Separate and interactive effects of eutrophication and climate variables on the ecosystem elements of the Gulf of Riga

There is currently a critical knowledge gap in how eutrophication and climate variables separately and interactively impact the dynamics of marine ecosystems. Based on long-term monitoring data we quantified the separate and combined impacts of nutrient loading, temperature, salinity, and wind conditions on zooplankton, zoobenthos and fish inhabiting a brackish water ecosystem in the Gulf of Riga. Changes in zoobenthos communities and herring stock were largely explained by climate variables. Zooplankton species were related to both eutrophication and climate variables, and models combining all environmental variables explained additional variation in zooplankton data compared to the separate models of climate and eutrophication. This suggests that zoobenthos communities and herring stock are largely driven by weather conditions, whereas the combined effect of weather and nutrient loads are likely the cause for dynamic zooplankton communities in the Gulf of Riga.     

Scleractinian coral population size structures and growth rates indicate coral resilience on the fringing reefs of North Jamaica

Coral reefs throughout the world are under severe challenges from many environmental factors. This paper quantifies the size structure of populations and the growth rates of corals from 2000 to 2008 to test whether the Discovery Bay coral colonies showed resilience in the face of multiple acute stressors of hurricanes and bleaching. There was a reduction in numbers of colonies in the smallest size class for all the species at all the sites in 2006, after the mass bleaching of 2005, with subsequent increases for all species at all sites in 2007 and 2008. Radial growth rates (mm yr⁻¹) of non-branching corals and linear extension rates (mm yr⁻¹) of branching corals calculated on an annual basis from 2000–2008 showed few significant differences either spatially or temporally. At Dairy Bull reef, live coral cover increased from 13 ± 5% in 2006 to 20 ± 9% in 2007 and 31 ± 7% in 2008, while live Acropora species increased from 2 ± 2% in 2006 to 10 ± 4% in 2007 and 22 ± 7% in 2008. These studies indicate good levels of coral resilience on the fringing reefs around Discovery Bay in Jamaica.     

利用综合评分方法评估CMIP5模式对北极海冰的模拟能力

北极海冰冰盖自20世纪以来经历了前所未有的缩减,这使得北极海冰异常对大气环流的反馈作用日益显现。尽管目前的气候模式模拟北极海冰均为减少的趋势,但各模式间仍然存在较大的分散性。为了评估模式对于北极海冰变化及其气候效应的模拟能力,我们将海冰线性趋势和年际异常两者结合起来构造了一种合理的衡量指标。我们还强调巴伦支与卡拉海的重要性,因为前人研究证明此区域海冰异常是近年来影响大尺度大气环流变异的关键因子。根据我们设定的标准,CMIP5模式对海冰的模拟可被归为三种类型。这三组多模式集合平均之间存在巨大的差异,验证了这种分组方法的合理性。此外,我们还进一步探讨了造成模式海冰模拟能力差别的潜在物理因子。结果表明模式所采用的臭氧资料集对海冰模拟能力有显著的影响。     

Persistent volcanic signature observed around Barren Island, Andaman Sea, India

This study delineates the formation of a warm pool (>34°C) of air to the west (downwind) of the active volcano of the Barren Island during October–November 2005. Barren Island is located in the Sumatra–Andaman region, about 135 km east of Port Blair, and lies within the Burma microplate, the southern tip of which experienced a submarine earthquake (M _w 9.3) causing a tsunami in December 2004. Barren Island is the only volcano, which has shown sustained eruptive activity since shortly after the Great Sumatran Earthquake of December 2004. Our observations require further corroboration to relate how submarine earthquakes activate volcanoes and how far these thermal emissions influence climate changes. Because it links global warming and climate changes to the frequent emissions from a volcano activated by submarine earthquakes, this case study is of special interest to the earth-ocean-atmosphere sciences community.     

气候变暖与海平面上升

本文通过大量实际资料分析认为,现代全球变暖与海平面上升,源于200多年前小冰期冷峰出现后的气候返暖、海平面回升过程演变的结果。近30年的世界海平面上升的速率,有着上世纪80、90年代和本世纪前10年世界平均气温每10年以0．2F°（0．11℃）为梯度的连续抬升为背景。在此以CO。含量为气候指标,划分出了公元200年以来的八个暖段（暖期）。若按冷暖极值距200年或250年计算,则由目前正在发展的暖期,将在公元2050年或2100年前后结束,而后开始降温。作者依据最近30年同一时段国内外验潮资料计算获得的绝对海平面升降速率为＋1．52±0．27mm／a及相对海平面升降速率为＋1．39±0．26mm/a。按照2010年坎昆气候大会决议要求,在对前人有关研究成果进行考量时,对将来的2050和2100年世界海平面预测及我国地面沉降较明显的沿海城市如天津、上海、厦门、海口等相对海平面升降值,进行了测算与评估。     

海底观测网发展现状及趋势研究

文中详细研究了当前世界上最典型的海底观测网的建设发展规模、形式、设备类型以及我国海底观测网的发展现状,并对国内外海底观测网的发展趋势进行总结。对日本、加拿大、美国及欧洲的海底观测网进行了设备级研究,对我国台湾地区、东海、南海的海底观测网现状进行了研究,并讨论了国外先进观测网对我国的海底观测网建设的借鉴意义。文中总结出海底观测网发展的整体趋势为:单节点网络加速验证新型设备及传感器的水下能力;区域尺度网络用于加速多学科发展并提升灾害预警能力;而浮标平台网络作为补充,铺设在远海区域以降低阶段建设成本。     

CICE5.0与BCC_CSM2.0模式的耦合及对北极海冰的模拟评估

本文将美国Los Alamos国家实验室发展的最新海冰模式CICE5.0引入国家气候中心气候系统模式BCC_CSM2.0,替代原有的海冰模式SIS,形成一个新的耦合模式。在此基础上,评估新耦合模式对1985-2009年北极海冰的模拟性能,检验引入CICE5.0后对耦合模式中北极海冰、海洋和大气模拟结果的改进。结果表明,引入CICE5.0后,模式能较好地模拟出北极海冰的空间分布、季节以及年际变化特征。相比于旧版本耦合模式,新耦合模式模拟的北极多年冰增多、一年冰减少,同时,海冰增厚、海冰流速减慢,模拟效果得到显著改进,对波弗特涡流模拟的改善尤为明显。进一步分析发现,相比于SIS,CICE5.0对北极海冰特别是海冰厚度模拟性能的提升,在耦合进入BCC_CSM2.0后,会触发冰-温的正反馈机制,改进了模式对海平面气压场、表层气温和海表温度的模拟,由此进一步提高了模式对北极海冰的模拟能力。     

Climate change: Social adaptation strategies for fishermen

As climate change continues to pose a major threat to the well-being of both people and the environment, adaptation to its negative effects has moved to the forefront among occupations that rely on natural resources for their livelihood. As one of the main occupational groups who are dependent on nature, fishermen are expected to experience many new challenges from the changing climate. Though an adequate amount of scientific research on climate change has been carried out, few studies have explored the social circumstances of the issue, particularly in the context of small scale fishermen. This paper aims to address this gap. Aspects such as risks reduction, social relationships, climate change knowledge, alternative skills, involvement in adaptation planning and access to credit are recommended to be considered as these are found to provide synergy for social adaptation, and it is hoped that such recommendation strategies will assist stakeholders in generating and engendering effective adaptation strategies for small-scale fishermen.     

Population connectivity of an overexploited coastal fish,Argyrosomus coronus (Sciaenidae), in an ocean-warming hotspot

The West Coast dusky kob Argyrosomus coronus is a commercially exploited fish with a distribution confined to the Angola–Benguela Frontal Zone (ABFZ) of the southeastern Atlantic Ocean. A previous study revealed that during a recent period of local warming the species extended its distribution into Namibian waters, where it hybridised with the resident and congeneric Argyrosomus inodorus. Environmental changes are a major threat to marine biodiversity and when combined with overfishing have the potential to accelerate the decline of species. However, little is known regarding the evolutionary history and population structure of A. coronus across the ABFZ. We investigated genetic diversity, population structure and historical demographic changes using mtDNA control region sequences and genotypes at six nuclear microsatellite loci, from 180 individuals. A single, genetically homogeneous population was indicated across the distributional range of A. coronus (φ_ST = 0.041, F_ST = 0.000, D = 0.000; p > 0.05). These findings imply that the oceanographic features within the ABFZ do not appear to significantly influence population connectivity in A. coronus, which simplifies management of the species. However, reconstruction of the demographic history points to a close link between the evolutionary history of A. coronus and the environmental characteristics of the ABFZ. This outcome suggests the species’ vulnerability to the rapid environmental changes being observed across this region, and highlights a pressing need for transboundary management to mitigate the impacts of climate change in this global hotspot of seawater temperature changes.