黄土与古季风

中国黄土的古季风记录研究，揭示了东亚季风区的环境变迁历史是来自中、高纬大陆的偏北冬季风与来自中、低纬海洋的偏南夏季风的环境效应优势期相互交替的历史。文中简要介绍了有关黄土高原黄土与古季风研究的重要进展，侧重讨论了中原地区末次冰期高分辨率黄土所记录的冬季风和夏季风变迁的特征，最后就今后全球变化计划中的黄土与古季风研究提出了几点意见。     

Mapping Farmer Identity: why,how, and what does it tell us?

Rural areas in developed economies are becoming increasingly multi-functional in that their character is being shaped by a mix of production, consumption and conservation values. Agriculture may remain the dominant land use, but many landholders do not see themselves as farmers by occupation. Researchers have demonstrated that occupational identity influences land use and management. However, efforts to explore the influence of occupational identity often rely on surrogate measures and have largely ignored identity theory. We build on research demonstrating that collective identity theory can be used to develop a valid and reliable measure of farmer identity and to then classify rural landholders across a natural resource management (NRM) region. The contribution of this paper is to explain how that measure of farmer identity can be mapped and then demonstrate the relevance of doing so for regional NRM in Australia. As expected, farmer identity varied across the case study region with distance from urban centres, and across different environmental assets. Those findings should lead to a more targeted approach to landholder engagement in NRM. We suggest that farmer identity (i.e. farmer-collective occupational identity construct; F-COIC) might provide a next step for responding to the challenges of interpreting and mapping multi-functionality.     

Are Australia’s suburbs swamped by Asians and Muslims? Countering political claims with data

Recent decades have seen substantial growth across many developed-world countries of right-wing populist political parties whose policies oppose immigration and multiculturalism as threats to the majority way of life there. These are exemplified in Australia by Pauline Hanson’s One Nation Party, which was successful at elections there at the turn of the twenty-first century and again in 2016. Part of this party’s rhetoric focuses on the geography of immigrant groups in Australia’s cities, with claims that their members live in ghettos. Is that factually correct? Using data from the 2011 Australian census this paper analyses the distribution of Asians and Muslims (the two groups picked out by One Nation and its leader) at four spatial scales within the country’s 11 largest urban areas. It finds no evidence at all of intensive residential segregation of Muslims, and although there are concentrations of Asians—notably in Sydney and Melbourne—most residents claiming Asian ancestry live in neighbourhoods and suburbs where they form a minority (in many cases a small minority) only of the local population.     

南海西南部海区近200ka来的动力环境与东亚古季风

包括南海在内的热带海洋是东亚夏季风的发源地,分析其动力环境特征的的演变历史,可提供东亚古季风活动的海洋证据。对取自该海区的NS93-5柱状样做了详细的粒度分析,结合氧内闰素地层结果、微体古生物观察统计和CaCO3测试资料,尝试采用高精度的粒度分析作为替代性指标,讨论近200ka以来的水动力及古生产力变化特征。结果认为,自末次盛冰期以来该海区的海洋动力环境发生了明显的变化,而在此之前则变化不显著,在倒数第2次冰期中由于夏季风作用致该局部区域上升流发育和海面温度偏高。古生产力变化规律一般是：在冰期较高,并呈稳定或上升趋势;在间冰期较低,出现下降现象。近200ka来的特殊情况出现于全新世早期,古生产力达到最高值。通过与黄土高原及其它地区的古季风环境对比,发现东亚古季风区内在全新世和末次盛冰期的遥相关较好,而在倒数第2次冰期中存在明显差别,说明在冬季风和夏季风的相互作用下,产生了特定时期内典型季风区的局部海洋区域性特征。     

Mesoscale structure of the mean East Australian Current System and its relationship with topography

We document the mean circulation of the East Australian Current (EAC) System, which is the major western boundary current in the southwest Pacific Ocean. A new high-resolution climatology of the region (CSIRO Atlas of Regional Seas, CARS) is used to produce regional fields of steric height and sections of geostrophic velocity. The realism of these fields has been enhanced by the high spatial resolution, allowance for bathymetric control and the influence of land barriers. The increased detail in the maps and sections reveal the major influence that the complex regional topography has on the circulation. The results also provide the appropriate resolution for comparison with recent model studies of the region. We have been able to both resolve well-known features with greater detail and identify previously unrecognized aspects of the circulation. Important results include: (1) The zonal inflow north of 30°S breaks into a series of individual jets after flowing through the island chains as suggested by recent model results. (2) The interaction of the zonal inflow with the local topography as it undergoes bifurcation is documented. (3) A detailed picture of the evolution of the EAC at the western boundary is presented, including surface currents and transports. (4) Separation and recirculation of the EAC within the Tasman Abyssal basin are shown to occur as a double cell structure constrained by bathymetry. (5) The EAC outflow is resolved as a series of eastward, and northeastward currents. (6) The path of the Tasman Front is defined as it interacts with the Tasman Ridge systems. (7) A quasi-permanent eddy is identified for the first time adjacent to the Norfolk Ridge, northwest of New Zealand.     

Natural reforestation of abandoned farmland: the role of soils

Natural regeneration of abandoned farmland in several areas within the catchments of the Sydney Water Board has been very slow. Several hypotheses have been put forward to explain the fact that natural reforestation has not occurred, even after up to 50 years of abandonment. This study examines regeneration in relation to substrate, soil types and soil chemistry. The abandoned farmlands occur on four main soil types: (i) eutrophic krasnozem, now occupied mainly by bracken fern (Pteridium esculentum) associated with young seedlings of Eucalyptus and Acacia; (ii) mesotro‐phic yellow earth, now occupied by blady grass (Imperata cylindrica), with few tree seedlings and scattered, dead Acacia trees; and (iii) mesotrophic alluvial soil, and (iv) oligotrophic lithosol, which both support stands of Acacia. The soil properties of the krasnozem and the yellow earth appear to be suitable for tree establishment and growth, and do not differ from similar soils in nearby areas currently under cultivation or supporting undisturbed forest. Poor forest establishment in these soils might be the result of frequent fires and biotic factors such as competition from the bracken and blady grass sward. The lack of eucalypt reforestation of the poorer soils might be explained by their poorer fertility, perhaps tolerated better by the Acacia species.     

中国湖泊沉积记录的环境演变:研究进展与展望

综合分析了８０年代后期以来中国湖泊沉积与环境演变研究的新进展,着重对湖泊沉积记录与亚洲古季风变迁、青藏高原湖泊沉积与环境演变、人与自然相互作用的湖泊响应等方面进行了扼要综述,指出今后研究的方向是：湖泊沉积环境指标与气候要素关系的定量研究、高分辨率环境演化时间序列与空间分异规律、现代湖泊沉积动态过程与环境、中国第四纪湖泊数据库与全球变化研究、科学交叉及与其它地质记录的比较研究。     

澳大利亚南极利益——现实挑战与政策应对

地理空间上的相对邻近性与最为广阔的领土主张,使得南极一直都是澳大利亚最为重要的战略重点之一。在积极参与南极事务的过程中,澳大利亚通过对其南极利益与面临的挑战所形成的明确具体的认识,逐渐建立起一系列完善、健全的政策机制,并将维护领土主权、加大科研投入、保护南极环境、获取经济收益作为现阶段的主要目标。     

2015/2016年超强El Nio在成熟/衰减阶段对澳洲夏季风环流与降水异常的影响

2015/2016年发生了超强El Nio事件,Nio3区海温异常在2015/2016年冬季超过了2.5℃,其对全球气候异常的产生具有重大影响。此次El Nio事件可归类为东部型。本文利用NCEP/NCAR再分析资料、Hadley中心海温资料及CMAP降水资料等,通过诊断分析,揭示了2015/2016年强El Nio事件盛期和衰减期海温异常对澳洲夏季风环流异常和降水变化的影响及其途径。澳洲地区受此次El Nio事件影响,大部分地区降水显著减少,某些地区降水减少达60%~80%。影响途径主要有:1)海温异常通过Gill型响应造成水平环流异常并进而影响澳洲夏季风减弱。2015/2016年ENSO事件成熟期及衰减期,在西太平洋赤道地区出现海温负异常,导致此处热带地区产生了负异常的热源分布,并由此激发产生了位于赤道北侧和南侧的异常反气旋式环流。位于海洋性大陆南侧的异常反气旋性环流引起澳洲夏季风减弱,从而利于抑制上升运动,造成了澳大利亚降水量显著减少;2)通过赤道中东太平洋地区上升和澳洲地区下沉的垂直环流异常导致澳洲降水显著减少。在El Nio事件盛期,因海温异常偏暖导致赤道中东太平洋地区产生显著的异常上升运动,其补偿性的下沉运动因Walker环流而出现在海洋性大陆地区,以及因澳洲大陆夏季风减弱而出现在澳大利亚中东部地区,由此构成了中东太平洋—澳洲副热带的垂直环流圈,此东北—西南向的垂直环流圈对澳洲降水减少的维持起到了重要作用。另外,中国南方的上升运动与海洋性大陆及澳洲地区的下沉运动之间通过局地经圈环流产生了联系,表明东亚冬季风异常减弱对澳洲夏季风减弱可能存在间接影响。这些结果对深刻认识超强ENSO事件对亚澳季风的影响机理以及寻找澳洲降水预测线索具有重要意义。     

Abundance and Ecology of Endemic Asterorotalia trispinosa from the Western Bay of Bengal: Implications for its Application as a Paleomonsoon Proxy

A total of 97 surface sediment samples were collected from the continental shelf and slope of the western Bay of Bengal to assess the potential application of Asterorotalia trispinosa as a paleomonsoon proxy. The relative abundance of living as well as total (living and dead) A. trispinosa ranges from being absent to a maximum of ~31%. The highest abundance of A. trispinosa is close to the outfall region of the Ganga-Brahmaputra Rivers and decreases away from the river mouths. Contrary to that, A. trispinosa is rare in front of both the Cauvery and Pennar river outfall regions, in the central part of the western Bay of Bengal. The living A. trispinosa abundance is the lowest in between two major river systems, viz. Ganga-Brahmaputra-Mahanadi and Krishna-Godavari. The relative abundance of both the total and living A. trispinosa is strongly positively correlated with ambient seawater temperature, and negatively correlated with %Corg and salinity. Based on the spatial distribution, we conclude that A. trispinosa is stenohaline in nature, rather than euryhaline, and further that the increased relative abundance of A. trispinosa indicates warmer and only marginally hyposaline environment. Even though the ecological preference of A. trispinosa suggests it as a potential paleomonsoon proxy, the restricted distribution implies limited application.