江苏高邮地震台地磁变化与地震关系的初探

分析了江苏高邮地磁台1980年至2002年地磁垂直分量日变幅逐日比值的高值异常与江苏及邻区ML5．0以上地震之间的关系，发现它们之间有良好的对应关系，通过分析地磁垂直分量谐波幅度的逐日比，提出了适用于高邮地磁台的地震分析预报参数，并对其内检预报效能进行了评价。     

地磁场与气候变化关系的新探索

对地磁场与气候变化的统计研究早已表明，二者有很好的相关关系。本文的目的是对它们的关系给出一种可能的物理解释。利用近600年的地磁场模型资料和全球平均温度序列分析了两者变化的关系，发现它们有很好的对应，且地磁场变化超前于全球气温变化。从地磁场的变化来看，21世纪初全球变暖的趋势应该减缓。文中对地表浅层热场（地热带、火山和地温场）的分布特征与地球内部软流圈－岩石圈边界上焦耳热场的分布特征进行了对比分析。结果表明，地表浅层热场与地球深层焦耳热的分布有很好的对应关系，这可能暗示地表浅层热场是地球深层焦耳热的反映，地磁场通过焦耳热的不断释旋影响气候变化。     

唐山7.8级地震前地磁异常的综合分析

利用昌黎等台的磁测资料,并用多种方法进行综合分析,结果显示,在震前出现了约3个月的短期异常,这对于地震的预测预报有一定意义。     

地磁匹配特征量的选择

论文旨在选择合适的地磁特征量用于匹配制导.从地磁匹配的实际要求出发,提出了选择匹配特征量时应重点考虑的几个因素,通过理论分析初步拟定了选取准则,并针对特定区域,依据IGRF(International Geomagnetic Reference Field)和WMM(World Magnetic Model)计算出的地磁数据,结合选取准则进行了综合分析,给出了初选结果,对地磁匹配基准图的制备、实时图的获取、匹配算法的研究,以及地磁场资源应用于其他领域的相关研究有一定的借鉴意义.     

Regional conductance map of Andaman and Nicobar region

To image the electrical conductivity distribution, fluxgate magnetometers are operated at five sites in Andaman and Nicobar region. Transfer functions are estimated for the period range 8–128 min, from nighttime transient geomagnetic variations, using robust regression analysis. The observed induction arrows in Andaman Islands are found to point towards east despite deep sea located towards its west. This indicates that fore-arc basin (Andaman–Nicobar deep) is more conducting than the region of outer non-volcanic Island arc.Thin sheet model requires the conductance of 10,000–35,000 S (with increase conductivity towards the south) for explaining the observed induction pattern. The observed induction pattern at Andaman–Nicobar stations can be explained in terms of high conducting Cretaceous–Tertiary sediments filling the Andaman–Nicobar deep. High conductivity over Invisible bank has been attributed to the partial melts/volatile fluids derived from the subducting Indian plate that are intruding into the eastern margin of fore-arc basin through the West Andaman Fault (WAF).The induction pattern at Great Nicobar station (Campbell Bay) may be related to the highly conducting sediments filling the Mergui basin along with mafic intrusions. Also crustal transition occurs below the Mergui Terrace at the Malayan coast contributing to the enhanced conductivity anomaly.     

Some thoughts on pulsation and binarity

Intensive monitoring of main-sequence stars for pulsational studies continuously reveals new binaries and multiple systems. The resulting extensive data sets lead to exact orbital parameters, and to accurate masses of the components. This is also the case higher up the main sequence, though less frequently. We discuss a few examples where intensive observational efforts are necessary in order to improve our knowledge of the pulsational behaviour in the upper main-sequence instability domains, but we emphasize that observational efforts alone that turn out more and more of the same type of data, are by far insufficient, and that there is urgent need for theoretical developments. Determination of highly accurate stellar parameters is of paramount importance and is much more needed than time-series observations.     

Geo-effectiveness of solar wind extremes

Examples of extreme events of solar wind and their effect on geomagnetic conditions are discussed here. It is found that there are two regimes of high speed solar wind streams with a threshold of ∼ 850 km s^-1. Geomagnetic activity enhancement rate (GAER) is defined as an average increase in Ap value per unit average increase in the peak solar wind velocity (Vp) during the stream. GAER was found to be different in the two regimes of high speed streams with +ve and-ve IMF. GAER is 0.73 and 0.53 for solar wind streams with +ve and -ve IMF respectively for the extremely high speed streams (< 850 km s^-1). This indicates that streams above the threshold speed with +ve IMF are 1.4 times more effective in enhancing geomagnetic activity than those with -ve IMF. However, the high speed streams below the threshold with -ve IMF are 1.1 times more effective in enhancing geomagnetic activity than those with +ve IMF. The violent solar activity period (October–November 2003) of cycle 23 presents a very special case during which many severe and strong effects were seen in the environment of the Earth and other planets; however, the z-component of IMF (Bz) is mostly positive during this period. The most severe geomagnetic storm of this cycle occurred when Bz was positive.     

Non-local impact of large-scale engineering in harbors and gulfs on the environment

A system of numerical tools to predict the non-local long-term impact of large-scale constructions on the environment is described. The predictions have to be results of successive examination of free water oscillations, turbulent boundary layers on the sea bottom, and turbulent pulsation effects on sediment transport. Numerical results related to free water oscillations in diverse gulfs are shown, and non-local effects of the dam construction are found for an example of the Baltic Sea. Feasibility of suggested tools for turbulent flow is manifested.     

Convection with heat flux prescribed on the boundaries of the system. I. The effect of temperature dependence of material properties

Abstract

We study the bifurcation to steady two-dimensional convection with the heat flux prescribed on the fluid boundaries. The fluid is weakly non-Boussinesq on account of a slight temperature dependence of its material properties. Using expansions in the spirit of shallow water theory based on the preference for large horizontal scales in fixed flux convection, we derive an evolution equation for the horizontal structure of convective cells. In the steady state, this reduces to a simple nonlinear ordinary differential equation. When the horizontal scales of the cells exceed a certain critical size, the bifurcation to steady convection is subcritical and the degree of subcriticality increases with increasing cell size.     

关于气候系统与地球系统的若干思考

分析了地球系统的基本特征和地球系统的能源和运转方式,指出地热涡和地冷涡是地面气候系统的重要成员. 利用全球地磁场资料,研究了地球内部焦耳热的分布和演变规律,结果表明:全球地磁场的变化与全球气温的变化有密切联系,而且焦耳热场的分布与地热带、火山分布、全球最大降水量带有很好的对应. 因此,要对气候变化有一个全面的认识,必须研究整个地球系统.