广西钦防海槽迁移与沉积-构造转换面

广西的钦州－防城－带，素以钦防海槽称之，系指加里东期构造运动后，扬子与华夏陆块间的“残留海”。其两侧为古隆所夹持，西为大明山古隆起，东为云开大山古隆起，其间划分为四个构造单元，由东向西依次为：博白坳陷，六万大山隆起，钦州坳陷和十万大山坳陷。现构造形迹的排列，反馈防海槽在早古生代至中生代间深海盆或浅海深水盆地在构造和沉积上有自东向西迁移的特点。晚古生代盆地迁移过程至少有八个沉积－构造转换面可记录盆地的构造演化：第1转换面为早奥陶世与晚寒武世间的沉积界面；第2转换面为早志留世与晚奥陶世间的沉积界面；第3转换面为早泥盆世早期与晚志留世间的海侵上超面；第4转换面为中泥盆世的海侵上超面；第5转换面为中二叠世与晚二叠世间的沉积界面；第6转换面为早三叠世的海侵面；第7转换面为中晚三叠世与早三叠世间的沉积界面；第8转换面为早侏罗世与晚三叠世间的沉积界面。前两个界面为盆山转换面，与华南加里东构造运动过程相耦合，为挤压的构造背景；第3界面为水下间断面，下泥盆统与上志留统为不连续沉积，在构造上应是挤压机制下的破裂不整合，也是加里东期构造运动的响应；第4界为海西期的海侵上超面，与盆地走滑拉张同步；第5界面则反馈于印支期造山的初始阶段，第6界面为中生代盆地迁移转换面；第7界面为印支期造山过程的盆地转换面；第8界面为燕山期造山造盆转换面。其转换面性质的转化，代表钦防海槽可能是个复杂大陆边缘前陆盆地演化史。     

成像干涉光谱仪信噪比分析

以Ｓａｇｎａｃ型成像干涉（傅里叶变换）光谱仪为例,详细推导了空间笛制型成像干涉光谱仪信噪比的一般表达式,分析了各种因素与信噪比之间的关系并得出了相应的结论。     

用小波变换提取雷达回波图像中的辐合特征线

采用小波变换的方法对滨州雷达资料的反射率图像进行处理,得到特征线增强后的图像,将其输入自动预报系统实现特征识别,可为雷暴预报提供初步资料。     

带有多道相关的抛物线Radon变换法分离P-P、P-SV波

因为多波多分量地震勘探中P-P波和P-SV波通常混杂在一起,所以较好地分离P-P波和P-SV波能够提高数据处理和解释的质量.抛物线Radon变换法在分离P-P波和P-SV波时取得了一定效果,但是在离散叠加的计算过程中会带来假频,这些假频会干扰波场分离.本文针对这一问题,将多道相关算法引入抛物线Radon变换,发展了带有多道相关的抛物线Radon变换法.该方法利用叠加信号具有相似性的特点,依据多道相关中衡量多道信号相似性的能量比标准,对叠加过程加以控制,压制变换中出现的假频.本文用该方法对合成地震记录进行了波场分离,取得了较好的效果.     

Study on ETKF-Based Initial Perturbation Scheme for GRAPES Global Ensemble Prediction

Initial perturbation scheme is one of the important problems for ensemble prediction. In this paper, ensemble initial perturbation scheme for Global/Regional Assimilation and PrEdiction System (GRAPES) global ensemble prediction is developed in terms of the ensemble transform Kalman filter (ETKF) method.A new GRAPES global ensemble prediction system (GEPS) is also constructed. The spherical simplex 14-member ensemble prediction experiments, using the simulated observation network and error characteristics of simulated observations and innovation-based in ation, are carried out for about two months. The structure characters and perturbation amplitudes of the ETKF initial perturbations and the perturbation growth characters are analyzed, and their qualities and abilities for the ensemble initial perturbations are given. The preliminary experimental results indicate that the ETKF-based GRAPES ensemble initial perturbations could identify main normal structures of analysis error variance and reflect the perturbation amplitudes.The initial perturbations and the spread are reasonable. The initial perturbation variance, which is approximately equal to the forecast error variance, is found to respond to changes in the observational spatial variations with simulated observational network density. The perturbations generated through the simplex method are also shown to exhibit a very high degree of consistency between initial analysis and short-range forecast perturbations. The appropriate growth and spread of ensemble perturbations can be maintained up to 96-h lead time. The statistical results for 52-day ensemble forecasts show that the forecast scores ofensemble average for the Northern Hemisphere are higher than that of the control forecast. Provided that using more ensemble members, a real-time observational network and a more appropriate inflation factor,better effects of the ETKF-based initial scheme should be shown.     

Coherent Structures Detected in Atmospheric Boundary-layer Turbulence using Wavelet transforms at Huaihe River Basin, China

The presence of coherent structures in turbulent shear flows suggests order in apparently random flows. These coherent structures play an important dynamical role in momentum and scalar transport. To develop dynamical models describing the evolution of such motion, it is necessary to detect and isolate the coherent structures from the background fluctuations. In this paper, we decomposed atmospheric turbulence time series into large-scale eddies, which include coherent structures and small eddies, which are stochastic by using Fourier digital filtering. The wavelet energy computed for the three components of the velocity fluctuations in the large-scale eddies appears to have local maximum values at certain time scales, which correspond to the scales or frequencies of coherent structures. We extract coherent signals from large-scale vortices at this scale by inverse wavelet transform formulae. This method provides an objective technique for examining the turbulence signal associated with coherent structures in the atmospheric boundary layer. The average duration of coherent structures in three directions based on Mexican hat wavelets are 33 s, 34 s and 25 s respectively. Symmetric andanti-symmetric wavelet basis functions give almost the same results. The main features of the structures during the day and night have little difference. The dimensionless durations for u, v and w have linear correlations with each other. These relationships are insensitive to the wavelet basis.     

多物理ETKF在暴雨集合预报中的初步应用

基于集合转换卡尔曼滤波（ETKF）的初值扰动方法是目前集合预报领域热点方法之一,但应用在短期集合预报中仍存在离散度不够、误差较大等问题。考虑到在区域短期集合预报中,模式不确定性和边界不确定性的影响不能忽略,本文尝试在ETKF生成分析扰动的过程中,同时考虑初值不确定性、物理不确定性与边界不确定性,进而构建多初值、多物理、多边界ETKF集合,并以2010年9月30日到10月8日海南岛特大暴雨作为研究个例,对其在暴雨集合预报中的应用展开初步研究,重点分析多种物理参数化过程对预报结果的影响。结果表明,多物理过程的ETKF（多物理ETKF）和单物理过程的ETKF（单一ETKF）均优于对照预报,多物理ETKF优势更加明显,其均方根误差、离散度等指标均得到很好的改善;对于降水采用SAL方法进行检验,发现多物理ETKF对于降水位置的预报有明显的改善,对于特大暴雨的强度预报也略有改善。研究表明,在ETKF初值扰动中加入多种物理过程,可以有效改善短期集合的离散度,提高预报准确率,有良好的发展前景和应用潜力。     

台风灾害综合等级评估模型及应用

选取全国范围内台风灾害中的农作物受灾面积、房屋倒损数、死亡人数、直接经济损失4个常用灾害指标,通过建立无量纲函数转换定义了全国范围内台风各个单项灾害指标的等级,并利用灰色关联度理论确定了全国范围内台风灾害综合等级划分标准,基于上述工作建立了台风灾害综合等级快速评估模型。利用此模型对2000-2007年登陆我国的台风灾害进行了评判与排序,分析结果较为合理。     

地震资料处理中小波函数的选取研究

本文给出了常见地震子波的一个模拟公式，可以很好地模拟零相位及混合相位子波，在一定意义上也可以近似模拟最大相位及最小相位子波．模拟出的子波加上适当的修正项后满足允许条件，可用作小波函数．与Ｍｏｒｌｅｔ小波类似，在实际应用中这些修正项在一定条件下可以略去，文中对Ｍｏｒｌｅｔ小波作了改造，使其能更好地适应于地震资料处理．研究了反射波能量及噪声等干扰波在时间－尺度域的分布特征与所选基本小波的关系．提出用地震子波（或与地震子波相近的函数）作为基本小波，对地震资料进行去噪及分频解释的方法．最后用实例证明方法的有效性．     

Tropical Cyclone Cloud Image Segmentation by the B-Spline Histogram with Multi-Scale Transforms

An efficient tropical cyclone(TC) cloud image segmentation method is proposed by combining the curvelet transform,the cubic B-Spline curve,and the continuous wavelet transform.In order to enhance the global and local contrast of the original TC cloud image,a second-generation discrete curvelet transform is implemented for the original TC cloud image.Based on our prior work,the low frequency components are enhanced by using an incomplete Beta transform and the genetic algorithm in the curvelet domain. The...