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    30 June 1960, Volume 21 Issue 2-English Previous Issue    Next Issue

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    Calculation of photosynthetically available radiation using multispectral data in the Arctic
    Zhao Jinping(赵进平)1* ,Wang Weibo(王维波)1 and Cooper Lee2
    2010, 21 (2-English):  113-126.  DOI: 10.3724/SP.J.1085.2010.00113
    Abstract ( 1213 )   PDF (534KB) ( 985 )  

    Photosynthetically Available Radiation (PAR) is an important bio-optical parameter related to marine primary production. PAR is usually measured by a broadband sensor and can also be calculated by multispectral data. When the PAR is calculated by multispectral data in polar region, four factors are possible error sources. PAR could be overestimated as the wavelengths of multispectral instrument are usually chosen to evade main absorption zones of atmosphere. However, both PARs calculated by hyperspectral and multispectral data are consistent with the error less than 1%. By the fitting function proposed here, the PAR calculated by multispectral data could attain the same accuracy with that by hyperspectral data. To calculate the attenuation rate of the PAR needs PAR0, the PAR just under the surface. Here, an approach is proposed to calculate PAR0 by the best fit of the irradiance profile of 1-5 m with a content attenuation coefficient under surface. It is demonstrated by theory and observed data in different time at same location that the attenuation coefficient of PAR is independent of the intensity of radiation. But under sea ice, the attenuation coefficient of PAR is little bit different, as the spectrum of the light has been changed by selective absorption through the sea ice. Therefore, the difference of inclusions inside sea ice will result in different PAR, and impact the attenuation of PAR. By the results of this paper, PAR can be calculated reliably by multispectral data.

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    Distribution and abundance of euphausiid larve and salps during austral summers in Prydz Bay, Antarctic
    Yang Guang(杨光)1,2,Li Chao lun(李超伦)1* and Sun Song(孙松)1,3
    2010, 21 (2-English):  127-136.  DOI: 10.3724/SP.J.1085.2010.00127
    Abstract ( 1567 )   PDF (698KB) ( 982 )  

    The distribution and abundance of euphausiid larvae and salps was studied from samples collected in 2002 and 2006 from Prydz Bay, Antarctica. Larvae of Thysanoessa macrura and Euphausia superb were mainly distributed in the north of the continental shelf. T. macrura was more abundant and had a relatively wider distribution. In 2006, with ice having retreated and higher seawater temperatures and chlorophyll a levels, E. superb and T. macrura occurred in higher abundances and at more mature developmental stages. Euphausia crystallorophias was mainly distributed in the neritic region. In 2002, with severe ice conditions in the neritic region, abundance of E. crystallorophias was only 95.6 ind?(1000 m)-3. In 2006 when a polynya existed, the abundance of E. crystallorophias reached 43966.6 ind?(1000 m)-3. The population mainly consisted of metanauplius (MN) and calyptopis I (CI). Salps, mostly Salpa thompsoni, had a low abundance in Prydz Bay. In 2002, S. thompsoni was only found at one station in the north of the bay with an abundance of 10 ind?(1000 m)-3. In 2006, S. thompsoni was found at three stations located near the continental slope and average abundance reached 146.7 ind?(1000 m)-3. Environmental factors, such as the timing of ice melt, polynya formation and food concentration appear to have a marked effect on the distribution and abundance of euphausiid larvae and salps.

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    A Case study of a snowstorm at the Great Wall Station, Antarctica
    YangQinghua(杨清华), ZhangLin(张林), XueZhenhe(薛振和),YinZhaohui(尹朝晖), XingJiany(邢建勇)
    2010, 21 (2-English):  137-146.  DOI: 10.3724/SP.J.1085.2010.00137
    Abstract ( 1473 )   PDF (8423KB) ( 878 )  

    A case of a snowstorm at the Great Wall Station was studied using data of NCEP (National Centers for Environmental Prediction) analysis, in situ observations and surface weather charts. The storm occurred on August 29th, 2006, and brought high winds and poor horizontal visibility to the region. It was found that the storm occurred under the synoptic situation of a high in the south and a low in the north. A lowlevel easterly jet from the Antarctic continent significantly decreased the air temperature and humidity. Warm air advection at high level brought sufficient vapor from lower latitudes for the snowstorm to develop. The dynamic factors relating to strong snowfall and even the development of a snowstorm were deep cyclonic vorticity at middle and low levels, the configuration of divergence at high level and convergence at low level, and strong vertical uplift. There was an inversion layer in the lowlevel atmosphere during the later phase of the storm. This vertical structure of cold air at low levels and warm air at high levels may have been important to the longevity of the snowstorm.

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    Surface mass balance and ice flow of the glaciers Austre Lovénbreen and Pedersenbreen, Svalbard, Arctic
    Xu Mingxing, Yan Ming, Ren Jiawen, Ai Songtao, Kang Jiancheng, E Dongchen
    2010, 21 (2-English):  147-159.  DOI: 10.3724/SP.J.1085.2010.00147
    Abstract ( 1398 )   PDF (5173KB) ( 1018 )  

    The glaciersAustre Lovénbreen and Pedersenbreen are located at Nylesund, Svalbard. The surface mass balance and ice flow velocity of both glaciers have been determined from the first year of observations (2005/2006), while the front edge of Austre Lovénbreen was also surveyed. The results are as follows:(1) The net mass balances of Austre Lovénbreen and Pedersenbreen are -0.44 and -0.20 m w.e., the annual ablation is -0.99 and -0.94 m w.e., and the corresponding equilibrium line altitudes are 478.10 and 494.87 m, respectively. (2) Austre Lovénbreen and Pedersenbreen are characterized as ice flow models of surge type glaciers in Svalbard. The horizontal vectors of the ice flow velocities are parallel or converge to the central lines of both glaciers, with lower velocities in the lower ablation areas and higher velocities in the middle and upper reaches of the glaciers. The vertical vectors of ice flow velocities show that there is a mass loss in the ablation areas, which reduces with increasing altitude, while there is a mass gain near the equilibrium line of Austre Lovénbreen. (3) The front edge of Austre Lovénbreen receded at an average rate of 21.83 m?a-1, with remarkable variability a maximum rate of 77.30 m?a-1 and a minimum rate of 2.76 m?a-1.

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    The climate background and synoptic situation of fog at Great Wall Station, Antarctica
    Xu Cong(许淙)* ,Yang Qinghua(杨清华) and Xue Zhenhe(薛振和)
    2010, 21 (2-English):  160-166.  DOI: 10.3724/SP.J.1085.2010.00160
    Abstract ( 1156 )   PDF (7679KB) ( 737 )  

    Based on the observed and NCEP reanalysis data from 1985 to 2006, the climate background and synoptic situation of fog at Great Wall Station were analyzed. It is shown that the seasonal variation of fog is controlled by the change of general circulation and local pressure field. Three favorable typical synoptic situations for fog development are found, the Front-of-A-Depression type, the Saddle-Shaped-Field type and the Passing-Weak-Cyclone type. The first one is the most important situation. Advection cooling fog is dominant at Great Wall Station, but there are other kinds of fog as well. As a result, some helpful principles for local fog forecasting are given.

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    Optimization of fluorescence in situ hybridization (FISH) for the identification of two polar coccoid green algae species
    Gao Xiaoyan, Li Yunguang, Li Huirong, Chen Wenli, Luo Wei
    2010, 21 (2-English):  167-179.  DOI: 10.3724/SP.J.1085.2010.00167
    Abstract ( 1209 )   PDF (8134KB) ( 876 )  

    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°C for 30 min; (2) the hybridization buffer including 20% formamide; (3) the hybridization condition was 47°C 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.

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    A Coupled Regional Arctic Sea Ice-Ocean Model: Configuration and Application
    Li Qun(李群)1*, Zhang Lu(张璐)1,2 and Wu Huiding(吴辉碇)1
    2010, 21 (2-English):  180-192.  DOI: 10.3724/SP.J.1085.2010.00180
    Abstract ( 2103 )   PDF (4699KB) ( 1211 )  

    A regional sea ice ocean coupled model for the Arctic Ocean was developed, based on the MITgcm ocean circulation model and classical Hibler79 type two category thermodynamicsdynamics sea ice model. The sea ice dynamics and thermodynamics were considered based on Viscous Plastic (VP) and Winton three layer models, respectively. A detailed configuration of coupled model has been introduced. Special attention has been paid to the model grid setup, subgrid paramerization, ice ocean coupling and open boundary treatment. The coupled model was then applied and two test run examples were presented. The first model run was a climatology simulation with 10 years (1992—2002) averaged NCAR/NCEP reanalysis data as atmospheric forcing. The second model run was a seasonal simulation for the period of 1992—2007. The atmospheric forcing was daily NCAR/NCEP reanalysis. The climatology simulation captured the general pattern of the sea ice thickness distribution of the Arctic, i.e., the thickest sea ice is situated around the Canada Archipelago and the north coast of the Greenland. For the second model run, the modeled September Sea ice extent anomaly from 1992—2007 was highly correlated with the observations, with a linear correlation coefficient of 0.88. The minimum of the Arctic sea ice area in the September of 2007 was unprecedented. The modeled sea ice area and extent for this minimum was overestimated relative to the observations. However, it captured the general pattern of the sea ice retreat.

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    The adaptability of three Arctic microalgae to different low temperatures
    Xia Lihua, He Jianfeng, Zhang Fang, Gao Yan, Zhang Rumin, Cui Shikai
    2010, 21 (2-English):  193-203.  DOI: 10.3724/SP.J.1085.2010.00193
    Abstract ( 1437 )   PDF (403KB) ( 956 )  

    In order to study the adaptability of Arctic microalgae to different environmental temperatures, the growth curves and antioxidase system of three microalgae (Skeletonema marinoi, Chlorella sp. and Chlamydomonas sp.) that were separated from the Ny-Ålesund, the high Arctic, at different low temperatures (0℃, 4℃ and 8℃) were determined. The result showed that the adaptability of the microalgae to temperatures depended on the species. The growth rate, SOD and CAT activities of Skeletonema marinoi were the highest at 4℃, but MDA content was the lowest. The growth rate and enzyme activity of Chlorella sp. were the highest at 8℃, while the lowest MDA content presented at 0℃. The growth of Chlamydomonas sp. at the different temperatures was not so significant, the lowest MDA content presented at 8℃. The change of antioxidase system also depended on species and temperatures. Three indexes of antioxidase system of Skeletonema marinoi between 0℃ and 4℃ showed extremely significant difference (p<0.01). SOD activity of Skeletonema marinoi and Chlorella sp.between 0℃ and 8℃ showed significant difference (p<0.05), and the other two indexes of them differed insignificantly. Antioxidase systems of Chlamydomonas sp. at the three temperatures differed insignificantly. In conclusion, the three microalgae had good adaptability to the three temperatures; their MDA content presented a low level, and had unique physiological mechanism to adapt to the environment with different low temperatures.

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    Distribution and Reproductive Behavior of Penguins on Ardley Island and their Environmental Impact Factors
    Sun Weiping, Cai Minghong, Wang Haiyan, Xing Chuang, Lu Bing, H. U. Peter, A. Froehlich
    2010, 21 (2-English):  204-213.  DOI: 10.3724/SP.J.1085.2010.00204
    Abstract ( 2080 )   PDF (728KB) ( 1228 )  

    During the 2006/07 Antarctic summer, the species population, distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated. Five species of penguin were recorded: gentoo penguin (Pygoscelis papua), adelie penguin (P. adeliae), chinstrap penguin (P. antarctica), King penguin (Aptenodytes patagonicus) and Emperor penguin (A. forsteri). The first three species bred locally, while the other two species were observed occasionally. Ardley Island is one of the most important breeding areas for penguins. After the breeding season of 2006/07, there were a total of about 17 234 penguins and the breeding success rate was 0.40—1.41. Comparing with historical data, changes in penguin species populations and distribution were analyzed, and their relationships with the environment, climate change and human activity were investigated.

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