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    30 December 2011, Volume 23 Issue 4 Previous Issue    Next Issue

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    PROGRESS IN THE POLAR UPPER ATMOSPHERIC PHYSICS RESEARCH IN CHINA
    LIU RuiYuan YANG HuiGen
    2011, 23 (4):  241-258.  DOI: 10.3724/SP.J.1084.2011.00241
    Abstract ( 1785 )   PDF (9446KB) ( 1686 )  
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    STATISTICAL STUDY OF SUBSTORM WAIT TIME:IMAGE OBSERVATION
    2011, 23 (4):  259-263.  DOI: 10.3724/SP.J.1084.2011.00259
    Abstract ( 1567 )   PDF (1088KB) ( 1223 )  

    This paper has analyzed 2760 substorm events in the northern hemisphere by using IMAGE FUV observations in order to get the probability distribution of substorm wait time (time interval between substorm onsets). The effects of the satellite orbit have been taken in account. It is found: (1) the most probable substorm wait time is between 2 and 3 hours. The wait time is longer for substorms occurring at lower latitudes (near Earth) than those occurring at higher latitudes (far tail); (2) For substorms occurring in the near Earth region, the wait time satisfies Gauss distribution, while for those in the far tail, the wait time satisfy both Gauss and Poisson distribution. This may indicate that the near Earth substorm events are more periodic than far tail events; (3) the satellite orbit affects the wait time distribution mainly after 10 hours. And it causes one psudo-peak around 8 hours, which is more apparent in the lower latitude events than in the higher latitude.

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    ANALYSIS THE I (557.7 NM)/I (427.8 NM) EMISSION RATE RATIO IN AURORAL SUBSTORM OBSERVED AT ANTARCTIC ZHONGSHAN STATION
    2011, 23 (4):  264-268.  DOI: 10.3724/SP.J.1084.2011.00264
    Abstract ( 1740 )   PDF (835KB) ( 1271 )  

    Auroral intensity ratios of different auroral lines happened in auroral substorm at Antarctic Zhongshan Station on April 8, 1999 was discussed together with the variety of penetrated electron energy. On this basis, it is concluded that the ratio range of I(557.7nm)/I(427.8nm) during quiet period varied from 5 to 22, as well as the range of I(630.0nm)/I(427.8 nm) from 1 to 2.76, and the cause of the change was not the atomic oxygen concentration variety, but maybe the penetrated electron energy variety or other mechanisms; the ratios decreased sharply during the auroral substorm, varied from 1.66 to 6.5 and 0.071 to 1 respectively, which mainly caused by the increase of penetrated electron energy. At the beginning of the auroral substorm, the ratio reached its minimum; means that the penetrated electron energy got its maximum, while auroral substorm wear off, the penetrated electron energy come back to the level of pre-substorm.

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    BASIC ANALYSIS OF SEASONAL ENVIRONMENTAL VATIATION IN GREAT WALL BAY, ANTARCTICA, USING A NEARSHORE MARINE ENVIROMENTAL MONITORING SYSTEM
    2011, 23 (4):  269-274.  DOI: 10.3724/SP.J.1084.2011.00269
    Abstract ( 2281 )   PDF (2103KB) ( 1595 )  

    The preliminary analysis of basic environmental and chlorophyll a concentration data in Great Wall Bay near Chinese Great Wall Station, King George Island, West Antarctica was carried out, based on the monitoring data from December 13, 2010 to March 22, 2011 by a POLAR COASTAL MARINE ENVIRONMENTAL MONITORING SYSTEM (PCMENS). Results show that, water temperature increased in general in this period, but influenced by fresh water inflow, the salinity were decreased in general. Water temperatures varied between 0.27°C and 2.52°C,and the obvious peaks occurred in middle January and late February; Salinities ranged from 33.86 to 34.19, and the marked low peaks were observed in the beginning of January, middle January, lat February and early March. Chlorophyll a concentrations increased rapidly from beginning to the end of December, and then maintained a relative higher level. Three peaks occurred in the observing period, which occurred in the end of December, middle January and late February. The maximum was 4.22 μg/L on 14 January. There was a significant correlation between chlorophyll a concentrations and water temperatures. The basic data analysis and comparison to the historical monitoring data obtained from traditional methods shows that, the PCMENS, as a new polar marine environmental monitoring tool, is successful and reliable, combined with the traditional methods, can carry out the fine environmental monitoring in the polar coastal waters.

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    DISTRIBUTION AND DEMOGRAPHY OF EUPHAUSIA SUPERBA DANA IN THE PRYDZ BAY DURING JUNUARY 2002
    2011, 23 (4):  275-282.  DOI: 10.3724/SP.J.1084.2011.00275
    Abstract ( 2332 )   PDF (3718KB) ( 1475 )  

    This study documents horizontal distribution, population structure and growth condition of Antarctic krill (Euphausia superba Dana), which collected by IKMT along three transects from the Prydz Bay during January 2002. E. superba dominated south of 64°S, and few krill was found north of 64°S. The average density/biomass, estimated from trawl catches, was 68.85 ind/1000 m3 or 24.16 g/1000 m3. The four stations with highest values were located in the open sea. Body length ranged from 30 to 55 mm (N = 1758), with a mean of 38.45 ± 3.68 mm (SD). The overall sex ratio was 1:1, 47.6% females (31.9% sub-adults and 5.7% adults), 46.6% males (42.7% sub-adults and 3.9% adults), while 5.8% were juveniles. The population structure of E. superba showed geographical difference. The high proportion of juvenile, low sexual maturity stage of male and good growth condition was found in the western part of the survey area, and the reverse was presented in the eastern part. The latitudinal difference was found at stations along 70.5°E and 73°E: the body length was small and sex ratio was high in the region of high latitude, while the size was large and sex ratio was low in the region of low latitude.

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    HIGH-LEVEL EXPRESSION OF A COLD-ADAPTIVE LIPASE GENE IN PICHIA PASTORIS
    2011, 23 (4):  283-288.  DOI: 10.3724/SP.J.1084.2011.00283
    Abstract ( 1783 )   PDF (1375KB) ( 1988 )  

    A cold-adaptive lipase gene lip-948 from Antarctic psychrophilic bacteria was ligated into the expression vector pPIC9K, which was transformed into yeast GS115 subsequently. High-level express yeast was obtained . Lipase activity of the supernant reached 27.5 U/mL after 48 h fermentation, which is higher than most of other low-temperature bacteria lipase genes expressed in Pichia pastoris.

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    COMPARISONS OF THERMODYNAMIC PROCESSES BETWEEN LAKE ICE AND LANDFAST SEA ICE AROUND ZHONGSHAN STATION, EAST ANTARCTICA
    2011, 23 (4):  289-298.  DOI: 10.3724/SP.J.1084.2011.00289
    Abstract ( 2060 )   PDF (5737KB) ( 1463 )  

    Thermodynamic processes of lake ice in three lakes and landfast sea ice around Zhongshan Station, east Antarctica have been investigated in 2006. The growth and decay processes of lake ice are compared with those of landfast sea ice on the basic of in situ data. The responds of lake-ice and landfast sea-ice temperatures at varying depths relative to the time series of local surface air temperature is explored. The vertical conductive heat fluxes at varying depths of lake ice and sea ice were derived from the vertical ice temperature profiles. The freeze-up of lake ice and landfast sea ice occurred from late Feb. to early Mar. The maximum lake-ice thicknesses occurred from late Sep. to early Oct., with the values of 156–177cm. The maximum sea-ice thicknesses occurred relatively later, which occurred from late Oct. to later Nov., with the values of 167–174cm. The temporal variations of internal temperatures for both lake ice and landfast sea ice were laggard compared to those of local surface air temperature. The high frequency fluctuation of local surface air temperature was attenuated by ice cover evidently. The temporal lag and the high-frequency attenuation were more significantly for sea ice than for lake ice, and more distinct for lower ice layer than for upper ice layer, which induced a larger conductive heat flux for sea ice than for lake ice, and a lower level fluctuation in the conductive heat flux for lower ice layer than for upper ice layer. The enhanced desalination during the melt season was consequently increases the melt point temperature for sea ice, which also made it different from fresh lake ice.

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    MULTIPLE DEFORMATIONS IN THE REINBOLT HILLS OF THE EASTERN AMERY ICE SHELF,EAST ANTARCTICA,AND THEIR TECTONIC IMPLICATIONS
    2011, 23 (4):  299-309.  DOI: 10.3724/SP.J.1084.2011.00299
    Abstract ( 1753 )   PDF (7889KB) ( 1021 )  

    Based on structural analysis and available geochronological data, four principal episodes of deformation (D1-D4) are distinguished in the Reinbolt Hills of the eastern Amery Ice Shelf, East Antarctica. The D1 deformation took place at >970 Ma and is responsible for the formative stage of the WE-trending regional gneissosity in metamorphic rocks. The D2 deformation is characterized by the EW-trending folds with steep axial plane occurred in orthogneisses during the early Neoproterozoic. Tight asymmetrical folds and low-angle stretching lineations developed on the shear foliations of the rock during this period. The D3 deformation is marked by high-angle normal faults resulted from the early Cambrian tectonic uplift. The emplacement of charnockites in the Jennings Promontory may also be related to this deformational event. The D4 deformation is responsible for the NE-NNE-trending fracture cleavages in the Reinbolt Hills and Jennings Promontory probably formed during the late Mesozoic to Cenozoic. The D1 and D2 deformational episodes in the Reinbolt Hills could be comparable with those in the northern Prince Charles Mountains, suggesting that the Rayner Complex might be extended eastward to the Reinbolt Hills. Taking into account the occurrence of the early Cambrain (i.e. Pan-African) charnockites in the Jennings Promontory, we infer a nearly SN-trending tectonic boundary separating the Reinbolt Hills and Jennings Promontory. Therefore, the Prydz belt might not extend westward to the Lambert terrane, but southward to the Grove Mountains and Gamburtsev Sub-glacial Mountains.

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    MONITORING RESULTS AND ANALYSIS OF ANOMALOUSLY LOW OZONE IN THE 2011 ARCTIC SPRING
    2011, 23 (4):  310-317.  DOI: 10.3724/SP.J.1084.2011.00310
    Abstract ( 1923 )   PDF (8211KB) ( 1286 )  

    Total ozone observations from the Total Ozone Unit (TOU) on board the second generation polar orbiting meteorological satellite of China, Fengyun-3/A (FY-3/A) revealed that the total column ozone over the Arctic declined rapidly from the beginning of March 2011. An extensive region of low column amount of ozone formed around mid March, the monthly mean total column ozone of March 2011 was about 30% lower than the average value observed during 1979-2010. The daily total column density of ozone near the center of low ozone area in mid March was below 240 DU, about half of the total column ozone amount observed during the same period of last 10 years. The data of total column ozone during 1979-2011 observed by different satellites are analyzed, the results show that the Arctic depletion of ozone in the spring of 2011 was initiated by the cold polar vortex in the lower stratosphere, the March mean value of total ozone over the Arctic has a decreasing trend during the past 32 years and its variation is strongly correlated with the polar vortex.

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    CONFLICTS OF LEGAL SYSTEMS INDUCED BY THE DELIMITATION OF THE CONTINENTAL SHELF IN THE ANTARCTIC REGION
    2011, 23 (4):  318-327.  DOI: 10.3724/SP.J.1084.2011.00318
    Abstract ( 2220 )   PDF (2186KB) ( 2308 )  

    The Antarctic has been under restriction of the Antarctic Treaty System including Antarctic Treaty as its core and other related agreements since Antarctic Treaty took effect in 1961. Nevertheless, the 1982 United Nations Convention on the Law of Sea (UNCLOS, hereafter be shorted as Convention) established the legal regime for continental shelf and requested coastal state to complete the delineation of the outer limits of continental shelf beyond 200NM within ten years upon its ratification of the convention. Since the Convention entered into force in 1994, Australia, Norway, Argentina and UK have successively and respectively claimed their sovereign rights over the continental shelves in the south of 60°S, namely the Antarctic region. Based on such background, the paper assesses the continental shelf submissions and preliminary information made by seven countries claiming territorial sovereignty or sovereign rights to the Antarctic region, and reviews the consideration and recommendations made by the Commission on the Limits of the Continental Shelf (CLCS). Following the above analysis, the paper scrutinizes the legal basis for continental shelf claims to the Antarctic region, and investigates the conflicts between the Antarctic Treaty System and the Convention. Meanwhile, the paper discusses the trend of legal regime development regarding the Antarctic region.

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    ANALYTICAL METHODS OF CR ISOTOPES AND THEIR APPLICATIONS IN COSMOCHEMISTRY
    2011, 23 (4):  328-337.  DOI: 10.3724/SP.J.1084.2011.00328
    Abstract ( 1923 )   PDF (767KB) ( 1500 )  

    Chromium isotope compositions have been widely applied in cosmochemistry field, as a new approaches to date and trace the early history of the evolution of the solar system. With the development of the analytic technique, the subtle variation of Cr isotopic compositions in extraterrestrial materials can be determined. This advantage give us a new chance to re-understand and re-evaluate the genetic model of Cr and its distribution in the solar system.

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    RESEARCH PROGRESS ON VOLCANIC RECORDS IN POLAR ICE CORES
    2011, 23 (4):  338-345.  DOI: 10.3724/SP.J.1084.2011.00338
    Abstract ( 1770 )   PDF (486KB) ( 1986 )  

    Sulfuric acid aerosols from volcanic eruptions are the important cause of climate change. These aerosols can be transported over long distances and eventually are deposited on polar ice sheets where they are preserved in the snow strata. Several detection methods of volcanic signals in polar ice cores have been developed according to the characteristics of volcanic aerosols. And volcanic records have been obtained from ice cores from Antarctica and Greenland. These volcanic records have provided valuable information on identifying stratospheric eruptions, dating ice cores and investigating the climatic impact of volcanism in the last millennium. However, the currently available information of volcanic records from existing polar ice cores is not sufficient for attaining a complete understanding of the climatic impact of volcanism. Therefore, improved chronology or dating and high resolution measurement for long/deep ice cores will be needed to establish the volcanic eruption history in time scale of tens of thousands to million years and to distinguish eruptions of climatic significance. Then better understanding of the climatic impact of volcanism can be expected.

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