首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The Matuyama/Brunhes polarity boundary (MBPB) is recorded in Chinese loess L8, which is associated with the glacial period. It is proved that loess L8 is capable of recording earth’s secular variation, and the lock-in depth in Chinese loess is no more than that of marine sediments. Comparison with the location of MBPB in Chinese loess and marine sediments, it is put forward that there is a recording phase lag between ocean and continent climate changes.  相似文献   

2.
A record of “double dawn” at State Zheng in the first year of the reign of King Yi in Western Zhou Dynasty in the chronicle “Bamboo Annals” (Zhushu Jinian) is discussed. We think that it may be a record of an annular solar eclipse happening in 899 BC. The record and the †T, which describes the secular variation of the earth’s rotation, are analyzed and discussed.  相似文献   

3.
地球自转对大气海洋运动的响应   总被引:1,自引:0,他引:1  
分析了地球自转的年际变化和异常变化,说明它们与热带太平洋的大气、海洋大尺度范围的年际变化——厄尔尼诺(ElNio)事件相当一致,而地球自转的异常变慢稍迟后于厄尔尼诺事件.可能由于伴随着厄尔尼诺事件大气角动量异常增加,引起了地球自转的变慢.可用天文测时资料的归算,监视日长年际变化的极小值,来预测厄尔尼诺事件的发生.  相似文献   

4.
Link between the geomagnetic polarity reversal and global-geology events   总被引:1,自引:0,他引:1  
The origin of the earth’s magnetic field is one of the five most important unsolved problems in physics, especially geomagnetic polarity reversal remains one of Nature’s most enigmatic phenomena. It is proposed that the geomagnetic polarity reversal links with some global-geology events, although it is difficult to clarify the mechanism of this correlation. The history of continental structures in eastern China would be also linked with some global-geology events.  相似文献   

5.
空间大地测量以高精度,高时空分辨率测定地球整体(地球自转)和各圈层(特别是大气,海洋与地壳)的运动,使地球动态变化的监测,研究及应用呈现了崭新的面貌,本文介绍了近年来国际地球动力学最新发展概况,内容包括地壳运动,地球自转,重力场时间变化等。  相似文献   

6.
The main geomagnetic field models of IGRF1900---2000 are used to study the latitude-dependence of the westward drift in the main field. The results show that the latitude-dependence exists in the magnetic components with different wavelengths (m=l-10). The globai-average westward drift rate of the component of m=l is 0.189°/a with the maximum of 0.295°/a at latitudes 40°-45°. The component of m=2 has an average drift rate of 0.411°/a with the maximum of 1.305°/a at latitude -60°. As for the components with further shorter wavelengths, the drift is generally restricted in a limited latitude range, and has many smaller drift rates. This latitude-dependence of westward drift can not be explained by rigid rotation of the earth's core. The results of this note also show that there is a negative dispersion in the westward drift, namely the components of long wavelengths drift faster than those of short wavelengths.This dispersion feature is not in agreement with Hide's MHD model. It is likely needed to find a new mechanism for explaining the observed feature of dispersion.  相似文献   

7.
根据宋晓东等的地球内核差异旋转研究成果,提出“月球轨道运动改变地球各圈层角动量”的物理模型。太阳系星球(尤其是木星)在轨道运行过程中对月球的摄动会影响月球的轨道运动,月球轨道运动会改变地球各圈层角动量,在形成地核差异旋转的同时,也使地球液核远月半球的角动量与近月半球的角动量存在巨大落差,造成地轴的晃动,激发地球的钱德勒极移。  相似文献   

8.
Based on the prerequisite that the earliest acid rock formed because of the initial global expanding tectonic processes, by combining it with other geological limitation conditions, and starting from the lithosphere elastic mechanics, the following is defined: the earth expansion started at about 4300 Ma ago, the average increasing rate of the earth radius is 0.40 mm/a, the initial expanding earth radius is 4651 km, and the initial global expansion of tectonic processes happened at 4183.7 Ma ago. From the natural and attenuation evolution condition of the earth and terrestrial planets, through the limit condition got from the combination of the mathematics logic and the geological significance, the limited expanding earth evolution model is established as follows: in whichR 0= 4.651×106 m,A =1.86×106 m, β = -6.01×10−10/ a andt s=3×108 a. From this model the maximum radiusR maxof the limited expanding earth evolution should be 6511 km. The earth’s radius increasing rate is about 0.1 mm/a at present.  相似文献   

9.
A floating dust weather happened on March 11–12, 1995 over the Qingdao region. Its source’s and throughput to the ocean were studied. The result indicated that the floating dust was caused by the dust storm that started in northwestern China and developed in northern China. 21 × 106t fine soil particles were carried to the ocean during the episode.  相似文献   

10.
Validating global hydrological models by ground and space gravimetry   总被引:1,自引:0,他引:1  
The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth’s tides and variations in the Earth’s rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water...  相似文献   

11.
Assessing the meridional atmosphere and ocean energy transport is one of the most classical problems in climate research.The meridional energy transport plays a critical role in maintaining the equilibrium of the earth system.Although the principle to calculate the meridional energy transport is simple,many fundamental questions remain unsolved.For example,what are the intrinsic mechanisms to maintain the hemispherically antisymmetric structure in the total energy transport? How on earth does the meridional energy transport partition between the atmosphere and ocean and,is there really a so-called "Bjerknes compensation" relationship between them? This relationship would provide us deep insight into the coupling mechanisms between the ocean and atmosphere in global scale.In this review we try to come out some important problems that are deserved in-depth investigations in current climate studies.  相似文献   

12.
The energy budget in the system of the earth, atmosphere and ocean conforms to the first law of thermodynamics, namely the law of conservation of energy, and it is balanced when the system is in a steady-state condition. However, the entropy budget following the second law of thermodynamics is unbalanced. In this paper, we deduce the expressions of entropy flux and re-estimate the earth, atmosphere and ocean annual mean entropy budget with the updated climatologically global mean energy budget and the climatologically air-sea flux data. The calculated results show that the earth system obtains a net influx of negative entropy (-1179.3 mWm-2K-1) from its surroundings, and the atmosphere and the ocean systems obtain a net input of negative entropy at about -537.4 mWm-2K-1 and -555.6 mWm-2K-1, respectively. Calculations of the entropy budget can provide some guidance for further understanding the spatial-temporal change of the local entropy flux, and the entropy production resulting from all kinds of irreversible processes inside these systems.  相似文献   

13.
将地球的潮汐力分解为两个分力 FC1,FC2 ,在黄道坐标系内分别讨论其连续性特征 ,针对各分力振幅的连续性俯视特征 ,映射出各潮汐分力的全球性特征分布 ,进而讨论了各个特征曲线交点的属性 ;在直角坐标系内研究了海潮等振幅曲线的表示方法 ,论述了潮汐振幅极大点在地球公转过程中的位置变化 ,及在自转过程中的时间、地点变化特点 .最后指出 :1由潮汐分力导致潮汐波的振幅具有对称性 ;2潮汐等振幅线为环形线 ;3海潮极大点的绝对振幅主要受所在海域的海水质量控制 ;4大气、地幔潮汐振幅的连续性特点与海潮具有相似性 .  相似文献   

14.
Whether the platinum group elements (PGE) can be taken as the indicators of extraterrestrial materials is a very important and interesting scientific problem. It is discussed on the basis of systematic investigation and study of a great amount of related literature. The following conclusions can be obtained: (ⅰ) extraterrestrial impact event can cause the PGE anomaly; conversely, the PGE anomaly may not represent the existence of extraterrestrial impact event, because the PGE anomaly can be caused by many terrestrial events (e.g. volcanic activity); (ⅱ) the PGE anomaly, especially the global PGE anomaly can inspire us to think it from extraterrestrial event, but it may not be as useful as previously thought as unambiguous identifiers of large extraterrestrial impact event in the earth's history.  相似文献   

15.
Periodicity of Holocene climatic variations in the Huguangyan Maar Lake   总被引:7,自引:0,他引:7  
There exist five primary periods of 2 930, 1 140, 490, 250 and 220 a in the Holocene climatic variations in the Huguangyan Maar Lake, according to the energy-spectrum and filter analyses of high-resolution time sequences (10–15 a) of the sediment dry density. The peak values of the three temperature-decreasing periods with the 2 930 a cycle occur at about 7 300, 4 250 and 1 200 Cal. aBP. There are 7–8 temperature-decreasing periods with the 1 140 a cycle, and the climate fluctuation range is largest in the early Holocene, and reduces gradually in the middle and late Holocene. The millennial-scale climatic change in the Holocene may adjust the global water cycle and the thermohaline circulation intensity through the harmonic tones of the earth’s precession cycle, which in turn influences the global climate change.  相似文献   

16.
鉴于近10多年来运用地球转速的变化做长期灾害天气预测取得的较好效果,试图运用地球的章动、地球转速和大气变化的关系,探索 重大灾害天气的深层次原因。仅就2006年发生在四川、重庆的高温干旱问题,讨论了副热带高压与东风层的关系,进而对地球的章动、转速的 变化做了对比分析。结果显示,地球大气的重要灾害天气的发生,不只限于大气本身的原因,而确有可用于天气预测的星体运行的变化信息。  相似文献   

17.
Compressional wave velocities in a trachybasalt, from Yichuan County, Henan Province, have been measured at 2.0 GPa and up to 1 350℃ in a YJ-3000 t cubic-anvil high-pressure apparatus. The run products have been gained at the same pressure but different temperatures, the observation of the thin sections of the run products indicates that, corresponding to the variation of the compressional wave velocity in the trachybasalt, the phase transition has taken place. The relationship between the change of the compressional wave velocity and the hydrous mineral dehydration, solid-solid phase transformation and partial melting has been discussed. The experimental data presented here are of great importance to elucidating the geological process in the earth's interior.  相似文献   

18.
The deep reason of severe disaster weather with the relationship among the earth nutation, rotation and atmos- pheric change is explored based on the effective results about the disaster weather prediction of the long term made by the variation of the earth rotation in near 10 years. It is discussed the relationship between the subtropical anticyclone and subtropical easterlies to aim at the problem of high temperature and drought in the globe, further more, the comparison analysis has been made to the earth nutation and the variation of rotation. The research results show that the reasons of severe disaster weather not only are due to atmosphere itself, but have some variation information of earth movement which could be used for the weather forecast.  相似文献   

19.
东亚季风区气候和生态系统相互作用的诊断和模拟研究   总被引:16,自引:0,他引:16  
大气圈和生物圈的相互作用是连接地球系统中生命世界和无生命世界的重要过程之一,也是地球环境变化中一个最基本的过程。通过卫星遥感植被和地表覆盖信息与气候要素关系的诊断分析以及生态和气候模式的数值模拟,揭示了东亚季风区气候和生态系统相互作用的基本特征,包括季节、年际和长期的季风气候变化对生态系统的影响和大范围植被覆盖状况的变化对季风气候的影响。结果表明,东亚季风区与气候与生态系统相互作用最为强烈的地区之一,这里陆地生态系统的时空变率表现出明显的对季风气候的响应特征;另一方面,人类活动引起的大范围植被覆盖状况的变化可以对季风气候产生显的反馈影响,它们是叠加在季风系统自然变率之上的一种重要变化。同时,虚拟试验表明,通过有序的人类活动,因地制宜,合理利用土地资源,保护和恢复自然植被,可以产生明显的气候和环境效应。  相似文献   

20.
The paleoenvironment indicated by the geochronology, major oxides SiO2, Al2O3 and TOFE (Fe2O3 + FeO), and CIA (Chemical Index of Alteration) value of the red earth and brown-yellow silt primarily characterized by the Linjiang stratigraphic section, based on the geological investigation of Late Quaternary along the river banks of northeastern part of China's Guangdong Province, south to the Nanling Mountains, allow us to hypothesize that the red earth on the first terrace in northeastern part of Guangdong belongs to reticulated red clay developed in a hot-wet environment of the last interglacial period (132-73 ka BP), similar to the monsoon environment in the northern margin of modern tropical zone, while the overlying brown-yellow silt layer mainly accumulated in a monsoon environment of warm temperate zone in the last glacial period (73-11 ka BP), with the aeolian sand LJ3 representing an extreme period of worsening climate. Such a hypothesis corresponds well with predecessors' research on the paleoenvironment indicated by abundant fossils in both south and east to the Nanling Mountains. Hence, it follows that the bioclimatic zone did experience a large and rapid vicissitude in northeastern part of China's Guangdong Province, and even in the full extent of the region south to the Nanling Mountains from the last interglacial period to the last glacial period, with the red earth being replaced by the brown-yellow silty sediment, and even maybe with the Ailuropoda-Stegodon Fauna being replaced by the Penghu Fauna. This study may provide an important geological demonstration for the environmental response to global change in China's low latitudes on a 10 ka scale.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号