellulase were detected. Lipases were generally present by bacteria living in polar oceans. Protease-producing bacteria held the second highest proportion in culturable isolates. Strains producing amylase kept a relative stable proportion of around 30% in different polar marine habitats. All 50 Arctic sea-ice bacteria producing proteases were cold-adapted strains, however, only 20% were psychrophilic. 98% of them could grow at 3% NaCl, and 56% could grow without NaCl. On the other hand, 98% of these sea-ice bacteria produced extracellular proteases with optimum temperature at or higher than 35℃, well above the upper temperature limit of cell growth. Extracellular enzymes including amylase, agarase, cellulase and lipase released by bacteria from seawater or sediment in polar oceans, most expressed maximum activities between 25 and 35℃. Among extracellular enzymes released by bacterial strain BSw20308, protease expressed maximum activity at 40℃, higher than 35℃ of polysaccharide hydrolases and 25℃ of lipase. 展开更多
关键词 Enzyme COLD-ADAPTED BACTERIA polar ocean.
在线阅读 下载PDF
Phylogenetic diversity of dinoflagellates in polar regions 被引量:3
15
作者 LUO Wei DAI CongJie +1 位作者 LI HuiRong GAO XiaoYan 《Chinese Journal of Polar Science》 2011年第1期35-41,共7页
Because of the limitations of sampling and seasonal study in polar regions, knowledge of dinoflagellate diversity, distribution and ecology are limited. Dinoflagellates have been incidentally reported from polar regio... Because of the limitations of sampling and seasonal study in polar regions, knowledge of dinoflagellate diversity, distribution and ecology are limited. Dinoflagellates have been incidentally reported from polar regions during some seasons and some populations have been reported as components of microalgae. Surveys of molecular diversity link the genotype of dinoflagellates from polar regions with environmental adaptation. In this study, 37 positive clones of dinoflagellates collected from different sites were used for genotype analysis, providing new insights into the biodiversity and distribution of these species based on 18S rRNA sequencing. Diverse genotypes were recorded for the summer season in Kongsfjorden (high Arctic) whilst a single novel genotype of dinoflagellate was recorded from winter samples from the Antarctic Ocean. Data from ice cores suggests that this single dinoflagellate genotype was adapted to extreme cold and clone library screening found that it was occasionally the only microbial eukaryotic genotype found in winter ice cores. The findings of this study could improve our understanding of the diverse dinoflagellate genotypes occurring in these perennially cold microbial ecosystems. 展开更多
关键词 BIPOLAR DINOFLAGELLATES molecular diversity 18S rRNA
在线阅读 下载PDF
Simultaneous optical and radar observations of poleward moving auroral forms under different IMF conditions 被引量:2
16
作者 XING Zanyang YANG Huigen +7 位作者 HAN Desheng WU Zhensen LIU Junming HU Zejun ZHANG Qinghe LIU Yonghua ZHANG Beichen HU Hongqiao 《Advances in Polar Science》 2012年第4期204-210,共7页
Using high temporal resolution optical data obtained from three-wavelength all-sky imagers at Chinese Yellow River Station in the Arctic, together with the EISCAT Svalbard radar (ESR) and SuperDARN radars, we invest... Using high temporal resolution optical data obtained from three-wavelength all-sky imagers at Chinese Yellow River Station in the Arctic, together with the EISCAT Svalbard radar (ESR) and SuperDARN radars, we investigated the dayside pole- ward moving auroral forms (PMAFs) and the associated plasma features in the polar ionosphere under difibrent interplanetary magnetic field (1MF) conditions, between 0900 and 1010 UT on 22 December 2003. Simultaneous optical and ESR observations revealed that all PMAFs were clearly associated with pulsed particle precipitations. During northward IMF, particles can precipi- tate into lower altitudes and reach the ionospheric E-region, and there is a reverse convection cell associated with these PMAFs. This cell is one of the typical signatures of the dayside high-latitude (lobe) reconnection in the polar ionosphere. These results indicate that the PMAFs were associated with the high-latitude reconnection. During southward IMF, the PMAFs show larger lati- tudinal motion, indicating a longer mean lifetime, and the associated ionospheric features indicate that the PMAFs were generated by the dayside low-latitude reconnection. 展开更多
关键词 PMAFs polar ionosphere RECONNECTION
在线阅读 下载PDF
Meteorological observations and weather forecasting services of the CHINARE 被引量:2
17
作者 SUN Qizhen ZHANG Lin +3 位作者 MENG Shang SHEN Hui DING Zhuoming ZHANG Zhanhai 《Advances in Polar Science》 2018年第4期291-299,共9页
By 2018, China had conducted 34 scientific explorations in Antarctica spearheaded by the Chinese National Antarctic Research Expedition(CHINARE). Since the first CHINARE over 30 years ago, considerable work has been u... By 2018, China had conducted 34 scientific explorations in Antarctica spearheaded by the Chinese National Antarctic Research Expedition(CHINARE). Since the first CHINARE over 30 years ago, considerable work has been undertaken to promote the development of techniques for the observation of surface and upper-air meteorological elements, and satellite image and data reception systems at Chinese Antarctic stations and onboard Chinese icebreakers have played critical roles in this endeavor. The upgrade of in situ and remote sensing measurement methods and the improvement of weather forecasting skill have enabled forecasters to achieve reliable on-site weather forecasting for the CHINARE. Nowadays, the routing of icebreakers, navigation of aircraft, and activities at Chinese Antarctic stations all benefit from the accurate weather forecasting service. In this paper, a review of the conventional meteorological measurement and operational weather forecasting services of the CHINARE is presented. 展开更多
关键词 Chinese National Antarctic Research Expedition (CHINARE) meteorological observations weather forecasting services
在线阅读 下载PDF
Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 被引量:1
18
作者 ZENG Yinxin LI Huirong +2 位作者 YU Yong CHEN Bo ZHENG Tianling 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2007年第4期93-103,共11页
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, ... A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria ( 〉 99% ), but also between polar marine bacteria and bacteria from other aquatic environments ( ≥ 98.8% ), including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 展开更多
关键词 BACTERIOPLANKTON diversity ARCTIC ANTARCTIC
在线阅读 下载PDF
Impact of Assimilation of Radiosonde and UAV Observations from the Southern Ocean in the Polar WRF Model 被引量:1
19
作者 Qizhen SUN Timo VIHMA +1 位作者 Marius OJONASSEN Zhanhai ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第5期441-454,共14页
Weather forecasting in the Southern Ocean and Antarctica is a challenge above all due to the rarity of observations to be assimilated in numerical weather prediction(NWP)models.As observations are expensive and logist... Weather forecasting in the Southern Ocean and Antarctica is a challenge above all due to the rarity of observations to be assimilated in numerical weather prediction(NWP)models.As observations are expensive and logistically challenging,it is important to evaluate the benefit that additional observations could bring to NWP.Atmospheric soundings applying unmanned aerial vehicles(UAVs)have a large potential to supplement conventional radiosonde sounding observations.Here,we applied UAV and radiosonde sounding observations from an RV Polarstern cruise in the ice-covered Weddell Sea in austral winter 2013 to evaluate the impact of their assimilation in the Polar version of the Weather Research and Forecasting(Polar WRF)model.Our experiments revealed small to moderate impacts of radiosonde and UAV data assimilation.In any case,the assimilation of sounding data from both radiosondes and UAVs improved the analyses of air temperature,wind speed,and humidity at the observation site for most of the time.Further,the impact on the results of 5-day-long Polar WRF experiments was often felt over distances of at least 300 km from the observation site.All experiments succeeded in capturing the main features of the evolution of near-surface variables,but the effects of data assimilation varied between different cases.Due to the limited vertical extent of the UAV observations,the impact of their assimilation was limited to the lowermost 1?2-km layer,and assimilation of radiosonde data was more beneficial for modeled sea level pressure and near-surface wind speed. 展开更多
关键词 numerical weather prediction RADIOSONDE SOUNDINGS unmanned AERIAL vehicles data ASSIMILATION ANTARCTIC Southern Ocean
在线阅读 下载PDF
China’s Recent Progresses in Polar Climate Change and Its Interactions with the Global Climate System 被引量:2
20
作者 Xichen LI Xianyao CHEN +12 位作者 Bingyi WU Xiao CHENG Minghu DING Ruibo LEI Di QI Qizhen SUN Xiaoyu WANG Wenli ZHONG Lei ZHENG Meijiao XIN Xiaocen SHEN Chentao SONG Yurong HOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第8期1401-1428,共28页
During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where trad... During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper. 展开更多
关键词 polar climate change recent progress in China Arctic amplification tropical-polar interactions global sea level rise stratospheric circulation
在线阅读 下载PDF
上一页 1 2 9 下一页 到第
使用帮助 返回顶部