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Precipitation samples collected at Point Barrow, Alaska in the August and September of 1994 was analyzed for pH, conductivity and all major ions. A mean pH value of 5.53 was gained, and the samples' conductivity showed no linear correlation with its acidity , which did not agree to the similar work results on the Qinghai, Tibet Plateau. Cl- and Na+ were found to originate mainly with seasalt. The concentrations of SO42- varied from event to event. But the exSO42- concentrations remained small, which indicated less anthropogenic effect on the environment at the site.
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The EISCAT data are used to confirm the important role of precipitation particles in the ionization rate in the auroral region. The height range of the effective ionization is quite different for particles with different energies. On the other hand, an enhancement of magnetospheric convection often results in decreasing of electron density,
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Textural composition, chlorophyll a and nutrients (phosphate, nitrate and silicate) of newly formed sea ice from the Weddell Sea, Antarctica, were analyzed during austral autumn in 1992. Frazil ice, congelation ice and mixed frazil/congelation ice were the main textural types. Mean concentrations of chlorophyll a and nutrients in sea ice were varied considerably with ice texture. High chlorophyll a occurred mostly in ice floes consisting predominantly or mainly of frazil ice. Nutrients showed an inverse relationship being significantly lower in frazil ice than in congelation ice. Similar observations were made for one year old sea ice.
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In this paper a comparison is made between the curve of climatic changes in the Alerce region of the southern Chile during the past 4000 a and the temperature and precipitation curves in the region around the Great Wall Station of Antarctica, and an inference is also made about the trend of precipitation change for the past 16000 a in the region of King George Island of Antarctica and the trend of the pendulation of the Antarctic Convergence for the past 4000 a. By analysis of the response time or the amplitude of environmental changes,the response of the Antarctic region to the global environmental changes is more sensitive. The climatic research of the South Georgia Island (54°~55°S, 36°~38°W) in the South Ocean also confirms the above environmental changes. The uniformity of environmental changes in the region of Antarctic Great Wall Station, the South Georgia Island and the Alerce region of the southern part of Chile shows that they are controlled by one similar factor, and the pendulation of the Antarctic Convergence is just the reflection of such an impact. Key words Antarctica, environment, global change.
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The results of 210Pb measurements in the lake sediment core from Antarctica are reported: the relative specific activities of 210Pb in the lake sediment were found to decrease exponentially with the depth in the study area; the sedimentation rate of the lake is about 0.072 cm/a. This paper shows that 210Pb method is applicable to Antarctic lake sediment,and during the 1960's the atmospheric nuclear tests have an effect on the rate of 210Pb deposition in Antarctica.
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In this paper, authors report some results obtained from systematic rock magnetic measurements on Core NP95-1 and Core NG93-1, which were collected from the Prydz Bay, Eastern Antarctica and Great Wall Bay (Maxwell Bay), Western Antarctica respectively during the 11th and 9th CHINARE and a sequence of paleoclimate variations is well established based on sediment rock magnetic properties. In Antarctica, the magnetic properties show a close linkage to paleoenvironmental variations. The Core NP95-1 well recorded several paleoclimatic events, such as Heinrich event 1, Bolling, Allerod warm period and Younger Dryas cold event. The Heinrich event 1 occurred at about 14. 2 ka B.F. , Younger Dryas cold event occurred between 11.7 ka B.P. and 10.3 ka B.P., and the boundary of Pleistocene and Holocene in Antarctica is 10. 3 ka B.P.. In Holocene, two warm periods were recorded at about 10.0 ka B. P. and 6.0 ka B. P. with a little cold period between them. After 6.0 ka B. P., two cores both recorded a cold climatic oscillation. Paleoclimate described by two cores rock magnetic measurements was simultaneously changed in Eastern and Western Antarctica during the same period two cores commonly covered.
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We have already continually taken the measurement of total column amount of O3, NO2 as well as stratospheric O3, NO2 over Zhongshan Station, Antarctica. This paper analyzes the seasonal variation of NO2 and its relationship to O3 during the Antarctic Ozone Hole in 1993-1995 and points out that the decrease of atmospheric NO2 is one of the important reason to the strengthening of Antarctic Ozone Hole.
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The horizontal and vertical distributions of Antarctic krill in the Prydz Bay region were investigated in 1991/1992 and 1992/1993. The result showed that the high density distribution area of Antarctic krill was within the area of 63°~67°S、68°E and the waters of above 70 m deep. The standing crops of Antarctic kill was 1.699 × 106
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Glacier-forming material shows no difference of oxygen isotope for different heights above sea level on Big Dome of Collins Ice Cap. δ18O variations of surface firn with depth (time) are extremely similar. Owing to the material and energy exchange between different annual layers, homogeneity of oxygen isotope arises and leads to no avail of δ18O ice-core dating on Big Dome Summit of Collins Ice Cap. Affected by seasonal variations of temperature, oxygen isotope composition of winter layer is distinctly different from that of summer layer whose S I8O value is higher and variation coefficient is smaller. By means of direct comparison oxygen isotope/temperature gradient of Collins Ice Cap is defined as 0.74‰/C in use of annual mean temperature and δ18O value on Big Dome Summit and Small Dome Top of Collins Ice Cap.
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In order to clarify the possible relationship between the changes of bchavior/personality and metabolic changes of 5-hydroxytryptamine (5-HT) in Antarctic expedition members, plasma tryptophan (Trp) and urinary 5-hydroxy-3-indoleacetic acid (5-HIAA) were studied for 24 winter, over and 19 summer, over members of the 8th and 11th CHINARE respectively. Results showed that plasma Trp decreased significantly after residing 1〜3 months at Great Wall Station and did not recover on returning back to Beijing from Antarctica by two weeks travelling. Urinary 5-HIAA increased significantly after residing 6 months at Great Wall Station, and recovered on returning back to Beijing from Antarctica in the winter-over members. The decrease of plasma Trp may be related to the decline of brain 5-HT which might play a role in the changes of behavior/personality . Increase of urinary 5-HIAA might reflect metabolic changes of 5-HT as a wholes but cold weather involving in the release response of platelet should be considered. Therefore, supplement of related food rich in Trp or intervention of L-Trp might be valuable.
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