南极长城站和中山站的近期气候变化及其对南极涛动的响应

利用长城和中山站的多种气象观测资料,揭示了南极气候在近15—30年全球气候变化关键时期的最新动态及其对南极涛动变化的响应。结果显示,近15年来,位于南极半岛地区的长城站增暖趋势减缓且有变冷迹象,并伴随气压下降和降水增多的趋势,表明全球增暖停滞期南极半岛经历了与过去几十年长期趋势有所不同的新变化,而位于南极大陆沿海的中山站气象要素变化趋势相对平缓,表明南极半岛和南极大陆气候变化特征存在显著的区域性差异。两站多个气象要素与南极涛动指数显著相关,两站温度与南极涛动相关关系相反等研究事实说明了两站气候与南极涛动及其对应的大气环流区域特征有着密切的联系。     

南极大陆沿海湖泊生态结构研究

南极大陆沿海地带是南极海、陆、冰的交集带,它同时受到来自海洋、大陆冰以及人类活动的影响,因而成为南极生态环境最脆弱的环节。存在于该地带的许多湖泊,因其各自的地理环境和发育过程,以及所受诸多外部因子如气候、降水等的不同影响,不同湖泊中水体的理化因子差异很大,由此造成湖泊中生物种类分布和生态结构的显著不同。本文报道了对南极大陆沿海维斯特福尔德丘陵和拉斯曼丘陵等地湖泊中以浮游生物为主体,各类生物的组成分布和群落结构进行考察研究的结果,并分析讨论了不同类型湖泊的生物多样性、生物营养结构及其与环境的关系,为深入研究全球气候变化对南极区域环境的影响,和制订南极生态环境保护决策提供科学依据。     

极地和青藏高原地区的气候变化及其影响

南极、北极和青藏高原素有地球三极之称,是多个国际计划研究全球变化的关键地区.南北极和青藏高原是全球气候变化的敏感地区,要了解全球气候变化,必须对南北极和青藏高原地区有所研究.在当前全球变暖的大背景下,地球三极地区的气候变化在时间和空间上都是多样的,这些变化对全球大气环流和我国的天气气候也会发生影响.加强对南极、北极和青...     

南极海冰问题评述:观测

海冰通过其对地面反照率的作用以及对大气和海洋之间热交换的局地障碍和对世界海洋环流的作用在全球热平衡和气候变化中起着重要的作用。南极海冰又因其极为显著的时空变化引起越来越多的关注。海冰的观测是海冰研究的重要内容 ,本文综述了南极海冰观测的发展过程 ,着重介绍了卫星在探测南极海冰方面的重要进展 .     

南极冰川学与全球变化研究新进展

南极冰川学与全球变化是最近举行的“南极与全球变化：相互作用和影响”国际学术研讨会的主题。南极冰盖净物质平衡的观测和估算，冰盖物质平衡与气候变化的预测模型；南极冰雪大气、气候和环境化学；南极深冰芯分析，及其与其它古环境记录的对比研究，是目前南极冰川学研究的几个热点、关键问题。     

从南极冰盖和气候演化研究历史的回顾看格罗夫山地区新生代沉积岩发现的意义

南极冰盖自形成以来就一直是全球环境体系最重要的组成部分 ,其扩展和消融的动态演化过程不仅是南极大陆最重要的地质过程 ,而且也是全球气候和环境变化最直接的反映和体现。因此 ,有关这一课题的研究一直是国际地质学界所关注的热点。本文回顾了南极冰川和气候演化研究的历史 ,总结了当前这方面研究的成果以及所存在的问题 ,探讨了其未来的发展趋势 ,在此基础上 ,对我国南极考察队发现格罗夫山 (GroveMountains)地区新生代沉积岩的意义进行了阐述     

十五万年来临夏黄土粒度变化的气候记录

风成黄土沉积的粒度变化受控于风力强度及大气环流,具有气候学意义。根据临夏北塬黄土剖面的粒度资料,结合沉积物的年代测定,研究了粒度参数随时间的变化恃征,表明临夏黄土自150ka以来,粒度参数反映的气候变化经历了8个主要阶段,完全可以与南极东方站冰岩芯温度记录及深海氧同位素阶段对比。但气候阶段的始末在时间上有一些差异。可能反映不同气候区域对全球气候变化的响应不同,而粒度参数与全球海面变化却非常一致;海面的升降及温度变化也控制和影响着大陆环流系统。最后,从粒度变化讨论了冰期、间冰期影响中国大陆环流系统的变化。     

南极冰架研究现状与埃默里冰架研究展望

南极冰架是揭示南极地区气候变化机制,预测全球气候变化的关键研究区域之一。概述了20世纪以来针对南极冰架所开展的科学研究工作,分别从冰架物质平衡过程、冰架形态特征及其内部结构监测、冰架海底海洋岩芯的沉积特征和冰架附近海域生态系统演化等方面总结了冰架研究所取得的丰硕成果。介绍了中国近几年在东南极洲埃默里冰架进行的科学考察活动,并依据南极冰架研究的国际未来计划提出了中国在埃默里冰架即将继续开展的研究工作。     

南极和北极地区变化对全球气候变化的指示和调控作用——第四次IPCC评估报告以来一些新认知

政府间国际气候变化专门委员会（IPCC）2007年发布了第4次评估报告后,全球气候变化问题再次成为国际社会、科技界和社会公众关注的焦点之一,并迅速成为了一个重要的国际科学和政治议题。 2007年以来,尤其是第4次国际极地年的实施,越来越多的观测和研究事实表明,北极和南极地区正在出现快速地变化着,这些变化也正在从量上到质量变化,当在跨越这种变化的阈门时,可能出现：北冰洋会在2040年前后出现夏季无海冰所引起的北半球大范围的持续暴雪的寒冷冬季;2050年左右南极上空臭氧空洞可能消失并恢复到上世纪80年代水平,南极地区可能会快速升温并引起东南极冰盖和海冰快速融化,使海平面升高加速;极区海水温度快速升高会驱动极区表层海洋和上覆大气之间CO2分压平衡加速,极区海洋也会大量吸收大气CO2,并诱发海水酸化及对极区生态系统产生不可逆的破坏。因此,南极和北极地区的快速变化,正在扮演对全球气候变化的指示和调控作用。     

“八五”期间我国南极固体地球科学研究成果和进展（代序）

南极大陆岩石圈结构和构造演化的研究，对于研究解决某些全球性构造和全球变化问题，具有重要意义，因而近年来受到各国政府和科学家的高度重视。１９９１年以来，我国地球科学家按照《中国南极科学考察研究“八五”计划》的要求，继续在西南极乔治王岛及其它岛屿、布兰斯...     

Ecology features of coastal saline lakes related to environmental evolution in the area of Antarctic continental ice edge

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海平面变化与南极大陆沿海西福尔丘陵湖泊环境演变

对东南极大陆沿海西福尔丘陵 ( Vestfold Hills,68°38′S,78°0 6′E)若干主要湖泊及其周边环境进行了现代生态学和古生态学研究。分析了不同类型湖泊的地理地貌环境和理化要素的动态特征、生态群落结构类型。利用湖岸古化石的生态组成与放射性同位素测定资料 ,推断了晚更新世以来随着全球海平面变化 ,该地区所经历的海侵、海退及其地理地貌改变过程 ,尤其重现了本区 1 80 0 0年以来因两次海侵而发生的湖泊生态演替过程。本文首次推出了该区海成湖泊 4种环境演化模式 ,认为这些湖泊环境演化模式不仅是区域环境生态历史演变的缩影 ,而且也是现今南极局部环境变化和全球气候变化的具体反映     

Study on ecological structures of coastal lakes in Antarctic continent

Coastal region on the Antarctic continent, where it is under the influences both of ocean and ice sheet, as well as frequent human activities, could be considered as a fragile zone in Antarctic ecological environment. There are many lakes in coastal region, showing much differences from each other in physical-chemical features because of individual evolutionary history in their geographical environments, and suffering from different outside factors, such as climate changes and precipitation. Thus, it results in respective biological distribution and ecological structure in lakes. The present paper reports the results from the studies of chemical components, species distributions and community structures, which mainly consisted of planktons in lakes in the Vestfold Hills (68°38′S, 78°06′E), and the Larsemann Hills (69°30′S, 76°20′E), East Antarctica. It also treats the biological diversities and nutrient relationships of these different types of lakes. So as to provide more scientific basis for monitoring of climate changes and environmental protection in Antarctica.     

Sea level change and environmental evolution of coastal lakes in Vestfold Hills, Antarctica

Ecological and palaeoecological studies were carried out in a series of lakes in the Vestfold Hills (68°38′S, 78°06′E) on eastern Antarctic continent. Dynamics types of the lakes in environmental geomorphology and physic chemistry, as well as features of biological community structures in different lakes were analyzed. Marine macro and micro fossils collected from the terraces and beaches surrounding these lakes and determined in 14 C radiocarbon ages to be the Late Pleistocene, were used as evidences to show the evolutionary processes of the lakes after sea level changes and transgressions since 18000 a B.P.. Basic modals of evolution for the lakes given in the paper could be regarded as not only explaining the history of environmental and ecological changes in VH lakes, and also reflecting of local environmental evolution in Antarctic region and global climate changes from past to present time.     

南极普里兹湾外海大磷虾声学映像的分布分析和生物量的初步估算

本文主要根据 1 990 /1 991年度中国南极考察队南大洋调查所获的探鱼仪的磷虾映像资料 ,经 WT- 2图像处理系统处理分析 ,结果表明 ,1 990 /1 991年度南极夏季 ,普里兹湾外海域 (6 2°- 6 9°S,6 8°- 1 0 8°E)的磷虾主要分布在 6 1°- 6 5°S,1 0 3°- 1 0 8°E海区 ,该海区的探鱼仪记录的磷虾群映像的面积占整个调查海区的 92 .3 2 %,磷虾群的分布水层主要在 3 0 - 6 0 m水层 ,在一天 2 4小时中 ,磷虾群映像面积的形心基本在 40 m层上下起伏 ,波动幅度约 1 0 m左右。在调查海区 (6 2°- 6 9°S,6 8°- 1 0 8°E)内 ,估算磷虾资源现存量为 2 2 0 0万吨 ,磷虾分布密度平均为 3 2 .5 t/km2。     

Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation

Isla de los Estados (54° 45′S, 63° 10′–64° 46′W) lies east of the main island of Tierra del Fuego and is the southeastern-most point in Argentina. Because of its geographic position near the latitudes of the Southern Hemisphere Westerlies and the strong influence of the Antarctic Circumpolar Current (ACC), the area is suitable for paleoecological and paleoclimate research. The island is not far north of the Subantarctic Front, which limits the northern boundary of the ACC. Paleoenvironmental study in this geographic location can shed light on past changes in atmospheric and marine circulation patterns. Diatom analysis of the lower part of a sediment sequence from Laguna Cascada (54° 45′ 51.3′′S, 64° 20′ 20.07′′W) enabled inference of changing lake conditions between 16 and 11.1 cal ka BP. Between 16 and 14.4 cal ka BP fragilarioid diatom species, often a pioneer group, dominated the record. Their presence shows seasonally open-water conditions from the onset of sedimentation. In zone II (14.4–12.8 cal ka BP), the dominance of planktonic/tychoplanktonic Aulacoseira spp. might represent longer ice-free periods and windier conditions, which would have kept this heavy species suspended in the water column. This period corresponds to the Antarctic Cold Reversal, when the Southern Hemisphere Westerlies were possibly centered on the latitudes of Tierra del Fuego, resulting in windy and wet conditions. Zone III (12.8–11.1 cal ka BP) is dominated by benthic diatom taxa that are mainly associated with peat and wetland vegetation. This suggests that climate conditions had become milder and less windy, favoring aquatic productivity and terrestrial vegetation development. This change in environmental conditions may have been a consequence of the southward movement of the Southern Hemisphere Westerlies at the start of the Antarctic Holocene thermal optimum.     

南极洲维斯特福尔德丘陵与菲尔德斯半岛冰缘地貌的比较研究

东南极大陆沿岸的维斯特福尔德丘陵(68°22'～68°40'S,77°55'～78°30'E)和西南极乔治王岛南端的菲尔德斯半岛(62°08'～62°20'S,58°45'～58°58'W)的气候条件不同。前者属于极地大陆性气候,气温低,冬季严寒,干燥、风大,夏季较短;后者属于极地海洋性气候,气温不很低,湿润、风小,夏季较长。因此,两地的冰缘地貌的组合类型及其发育过程存在明显的差异。前者冰缘地貌单一,发展速度较慢;后者冰缘地貌复杂多样,发展速度较快。 本文根据实地观测资料,对极地大陆型和极地海洋型两类冰缘地貌作一些比较,并且提出,年冻融日数是决定冰缘作用强弱的最重要指标。     

Late Quaternary Lakes in the McMurdo Sound Region of Antarctica

Lake levels within the enclosed drainage basins of the Dry Valleys adjacent to McMurdo Sound have fluctuated widely during the Late Quaternary due to (a) local climate change and the consequent variation in the evaporation–precipitation regime, and (b) glacial fluctuations, resulting in changes in the catchment and meltwater drainage areas of the glaciers and, in some cases, in the volumes of the available lake basins. Three types of lakes can be distinguished on the basis of their water source: (1) lakes receiving the bulk of their water from melting of local alpine glaciers; (2) proglacial lakes associated with outlet glaciers from the East Antarctic Ice Sheet; (3) proglacial lakes associated with the marine oxygen-isotope stage 2 Ross Sea ice sheet and its precursors. The Dry Valleys contain an exceptionally long lacustrine record, extending back at least 300,000 years. Lacustrinesedimentation is cyclical, occurring over periods of about 100,000 years. During the last such cycle, relatively small lakes, both adjacent to East Antarctic outlet glaciers and fed by meltwater from alpine glaciers, existed during stage 5. However, these local lakes gave way to large proglacial lakes adjacent to the Ross Sea ice sheet in stage 2. The same relationship apparently occurred during the previous 100,000-year cycle. Dating of lacustrine sediments suggests that lakes proglacial to the Ross Sea ice sheet have existed during episodes of sea-level lowering during global glaciations. Lakes proglacial to outlet glaciers from the East Antarctic Ice Sheet have formed coincident with episodes of high eustatic sea level during interglacial periods.     

Modelling diatom responses to climate induced fluctuations in the moisture balance in continental Antarctic lakes

The water chemistry of lake systems on the edge of the Antarctic continent responds quickly to changes in the moisture balance. This is expressed as increasing salinity and decreasing lake water level during dry periods, and the opposite during wet periods. The diatom composition of the lakes also changes with these fluctuations in salinity and lake water depth. This is important, as their siliceous remains become incorporated into lake sediments and can provide long-term records of past salinity using transfer functions. In order to develop transfer functions, diatoms and water chemistry data were inter-calibrated from five different East Antarctic oases, namely the Larsemann Hills, the Bølingen Islands, the Vestfold Hills, the Rauer Islands and the Windmill Islands. Results indicate that salinity is the most important environmental variable explaining the variance in the diatom flora in East Antarctic lakes. In oligo- saline lakes the variance is mainly explained by lake water depth. This dataset was used to construct a weighted averaging transfer function for salinity in order to infer historical changes in the moisture balance. This model has a jack-knifed r² of 0.83 and a RMSEP of 0.31. The disadvantage of this transfer function is that salinity changes in oligo-saline lakes are reconstructed inaccurately due to the edge effect and due to the low species turnover along the salinity gradient at its lower end. In order to infer changes in the moisture balance in these lakes, a second transfer function using weighted averaging partial least squares (with two components) for depth was constructed. This model has a jack-knifed r² of 0.76 and a RMSEP of 0.22. Both transfer functions can be used to infer climate driven changes in the moisture balance in lake sediment cores from oligo-, hypo-, meso- and hyper-saline lakes in East Antarctic oases between 102–75°E. The transfer function for lake water depth is promising to track trends in the moisture balance of small freshwater lakes, where changes in shallow and deep-water sediments are readily reflected in changing diatom composition.