During the austral summer of 1989/1990,cell size-fractionated biomass and productivity of phytoplankton,particulate organic carbon(POC) and the relevant environmental parameters in the surface of a large scale sea area encircling the Antarctic continent were observed.The results showed that,in the Antarctic waters,the Southern Atlantic Ocean is the most fertile,chlorophyll a concentration averaged over 2 μg/dm 3;average POC concentration was also the highest (>100μg/dm 3),while being lower in the Drake Passage and the Southern Indian Ocean.The results of size-fractionated chlorophyll a showed that netplankton with cell >20μm in the Southern Atlantic Ocean having abundant nutrients accounted for the highest proportion(65%),while in infertile Southern Indian Ocean,picoplankton accounted for the highest proportion,for example,averagely accounting for 47% in the Southern Indian Ocean.The results of size-fractionated productivity showed that the contribution of picoplankton to total productivity was the largest in the Southern Atlantic ocean and Drake Passage,that of nanoplankton and netplankton were approximate.The relative high photosynthesis assimilation number of picoplankton menifests their importance in marine ecosystems of the Antarctic water.In comparison with the Antarctic water,the Subantarctic and Subtropical waters are infertile.
This paper briefly reviews effects of the winter Arctic Oscillation (AO)(the North Atlantic Oscillation, NAO) and the Arctic sea ice variations on climate variations over East Asia, problems existed in studies, and scientific issues that need to be resolved urgently in the future.
Chinese Antarctic Scientific Expedition (CHINARE) has been to the Grove Mountains, East Antarctica twice from 1998 to 2000. Meteorites search and collection was one of its major missions. A total of 32 samples were recovered. On the basis of the distribution area, density as well as the diversity of the petrographic, mineralogic and chemical characteristics, we regard the Escarpment zone in the Grove Mountains as a new meteorites enrichment area.
The hydrographic feature and water masses in the Bering Sea and the Chukchi Sea are analyzed on the basis of the observations of the first Chinese National Arctic Research Expedition. The results show that:(1)The distribution of temperature and salinity present obvious regional difference in both the Bering Sea and the Chukchi Sea. (2)The Intermediate Cold Water, which is the main feature of the temperature vertical structure, occurred in the depth between 20 and 250m in the most areas of the Bering Sea in summer.(3)Both the temperature and the salinity decrease obviously in the sea areas north of 70°N, where a thermobaline front is formed.(4)There are three and two kinds of different water masses in the Bering Sea and the Chukchi Sea respectively.
Based on 48 net samples and 24 water samples from Chukchi Sea(66°0.3N-75°18.6N,153°36.5E-174°59.5W) and Bering Sea (55°59.8N -66°0.3N, 173°21.1E-175°53.9W) collected during FCNARE(1999) cruise of Xuelong Research Vessel of SOA, China, 121 phytoplankton species (including varieties and forms) in 43 genera of 3 phyla have been identified. Among them, 103 species in 33 gerera were from Chukchi Sea , 71 species in 25 genera were from Bering Sea, and 49 species were from both two seas. These species can be divided into 4 ecological groups:(1) Arctic group; (2) Arto-subarctic group; (3) Boreal-temprate group and (4) Eurythemal group. The dominant species were respectively Nitzschia grunowii, Thalassiosira nordenskioldi and Chaetoceros socialis in Chukchi Sea, and Denticula seminae, Nitzschia delicatissima, Nitzschia seriata and Thalassiothrix longissima in Bering Sea. The average abundance (8.32×10 7cells/m 3) of phytoplankton from Chukchi Sea was higher than that (1.58×10 6cells/m 3) in Bering Sea. The distribution characteristics of phytoplankton in surveyed areas and their relationship with the environmental factors (including biological factors) are discussed .
The digestive proteinases and other active substances derived from Antarctic Krill was introduced. The biochemical composition and its potential chemonucleolytic agents value was also summarized.
The Pacific water enters the Arctic Ocean through the Bering Strait, influencing the sea ice, water masses and circulation in the Arctic Ocean. During the past decade, a series of abnormal variations occurred in the Arctic Ocean. At the same time, the volume transports and features of the Pacific inflow in the Bering Strait varied obviously and the route and influence area of the Pacific water changed greatly. The relationships between these variations are still kept unrevealed. This paper reviews the advances on the relative studies and discusses the possible links between the abnormal variations in the Arctic Ocean and the changes of the Pacific inflow.
This paper discussed the theories and methods of GPS data processing by GAMIT/ GLOBK.The flow chat of the processing every session solution by GAMIT,the synthetical pro- cessing the single session solution by GLOBK were described in detail.The SCAR GPS data was processed in order to demonstrate how to processing CPS data by GAMIT/GLOBK.Finally,the noteworthy problem in data processing were discussed in this paper.
The auroral data observed by All Sky TV Camera during 1995 and 1997 at Zhongshan Station of Antarctica are used to analyze the statistic characteristics of the aurora appearing over Zhongshan Station. Around postnoon(1400￣1800MLT)and midnight (2200￣0300MLT), aurora appears more frequently and stronger than that around evening(1800￣2200MLT).The corona type aurora mainly occurs at polarward and overhead of Zhongshan Station during postnoon and around midnight. The band type aurora mainly appears during postnoon, while during evening and around midnight only appears at equatorward. The active surges mostly appear around midnight, while the transpolar arcs mainly occur after midnight. And except for the transpolar arcs, the appearance frequences of other three kinds of aurora are related with Kp index. Usually Zhongshan Station enters the auroral oval at postnoon, the exact time depends on Kp index.
Six of a total of 28 meteorites collected by the 16th CHINARE from Grove Mountains, Antarctica, were classified as L3, and they show highly primitive petrography and mineralogy. In these unequilibrated chondrite, chondrules are very sharp-outlined; fine-grained matrix is almost opaque with few recrystallized grains; olivine and low-Ca pyroxene are commonly zoned, and have wide ranges of composition. Abundance of metallic Fe-Ni, calculated total Fe concentration, and mean Fa content of olivine are within the ranges of L group. Based on Percent Mean Deviation ( PMD) of Fa content of olivine, and its correction with petrographic subtype of unequilibrated ordinary chondrites( Sears et al. , 1982) , these 6 L3 chondrites are subdivided into as following; GRV 99022, 13.0-3.4; GRV 99001, L3.4; GRV 99020, GRV 99021 and GRV 99026, L3.5; GRV 99019, L3.6.
For the uniquely geographic and climatic features in Antarctic, there are abundant resources of cold adapted microorganisms, and these microorganisms possess specially genetic and physiological and biochemical properties. Microorganisms act as an important role in the ecosystems in Antarctica, and they possess a considerable potential in basic research and biotechnological application (waste treatment at ambient temperatures, enzymology, food industry, medicine),too. This article briefly describes the general situations of researching in antarctic cold adapted microorganisms and researching achievements (emphasized on microbiological physiology, biochemistry and gene) in recent years, and make further discussion on prospects of these cold adapted microorganisms in application.
Of a total of 28 meteorites collected in Grove Mountains, Antarctica, by the 16th CHIN-ARE, there are 20 equilibrated ordinary chondrites. The others include 1 martian meteorite, 1 HED meteorite and 6 L3 ordinary chondrites. These 20 equilibrated ordinary chondrites are classified into chemical groups of H, L and LL, respectively, based on mean Fa content of oli-vine, mean Fs of low - Ca pyroxene and abundance of Fe-Ni metal. Their petrographic types of 4 to 6 are assigned according to structures of chondrules, degree of recrystallization of matrix and homogeneity of composition of major phases. Classification of these 20 equilibrated ordinary chondrites are as following; 6 meteorites of H group (3 H4, 1 H5 and 2 H6) , 9 of L group (3 L4, 1 L5 and 5 L6) and 5 of LL group (2 LL4 and 3 LL5).
Sedimentary organic carbon accumulation rate in continental margin seas is more than one order higher than that of the oceans. Ocean margins play a very important role in global carbon budget since about 80% of terrestrial and marine organic carbon buried in the continental shelves. Of the Arctic Ocean total area over 30% is shelf, and it is accounted for one-fourth of global shelf area. Because of its ice cover biological pump in the Arctic Ocean was thought to be very limited, thus it has not been considered as a sink of carbon dioxide. With the recent observation of global warming, decreasing of ice cover in shelf area would lead to potential simulate primary production, thus increase sedimentary organic carbon accumulation rate in the shelves. In this review paper, organic carbon sources, riverine discharge of sediment and nutrients, sea ice cover variation, and biological pump were discussed in order to evaluation potential increasing of sedimentary organic carbon accumulation in the arctic shelves under global warming.
We collected three kinds of tundra plants including Dicranum angustum, Puccinellia phryganodes and Salix polaris each on total 12 different sites from a coal-mining gradient profile in Ny-lesund (78°55′N, 11°56′E), Arctic. At the same time, the soil on the profile was also collected. The concentrations of 10 heavy metal elements (Hg, Pb, Cd, Cu, Zn, Ni, Fe, Mn, As, Se) , S and TOC were analyzed in our lab. The results showed that the modern pollution source of Hg, Cd and S in Ny-lesund is the local human's coal-mining activities. The tundra plant Dicranum angustum has the highest ability in absorbing heavy metal elements. The content of heavy metal elements in Dicranum angustum in mining area is much higher than that in non-mining area, which also suggests the pollutant source is mostly derived from coal-mining. Meanwhile, we have compared the distribution rule of these elements between plant Dicranum angustum and soil and found that, as a whole, the variation trend of them on the profile is quite similar, which showes the tundra plant Dicranum angustum can record the environmet conditions very well. So maybe Dicranum angustum can be chosen as bio-indicator for contamination in Ny-lesund. Comparing from other areas in the world, we found that the level of pollutants of Hg, Cd, S in Ny-lesund is lower than that in developed countries in Northern European, but is the highest in Arctic, and higher than that in Antarctic.
Using sea ice concentration dataset covering the period 1968-2002 obtained from the Hadley Center of UK, this paper investigated characters of Antarctic sea ice variations. The finding demonstrated that the change of sea-ice extent is almost consistent with that of sea-ice area in every longitude, so we last choose sea-ice extent to go on this research. The maximum and the minimum of Antarctic sea ice appear in September and February respectively. The maximum and the maximal variation of sea ice appear in Weddell Sea and Ross sea, while the minimum and the minimal variation of sea-ice appear inAntarctic Peninsula. In recent 35 years, as a whole, the sea ice in Antarctica decrease distinctly. There are 5 subdivision regions in total considering their different variation. Thereinto, the sea-ice extent of Weddell Sea and Ross Sea regions extends and area increases, while the sea-ice extent of the other three regions shrinks and area decreases. They are all of obvious 2-3 years and 5-7 years significant oscillation periods. It is of significance for further understanding the sea-ice-air interaction in Antarctic region and discussing the relationship between sea-ice variation and atmospheric circulation.
The colorful satellite image map at the scale of 1:100,000was made by processing the parameters on satellite on the condition of no data of field surveying.It had ensured the smooth performance of the choice of expedition route,navigation and research task before the Chinese Antarctic Scientific Expedition (CHINAER)first went researching to the Grove Mountains.Moreover,on the basis of the visual interpretation of the satellite image,we preliminarily analyze and discuss the relief and landform,blue ice and meteorite distribution characteristic in the Grove Mountains.
In this paper, we present some aspects of meteorites collection in the Grove Mountains, East Antarctica, by the 15th and 16th Chinese National Antarctic Research Expedition (CHIN-ARE) , from 1998 to 2000. A total of 32 samples were retrieved. Of the newly found meteorites, there is a martian lherzolite. The coming 19th CHINARE are expecting much more gifts from the blue ice.
In this paper, we synthesized and analysed the structure and the interrelationship of the four ecosytems: terrestrial ecosystem, freshwater ecosystem, intertidal ecosystem, and shallow sea ecosystem in Fildes Peninsula, Antarctica, based on the research results during the past 10 years in this region, and also on the related results in other regions of Antarctica. Through our analysis, the nutrient flow integrates the four ecosystems as a whole. During the process of nutrient flow, the role of animals is very important, for example, sea birds redistribute the nutrient among the four ecosystems through their activity of breeding, feeding etc. The physical impact is also unignorable, for example, the rainfall, runoff, and tidal current bringing the nutrients from one ecosystem to another.
On the basis of the analysis of atmospheric carbon dioxide concentration variations and the annual mean air temperature at Syowa Station, Antarctica in 1984-1988 period, the following results are easily obtained. (1) The annual mean values of the atmospheric carbon dioxide concentration are gradually increased and equal to 342.59, 343,80, 345.15, 346,83 and 348.82 ppmv for 1984, 1985, 1986, 1987 and 1988, respectively. Its growrh rates of the year to year are 1.21,1.35, 1.68 and 1.99 ppmv/yr, for 1984-1985, 1985-1986, 1986-1987 and 1987-1988, respectively and are raised year after year. The seasonal variations are observed and the maximum concentration in spring and the minimum concentration in autumn. (2) The increased tendency of the annual mean value of the atmospheric carbon dioxide concentration is consistent with that of the annual mean value of air temperature*
Polar microorganisms possess specially genetic, physiological and biochemical properties for the uniquely geographic and climatic features in Antarctic and Arctic. The cold temperature of polar environment has a wide ranging influence on all of the microbial ecosystems of this region. Adaptation mechanisms of polar microorganisms for this environmental factor are studied in detail in recent years. This paper briefly describes the advances in molecular mechanism of cold adaptation of polar microorganism in aspects including low temparature enzymes, cell membrane, cytoplast and so on.
