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报告分类:外文技术报告 所属行业:水利、环境和公共设施管理业

  • 251.大气辐射测量气候研究设施运营季度报告:2012年10月1日-12月31日

    [水利、环境和公共设施管理业] [2014-08-28]

    Individual datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research sites are collected and routed to the Data Management Facility (DMF) for processing in near-real-time. Instrument and processed data are then delivered approximately daily to the ARM Data Archive, where they are made freely available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Data Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year dating back to 1998.
    关键词:大气辐射;辐射测量;气候;数据库管理;数据采集
  • 252.自适应网格加密可压缩方程的有限元解决方案与应用大气模拟分析

    [水利、环境和公共设施管理业,信息传输、软件和信息技术服务业] [2014-08-28]

    The resolutions of interests in atmospheric simulations require prohibitively large computational resources. Adaptive mesh refinement (AMR) tries to mitigate this problem by putting high resolution in crucial areas of the domain. We investigate the performance of a tree-based AMR algorithm for the high order discontinuous Galerkin method on quadrilateral grids with non- conforming elements. We perform a detailed analysis of the cost of AMR by comparing this to uniform reference simulations of two standard atmospheric test cases: density current and rising thermal bubble. The analysis shows up to 15 times speed-up of the AMR simulations with the cost of mesh adaptation below 1of the total runtime. We pay particular attention to the implicit-explicit (IMEX) time integration methods and show that the ARK2 method is more robust with respect to dynamically adapting meshes than BDF2. Preliminary analysis of preconditioning reveals that it can be an important factor in the AMR overhead. The compiler optimizations provide signi cant runtime reduction and positively a ect the e ectiveness of AMR allowing for speed-ups greater than it would follow from the simple performance model.
    关键词:大气模式;可压缩流动; Euler方程;伽辽金法;算法;
  • 253.关于2005年飓风丽塔在雨带和辅助眼墙中生成对流位涡的评论

    [水利、环境和公共设施管理业] [2014-08-28]

    In a previous paper Judt and Chen propose that secondary eyewall formation can be the result of the accumulation of convectively generated potential vorticity in the rainbands. They argue that secondary potential vorticity maxima precede the development of the secondary wind maximum and conclude that vortex Rossby waves do not contribute to the formation of the secondary eyewall. Amidst examination of their thought-provoking study, some questions arose regarding their methodology, interpretation, and portrayal of previous literature. Here the authors inquire about aspects of the methodology for diagnosing vortex Rossby waves and assessing their impact on their simulation. Inaccuracies in the literature review are noted and further analysis of existing, three-dimensional, full-physics, numerical hurricane integrations that exhibit canonical secondary eyewalls are encouraged.
    关键词:对流(大气);飓风;雨;风;涡;雨带
  • 254.从高频湍流风量测量结果确定风能发电的平均有效值

    [水利、环境和公共设施管理业] [2014-08-28]

    Using weighted power means, as opposed to arithmetic means, for wind speed statistics is recognized as more relevant to predicting power production from wind turbines. Yet computer models used for hub height wind prediction output arithmetic means, due to the lack of accurate information on wind speed distributions generated by the turbulent flow. The following demonstrates methods used to calculate wind speed statistics using power means, generated from high-frequency (32 Hz) wind measurements, from turbulent flow in the vicinity of a wind turbine array. The dependence of errors, as a function of turbulence intensity, in power production forecasts resulting from the use of arithmetic instead of power means is presented.

    关键词:电;计算机模型;错误;预测;测量;大气
  • 255.使用C++计算大气条件(温度,压力,空气密度和声速)

    [信息传输、软件和信息技术服务业,水利、环境和公共设施管理业] [2014-08-28]

    This report presents a set of functions, written in C++, that can be used to calculate atmospheric conditions (temperature, pressure, air density, and speed of sound), as well as gravitational-field strength. The functions are based on the atmospheric model presented in U.S. Standard Atmosphere, 1976 (National Aeronautics and Space Administration. U.S. Standard Atmosphere, 1976; NASA-TM-X-74335; U.S. Government Printing Office: Washington, DC, October 1976).
    关键词:大气模型;密度;比重;压力;声音;温度;空气密度
  • 256.用于大气性能预测的校准过程中重新进入的大气数据系统(FADS)的设计与嵌入

    [水利、环境和公共设施管理业] [2014-08-28]

    In this effort was developed a high temperature 1-D solver to reconstruct the Longshot wind tunnel conditions. It supports calorically imperfect, thermally perfect flows in thermal equilibrium or non-equilibrium.
    关键词:飞行器;校准;热值;能量转移;嵌入式大气数据系统
  • 257.EMSL科学专题咨询小组研讨会:大气气溶胶化学,气候变化和空气质量

    [水利、环境和公共设施管理业] [2014-08-28]

    Environmental quality and climate change are major challenges facing our nation and the worldwith current and potential impacts in the near and distant future. Fundamental understanding of atmospheric processes and coupling between the atmosphere, oceans, and biosphere are needed to understand and predict the interactions between climate and environmental processes and energy production practices. This is critical for providing policy makers with accurate information needed to develop cost-effective strategies to monitor, control, mitigate, and adapt to a changing climate. Reducing uncertainties in key components necessary to understand the Earth's complex climate and environmental systems is an important scientific objective, as discussed in National Research Council and National Science Foundation reports and embraced by the Climate and Environmental Sciences Division (CESD) within the Department of Energy's Office of Biological and Environmental Research (DOE-BER). The Environmental Molecular Sciences Laboratory (EMSL), a DOE scientific user facility located in Richland, Washington, encourages and enables molecular-level research that leads to discovery and innovation which enhances the quality of life, now and for generations to come. Because of the growing recognition of atmospheric aerosol chemistry impacts on climate change, regional pollution, and weather patterns, EMSL conducted a Science Theme Advisory Panel (STAP) workshop focused on atmospheric aerosol chemistry. Thirty-eight scientists from 11 institutions participated in the workshop held on January 30, 2013. Workshop participants were asked to evaluate areas where understanding the chemical details and time evolution of aerosol formation and development, as well as their chemical and physical properties, could have the largest impact on the development of reliable process-level understanding of regional and global atmospheric climate models.
    关键词:大气化学;气溶胶;气候变化;空气质量;空气污染
  • 258.夏威夷上层海洋结构的一维和三维模拟观察比较

    [水利、环境和公共设施管理业] [2014-08-28]

    Local, one-dimensional (1-D) simulations of the upper-ocean structure observed at the Hawaii Ocean Time Series (HOTS) mooring located 100 km north of Oahu are compared with output from the operational Global NCOM ocean forecast system at the location of the mooring. The observations from the mooring indicate that the upper-ocean density structure and mixed-layer depth (MLD) in this area are significantly affected by the extensive eddy field that exists there. Local, 1-D simulations do not account for the modulation of the upper-ocean density structure by the eddies. However, Global NCOM, along with the data assimilation that it uses, provides a reasonably accurate simulation of the eddies and does a fairly good job of accounting for the effect of the eddies on the upper-ocean density structure and MLD. Comparison of atmospheric fields from NOGAPS, which are used by Global NCOM, with observations from the mooring show fairly good agreement, which contributes to the skill shown by Global NCOM in simulating the sea-surface temperature and MLD observed at the mooring.
    关键词:海洋模式;空气与水的相互作用;大气;表面混合层
  • 259.合作研究:利用高分辨率的区域北极气候系统模型对气候变化进行深入了解和预测

    [水利、环境和公共设施管理业] [2014-08-28]

    The motivation for this project was to advance the science of climate change and prediction in the Arctic region. Its primary goals were to (i) develop a state-of-the-art Regional Arctic Climate system Model (RACM) including high-resolution atmosphere, land, ocean, sea ice and land hydrology components and (ii) to perform extended numerical experiments using high performance computers to minimize uncertainties and fundamentally improve current predictions of climate change in the northern polar regions. These goals were realized first through evaluation studies of climate system components via one-way coupling experiments. Simulations were then used to examine the effects of advancements in climate component systems on their representation of main physics, time-mean fields and to understand variability signals at scales over many years. As such this research directly addressed some of the major science objectives of the BER Climate Change Research Division (CCRD) regarding the advancement of long-term climate prediction.
    关键词:气候变化;北极地区;预测;大气环流
  • 260.在波伊尔磨房路大桥及科本斯马里兰州弗雷德里克县的水量和沙量和密度

    [水利、环境和公共设施管理业] [2014-08-25]

    To assist in understanding sediment loadings and the management of water resources, a bathymetric survey was conducted in the part of Lake Linganore between Boyers Mill Road Bridge and Bens Branch in Frederick County, Maryland. The bathymetric survey was performed in January 2012 by the U.S. Geological Survey, in cooperation with the City of Frederick and Frederick County. A separate, but related, field effort to collect 18 sediment cores was conducted in March and April 2012. Depth and location data from the bathymetric survey and location data for the sediment cores were compiled and edited by using geographic information system (GIS) software. A three-dimensional triangulated irregular network (TIN) model of the lake bottom was created to calculate the volume of stored water in the reservoir. Large-scale topographic maps of the valley prior to inundation in 1972 were provided by the Frederick County Division of Utilities and Solid Waste Management and digitized for comparison with current (2012) conditions in order to calculate sediment volume. Cartographic representations of both water depth and sediment accumulation were produced, along with an accuracy assessment for the resulting bathymetric model. Vertical accuracies at the 95-percent confidence level for the collected data, the bathymetric surface model, and the bathymetric contour map were calculated to be 0.64 feet (ft), 1.77 ft, and 2.30 ft, respectively. A dry bulk sediment density was calculated for each of the 18 sediment cores collected during March and April 2012, and used to determine accumulated sediment mass.
    关键词:水资源;湖泊;水深;淤积;磷酸盐;固体废弃物
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