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Bacterial diversity in sea ice brine samples which collected from four stations located at the Canada Basin, Arctic Ocean was analyzed by PCR-DGGE. Twenty-three 16S rDNA sequences of bacteria obtained from DGGE bands were cloned and sequenced. Phylogenetic analysis clustered these sequences within γ-proteobactcria,
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The phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from the high latitude regions of Canadian Basin and Chukchi Sea, Arctic, was investigated. A total of 34 psychropilic strains were isolated using three methods of (Ⅰ) dilution plating (at 4℃), (Ⅱ) bath culturing (at -1℃) and dilution plating, and (Ⅲ) cold shock (-20℃ for 24h), bath culturing and dilution plating under aerobic conditions. Sea-ice samples were exposed to -20℃ for 24h that might reduce the number of common microorganisms and encourage outgrowth of psychrophilic strains. This process might be able to be introduced to isolation psychrophilic bacteria from other environmental samples in future study. 16S rDNA nearly full-length sequence analysis revealed that psychrophilic strains felled in two phylogenetic divisions, γ-proteobacteria (in the genera
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The Antarctic circumpolar wave(ACW)has become a focus of the air-sea coupled Southern Ocean study since 1996, when it was discovered as an air-sea coupled interannual signal propagating eastward in the region of the Antarctic Circumpolar Current(ACC).In order to analyze the mechanism of discontinuity along the latitudinal propagation, a new idea that ACW is a system with a traveling wave in the Southern Pacific and Atlantic Ocean and with a concurrent standing wave in the southern Indian Ocean is proposed in this paper.Based on the ideal w ave principle, the average wave parameters of ACW is achieved using a nonlinear approximation method, by which we find that the standing part and the traveling part possess similar radius frequency, proving their belonging to an integral system.We also give the latitudinal distribution of wave speed with which we could tell the reason for steady propagation during the same period.The spatial distribution of the propagation reveals complex process with variant spatial and temporal scales—The ENSO scale oscillation greatly impacts on the traveling process, while the result at the south of Australia indicates little connection between the Indian Ocean and the Pacific, which may be blocked by the vibration at t he west of the Pacific.The advective effect of ACC on the propagation process should be examined clearly through dynamical method.
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The Grove Mountains are located in Princess Elizabeth Land, East Antarctica, ext ending from 72° to 73°S latitude and 73° to 76°E longitude, covering approximately 8000 km2 areas.During the 2002/2003 austral summer season, the 19th CH INARE(Chinese National Antarctic Research Expedition)carried out the third expedition in Grove Mountains, East Antarctica.The Geodetic network was established, which can provide ground control for the satellite image map for the multi-discipline expedition in the Grove Mountains where seven permanent GPS benchmarks were set up supported by the helicopter and snow vehicles.All GPS sites bes ides Z001 were observed at least for one hour using the dual frequencies Trimble 4000ssi GPS receivers.The data were processed by the comprehensive GPS analysis package—GAMIT/GLOBK and the precision is good enough to satisfy with the acquirement of satellite mapping in this area.
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The Amery Ice Shelf is the largest ice shelf in East Antarctica. A new DEM was generated for this ice shelf, using kriging to interpolate the data from ICESat altimetry and the AIS-DEM. The ice thickness distribution map is conver ted from the new DEM, assuming hydrostatic equilibrium. The Amery Ice Shelf mari ne ice, up to 230 m thick, is concentrated in the northwest of the ice shelf. The volume of the marine ice is 2.38×103 km3 and accounts for about 5.6% of t he shelf volume.
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During the 2nd Chinese Arctic Research Expedition, 20 pair of atmospheric samples were collected on the cruising route from Shanghai to Arctic Ocean using NOAA/ESRL flask sampling unit Mean concentration of CO2 and CH4 were analyzed in different latitude zone from 30°N to 80°N and the distribution characteristics were studied. Mean concentration of CO2 decrease toward high latitude which indicates the up take effect of CO2 by ocean. Coinciding with the CH4 global distribution character, mean CH4 concentration increase from 45°N to the North Pole region. Regional or local air mass may influence the greenhouse gas concentrations near sea shore in the middle latitude (30°N-45°N).
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This paper summarized the on-orbit measurement performance of GLAS, and analyzed the precision of its data products. By comparing the high-accuracy ICE Sat measurements with the GPS ground surveys during 21st CHINARE inner ice sheet s expedition, it is analyzed and validated that the suggested Dome A area and the measured peak point of Antarctica inner ice sheets defined during 21st CHINARE are both correct.
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Using the monthly 1°×1° sea-ice concentration data of Hadley center and the monthly NCEP geopotential height data from January 1953 to February 2003, temporal and spatial changing characters of sea-ice are examined. The results show almost all of the sea-ice of eight regions was decreasing, especially all seasons in Europe.But in Asia part, those display some increasing trends in spring and winter. Abrupt times of sea-ice in Europe were at end of 1970's and in Asia the times in summer/fall (spring/winter) were at end of 1980's.
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As an important part of global climate system, the Polar sea ice is ef fecting on global climate changes through ocean surface radiation balance, mass balance, energy balance as well as the circulating of sea water temperature and salinity. Sea ice research has a centuries-old history. The many correlative sea ice projects were established through the extensive international cooperation d uring the period from the primary research of intensity and the bearing capacity of sea ice to the development of sea/ice/air coupled model. Based on these rese arches, the sea ice variety was combined with the global climate change. All res earch about sea ice includes: the physical properties and processes of sea ice a nd its snow cover, the ecosystem of sea ice regions, sea ice and upper snow albe do,mass balance of sea ice regions,sea ice and climate coupled model. The simu lation suggests that the both of the area and volume of polar sea ice would be r educed in next century.With the developing of the sea ice research,more scient ific issues are mentioned.Such as the interaction between sea ice and the other factors of global climate system, the seasonal and regional distribution of pol ar sea ice thickness, polar sea ice boundary and area variety trends, the growth and melt as well as their influencing factors, the role of the polynya and the sea/air interactions. We should give the best solutions to all of the issues in future sea ice studying.
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