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本文基于2007—2018年Landsat系列遥感卫星数据开展田湾核电站温排水时空变化特征及其影响分析。采用辐射传输方程算法和劈窗算法对核电站周围海域的海表温度进行反演,通过星星匹配对反演温度的精度进行验证。匹配验证结果表明,反演的Landsat海表温度与MODIS海表温度产品具有较好的一致性,决定系数达到0.91。基于研究海域温度反演结果分析了核电站温排水面积的季节变化、年际变化和潮周期内变化特征,并且分析了潮汐与风场对温排水扩散的影响。结果表明,核电站周边海域各季节的温升区面积存在明显差异,春季最大,可达秋季的7倍;2007—2018年,随着装机容量的扩大,温排水面积不断扩大,2018年达到峰值,瞬时最大面积可达101.7 km2;潮汐对温排水扩散有影响,涨憩时刻温升区面积较落憩时刻大;有利风会促进温排水扩散,但影响有限。 相似文献
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全球导航卫星系统反射（Global Navigation Satellite System-Reflectometry,GNSS-R）技术是一种新兴的监测海平面高度变化的技术。本文依据GNSS-R技术中的信噪比分析法的原理,通过分析其分离趋势项和提取振荡频率的过程,建立了新的估测模型以提高反演精度。针对传统模型存在的信号分离不佳的问题,本文提出使用变分模态分解（Variational Mode Decomposition,VMD）算法替换传统的最小二乘拟合法（Least Squares Fitting, LSF）进行趋势项分量的分离。在此基础上,本文引入基于凯塞窗函数改进的LSP（Lomb-Scargle Periodogram）频谱分析法（记为WinLSP）来减弱因频谱泄露带来的反演误差。在瑞典翁萨拉的GTGU站和美国阿拉斯加州的SC02站开展的海平面高度反演实验结果表明,本文建立的估测模型相比于传统模型具有更高的反演精度。基于VMD+WinLSP估测模型得到的GTGU站反演结果的均方根误差（RMSE）、相关系数和反演点数分别为4.70 cm、0.98和5 647。与传统的LSF+LSP估测模型相比,反演精度和GNSS数据利用率分别提高了约29.7%和15.0%。SC02站的RMSE、相关系数和反演点数分别为14.34 cm、0.99和1 785,反演精度和GNSS数据利用率分别提高了约12.3%和9.4%。 相似文献
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大洋海区海-气CO_2通量单参数遥感算法的适用性检验 总被引：1，自引：0，他引：1
利用卫星遥感技术的优势,基于LDEO数据库的全球海表二氧化碳分压（PCO2）及海表温度（SST）等实测数据,初步建立东太平洋海区PCO2与SST的单参数经验算法,并采用相同区域的独立实测数据检验.结果表明,单参数算法在寡营养大洋海区具有良好的适用性,反演值与实测值之间的均方根误差（RMS）为0.51 Pa（1 Pa=9.869μatm）,由此估算出2003年6月该海域CO2通量为-1.4 mmol/（m2.d）,与实测估算的碳通量基本相符,能够很好地反映出海区CO2源汇特征.将该遥感算法运用到西大西洋海域（15°~25°N,60°~75°W）,反演值与实测值之间均方根误差（RMS）为0.69 Pa.检验结果表明,在寡营养大洋海区,单参数遥感算法具有一定的适用性,在受相似因子调控的同纬度海区可以使用同一遥感算法. 相似文献
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基于Argo浮标数据的星载微波辐射计Aquarius数据产品质量评估 总被引：3，自引：1，他引：2
Aquarius是专门用于海洋盐度监测的L波段辐射计,于2011年6月发射入轨,目前已进入业务化运行阶段。本文以太平洋为研究区域,利用Argo盐度现场数据对星载微波辐射计Aquarius的2012年2级数据产品质量进行了分析与讨论,结果表明:与Argo数据比较,Aquarius数据盐度存在0.1的负偏差,标准差约为0.7,升轨和降轨数据差异不明显;受亮温陆地污染和无线电射频干扰的影响,近岸海域反演误差较大;海面温度较高的低纬海域反演结果优于中纬度海域;受亮温敏感性及粗糙海面发射率模型的影响,Aquarius在低温水域以及高风速条件下盐度反演误差较大,标准差可达1以上。 相似文献
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介绍了一种将大气效应考虑在内、利用Landsat TM、ETM+热红外数据进行近海岸海表水温反演的单窗算法.在该算法中,将地表气温、相对湿度等常规气象资料作为初始参数,根据对流层中大气温度随高度呈线性降低、水汽随高度呈指数衰减的规律,建立了估算平均大气温度及水汽含量的通用模式.通过与实测数据及MODIS Terra海表水温产品比较发现,该算法能够提高运用TM/ETM+TIR单波段数据进行近岸海表水温(SST)反演的精度:一方面,反演所得结果更接近于海表实际水温;另一方面,它在一定程度上剔除大气中的水汽对SST反演的影响,进而提高海表水温的温度对比度.该提出的大气校正算法只需地表大气温度及相对湿度资料,该算法也无需进行大气模式的界定. 相似文献
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文章利用舟山近岸海域实测水体光谱及泥沙浓度数据，分析光谱反射率与悬浮泥沙浓度的相关性，并结合Landsat8遥感数据进行该海域的悬浮泥沙浓度遥感反演。研究表明：随着水体悬浮泥沙浓度的增加，各波段的反射率相应增加，且不同波段的增幅有明显不同，水体光谱曲线存在“双峰”现象；Landsat8遥感数据的波段4与波段3的比值与悬浮泥沙浓度的相关性较好；舟山群岛海域总体处于高泥沙浓度的状态，岛屿近岸悬浮泥沙浓度明显高于开阔水域，岛屿周围的悬浮泥沙浓度呈现“西高东低”的格局；一元二次方程模型（二次模型）对舟山海域水体的悬浮泥沙浓度反演精度较其他模型（线性模型，对数模型，指数模型，幂指数模型）高；Landsat8遥感数据可用于舟山海域悬浮泥沙浓度的监测。本研究成果能为近岸海域港口建设、航道安全、环境监测等研究提供数据支持。 相似文献
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一维综合孔径微波辐射计能够有效提高观测的空间分辨率，其观测入射角通常在0°~55°范围内变化。为了开发适用于一维综合孔径微波辐射计的海面温度反演算法，需要评估其观测亮温对海洋大气环境要素的敏感性。利用海面发射率模型和大气辐射传输模型，构建了适用于一维综合孔径微波辐射计的微波海洋大气辐射传输模式，研究了C波段垂直和水平极化微波辐射亮温在不同入射角下对海洋大气环境要素的敏感性变化情况，并定量计算了相应的敏感系数。结果表明:垂直和水平极化亮温对海洋大气环境要素的敏感性表现出不同的特性。随着入射角的增大，垂直极化亮温对海面温度的敏感性增强，对海面风场的敏感性相对减弱；水平极化亮温则相反。由大气水汽含量和云液态水含量误差引入的垂直和水平极化亮温误差随入射角增大而增大，但是，即使在55°的大入射角下垂直和水平极化亮温误差仍小于0.12 K。对于海面温度反演精度优于1 K的要求，一维综合孔径微波辐射计的测温精度需优于0.6 K。研究结果对于一维综合孔径微波辐射计海面温度反演算法的研究和载荷设计具有一定的理论指导意义。 相似文献
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总悬浮物浓度是海洋的重要水质参数之一,其对水体透明度、水下光场及初级生产力有显著影响,同时对河流入海口与海岸带冲淤变化过程有重要作用。本文基于我国自主研制的SDGSAT-1卫星遥感影像,使用准分析算法（Quasi-Analytical Algorithm,QAA）获取水体固有光学量,并结合2022年4月黄河口区域总悬浮物浓度实测数据,建立水体固有光学量与总悬浮物浓度实测数据的单波段、波段加减、波段比值,以及多波段组合等模型并开展遥感反演,最后将反演结果同实测数据及基于Sentinel-2B影像的总悬浮物浓度反演结果进行对比。研究结果表明：基于SDGSAT-1影像的总悬浮物浓度反演结果在黄河口高浓度区域的决定系数为0.622,均方根误差为7.94 mg/L;基于Sentinel-2B影像的总悬浮物浓度反演结果在黄河口高浓度区域的决定系数为0.589,均方根误差为8.27 mg/L。故在我国近岸海域总悬浮物浓度反演方面,SDGSAT-1影像反演精度与Sentinel-2B影像反演精度相媲美。 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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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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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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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