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    30 December 2008, Volume 20 Issue 4 Previous Issue    Next Issue

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    CORRECTION OF SNOW ACCUMULATION IMPACTED ON AIR TEMPERATURE FROM AUTOMATIC WEATHER STATION ON THE ANTARCTIC ICE SHEET
    2008, 20 (4):  299-309. 
    Abstract ( 1537 )   PDF (526KB) ( 1585 )  

    The heights of the Automatic Weather Station(AWS)sensors are nominal,which change with the snow accumulation or ablation,over the Antarctic ice sheet.Therefore,the measured data can not be used directly.In this study,air temperatures from three AWSs,deployed on the traverse route from Zhongshan station to Dome A on East Antarctica ice sheet,are corrected to a certain real height relative to the snow surface with the impacts of snow accumulation,to improve the authenticity and representativeness of the observation data from AWS.The results showed that(1)the average accumulation at Dome A,Eagle and LGB69 is approximately 0.11 m,0.30 m and 0.49 m snow per year,and the corresponding annual mean air temperature difference at 1m height between corrected and measured is 0.34 ℃,0.29 ℃ and 0.35 ℃,respectively.The values are less than 0.1 ℃ at 2 m and 4 m heights.(2)The impact on air temperature from accumulation is decreasing with the height from the surface.(3)The relationship between air temperature correction and accumulation is not a simple direct proportion.It also relates to the characteristics of air temperature seasonal variation and the intensity of the local surface inversion.(4)The average air temperature correction is almost positive except in summer without inversion at times.The magnitude of it is mainly determined by accumulation and the intensity of surface inversion.

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    TEMPORAL AND SPATIAL VARIATIONS OF ATMOSPHERIC METHANE CONCENTRATION AND ITS δ~(13)C NEAR THE SURFACE ON MILLOR PENINSULA,EASTERN ANTARCTICA
    2008, 20 (4):  310-319. 
    Abstract ( 1348 )   PDF (454KB) ( 1563 )  

    During the 22nd Chinese Antarctic Research Expedition(CHINARE-22),the atmospheric gas samples near the surface were taken on Millor Peninsula and adjacent areas,eastern Antarctica,using Tedlar gas bags.Methane(CH4)concentration and its δ13C in these air samples were analyzed in the laboratory.The average of atmospheric CH4 concentrations on this peninsula was about 1.87±0.12 ppm,slightly higher than the average CH4 concentration in the global atmosphere.The summertime variation of CH4 concentrations showed a large fluctuation,corresponding to the air temperature.The average δ13C-CH4 was about(-38.26±0.52)‰.CH4 concentrations and δ13C-CH4 values at different sites varied between 1.74 and 2.56 ppm and between-39.31‰ and-31.25‰,respectively.The factors affecting CH4 concentration and its δ13C values have also been discussed in this study.

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    ECO-BIOLOGY OF EGGS OF EMPEROR PENGUIN AND ITS COMPARISON WITH OTHER SEA BIRD EGGS IN ANTARCTICA
    2008, 20 (4):  320-328. 
    Abstract ( 1511 )   PDF (489KB) ( 1562 )  

    Eggs of emperor penguin from Amanda Bay,Antarctica were measured and analysed in statistics and eco-biology.The results show that the eggs were typical ovum in the shape,and it was 121.3 mm in mean length and 83.8 mm in breadth,with mean volume of 409.3 ml(range of 322.6—506.4 ml)and mean thickness of 1.11 mm(range of 0.94—1.32 mm).Because of dry Antarctic weather and embryonic metabolism as well,the inner materials of egg would be changed and lost with the time.In comparison of the eggs of Emperor Penguin,Southern Giant Petrel,Papua Penguin and South Polar Skua,their egg size has quite positive relationship with egg volume.Meanwhile,the egg which has larger volume could homologically have thicker shell to enhance egg strength.Eco-biological parameters of birds' eggs in Antarctic,such as egg size,colour and speckles,as well as thickness,are important species features,which could be well coordinated with clutch size and breeding habits by adults,so as to adapt and survive in severe environment condition in Antarctica.

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    DISTRIBUTION OF ORGANOCHLORINE PESTICIDES AND POLYCHLORINATED BIPHENYLS IN NY-LESUND OF ARCTIC AREA
    2008, 20 (4):  329-337. 
    Abstract ( 1332 )   PDF (432KB) ( 1778 )  

    Sediment,moss and seabird-dropping samples were collected from Ny-lesund to investigate the distribution of organochlorine pesticides(OCPs)and polychlorinated biphenyls(PCBs)in Arctic areas.OCPs and PCBs were analyzed by the method of capillary gas chromatography(GC-ECD).Recoveries of all samples and blanks were at the range of 69.5%—92.2%(78.8%),75.1%—112.1%(98.5%)and 67.7%—95.1%(79.5%),respectively,and the relative standard deviations were 6.7%,8.0% and 11.3%.The major monomers of the OCPs were HCHs with the major isomers of α,β-HCH and DDTs with the major isomer of p,p'-DDD,whose concentrations were at the range of 0.86—4.50 ng/g(2.24 ng/g)and 0.22—1.09 ng/g(0.55 ng/g).The concentrations of PCBs were 0.20—3.25 ng/g(0.84 ng/g)and the major congeners were 4,5 and 6 chlorinated species,which were up to 23.8%,26.7% and 32.3% of total PCBs,respectively.Through the ratio analyses of HCHs and DDTs and the principal component analysis of PCBs,the atmospheric transport was proved to be one of major ways of contaminant source and the source of the POPs was imported by the same way.

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    MONITORING SNOW-COVER AREA CHANGE IN ANTARCTIC COASTLINE REGION BY USING MODIS PRODUCT DATA
    2008, 20 (4):  338-345. 
    Abstract ( 1507 )   PDF (420KB) ( 1884 )  

    Based on MODIS snow products,we studied the changes of snow cover area during 2003—2006 in Antarctic coastline region,and on the basis of that,we selected 18 typical regions for further analysis.The result showed that the change of snow cover area was in a fluctuant downward trend on a whole,and was more marked in warm season than in cold season.In temporal scale:for the season cycle,the snow cover extent increased rapidly in cold season(April—October),while the performance in warm season(November—March)was not exactly the same during the four years.In warm season,the snow cover extent decreased at first and then increased in the year of 2004 and 2006,however,increased firstly and then decreased in 2005,but reduced on the whole,which was a positive feedback.For the interannual cycle,snow cover extent was the biggest in 2003,but reached the lowest level in 2004,and then increased gradually during 2005—2006,whereas,it reduced on the whole.In spatial scale,along the coastline region of Antarctic continent is the mainly changed area,meanwhile,the change is more obvious in West Antarctica than in East Antarctica.

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    USING THE SEA ICE DATA OF MODIS TO INSPECT THE SEASONAL VARIETY OF THE SURROUNDING SEA ICE OF ZHONGSHAN STATION
    2008, 20 (4):  346-354. 
    Abstract ( 1755 )   PDF (437KB) ( 1735 )  

    Using the sea ice data of MODIS covering the period 2000—2002 obtained from the NSIDC,this paper investigated the surrounding sea ice of Zhongshan Station to inspect the seasonal melting and freezing,and the variety of the ice surface temperature.The method of this study is:first,delaminate the sea ice data of the MODIS to two parts,one is the sea ice distributing,and the other is the sea ice temperature;then synthesize the data of sea ice distributing;and,count the sea ice extent on real time;at last,distill the surface temperature of the sea ice.The results indicate:the sea ice surrounding Zhongshan Station melts from October to February in the next year,and from then to April is the time of freezing without airproof,and from May to September is the time of airproof freezing,when the sea ice bestrews the sea area surrounding the Zhongshan Station.The minimum of sea ice in this district appears in February,and the highest and lowest temperatures of the ice surface appear in January and August respectively.These results are partly validated by the former study of Antarctic sea ice,and receive some more accurate data near Zhongshan Station.Besides,this paper validated the feasibility of using the sea ice data of MODIS to inspect the variety of Antarctic sea ice.

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    ADVANCE IN ICE CORE CONTINUOUS FLOW ANALYSIS TECHNOLOGY
    2008, 20 (4):  355-362. 
    Abstract ( 1607 )   PDF (402KB) ( 1656 )  

    The full extraction of glaciological chemical information preserved in ice core has been a bottleneck restricting the development of ice core analytical technologies.Previous discrete sample preparations limit the numbers and the speeds of the samples and the samples are prone to be contaminated and destroyed during the preparation resulting in the loss of important information.CFA(Continuous Flow Analysis)has solved this problem successfully and become one of the most popular preparation technologies of ice core sample.This paper summarizes the present conditions and demonstrated the application of CFA used in the analysis of ice core sample analysis in polar region in recent years.At last the prospect of CFA is also described.

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    2008, 20 (4):  363-370. 
    Abstract ( 1726 )   PDF (441KB) ( 1830 )  
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    2008, 20 (4):  371-378. 
    Abstract ( 1596 )   PDF (473KB) ( 1793 )  

    Dome Argus,the highest ice dome in Antarctica,due to its unique geographic location and potential science resource,draws international attention,and has become an important frontier of Antarctic ice sheet studies.During the 24th Chinese National Research Expedition(CHINARE-24)in 2007/2008 austral summer,the second ground investigations of Dome A were performed.This expedition,with particular emphasis on Chinese first inland station pre-site survey and the implement of IPY Chinese program—PANDA,consisted of a 17-member team with a range of scientific equipment,transported by an over-ice tractor convoy.The team stepped onto the summit of Dome A successfully and performed systematic and multi-disciplinary scientific investigations in the centre of Dome A,as well as the transect surveying from Zhongshan Station,achieved significant expedition outcomes in the fields of Dome A scientific expedition,Chinese inland station pre-site survey and Chinese inland traverse capability building.

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