四维资料同化方法的特点分析和发展趋势

与反任意分布的观测值通过空间和时间插值分析到网格点的方法相比较，利用动力关系分析问题，其优势性十分明显，在一个能提供时间连续和动力耦合的模式预报方程中，有机地结合现在和过去的资料，即众所周知的四维资料同化。从目前经常应用的四维资料同化方法出发，详细分析了它们的特点和今后四维资料同化方法在预报模式中的应用前景。     

不规则区域面积的计算方法

本文提出了一种允许用于不等区间的广义辛普森1/3公式。广义辛普森(GS)公式是以拉格朗日三点插值多项式为基础推导出来的。而后提出计算任意偶数区问面积的复合GS公式,将其推广得到用于奇数区间情况下的推广公式,式中最后一个区间面积的计算是基于将边界形状做近似处理的二次多项式。此即为适用于偶数或奇数任意区间且不规则区域面积计算的方法,最后以实例加以说明。     

温州港台风暴潮高潮最大增水分析和预报

本文统计分析了温州港台风暴潮的情况，着重分析预报登陆型台风在登陆前和登陆后高潮时温州港的增水，并分析了海上转向型台风在高潮时的最大增水。通过统计相关建立起相应的预报公式，为温州港台风暴潮预报提供一定依据。     

台风风暴潮极值高潮位的统计预报

本文通过分析前期高潮位、台风参数与极值高潮位的关系，建立了一个包括台风中心气压、局地风速、前期高潮位的三元线性回归的极值高潮位预报公式，并考虑到同一参数对极值高潮位不同时刻的影响，引进权函数，在此基础上，实现了回归计算和极值高潮位预报的计算机自动化。在实时预报中，只需输入台风参数，即可得到极值高潮位值。     

2002～2003年冬季渤海的冰情及预报

本文简要地分析了2002～2003年冬季渤海冰情特征，将海冰数值预报模式与传统的中长期海冰统计预报有机地结合起来，有效地提高了海冰预报精度，初步形成预报时效互补、点面结合、预报产品多样化、预报传递网络化的业务化海冰预报系统，满足不同用户和社会的需求，在防冰减灾工作中提高了经济和社会效益。     

重力异常垂向一阶导数的一种简便算法

利用拉格朗日插值导出了重力异常垂向一阶导数的计算公式，给出了地面以及地面之上不同高度的求导系数。该公式可以计算地面上的重力垂向一阶导数，还可以直接计算地面之上任意高度上的垂向一阶导数。鉴于该公式除系数不同外，与上延公式完全相同，因此，程序设计尤为简单。使用本公式对模型数据和实际资料进行了处理，证明了本算法的实用性。     

北印度洋海浪背景误差分析和同化预报初步评估

基于背景误差分析中的观测法,利用Jason-1卫星高度计沿轨有效波高数据并结合Wave Watch Ⅲ海浪模式预报结果,进行北印度洋海域海浪背景误差分析,得到海浪场背景误差方差和各向同性假设下背景误差相关长度的时空分布特征。按经验函数拟合该海域有效波高背景误差协方差时总残差平方和最小的原则给出了更为适用于该海域的描述公式。在上述工作基础上,采用最优插值同化方法将Jason-1和Jason-2卫星高度计有效波高数据连续同化到海浪模式Wave Watch Ⅲ,按业务化标准对2013年1月北印度洋海域的海浪场进行了同化预报试验,经浮标数据检验发现同化可使海浪24 h预报得到明显改进。     

基于BP神经网络的高频地波雷达海流空间插值

高频地波雷达是海洋环境监测的重要手段，当前已经实现对海流的业务化观测，但是外部因素常引起海流空间探测的不连续性。为解决此问题，尽量保障区域数据的完整性和准确性，本文将BP神经网络技术与空间插值相结合，建立了海流的BP神经网络插值模型，并进行了针对实测数据的缺失插值仿真，通过与反距离权重法和线性插值法插值结果的对比，分析该模型在区域海流大面积缺失、流速整体较大和流速整体较小3个方面的性能。结果表明，BP神经网络插值模型的海流预测效果明显优于其他两种方法，且在流场数据大范围缺失下也取得了良好的效果。     

基于随机分形插值实现地震道伪测井曲线反演

在随机分形理论研究的基础上,将随机分形插值用于实现地震道与测井曲线的联合反演.通过比较分析,研究并给出测井曲线随机分形插值的有效公式,探讨并框定地震道与测井曲线联合反演策略和流程,并进行实例应用分析,最终较好实现地震道的伪测井曲线反演.研究表明随机分形插值方法巧妙地将地震和测井曲线进行联合反演,利用分形参数的空间插值,试图将地震道转化为测井曲线,思路和实现策略均体现独特性,是1种适于描述纵向非均质模型的地震资料测井曲线反演方法,具有可行性和应用前景.     

重力异常垂直梯度中央区效应的精密计算

为提高利用重力异常计算重力异常垂直梯度中央区效应的精度,视中央区为矩形域,将重力异常表示成双三次多项式插值形式,引入非奇异变换,推导出了重力异常垂直梯度中央区效应的精密计算公式。以低纬度区域分辨率为2＇×2＇的重力异常数据为背景场进行了仿真分析,结果表明在解算计算点所在的1个网格的中央区效应时,传统公式与本文导出公式计算结果差值的最大值达数E。该导出公式可为重力异常垂直梯度中央区效应的精密计算提供理论依据。     

Mapping Submerged Aquatic Vegetation with GIS in the Caloosahatchee Estuary: Evaluation of Different Interpolation Methods

This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision.     

Mapping Submerged Aquatic Vegetation with GIS in the Caloosahatchee Estuary: Evaluation of Different Interpolation Methods

This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision.     

海洋资料整理中一种单调分段插值方法的应用

以三次Hermite插值函数和另二类初等形式的函数为基础所构造的一种混合型分段插值函数进行海洋资料整理中的插值和绘线处理，结果更加合理。特别对具有累加或统计性质的数据，不但给出光滑的插值函数及其图形，而且还能给出大部分光滑的导函数图形。本文同时介绍了上述方法在不同专业领域中的一些应用实例。     

基于GIS空间分析的海底表层沉积物粒度分布特征插值研究

为了对比研究不同空间插值方法在沉积物粒度空间分布表述上的精度及适用性,在2004年11月荣成宁津小型海湾-黑泥湾综合调查的基础上,探讨了表层沉积物粒度参数的空间插值,比较了IDW(反距离加权法)、Kriging(克里金插值法)、Spline(样条插值法)与NN(自然邻域法)4种GIS空间分析方法的特征、差异及实效性,并对影响插值结果准确性的因素进行分析。结果显示,在黑泥湾表层沉积物粒度结果的空间插值计算中,从插值准确性和空间表达能力两方面考虑,IDW,Spline,Kriging和NN中以IDW法较为适宜,但要考虑到"牛眼效应"的出现会与局部实际情况存在差异;Kriging法和NN法的插值结果准确性较高,但其空间表达能力稍逊;Spline法在近岸带表层沉积物粒度特征插值中的应用性相对较差。海洋调查要素空间分布的内在规律性是控制插值结果的主要因素,表层沉积物分布以长期稳定的潮流、地形特征为主导因素,呈现由岸向海条带状分布的特征。数据均匀分布区域的插值结果要优于边界区和突变区;另外,在选取的3个观察尺度上,不同插值方法的误差均与野外取样网格间距呈显著线性正相关。     

ARGO data assimilation into the ocean dynamics model with high spatial resolution using Ensemble Optimal Interpolation (EnOI)

The article proposes parallel implementation of the Ensemble Optimal Interpolation (EnOI) data assimilation (DA) method in eddy-resolving World Ocean circulation model. The results of DA experiments in North Atlantic with ARGO drifters are compared with the multivariate optimal interpolation (MVOI) DA scheme. The sensitivity of the model error, i.e., the difference between the model and observations depending on the number of ensemble elements, is also assessed and presented. The effectiveness of this method over the MVOI scheme is confirmed. The model outputs with and without assimilation are also compared with independent sea surface temperature data from ARMOR 3d.     

A solution for the correct interpolation of data across regions with abrupt changes in tidal phase-lag

This paper provides an explanation of an automated solution for correctly interpolating phase-lags across abrupt boundaries. Although an automated solution to this problem has existed for several years, this is not commonly known and so many researchers continue to perform corrections manually. Interpolation errors commonly occur when tidal propagation surfaces are generated for regimes with amphidromic points. General correction methods are manual, clunky and prone to operator error. The problem can be solved by applying a simple method to scalarize the phase-lag vectors pre-interpolation. This approach successfully and automatically generates correct tidal phase-lag interpolation values and may be applied to any surface mapping software used to interpolate phase-lags.     

Evolving a Bayesian network model with information flow for time series interpolation of multiple ocean variables

Based on Bayesian network (BN) and information flow (IF), a new machine learning-based model named IFBN is put forward to interpolate missing time series of multiple ocean variables. An improved BN structural learning algorithm with IF is designed to mine causal relationships among ocean variables to build network structure. Nondirectional inference mechanism of BN is applied to achieve the synchronous interpolation of multiple missing time series. With the IFBN, all ocean variables are placed in a causal network visually, making full use of information about related variables to fill missing data. More importantly, the synchronous interpolation of multiple variables can avoid model retraining when interpolative objects change. Interpolation experiments show that IFBN has even better interpolation accuracy, effectiveness and stability than existing methods.     

顾及垂线偏差的重力大地水准面差距内插法

指出传统距离加权内插法的不足,推导了垂线偏差同大地水准面差距偏导数的转换公式,在此基础上利用间接平差模型得到了顾及垂线偏差的重力大地水准面差距内插法,改进了传统距离加权平均法。