初始场结构对台风路径影响的数值试验     

叶更新  马镜娴 《南京气象学院学报》1994,17(4):438-442

设计了一个套网格的准地转正压模式，对模式的可用性进行了检验。用该模式实施了两组不同初始场的试验，分析了初始场结构对台风路径的影响，指出台风移动具有内在随机性的特征。  相似文献   

Estimation　of　Winds　at　Different　Isobaric　Levels　Based　on　the　Observed　Winds　at　850　hPa　Level　Using　Double　Fourier　Series     

S. N. Bavadekar  R. M. Khaladkar 《大气科学进展》1994,11(3):327-334

ＥｓｔｉｍａｔｉｏｎｏｆＷｉｎｄｓａｔＤｉｆｆｅｒｅｎｔlｓｏｂａｒｉｃＬｅｖｅｌｓＢａｓｅｄｏｎｔｈｅＯｂｓｅｒｖｅｄ　Ｗｉｎｄｓａｔ８５０ｈＰａＬｅｖｅｌＵｓｉｎｇＤｏｕｂｌｅＦｏｕｒｉｅｒＳｅｒｉｅｓＳ．Ｎ．ＢａｖａｄｅｋａｒａｎｄＲ．Ｍ．Ｋｈ?..  相似文献   

Intercomparison campaign of vertical ozone profiles including electrochemical sondes of ECC and Brewer-Mast type and a ground based UV-differential absorption lidar     

M. Beekmann  G. Ancellet  G. Mégie  H. G. J. Smit  D. Kley 《Journal of Atmospheric Chemistry》1994,19(3):259-288

An intercomparison campaign was conducted at the Observatoire de Haute Provence (OHP) in Southern France in September 1989 in order to compare the three instruments used for vertical tropospheric ozone profiling in the European TOR (Tropospheric Ozone Research Project) network: balloon borne ECC and Brewer-Mast sondes and a ground based UV-DIAL (DifferentialAbsorptionLidar). Additionally, a stratospheric lidar system and the Dobson spectrophotometer of the OHP were operated. Seven simultaneously measured vertical ozone profiles gave evidence for systematic differences of 15% between both types of electrochemical sondes in the troposphere, the Brewer-Mast sondes reading the smaller ozone values. These differences might be explained on the one hand by a possible contamination of the ozone sensor with reducing substances, causing a negative bias mainly for Brewer-Mast sondes and, on the other hand, by the evolution of the sonde background current during the flight, causing a positive bias for ECC sondes and a negative bias for Brewer-Mast sondes. The tropospheric lidar system, measuring the vertical ozone distribution between 6 and 12–15 km, showed ozone concentrations intermediate between the sonde results. This is in good agreement with its estimated systematic error of better than 7% in the upper troposphere. In the stratosphere, the differences between electrochemical sondes and the lidar are between 5 and 10% before the normalisation with the total ozone values measured by the Dobson spectrophotometer, and always below 5% after. While the Dobson normalisation thus corrects rather well the stratospheric part of the sonde profile, it only partially reduces errors occurring in the troposphere.  相似文献   

利用卫星重力数据计算地球内部密度异常   总被引：5，自引：0，他引：5  

方剑 《地球物理学进展》1994,9(3):60-65

地球外部重力场是由地球内部物质分布决定的。本文利用ＲＡＰＰ８１１８０阶卫星重力位系数根据异常源埋深与重力位系数阶数的关系和重力场分离方法计算了经度为９０°Ｅ的地球密度异常剖面，得到了地球内部不同深度的密度异常结果，并初步作了地球物理解释．计算结果得到的深度为６５ｋｍ处的低密度异常带与地球模型的ＬＩＤ层和Ｃ层较为接近。  相似文献   

Application of numerical wave-propagation techniques to study local soil effects: The case of Benevento (Italy)     

D. Fäh  P. Suhadolc 《Pure and Applied Geophysics》1994,143(4):513-536

Many of the numerical techniques used for seismic zonation studies treat one-dimensional structural models and/or the incidence of plane polarized body waves. These techniques are often not adequate for laterally heterogeneous structures and for sources that are not located beneath the site of interest. In such cases a more rigorous treatment of the combined effects of the source, the path and the site response is needed. This can be accomplished with a hybrid approach combining modal summation and the finite-difference technique. To demonstrate the differences between these techniques, the ground motion in the city of Benevento (Italy) is modelled. We first compare the results obtained with one-and two-dimensional structural models for vertical incidence of plane polarized body waves. These results are then compared with those obtained with the hybrid approach for two-dimensional structural models.The comparisons have allowed us to find important differences in the response obtained with the different modelling techniques. For the same site, these differences consist of strong variations in amplitude and in the shape of the spectral amplifications. For a seismic source which is not located beneath the site, vertical incidence of waves significantly overestimates the local hazard in a laterally homogeneous structure. For a laterally heterogeneous area, we can conclude that one-dimensional modelling fails to estimate the seismic hazard, whereas for a seismic source which is not located beneath the site of interest, two-dimensional modelling with vertical incidence of plane polarized body waves may not allow reliable estimates to be made of the frequency bands at which amplifications occur. The results obtained for two-dimensional structural models are used for a zonation of the city of Benevento.  相似文献   

关于地壳垂直形变数据处理及分析的几个问题     

杨国华  王若柏 《四川地震》1994,(2):30-33

本文对目前地壳垂直形变的数据采集、使用、信息提取及解释的现状等进行了分析，指出了存在的一些缺陷或不足，同时也提出了一些有关的看法。如果这些问题得不到较好的解决，则必然会导致形变分析的混乱，以致于影响形变研究的深入。  相似文献   

地震前兆观测资料的分形处理方法     

陈棋福  马丽 《中国地震》1994,10(1):47-53

本文从自仿射分形的角度探讨地震兆汾观测资料的分形处理方法。在对自仿射分形的分维量测方法进行对比分析的基础上，给出了处理地震前兆观测资料较为适用的分形方法和满足计算需要的样本点数，从对部分水氡和地电阻率资料进行了处理分析中，得到了有益的启示：地震前兆时序观测资料可用分形方法处理分析，分维值可反映观测资料的结构变化特征，其作为一个无量纲量为综合对比分析各类前兆现象，探讨地震前兆场的复杂性特征提供了有效  相似文献   

Seismic ground motion in a layered half-space due to a Haskell-type source. I: Theory     

Andronikos P. Theoharis  George Deodatis   《Soil Dynamics and Earthquake Engineering》1994,13(4)

In this paper, closed-form analytic expressions for the frequency-wave number domain Fourier amplitudes of the displacement field at the free surface of a layered, anelastic half-space are established. The displacement field is caused by a seismic source described by a shear dislocation propagating with constant velocity over a rectangular fault (Haskell's model). Three-dimensional plane wave propagation is considered in the layered half-space using a propagator-based formalism. The wave radiation from the source is decoupled into P-SV and SH motions and the two problems are treated separately. First, analytic expressions are calculated for the displacement field at the free surface due to unidirectional unit impulses. Then, these expressions are used to compute solutions for the displacement field due to effective point sources associated with a pure strike slip and a pure dip slip. Finally, these solutions are combined and integrated over the rectangular fault area to establish closed-form analytic expressions of the total displacement field at the free surface.  相似文献   

Bayesian Attenuation Regressions: an Application to Mexico City   总被引：1，自引：0，他引：1  

M. Ordaz  S. K. Singh  A. Arciniega 《Geophysical Journal International》1994,117(2):335-344

  相似文献   

板块构造理论研究新进展   总被引：2，自引：0，他引：2  

金性春 《上海国土资源》1993,(2):9-16

本文评述了80年代以来板块构造理论的重要研究成果,就板块划分与板块运动学研究,大洋中脊与板块的扩张,活动边缘与板块的俯冲,板块再造和造山研究等方面的进展,展示板块构造的许多概念已更趋复杂化,板块构造理论变得更加成熟了。  相似文献