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山东省气象业务一体化平台（简称“一体化平台”）,是在气象业务系统集约化、自动化、智能化的建设要求下,为满足山东气象现代业务发展要求,解决山东气象业务运行中的诸多关键问题,利用互联网技术,面向山东全省天气预报业务设计研发的高度集约化的智能业务平台。一体化平台实现了基于内网 WebGIS 的气象数据渲染,基于 CIMISS、Oracle、Redis的三级数据库架构,基于 FTP、SMTP、传真服务器、阿里短信等技术的一键式发布引擎,基于 WebOffice的智能网格预报定制化气象服务,建立了山东短时和临近预报业务体系,融合了山东省气象部门近年来的多项科研成果。在此基础上实现了实况监测、短时临近预报、山洪预警、网格预报、产品制作发布、预报共享、预报检验和业务管理等功能。一体化平台支撑了 “省—市—县” 三级台站的天气预报业务和重大活动气象保障服务,提升了监测分析、短时和临近预警、决策服务能力。 相似文献
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《海洋气象学报》2019,(4)
灾害性天气的总结是研究其形成机理和变化规律的基础,也是提高预报预测准确率的有效途径,而决策气象服务是围绕天气变化进行的一项有中国特色的特殊服务,是政府部门科学决策的依据,工作对象的特殊性决定了天气预报预测能力需要不断提升和增强,决策气象服务技术需要不断改进和创新。通过对2018年全国灾害性天气特征和决策气象服务工作进行归纳、分析,并结合业务实际和未来发展,探讨性地提出改进措施,旨在建立灾害性天气和决策气象服务的内在联系,增强业务人员对天气变化规律的认知和对决策气象服务的深度理解,以预报发展推动服务水平提升,以服务需求促进预报技术提高,从而更好地发挥新形势下的决策参谋作用。 相似文献
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台风预报的准确性在风暴潮预报中起着重要作用。台风强度和路径的不确定性意味着使用集合模式来预报风暴潮。本文利用中央气象台的最优路径台风参数驱动国家海洋环境预报中心业务化的水动力学模型,开展华南沿海的风暴潮模拟,模式模拟结果与实测吻合较好。为了改进计算效率,采用CUDA Fortran 语言对模型进行了改造,改造后的模型在计算结果与原模型基本一致的基础上,计算时间缩短了99%以上。通过融合欧洲中期天气预报中心（ECWMF）的50条路径与3种可能台风强度构造出了150个台风事件,并用150个台风事件驱动改进的风暴潮数值模型,计算结果可以提供集合预报产品和概率预报产品。通过“山竹”台风风暴潮过程可以发现集合平均预报结果和概率预报结果与实测吻合较好。改进的数值模型可以运行普通工作站上,非常适合风暴潮集合预报,并且可以提供更好的决策产品。 相似文献
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利用山东122个国家级地面气象观测站2017—2021年中1—3月和11—12月“24 h降雪量p≥10.0 mm”的暴雪实况资料,采用二分类法、邻域空间检验法（以下简称“邻域法”）、时间偏移法和量级模糊法等4种方法对山东暴雪预报进行检验与对比。结果表明：（1）山东暴雪具有明显的时空分布特征,暴雪主要出现在半岛北部地区,鲁东南和半岛南部产生暴雪的概率最小;暴雪出现次数的年际变化和月际变化较大,最多年份出现98次,最少年份仅有5次,2月是高发月,占全年暴雪总次数的38.5%。（2）现行业务中应用最广泛的二分类法检验的预报命中率较低,其中24 h预报命中率仅为12.08%,主要原因是该方法受到空间、时间和量级的多重影响,不能精细准确地反映预报能力。（3）邻域法、时间偏移法和量级模糊法对24 h的暴雪预报命中率分别为14.40%、14.69%和30.05%;相较于二分类法,这3种检验方法的预报命中率均有较大幅度提高,空报率和漏报率均有较大幅度下降。（4）融合邻域法、时间偏移法和量级模糊法的综合检验法,能从空间、时间和量级3个维度区分出预报差异,检验结果更加精细准确,有利于引导预报员放下“检验评分低”的思想包袱,做出更加科学客观的预报,进一步提升预报服务效果。 相似文献
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基于观测和再分析数据的LSTM深度神经网络沿海风速预报应用研究 总被引：3，自引：1，他引：2
基于海洋气象历史观测资料和再分析数据等,利用LSTM深度神经网络方法,开展在有监督学习情况下的海面风场短时预报应用研究。以中国近海5个代表站为研究区域,通过气象台站观测数据和ERA-Interim 6 h再分析数据构建数据集。选取21个变量作为预报因子,分别构建两个LSTM深度神经网络框架(OBS_LSTM和ALL_LSTM)。经与2017年WRF模式6 h预报结果对比分析,得出如下结论:构建的两个LSTM风速预报模型可以大幅降低风速预报误差,RMSE分别降低了41.3%和38.8%,MAE平均降低了43.0%和40.0%;风速误差统计和极端大风分析发现,LSTM模型能够抓住地形、短时大风和台风等敏感信息,对于大风过程预报结果明显优于WRF模式;两种LSTM模型对比发现,ALL_LSTM模型风速预报误差最小,具有很好的稳定性和鲁棒性,OBS_LSTM模型应用范围更广泛。 相似文献
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海面高度异常是反映海洋环境状况的主要变量之一。本文使用1993—2019年的融合月均海面高度异常数据,建立了基于深度学习的海面高度异常预测神经网络模型,提出了基于融合U型网络(U-Net)和卷积长短记忆网络(ConvLSTM)的中长期海面高度异常预报模型。在研究海域0.25°×0.25°的空间分辨率下,模型测试集预报结果的均方根误差和平均绝对误差分别为0.039 m和0.027 m,均优于全连接LSTM预报模型和ConvLSTM+CNN预报模型,为大中尺度的海面高度异常预报提供了新的方法。 相似文献
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Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
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Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
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Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
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海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
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Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology, 相似文献
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Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献