The establishment of GPS network in Grove Mountains,East Antarctica

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 approxi mately 8000 km～2 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 establ ished,which can provide ground control for the satellite image map for the mult i-discipline expedition in the Grove Mountains where seven permanent GPS benchm a rks 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 analysi s package—GAMIT/GLOBK and the precision is good enough to satisfy with the acqu irement of satellite mapping in this area.     

Evidence for warmer event from quartz grains in the soil of Grove Mountains,East Antarctica

<正> The cold desert soil has been discovered at first time in southern ridge ofMount Harding,Grove Mountains of interior East Antarctica Ice Sheet.Based on themicro structural observation,dominant characteristics of quartz grains include:dis-tinct surface stria and fractures,and clean features of frost action at both of crystalmargins and micro crannies of quartz grains.These features show a pedogenesis envi-ronment of few water,short transportation and frost action,revealing a warmer climat-ic event existed in this region.     

东南极格罗夫山地区冰碛石碎石带中高压麻粒岩和正片麻岩的锆石年代学研究及其构造意义

东南极的格罗夫山是普里兹造山带向南极内陆的延伸部分。对格罗夫山不同碎石带中收集的高压麻粒岩和正片麻岩进行锆石U-Pb年代学研究。四个高压麻粒岩的锆石多数为变质新生锆石,仅少数保留有继承核,其年龄为2633—2502 Ma。在变质锆石中获得~570 Ma和~555—545 Ma两个阶段变质年龄,锆石微量元素特征显示为重稀土亏损,结合前人研究结果,推测这两阶段年龄分别代表了变质作用过程中的进变质和高压峰期变质年龄。两个正片麻岩的锆石普遍发育核-边结构,由一个发育振荡环带的岩浆核和均匀无环带的变质边组成。正片麻岩的原岩年龄存在差异,在样品GR14-3-4的锆石核部获得了1060±40 Ma的上交点年龄,其原岩可能来自格罗夫山东南部的冰下高地,而在样品GR14-5-4的锆石核部获得的原岩年龄为917±4 Ma,与格罗夫山基岩中的基性麻粒岩和正片麻岩的原岩年龄一致。在锆石边部获得的变质年龄较为一致,为~530 Ma,与以前在高压麻粒岩中获得的退变质年龄相当。本次研究确认了高压麻粒岩在格罗夫山地区不同碎石带中分布的广泛性,表明其可能普遍存在于格罗夫山冰下高地之中。同时也进一步证明格罗夫山冰下高地并没有受到格林维尔期构造热事件的影响,而是只经历了泛非期的单相变质构造旋回。     

Limnological characteristics of vertical structure in the lakes of Syowa Oasis,East Antarctica

We investigated the vertical structure of physicochemical properties in 27 lakes at Skarvsnes and Langhovde, Syowa Oasis, East Antarctica, from December 2003 to February 2004. The lakes were classified into three types based on their origin and geographical characteristics: non-marine relic lakes, marine relic and lotic lakes, and marine relic and lentic lakes. We describe the physicochemical characteristics of each lake type. When the non-marine relic lakes were partly covered with ice, the water column was stratified beneath the ice. In the non-marine relic lakes, during the season with no ice cover, physicochemical parameters were uniform throughout the water column, probably due to frequent vertical mixing induced by wind force and thermal convection within the shallow basins. Similarly, in marine relic and lotic lakes, lake waters appeared to be completely mixed because of a large inflow of meltwater from glaciers and outflow to other lakes and the coastal sea. In the marine relic and lentic lakes, except for Lake Himebati-ike, the lake water was vertically stratified with a strong halocline. In Lakes Suribati-ike and Hunazoko-ike, salinity was very high (up to 20%) due to evapoconcentration. Lake Suribati-ike is a meromictic lake, with a monimolimnion developed below 10 m water depth.     

东亚夏季副热带季风活动范围研究进展

东亚夏季副热带季风(EASSM)的活动范围和强度对中国大陆的中东部、日本、朝鲜半岛和西北太平洋地区的降水有重要影响.综述东亚夏季副热带季风活动范围研究成果,分析东亚夏季副热带季风活动范围变化的可能原因,对今后如何进一步开展这方面研究提出了一些建议,这对于东亚夏季副热带季风的进退、季风边缘带的气候变化、中国北方干旱化和生态环境的演变等科学问题的研究都有借鉴作用.季风活动的范围是一个动态区域,东亚夏季副热带季风活动的边界可用其活动所能到达地区的概率来划分.东亚夏季副热带季风活动的范围和边界的变化不仅与热带季风向北爆发的强弱有关,还与极地和中高纬度的环流系统,以及青藏高原对季风的动力、热力作用都有密切的关系,今后应加强这方面的研究工作,尤其要加强定量描述东亚夏季副热带季风变化的研究工作,这将有助于进一步科学界定东亚夏季副热带季风活动范围.     

热烈的祝贺(发刊词)

《南极研究》与广大读者见面了.我怀着十分高兴的心情为它的创刊致以热烈的祝贺!我国的南极考察工作起步较晚,但发展较快,尤其是近几年,建成了南极长城站,已在长城站地区进行了三次较大规模的多学科考察,初步取得了可喜的成果.我国已经具备了独立开展南极考察的能力,并取得了一些经验.这些成绩是在党中央、国务院的关怀和支持下取得的,     

2003年10月底太阳风暴期间中山站电离层吸收效应的观测与分析

本文介绍了成像式宇宙噪声接收机技术和数据分析方法,通过对南极中山站成像式宇宙噪声接收机在2003年10月底太阳风暴期间的观测数据进行分析,得到了相应的极区电离层的吸收效应,它们主要是强度为2. 7dB的宇宙噪声突然吸收和强度高达31dB持续4d的极盖吸收。     

东亚季风边缘活动带研究综述

由于其同时具有的生态脆弱性和气候敏感性,东亚季风边缘研究有利于加深认识季风以及生态系统在过渡带上的特性,而且它对于国家的西部大开发战略以及南水北调工程都有重要的气候学指导意义.从天气学原理角度出发,分析指出青藏高原等地形以及海陆热力差异是对东亚季风边缘影响的重要因子,ENSO和全球变暖等因子对季风边缘活动也有影响.阐述了季风的年际变化,季风边缘,季风边缘进退等概念.通过对代用资料如湖相沉积,湖面大小变化,陆相沉积以及农牧交错带演变研究的综述,对古季风的演变做了分析,指出近几千年来干旱化趋势的存在.利用现有气象观测资料所作的东亚季风边缘的年际和年代际变化很少,这是一个可以深入研究的方面,已有的气候平均态的研究可以对此做一定的指导.同时,北方干旱化和东亚冬季风边缘研究既有区别又有联系,两方面相互促进.     

初夏东亚季风的变异及其对我国东部地区降水的影响

该文分析了近三十年我国东部地区六月的降水资料,发现初夏华北降水和江南降水的变化趋势基本上是相反的. 文章分析了初夏夏季风强弱时期的大气环流特征和结构,找出了它们之间的主要差异及其对我国东部地区降水分布变化的影响. 通过对整个季风系统的分析,发现东亚夏季风系统存在着3-4年左右的长期振荡,并和赤道东太平洋海面温度变化有相互作用,从而形成了一个相互反馈的耦合振荡过程.由此提出了海风通过季风系统变化影响初夏我国东部地区降水分布的可能长期天气过程模式.     

北极加拿大海盆中一个次表层涡旋的结构研究

利用2003年7-9月中国第二次北极科学考察期间,在北冰洋加拿大海盆的一个冰站上得到的温度、盐度和流速的连续剖面观测资料,对一个次表层的北冰洋涡旋进行了分析。在温度断面图中,该涡旋表现为一个核心位于60m深度、最低温度为-1.5°C的孤立冷水块,比周边水体的温度低约0.5°C。涡旋中的等密度面呈现凸透镜的结构,表明该涡旋是反气旋式的。虽然同步观测的流场中确实存在速度接近0.4ms-1的异常强流,但实测流场的结构却与一个典型的涡旋流场相去甚远。进一步分析发现,涡旋所在的次表层流场存在变化幅度与涡旋旋转速度相当的惯性频率振荡。在滤除惯性流和平均流之后,得到了轴对称的涡旋流场,涡旋的最大流速半径约为5km。对涡旋核心及其周边海域水体的温盐性质对比分析表明,该涡旋可能在楚科奇陆架上形成,然后向东北方向运动并进入了加拿大海盆。     

Magnetotelluric sounding study in the region of Zhongshan Station，East Antarctica

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Annual variations in the meteorological parameters at Jinnah Station，East Antarctica

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东亚夏季风的变化特征及其对甘肃夏季暴雨日数的影响

采用NCEP/NCAR再分析资料,计算了1974—2013年乔云亭等定义的东亚季风指数,研究了东亚夏季风的变化特征,利用甘肃省80个站逐日降水资料,分析了东亚夏季风对夏季甘肃暴雨日数的影响。结果表明：（1）夏季,西南季风、东南季风和偏北季风存在明显的年际变化且有所差异。（2）夏季,西南季风、东南季风对甘肃省暴雨日数的影响存在很大差异：当西南季风盛行时,西太平洋副热带高压位置偏西,东亚大槽位于贝加尔湖至中国西北部,冷空气与西太平洋副热带高压输送的暖湿气流在陇东南一带交汇,贝加尔湖至张掖为西南暖湿和西北干冷气流,孟加拉湾水汽输送在陇东南地区辐合,造成河东陇南南部、天水东部、平凉、庆阳西部一带和河西张掖地区暴雨日数偏多;当东南季风盛行时,西太平洋副热带高压西伸北抬,冷暖空气主要交汇于甘肃中西部,孟加拉湾西南水汽输送在河东西南部辐合,造成甘南高原、甘肃中部、河西武威一带和酒泉地区暴雨日数偏多。     

关于拉斯曼丘陵泛非期高级变质作用时代的新限

就目前认识,拉斯曼丘陵地区的所有基底和盖层岩石都卷入到了格林威尔期和泛非期高级变质和变形作用。泛非期高峰变质的时代大致在550—530 Ma,其造山晚期的花岗质岩浆作用遍及全区。我们观察到,中山站区石榴黑 云斜长片麻岩固相变质作用过程,主要是对早期锆石的重启、改造,例如,对早期岩浆锆石环带的模糊化,对锆石棱、角的溶蚀,甚至同位素体系的重启等,难以形成变质锆石（边）,退变或重启年龄平均值为522.7±6.6 Ma。峰期变质 之后侵位的花岗岩结晶年龄为545±9 Ma,意味着峰期变质应不晚于该年龄。泛非期的变形、变质作用及花岗岩可对早期“干”岩石进行某种程度的退变质改造,从而造成高级变质岩变质结构的复杂性。这种变质作用及有关的花岗岩活动似乎缘于陆块内部的活化,而不是不同陆块间的碰撞所致。     

Summer sea ice characteristics of the Chukchi Sea

During August 1999, we investigated sea ice characteristics; its distribution, surface feature, thickness, ice floe movement, and the temperature field around inter-borders of air/ice/seawater in the Chukchi Sea. Thirteen ice cores were drilled at 11 floe stations in the area of 72°24′ 77°18′N, 153°34′ 163°28′W and the ice core structure was observed. From field observation, three melting processes of ice were observed; surface layer melting, surface and bottom layers melting, and all of ice melting. The observation of temperature fields around sea ice floes showed that the bottom melting under the ice floes were important process. As ice floes and open water areas were alternately distributed in summer Arctic Ocean; the water under ice was colder than the open water by 0.4 2.8℃. The sun radiation heated seawater in open sea areas so that the warmer water went to the bottom when the ice floes move to those areas. This causes ice melting to start at the bottom of the ice floes. This process can balance effectively the temperature fluctuating in the sea in summer. From the crystalline structure of sea ice observed from the cores, it was concluded that the ice was composed of ice crystals and brine-ice films. During the sea ice melting, the brine-ice films between ice crystals melted firstly; then the ice crystals were encircled by brine films; the sea ice became the mixture of ice and liquid brine. At the end of melting, the ice crystals would be separated each other, the bond between ice crystals weakens and this leads to the collapse of the ice sheet.     

Spatial Sciences on Ice: 50 years of Australian activities on the Amery Ice Shelf,East Antarctica

The Antarctic climate system involves many complex interactions between the atmosphere, oceans and ice and is sensitive to variations in these components. Ice shelves represent the ice–ocean–atmosphere interface of the Antarctic continent and are therefore very important indicators of climate change in the region. The Amery Ice Shelf is the largest ice shelf in East Antarctica and has been the focus of many scientific research projects over the past 50 years. This paper presents a history of the use of spatial science techniques from basic survey equipment to satellite systems in Australian research projects based on the Amery Ice Shelf (and surrounding glaciers) since 1955. The application of these spatial data to projects based primarily in the fields of geodesy, glaciology, climatology, and oceanography has allowed the measurement and monitoring of the physical, dynamic and environmental characteristics of this large and remote region. This new information provides scientists with a better understanding of the ice shelf/ocean/atmosphere system allowing future monitoring to observe the effects of global climate change.     

Plant Community and Nutrient Status of the Soils of Schirmacher Oasis,East Antarctica

Investigations on plant community and micronutrient status of Schirmacher Oasis,East Antarctica have been presented in this paper.The dominant plant com- munities include moss and lichen.The frequency of species occurrence and changes in species composition at different location varied.Thirty-four soil samples were ana- lyzed for chemical properties of the soils of Schirmacher Oasis and Nunatak,East Ant- arctica.The most common plant species growing throughout the areas of Schirmacher Oasis and Nunataks are:Candelariella flava (lichen) and Bryum pseudotriquetrum (moss).Large variations were observed among different soil samples in all the nutri- ents and other measured soil chemical parameters.The soils are characterized by a- cidic pH ranging from 4.42-6.80.The mean organic carbon content was 0.62 and ranged from 0.06-1.29%.The electrical conductivity in 1:2 soil water ratio ranged from 0.06-1.29.The average content of macronutrient cation,which are ammonium acetate extractable was in the order of Ca>K>Na>Mg.The average content of DTPA extractable micronutrient cations was in the order of Fe>Mn>Cu>Zn.Thirty one out of 34 samples contained less than 0.80 ppm DTPA extractable Zn. Correlation studies revealed that content of macronutrient cations significantly and positively correlated to that of chlorides.Electrical conductivity exhibited significant and positive relationship with pH,K,Ca,Mg,Na and chloride content.Sodium (r =0.876~(**)) exhibited highest correlation followed by K (r=0.831~(**)) with chlo- ride content.The correlation coefficient for chlorides was higher with electrical con- ductivity (r=0.732~(**)) than pH (r=0.513~(**)).Organic carbon content of the soil was positively correlated with Fe (r=0.442~*).The nutrient status did not ap- pear to be a limiting factor in growth of plants.Lichen and moss community structure and composition in the study area were not related with fertility status of soil.Terres- trial mosses are most abundant and luxuriant along the soil habitats near bank of water bodies and the melt water streams.     

The chemical characteristics of seawater in the Prydz Bay,Antarctica

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