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    30 September 2011, Volume 23 Issue 3 Previous Issue    Next Issue

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    A comparative study of the polar Ionospheric F2 Layer at cusp latitude between IRI model prediction and observations in both hemispheres in solar minimum
    2011, 23 (3):  159-167.  DOI: 10.3724/SP.J.1084.2011.00159
    Abstract ( 1811 )   PDF (3594KB) ( 1306 )  

    A long run of EISCAT Svalbard Radar and DPS-4 in Zhongshan Station, between December 2006 and December 2007, have been analyzed with respect to diurnal variability in the F2 region critical frequency(f0F2) and peak altitude(hmF2). Comparison with the international reference ionosphere model (IRI-2007) clearly demonstrates that the observations in both stations were consistent with the IRI prediction in summer, but with great deviations in winter. It suggested that though the photoionization factor had been well considered in the model, the electron precipitation should be taken into account, especially in winter.

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    A Method for Extracting Auroral Ovals in UVI Images and Its Evaluation
    Wang Qian, Meng Qinghu, Hu Zejun, Xing Zanyang, Liang Jimin, Hu Hongqiao
    2011, 23 (3):  168-177.  DOI: 10.3724/SP.J.1084.2011.00168
    Abstract ( 1789 )   PDF (9222KB) ( 1326 )  

    The equatorward and poleward boundaries of auroral oval are important geophysical parameters which are closely related with the energy coupling between solar wind and magnetosphere. A new method of acquiring the boundaries of auroral oval in Ultraviolet Auroral Imager (UVI) aboard Polar satellite is evolved from the algorithm named fuzzy local information c-means clustering (FLICM). The method can get the integrated, real boundaries of auroral oval. The results of cross validation based on the precipitating electron boundaries from DMSP satellite precipitation particles data show that the auroral boundaries from new algorithm are more accurate than that from previous methods.

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    Statistical study of SAPS characteristics in both hemispheres
    Wang Hui Hua Ying Yang Bing Ma Shuying
    2011, 23 (3):  178-182.  DOI: 10.3724/SP.J.1084.2011.00178
    Abstract ( 1784 )   PDF (2069KB) ( 1333 )  

    This work has investigated the seasonal and universal time (UT) variation of the occurrence frequency and magnetic latitude (MLat) of SAPS in both hemispheres by using DMSP particle observations. It is found: (1) SAPS tend to occur mostly at equinox seasons, showing strong magnetic activity dependence. (2) SAPS tend to occur secondly in winter, which may be related to substorm processes. (3) Ionospheric conductivity has important influences on SAPS occurrence, with more occurrence at lower conductivity. (4) SAPS tend to shift equatorward with low ionospheric conductivity.

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    ANALYSIS OF CHLOROPHYLL FLUORESCENCE CHARACTERISTICS ON TEN KINDS OF POLAR MICROALGAE
    Guang Yingzhi Zhang Fang Zhang Qianqian Cai Minghong He Jianfeng
    2011, 23 (3):  183-188.  DOI: 10.3724/SP.J.1084.2011.00183
    Abstract ( 1883 )   PDF (2489KB) ( 1282 )  

    Marine phytoplanktons are important primary producer in aquatic environment and the productivity of them is related to its photosynthetic capacity. Chlorophyll fluorescence parameters (Fv /Fo, Fv /Fm, ΦPSⅡand NPQ) as well as the rapid light curve containing photosynthetic efficiency (a), maximal electron transport rate (Pm) and minimum saturating irradiance (Ik) of ten kinds of polar microalgae strains were measured by Water-PAM respectively. Nine kinds of strains except for CCMP2084 were in healthy physiological status. Fv /Fo of eight strains, whose values were higher than 1.0, showed activity sequence of PSⅡ as CCMP1056>CCMP1204>CCMP165>CCMP2095>CCMP1309>CCMP445>CCMP213>CCMP2087. Besides, three strains including Chaetoceros brevis CCMP165, Attheya sp.CCMP213 and Thalassiosira sp CCMP1056, exhibit stronger photoprotection with the NPQ value higher than 2.0. Compared by Ik value, the sequence of light tolerance was CCMP213>CCMP1056>CCMP165. The strains of Attheya sp CCMP213 and Thalassiosira sp.CCMP1056 showed better adaptation to high irradiance than Chaetoceros brevis CCMP165.

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    PRELIMINARY STUDY ON ANTIBACTERIAL ACTIVITY OF A TRICHODERMA STRAIN FROM AN ANTARTIC MOSS HABITAT AND ITS SALT,COLD RESISTANCE ON PLANTS
    JIA Wei TIAN Li TAO Jingjing SHI Zhenping ZHANG Jiuming
    2011, 23 (3):  189-195.  DOI: 10.3724/SP.J.1084.2011.00189
    Abstract ( 1638 )   PDF (5306KB) ( 1271 )  

    Using traditional taxonomic methods, ITS sequences and phylogenetic analysis, Trichoderma strain NTYM-0112 isolated from an Antarctic moss habitat was identified as T. asperellum. A preliminary study was made of its antibacterial activities and range in inducing salt and cold resistance effects in plants. The antibacterial activities results revealed that strain NTYM-0112 showed obvious inhibition to seven common plant pathogens including Pyrfcularia oryzae, Verticillium dahlia and Fusarium graminearum. Salt resistance results indicated that the germination rate of tomato seeds increased 13.4% compared with the control after treatment with strain NTYM-0112; the salt injury index reduced significantly by 35.7%; and the survival rate and water content of tomato dry weight increased by 34.4% and 20.4%, respectively, after treatment with strain NTYM-0112. The MDA content of leaves was obviously reduced compared with the control. The cold resistance results showed that after treatment with strain NTYM-0112, the electrolyte leakage rate of cucumber seedlings at 0°C, 5°C and 10°C reduced by 13.1%, 20.9% and 32.8%, respectively, and the extravasation values of soluble sugar decreased by 18.0 mg/g, 28.6 mg/g and 48.4 mg/g, respectively. All of these results confirmed Antarctic habitat strain Trichoderma asperellum possessed preferable antibacterial activity and effect of inducing plant resistance to stress.

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    Ultrastructure, growth, physiological property, oligotrophic and nutritious liquid fermentation medium studies of Alteromonas stellipolaris sp. nov.
    Zhao Jialu Yang Jifang Chen Fusheng
    2011, 23 (3):  196-204.  DOI: 10.3724/SP.J.1084.2011.00196
    Abstract ( 1908 )   PDF (5794KB) ( 1384 )  

    Oligotrophic bacteria are a class can take advantage of low concentrations of organic nutrients matrix of bacteria, Oligotrophic bacteria AT52 is a strain isolated from the Antarctic polar ocean,its found AT52 cell have appendages, with flagella, cell budding , appendages of different lengths, surrounded by a layer of plasma membrane under the conditions in deep nutrient-rich. Oligotrophic bacterial cells to survive starvation is relatively small, nearly spherical, the edge is not smooth, without appendages such as flagella ultrastructure of cells as non-dormant buds of reproductive processes.This experiment studied the growth physiological characteristic of AT52,separately,in oligotrophic environment and rich nutrition environment.The optimal matrix: Poptone 5g,Yeast Extract 1g,the Antarctic seawater 1000mL.The optimal conditions: temperature 12℃,pH 8.0,rotation speed 180r/min, inoculation density 5% and 200mL liquid medium joined into the 500mL Triangle bottle to ensure enough oxygen. AT52’s production cycle was shorted by thses conditions which provides the basis for industrial production.

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    Status of Arctic Sea Ice and Atmospheric Circulation during the period of Chinese Fourth Arctic Research Expedition
    Sui Cuijuan Zhang Zhanhai Ling Tiejun Wu Huiding Yu Lejiang
    2011, 23 (3):  205-216.  DOI: 10.3724/SP.J.1084.2011.00205
    Abstract ( 1886 )   PDF (11598KB) ( 1146 )  

    Based on the data from National Sea Ice Data Center (NSIDC), we presented the Arctic sea ice extent and concentration during the Fourth Chinese Arctic Research Expedition 2010, and analyzed the corresponding atmospheric circulation using NCEP/NCAR reanalysis data. It was found that the positive dipole anomaly caused the increase of ice melt rates in June and August. The ice extent in June of this year reached the minimum of historical records in June. The melt rate was reduced in July due to the control of low pressure. In August, leads and polynyas presented in large area spanning the North Pole from Pacific Ocean to Atlantic Ocean where the ice concentration is lower than 80%. We therefore made the conclusion that the ice extent and concentration were significantly affected by the atmospheric circulation. Additionally, we also pointed out that the earlier clearing of sea ice along the Northwest Passage was caused by the abnormally higher temperature during springtime in the Canadian Arctic area.

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    Analysis on the Legal Issues of Delimiting the Outer Limits of the Arctic Continental Shelf beyond 200 Nautical Miles
    Wu Di
    2011, 23 (3):  217-225.  DOI: 10.3724/SP.J.1084.2011.00217
    Abstract ( 1728 )   PDF (4272KB) ( 1534 )  

    In the near future, it’s technically possible for the Arctic coastal countries (Russia, Denmark, Norway, Canada and the United States) to exploit the natural resources hidden in the Arctic region as the Arctic ice cap is melting rapidly. Geological structure of the Arctic continental shelf, the non-legally binding recommendation of the Commission on the limits of the Continental Shelf, the defects of the dispute settlement mechanism of UNCLOS as well as the fragile Arctic environment system jointly determined the delimitation of the continental shelf in the Arctic will be a complicated procedure. This article is mainly about the treaty law basis, legal issues and the Settlement Model of Delimiting the Arctic Outer Continental Shelf. The Arctic outer continental shelf issues are not only regional affairs, but also closely relating to China’s vital interests. In order to ensure China's sustainable and stable development of economy, we should pay more attention on the legal rights on natural resources in high seas. China is expected to influence the final settlement of the Arctic Outer Continental Shelf through active and stable legal methods in order to safeguard its own legitimate interests.

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    THE DEVELOPMENT OF GEODETIC COORDINATE SYSTEM IN ANTARCTIC
    E Dongchen Zhang Shengkai
    2011, 23 (3):  226-231.  DOI: 10.3724/SP.J.1084.2011.00226
    Abstract ( 1642 )   PDF (2729KB) ( 1317 )  

    Geodetic coordinate systems are fundamental to the study of geodesy. We start by defining several coordinate systems, such as a rectangular space coordinate system, a geodetic coordinate system, a topocentric coordinate system and a planar coordinate system. Then the World Geodetic System WGS72 and WGS84 and International Terrestrial Reference Frames ITRF2000 and ITRF2005 are introduced. The history of international geodetic coordinate systems in Antarctica is briefly reviewed and the development of geodetic coordinate systems at the Great Wall Station and Zhongshan Station is introduced. Finally, the issue of coordinate transformation is discussed.

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    DESIGN AND IMPLEMENTION OF POLAR INFORMATION SYSTEM BASED ARCGIS SERVER
    Liu Jian Gao Xizhang LiShenggui ZhuJiangang ChengWenfang
    2011, 23 (3):  232-240.  DOI: 10.3724/SP.J.1084.2011.00232
    Abstract ( 1925 )   PDF (10765KB) ( 1291 )  

    A Geographic Information System (GIS) can provide users with convenient and efficient mapping service, this paper applied the data on various topics obtained by previous Antarctic Survey, based on ArcGIS Server platform, designed and implemented for the public's polar information system. This paper discussed the system design and building process gradually. The main functions of the system are introduced, with emphasis on the information inquiry function and spatial analysis capabilities. The system interface is friendly, easy operation. Thematic data in the realization of polar information are shared, and at the same time, provide for the majority of polar intuitive and efficient services to polar science.

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