Paleogene of the Huanghekou Sag in the Bohai Bay Basin,NE China: deposition–erosion response to a slope break system of rift lacustrine basins

The sequence architecture and depositional systems of the Paleogene lacustrine rift succession in the Huanghekou Sag, Bohai Bay Basin, NE China were investigated based on seismic profiles, combined with well log and core data. Four second‐order or composite sequences and seven third‐order sequences were identified. The depositional systems identified in the basin include: fan delta, braid delta, meander fluvial delta, lacustrine and sublacustrine fan. Identification of the slope break was conducted combining the interpretation of faults of each sequence and the identification of syndepositional faults, based on the subdivision of sequence stratigraphy and analysis of depositional systems. Multiple geomorphologic units were recognized in the Paleogene of the Huanghekou Sag including faults, flexures, depositional slope break belts, ditch‐valleys and sub‐uplifts in the central sag. Using genetic division principles and taking into consideration tectonic features of the Paleogene of the Huanghekou Sag, the study area was divided into the Northern Steep Slope/Fault Slope Break System, the Southern Gentle Slope Break System and T10 Tectonic Slope Break System/T10 Tectonic Belt. Responses of slope break systems to deposition–erosion are shown as: (1) basin marginal slope break is the boundary of the eroded area and provenance area; (2) ditch‐valley formed by different kinds of slope break belts is a good transport bypass for source materials; (3) shape of the slope break belt of the slope break system controls sediments types; (4) the ditch‐valley and sub‐sag of a slope break system is an unloading area for sediments; and (5) due to their different origins, association characteristics and developing patterns, the Paleogene slope break belt systems in the Huanghekou Sag show different controls on depositional systems. The Northern Fault Slope Break system controls the deposition of a fan delta‐lacustrine‐subaqueous fan, the Southern Gentle Slope Break system controls the deposition of a fluvial–deltaic–shallow lacustrine and sublacustrine fan, and the T10 Tectonic Slope Break System controls the deposition of shallow lacustrine beach bar sandbodies. The existence of a slope break system is a necessary but not a sufficient condition for studying sandbody development. The formation of effective sandbodies along the slope break depends on the reasonable coupling of effective provenance, necessary association patterns of slope break belt, adequate unloading space and creation of definite accommodation space. Copyright © 2013 John Wiley & Sons, Ltd.     

Observation-based blended projections from ensembles of regional climate models

We consider the problem of projecting future climate from ensembles of regional climate model (RCM) simulations using results from the North American Regional Climate Change Assessment Program (NARCCAP). To this end, we develop a hierarchical Bayesian space-time model that quantifies the discrepancies between different members of an ensemble of RCMs corresponding to present day conditions, and observational records. Discrepancies are then propagated into the future to obtain high resolution blended projections of 21st century climate. In addition to blended projections, the proposed method provides location-dependent comparisons between the different simulations by estimating the different modes of spatial variability, and using the climate model-specific coefficients of the spatial factors for comparisons. The approach has the flexibility to provide projections at customizable scales of potential interest to stakeholders while accounting for the uncertainties associated with projections at these scales based on a comprehensive statistical framework. We demonstrate the methodology with simulations from the Weather Research & Forecasting regional model (WRF) using three different boundary conditions. We use simulations for two time periods: current climate conditions, covering 1971 to 2000, and future climate conditions under the Special Report on Emissions Scenarios (SRES) A2 emissions scenario, covering 2041 to 2070. We investigate and project yearly mean summer and winter temperatures for a domain in the South West of the United States.     

广西栗木钨锡铌钽矿区流体包裹体及氢氧同位素研究

本文通过对广西栗木矿区金竹源矿床和水溪庙矿床的流体包裹体研究,得出该矿区流体包裹体主要有两相H_2O-NaCl和H_2O-NaCl-CO_2两种类型。显微测温结果表明:两相H_2O-NaCl型流体包裹体均一温度主要集中于181.9~258.8℃,盐度w(Na Cleq)主要集中于4.01%~6.87%,密度0.690~0.988 g/cm3;H_2O-NaCl-CO_2型流体包裹体均一温度为178.5~331.1℃,主要集中在两个温度段,分别为高-中温段(265.3~315.5℃)和中-低温段(202.3~264.1℃),盐度w(NaCleq)主要集中在0.21%~5.05%,密度为0.678~0.886 g/cm3。栗木矿区成矿流体有两个温度集中段,且具有低盐度、低密度的特征。氢氧同位素研究结果表明:金竹源矿床钨锡铌钽矿化花岗岩石英δD值为-73.6‰~-62.8‰,δ~(18)OV-SMOW值为7.5‰~8.9‰,计算得δ~(18)OH2O值为6.00‰~7.40‰;水溪庙矿床钨锡铌钽矿化花岗岩石英δD值为-73.8‰~-58.3‰,δ~(18)OV-SMOW值为11.0‰~13.2‰,计算得δ~(18)OH2O值为9.50‰~11.70‰,水溪庙矿床含钨锡石英脉石英δD值为-75.3‰~-56.6‰,δ~(18)OV-SMOW值为11.8‰~14.1‰,计算得δ~(18)OH2O值为2.20‰~4.50‰。栗木矿区钨锡铌钽矿化花岗岩成矿流体来源于岩浆水,含钨锡石英脉成矿流体来源于岩浆水和大气降水的混合流体。     

Mesoscale numerical simulation study of warm fog dissipation by salt particles seeding

Based on the dynamic framework of WRF and Morrison 2-moment explicit cloud scheme, a salt-seeding scheme was developed and used to simulate the dissipation of a warm fog event during 6–7 November 2009 in the Beijing and Tianjin area. The seeding effect and its physical mechanism were studied. The results indicate that when seeding fog with salt particles sized 80 μm and at a quantity of 6 gm~(-2) at the fog top, the seeding effect near the ground surface layer is negative in the beginning period, and then a positive seeding effect begins to appear at 18 min, with the best effect appearing at 21 min after seeding operation. The positive effect can last about 35 min. The microphysical mechanism of the warm fog dissipation is because of the evaporation due to the water vapor condensation on the salt particles and coalescence with salt particles.The process of fog water coalescence with salt particles contributed mostly to this warm fog dissipation. Furthermore, two series of sensitivity experiments were performed to study the seeding effect under different seeding amounts and salt particles sizes. The results show that seeding fog with salt particles sized of 80 μm can have the best seeding effect, and the seeding effect is negative when the salt particle size is less than 10 μm. For salt particles sized 80 μm, the best seeding effect, with corresponding visibility of 380 m, can be achieved when the seeding amount is 30 g m~(-2).     

复杂地形城市多尺度气流对大气污染影响的研究进展

复杂地形城市一般建立在山地、丘陵、沿海地带。复杂地形下的大气污染传输、扩散机制是一个复杂的问题。本文依据城市地形地貌将复杂地形归类为河谷地形、三面环山临海地形、盆地地形、马蹄型地形和峡口地形。结合国内外对这五类地形下城市污染物传输扩散及污染形成机制的研究成果,介绍了不同地理位置、不同复杂地形城市多尺度气流相互或交替作用的特点及其对污染传输扩散的影响,期望能够为其它复杂地形城市污染形成机制研究和大气污染防治提供一些借鉴。     

一种基于重要性评估的河网分级方法

提出了一种改进的河网分级方法,该方法首先对河段的重要性程度进行评估,并利用树结构实现河网的拓扑关系;之后基于河段重要性指数筛选河网主干,并利用主干抽离算法对河网进行逐层遍历;最后基于遍历结果完成河网地层次划分。试验表明,新方法在算法性能和分级结果上均优于传统方法,因此,新方法能够更好地应用于实际的河网分级工作中。     

基于偏移四叉树投票的“大尺寸”点状符号多尺度无压盖可视化

为解决Web 2.0环境下点状符号地图混搭中的制图问题,本文研究并实现了一种可100%避免压盖的"大尺寸"点符号高效可视化方法。该方法的核心思想是四叉树网格单选,采用网格平移对多次单选结果投票来计算符号在各缩放级别的显著性等级,可解决符号在相邻网格的空间冲突。该过程不需要显式探测冲突,因而处理效率极高。随着地图放大,重要性较低的符号也逐级显现,实现了语义层次的多尺度表达。针对符号和网格大小比率关系、有效网格平移方案及图面利用率不足问题提出两种扩展:格网增选和多级符号叠加。对方法的可行性进行了试验验证,并分析了该方法在用户查询条件改变下的稳定性和不同数据量下的伸缩性(非优化实现可达到105量级数据的亚秒级处理)。     

顾及像面畸变的卫星视频稳像

卫星视频每帧影像外方位元素数值存在差别,相邻帧影像间的同名点在像面位置不同,且由于每帧影像均存在几何畸变,经典的帧间的投影变换模型、仿射变换模型等视频稳像的配准模型不能精确描述帧间的同名点关系。针对该问题,本文提出顾及像面畸变的卫星视频稳像算法,基于仿真的卫星视频,验证了该算法的可行性和精度。     

全球气候数据集生成及气候变化应用研究

科技部在"十三五"期间部署的国家重点研发计划"全球变化及应对"专项资助了"全球气候数据集生成及气候变化关键过程和要素监测"研究项目。项目围绕由全球气候观测系统提出的基本气候变量,完善地空天基观测体系,生成中国首套以遥感数据为主体的涵盖大气、海洋和陆表长时间序列、高精度、高时空一致性的产品,即气候数据集,动态监测全球变化关键过程和要素。