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481.
A crustal upheaval in a coastal zone is studied by introducing a simplified theoretical model of an equivalent elastic plate on which oceanic water is acting as a static loading. With a solution for the plate, the author notes what is seen as a crustal upheaval under the loading of static oceanic water in a qualitative scope. The solution requires some assumed parameters for the plate and the loading. Some other conditions should be also given to realize a possible dynamical understanding of a sea level rise seen after global climatological warming and glacial melting.  相似文献   
482.
The probability distribution of the height of global maximum for a Gaussian random field evolving in time is studied. In particular, the effect of spreading is studied and the role of the wave kinematics is discussed. It is observed that taking into account time dynamics of spatial characteristics results in distributions different from those obtained for the static case. The results are illustrated by computing the derived distribution for different Gaussian seas for three distinct sampling schemes. The resulting distributions are also used to compute return periods for rogue waves.  相似文献   
483.
海洋声层析法作为检测海洋内部变化一有力手段,正面临着海洋声学大尺度观测新挑战。本文就海洋声传播的绝热近似;声传播时间的非线性偏移;声速剖面的线性及非线性反演等与声学大尺度观测相关的一些水声学问题的发展现状及存在问题等进行了综述性论述。文中还介绍了赫德岛预演实验等利用声层析法观测海洋内部变化的一些具体应用例  相似文献   
484.
The governance of labour in global production networks (GPNs) has become a critical area of concern amongst academics and policymakers alike. To date, GPN research has focused on the role of private company codes and multi-stakeholder ethical initiatives primarily driven by lead-firms. Other GPN studies highlight the critical role of civil society organisations (CSOs) in challenging lead-firm purchasing practices and shaping regulatory outcomes at local production sites. However, GPN research has not sufficiently incorporated the role of nation states in regulating work through legislative frameworks and enforcement regimes, often referred to in the literature as ‘state’ or ‘public’ governance. This is despite a ‘regulatory renaissance’ taking place across certain developing countries, seeking to strengthen their national regulatory labour institutions (Piore and Schrank, 2008:1).The GPN framework provides an analytical lens through which to conceptualise cross-cutting strands of trans-scalar governance regimes, involving complex networks of state, private and civil society actors operating at multiple scales. Notions of territorial and societal embeddedness are used to elucidate how global ethical standards derived from particular country contexts become enmeshed in national regulatory frameworks and local societal relations, shaping governance outcomes for precarious workers incorporated into GPNs. The paper draws attention to the ‘trans-scalar embeddedness’ of labour governance regimes which interact across geographical scales and, in the case of South African fruit, reflect a ‘trans-scalar governance deficit’ for precarious workers. It is argued that the influence of national regulatory regimes should be more fully incorporated into analytical frameworks for understanding governance outcomes in GPNs.  相似文献   
485.
This paper explores the phenomenon of local climate perception and the extent to which public perceptions match climate conditions as recorded in instrumental climate data. We further examine whether perceptions of changes in local climates are influenced by prior beliefs about global warming, through the process of motivated reasoning. Using national survey data collected in the United States in 2011, we find that subjective experiences of seasonal average temperature and precipitation during the previous winter and summer were related to recorded conditions during each season. Beliefs about global warming also had significant effects on subjective experiences with above-normal temperatures, particularly among those who believed that global warming is not happening. When asked about the summer of 2010, those who believed that global warming is not happening were significantly less likely to report that they had experienced a warmer-than-normal summer, even when controlling for demographics and local climate conditions. These results suggest that the subjective experience of local climate change is dependent not only on external climate conditions, but also on individual beliefs, with perceptions apparently biased by prior beliefs about global warming.  相似文献   
486.
The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event is most clearly reflected in an abrupt shift in deuterium excess values, accompanied by more gradual changes in δ18O, dust concentration, a range of chemical species, and annual layer thickness. A timescale based on multi‐parameter annual layer counting provides an age of 11 700 calendar yr b2 k (before AD 2000) for the base of the Holocene, with a maximum counting error of 99 yr. A proposal that an archived core from this unique sequence should constitute the Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) has been ratified by the International Union of Geological Sciences. Five auxiliary stratotypes for the Pleistocene–Holocene boundary have also been recognised. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
487.
Climate change adaptation, which has previously been seen as a national and local matter, is today systematically addressed by international institutions such as the UNFCCC, the FAO and the WTO. Research has focused on the overarching institutional architecture of global adaptation, particularly how it relates to development, political economy, efficiency and equity. In contrast to the transnational dimension of climate mitigation, the transnationalization of adaptation governance has received scant attention. By creating a dataset of adaptation projects, we examine transnational adaptation governance in terms of its scope, institutionalization and main functions. We find transnational adaptation governance to be firmly anchored within the UNFCCC, but a recent change towards adaptation governed by a transnational constituency can be identified. When non-state actors become integral to the project of governing adaptation, a ‘fourth era’ of adaption seems to be emerging. This new era is not replacing other forms of governing, but is emerging alongside and in a complementary fashion. In the ‘fourth era’, adaptation is increasingly governed globally and transnationally, and the attention is turned toward ‘softer’ forms of governance such as agenda setting, information sharing and capacity building.  相似文献   
488.
Populations and metropolitan centers are accumulated in coastal areas around the world. In view of the fact that they are geographically adjacent to coasts and intense anthropogenic activities, increasing global offshore pollution has been an important worldwide concern over the past several decades and has become a very serious problem that needs to be addressed urgently. Due to offshore pollution, various geological disasters occur in high frequency, including intensified erosion and salinization of coastal soils, frequent geological collapses and landslides and increasing seismic activities. Moreover, offshore pollution shows increasingly serious impacts on the topography and geomorphology of offshore and coastal areas, including coastal degradation, retreating coastlines and estuary delta erosion. Offshore sedimentation processes are strongly influenced by the pH changes of terrestrial discharges, and sedimentary dynamics have become extremely acute and complex due to offshore pollution. The seabed topography and hydrodynamic environment determine the fate and transport of pollutants entering offshore regions. Coastal estuaries, port basins and lagoons that have relatively moderate ocean currents and winds are more likely to accumulate pollutants. Offshore regions and undersea canyons can be used as conduits for transporting pollutants from the continent to the seabed. It is particularly noteworthy that the spatial/temporal distribution of species, community structures, and ecological functions in offshore areas have undergone unprecedented changes in recent decades. Due to increasing offshore pollution, the stable succession and development trend of marine ecosystems has been broken. It is thus important to identify and regulate the quantity, composition and transportation of pollutants in offshore regions and their behavior in marine ecosystems. In particular, crucial actions for stabilizing marine ecosystems, including increasing species and biodiversity, should be implemented to enhance their anti-interference capabilities. This review provides an overview of the current situation of offshore pollution, as well as major trends of pollutant fate and transportation from continent to marine ecosystems, transformation of pollutants in sediments, and their bioaccumulation and diffusion. This study retrospectively reviews the long-term geological evolution of offshore pollution from the perspective of marine geology, and analyses their long-term potential impacts on marine ecosystems. Due to ecological risks associated with pollutants released from offshore sediments, more research on the influence of global offshore pollution based on marine geology is undoubtedly needed.  相似文献   
489.
The complexity of the tropical climate system demands the development of a hierarchy of models to ensure our understanding of its response to anthropogenic forcing. The response of the tropical Pacific Ocean to radiative forcing has been studied previously with a box model. The model has provided insights into the tropical Pacific climate change that are otherwise not easily attainable. But that model only encompasses the tropical Pacific region. Recent studies have also shown that the Indian Ocean (IO) may be important in the response of the Pacific Walker circulation to radiative forcing, raising the need to expand the model to take into account the role of IO. This study presents the results concerning the tropical Pacific response to radiative forcing from an expanded-box model that includes the tropical IO, which influences the tropical Pacific through an inter-basin SST gradient.The three-box model predicts an enhanced zonal SST gradient in tropical Pacific in response to the increased radiative forcing, similar to the previous two-box model. It is further noted that in the three-box model, a warmer IO relative to the Pacific enhances Pacific easterlies and subsequently strengthens the equatorial ocean circulation. Because of this ocean dynamical cooling, the warming response in the Pacific is effectively reduced in the three-box model that includes the role of IO compared with that in the two-box model. The role of the IO warming trend in enhancing the Pacific trade winds is confirmed using an atmospheric general circulation model experiment. These results may help to fully explain the relatively small observed warming trend in the tropical Pacific compared to that in the tropical IO evident in 20th century SST reconstructions.  相似文献   
490.
在全球气候变暖背景下,中国江淮流域梅雨期的气候响应趋于复杂,给江淮流域梅雨期的气候预测带来了更多的不确定因素。研究江淮梅雨期气候对全球变暖的响应,对于认识江淮梅雨变化新趋势、提高新气候背景下的汛期预报及制定防灾减灾政策均有深远意义。采用中国地面气温和降水日值数据集对近几十年来江淮地区梅雨期的气温和降水变化进行了深入分析,基于观测结果,评估了国际耦合模式比较计划第5阶段(CMIP5)的22个模式结果,并对CMIP5模式预估的21世纪中排放(RCP4.5)和高排放(RCP8.5)情景下中国江淮流域梅雨期的气温和降水变化进行了分析,并对梅雨期气候变化的机理进行了探讨。研究结果表明,在全球变暖背景下,江淮地区梅雨期气候亦发生了相应的变化,气温呈现出显著的升高趋势,降水亦发生了相应调整,在较暖年降水偏多,较冷年降水偏少。在未来全球进一步变暖的背景下,江淮地区梅雨期平均气温进一步升高,降水进一步增多,且随着排放量的增加,降水的空间分布不均匀性也在加剧。   相似文献   
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