Geochemical speciation and spatial distributions of phosphorus in surface sediments from the basin of the Marcus-Wake seamounts in the western Pacific Ocean

The concentrations of five forms of phosphorus(P) including exchangeable or loosely adsorbed P(Ex-P), Febound P(Fe-P), authigenic P(Auth-P), detrital P(Det-P), and organic P(Org-P) from the basin among the Marcus-Wake seamounts(19.4°–24°N, 156.5°–161.5°E) in the western Pacific Ocean were quantified using a sequential extraction method(SEDEX) to investigate the distribution and sources of different P species.Concentrations of total P(TP) varied from 14.0 μmol/g to 44.1 μmol/g, with an average of...     

The effect of Antarctic Circumpolar Current transport on the frontal variability in Drake Passage

The Antarctic Circumpolar Current (ACC) is composed of three major fronts: the Sub-Antarctic Front (SAF), the Polar Front (PF), the Southern ACC Front (SACCF). The locations of these fronts are variable. The PF can shift away from its historical (mean) location by as much as 100 km. The transport of the ACC in Drake Passage varies from its mean (134 Sv) by as much as 60 Sv. A regional numerical circulation model is used to study frontal variability in Drake Passage as affected by a range of volume transports (from 95 Sv to 155 Sv with an interval of 10 Sv). Large transport shifts the fronts northward while the smaller transport causes a southward shift. The mean shifting distance of the PF from the historical mean location is minimum with 135 Sv transport. The SAF and the SACCF are confined by northern and southern walls, respectively, while the PF is loosely controlled by the topography. Due to impact of the eddies and meanders on the PF at several regions in Drake Passage, the PF may move northward to join the SAF or move southward to combine with the SACCF, especially in central Scotia Sea. The SAF and PF are more stable with higher transport. The SAF behaves as a narrow, strong frontal jet with large transport while displaying meanders with smaller transport. In the model simulations, the Ertel Potential Vorticity (EPV) is strongly correlated with the volume transport stream function. EPV at depths between 1000 and 2500 m is correlated with the transport stream function with a coefficient above 0.9. Near the bottom, the correlation is about 0.6 due to the disruptive influence of bottom topography. Within 750 m of the surface, the correlation is much reduced due to the effect of K-Profile Parameterization (KPP) mixing and eddy mixing.     

全球海洋资料同化系统ZFL_GODAS的研制和初步评估试验

本研究发展了一个全球海洋资料同化系统ZFL_GODAS。该系统是一个短期气候数值预测业务系统的子系统,为短期气候预测海气耦合模式提供全球海洋初始场。系统能够同化的观测资料包括卫星高度计资料、卫星海表温度(SST)资料,以及Argo、XBT、TAO等各种不同来源的现场温盐廓线资料。系统使用的海洋模式为中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室开发的气候系统海洋模式LICOM1.0,同化方案为集合最优插值(EnOI)方案。系统使用一个由海洋模式自由积分得到的静态样本来估计背景场误差协方差。这样的基于集合样本的背景场误差协方差具有多变量协变、各向异性的特征,且能反映海洋物理过程固有的空间尺度特征。针对EnOI同化程序的特点,开发了一套特色鲜明、负载均衡、高效的并行化同化程序。本文通过与不同类型观测资料的比较,对同化系统的性能进行了评估。通过比较海表温度和海面高度的年际变率,海表温度异常随时间的变化,SST、海面高度异常(SLA)以及次表层温盐预报产品的均方根误差,5年平均温度偏差廓线、平均盐度廓线、平均纬向流速廓线等发现:系统工作正常、同化效果较好;经过同化以后,各变量都更加接近观测,误差更小,与观测场的相关性更好,可以为短期气候预测系统提供较好的海洋初始场,也可以为物理海洋学的研究提供有效的再分析资料。     

Geo-political genetics: Claiming the commons through species mapping

Genetic techniques are increasingly employed in the field of conservation biology; our understanding of sea turtle biology, and particularly of sea turtle migrations and population structures, has increased through genetic analyses that ‘match’ turtles found in various and often widely distributed habitats (e.g. nesting beaches, foraging grounds, migratory corridors). This relatively recent technological development has implications for how sea turtles are conceived, both as resources and as objects of conservation. Traditionally, sea turtle populations have been identified with nesting beaches, and most conservation efforts have been focused on these discrete geographic locations and undertaken by the state. The more complete understanding of relationships among turtles found in geographically disparate areas, achieved via genetic analysis, can take conservation beyond the beaches and territorial waters of individual states; foraging populations can now be linked to nesting populations sometimes hundreds of kilometers distant. In this paper, we explore the implications of genetic analysis for sea turtle conservation, the scale at which it is undertaken, and the variety of actors with competing interests in it. We focus on the case of hawksbill sea turtles in the Caribbean, where genetic data are invoked in conservation conflicts. We are particularly interested in the way genetic data can support the scaling-up of sea turtle conservation, creating new ‘conservation territories,’ and we draw on political ecology and common pool resource theory to explore the implications thereof.     

The Effect of Regional Ocean-Atmosphere Coupling on the Long-term Variability in the Pacific Ocean

A fully coupled ocean-atmosphere model is applied to highlight the mechanism of the long-term variability (including decadal and longer time scales) in the Pacific Ocean. We are interested in the effect of ocean-atmosphere coupling of different regions during these processes. The control run successfully simulates the Pacific long-term variability, whose leading modes are the Pacific (inter) Decadal Oscillation (PDO) and the North Pacific mode (NPM). Furthermore, three numerical experiments are conducted, s...     

Provenance of a prominent sediment drift on the northern slope of the South China Sea

The sedimentation rate of the sediment drift in the southeast of Dongsha Islands is as high as 49 cm/ka in the last 1.05 Ma. Although the sedimentation rate changes with time, the contents of rare elements of the sediments remain almost the same, indicating that the source area of the sediments has been constant with time. On the triangular diagrams of La-Th-Sc and Th-Sc-Zr/10, the samples from the southeast of Dongsha Islands fall within the continental island arc field, overlapping the samples from Taiwan, while the samples from the Pearl River, those from the west of the Philippines that contain volcanic material, are separated from them. This indicates that the sediments from the southeast of Dongsha Islands have a close relationship to those from Taiwan in terms of provenance. In fact, the sediments on the northern slope of the South China Sea were derived from northeast direction, as well as from Taiwan, most probably transported from Taiwan through Penghu channel into the South China Sea. The terrigenous part of the deep-sea sediments in the north of the South China Sea was provided by different sources.     

罕见的“强烈震群”活动

本文介绍了全世界范围内的“强烈震群”的地区分布、活动频率和强度等特征，并指出“强烈震群”主要分布在太平洋西半部的岛弧－海沟地带，这些“强烈震群”是依据近百年来的现代地震仪观测数据获得的。     

滇西云县地区中二叠世火山岩的发现及其对昌宁- 孟连古特提斯洋俯冲作用的约束

多年来，对滇西云县- 南涧一带广泛出露的中晚三叠世火山岩的形成时代及大地构造属性一直存在争议。出露于云县漫湾地区的原划中三叠统忙怀组中新发现有厚数米的英安岩、英安质凝灰岩夹流纹岩、凝灰岩组合。本次研究采集英安岩D0001进行锆石U- Pb LA- ICP- MS定年，获得262. 5±3. 1Ma的岩浆结晶年龄和447. 4±9. 1Ma的继承性年龄，时代厘定为中二叠世晚期，而非前人认为的中三叠世。对岩石组合、同位素测年及地球化学的详细研究表明，这套火山岩属石炭- 二叠系龙洞河组，为一套中酸性火山岩组合；SiO2含量68. 14%~74. 62%，Eu负异常，在TAS图解中全部落入英安岩- 流纹岩区；微量元素蛛网图明显富集Rb、Th、Ce等大离子亲石元素，亏损Nb、Ta、Ti等高场强元素，具典型火山岛弧特征，是目前临沧岩浆弧发现的最为年轻的岛弧型酸性火山岩记录，其岩浆源区为受壳源物质混染的下地壳镁铁质岩石部分熔融；应为早中二叠世昌宁- 孟连洋向东俯冲的产物。本次的发现，为西南三江地区昌宁- 孟连洋向东俯冲提供有利的岩石学记录及时代约束，也为石炭- 二叠系龙洞河组北延提供有利支撑，澜沧江断裂以西区域前人划分的忙怀组的分布范围和规模需要重估。     

The biogeochemical distribution of trace elements in the Indian Ocean

The present review deals with the distributions of dissolved trace metals in the Indian Ocean in relation with biological, chemical and hydrographic processes. The literature data-base is extremely limited and almost no information is available on particle processes and input and output processes of trace metals in the Indian Ocean basin and therefore much research is needed to expand our understanding of the marine chemistries of most trace metals. An area of special interest for future research is the Arabian Sea. The local conditions (upwelling induced productivity, restricted bottom water circulation and suboxic intermediate waters) create a natural laboratory for studying trace metal chemistry.     

Regional variation of Rayleigh wave attenuation coefficients in the Eastern Pacific

Seismograms recorded for five earthquakes on the east Pacific rise have been analyzed to obtain the attenuation coefficients of the fundamental Rayleigh mode for the eastern Pacific in the 15–110 second period range. The attenuation coefficients have been obtained using two new methods, a reference-station method, and an iterative method by which the seismic moment and regionalized attenuation coefficient values are obtained simultaneously after considering the effect of the source directivity and time-function. The reference-station method was applied to the entire eastern Pacific, excluding paths along the east Pacific rise. When using the iterative method we divided the eastern Pacific into three sub-regions, designated as the north-eastern Pacific, the Nazca plate and the east Pacific rise. Although much scatter is present, the data suggest that attenuation coefficients for the Nazca plate are higher than those for the northeastern Pacific, and both are substantially higher than average values obtained for the entire Pacific Ocean. Two paths that lie along or near the east Pacific rise are characterized by especially high attenuation coefficients. These values suggest that a low-Q zone exists beneath that narrow feature.