地球轨道偏心率40万年和10万年周期的行星驱动

本文在创建行星会合指数(K)运动学方程,并获得太阳绕太阳系质心绕转具有约22年周期的基础上,试从行星摄动对地球轨道偏心率(e)影响出发.分析了行星系统中对地球引力最大的地外行星-木星和引力其次的地内行星-金星的轨道拱线与地球轨道拱线的会合周期,发现木星可造成e具有40万年周期性变化,而金星可造成e具有10万年周期性变化.     

地球自转角速度长周期变化对太阳轨道运动特征的一种响应机制

地球自转角速度的季节性和年变化的成因已达成基本共识,但更长时间尺度的周期性变化成因尚无定论,它们或归因于太阳活动、日月引潮力、地壳反弹、大气圈波动或行星摄动的影响等.直至目前,地球自转变化的规律和机制还没有完全弄清楚.研究发现:根据行星会合指数(K)标定太阳轨道运动特征的方法是可行的.通过对行星会合指数(K)的FFT检测发现太阳轨道运动周期与前人研究的地球自转日长(LOD)变化周期具有极强的相关性.太阳轨道运动在受到行星系统力矩作用的同时,致使近日行星轨道运动受到太阳引力作用的波动影响而产生扰动.受太阳巨大引力作用的牵制,导致地球轨道角动量和太阳轨道角动量的变化具有正相关关系.根据地球轨道角动量和自转角动量之和守恒,进而推断地球自转角速度的变化对太阳轨道运动特征的响应,这在思想方法上是一种突破.     

地球和月球的弹性潮汐形变解

本文根据一个由较新的月震、月球形状、月球重力及月球天平动资料所建立的真实月球内部结构模型,解算了在地球和太阳的引潮力作用下月球表面的弹性潮汐形变。得到了表征月球弹性潮汐形变的特征数--月球勒夫数。这个结果与国外一些学者采用假想或简单月球模型所得结果有较大不同。同时,本文还根据近年来出现的新的地球模型,再次求解了地球的静态勒夫数。结果表明,采用不同的地球模型对解算地球的静态弹性潮汐形变的结果影响很小。     

太阳轨道运动长周期性韵律的成因

太阳轨道运动具有双世纪(约200年)和哈尔斯塔(约2500年)长周期规律.这两个周期可以通过行星会合指数方程获得.根据图像获知,这两个太阳轨道运动周期都是由太阳最基本的22年轨道运动周期集合而成.太阳轨道运动的22年周期和太阳活动的22年磁周期是一一对应的.本文通过行星会合指数图像与太阳轨道运动角动量变率(Jose,1965)图像和树木年轮-珊瑚综合指标所指代的太阳活动图像(Charvátová,2000)的比对,以及对太阳轨道运动角动量与太阳自转角动量呈负相关关系的分析,认为太阳的自转运动规律决定着太阳自身的活动规律.从而得出,行星会合指数不但可以指代太阳的轨道运动规律,同时也可指代太阳的活动规律.     

行星会合指数K与行星直列指数I的比较分析

标识行星会合或排成直列程度的方法,是分析行星系统与太阳活动关系的关键.两颗行星会合可以给出准确的会合周期.行星越多获得准确的会合周期就越困难.以往表达多个行星排成近似直列的方法多采用I指数,I取值在0和1之间.但I指数无法呈现多个行星排成直列程度的连续变化过程,也无法区分行星在I指数构成中是位于太阳一侧还是分居在太阳两侧,更无法确定行星系质心与太阳位置关系的变化.K指数是将8大行星轨道半径按质量权重构成的矢量和的模除以一个天文单位的距离长度.K取值在0和7.5105之间.研究表明,行星引潮力会合指数KJ-M具有指代对太阳造成引潮力和引力周期规律的作用.行星质量权重会合指数KJ-N具有指代行星系质心绕太阳系质心的运动规律,进而指代太阳绕太阳系质心的运动规律.这为进一步探讨太阳轨道运动和太阳活动关系研究提供一种有效方法.     

干旱、地震与月球赤纬角变化

计算了月球赤纬角最大和最小时地球的潮汐形变值．结果表明,当赤纬角最大时月球引潮力所引起的地球表面积和地壳容积变化量是赤纬角最小时所引起的相应变化量的２．３倍．因此,当月球赤纬角最大时地球大量放气,而月球赤纬角最小时气候干旱,中国大陆出现旱灾．用地球自转速度变化周期和地震周期对上述结论进行了论证．     

27.3及13.6 d周期的大气潮

对比分析了25 a (1973~1998年)的日长(Length of day, 以下简称LOD)、大气环流及月球相位随时间的变化. 发现伴随着月球相位的交替变化, 地球大气的纬向风速场、地球位势高度场及LOD作27.3及13.6 d的周期振荡. 每5~9 d (平均6.8 d), 随着月球视赤纬角从0°变为最大值(绝对值)或从最大值变为0°, 全球纬向风速场、地球位势高度场及LOD经历一次突然变化. 这种周期性的大气振荡, 被视为一种大气潮. 对比月球视赤纬角变化及与其对应的LOD、大气纬向风速场及地球位势高度场变化, 分析了10个大气潮个例. 月球对地球大气引潮力作用的周期变化, 是引发27.3及13.6 d周期大气潮的主要原因. 月球对地球大气的作用是巨大的, 它引起大气纬向风速场及地球位势高度场的变化. 当月球围绕地球运转至天赤道上空时, 月球视赤纬角等于0°, 这时月球对大气的引潮力最大, 大气的纬向风速增加, 地球的自转角速度减小, 日长(LOD)增加. 反之, 当月球视赤纬角最大(绝对值), 月球对大气的引潮力减小, 大气纬向风速减小, 地球的自转角速度增加, LOD减小. 27.3及13.6 d周期的大气潮值得更深入地研究. 月球对地球大气的引潮力作用, 应该在大气环流及中短期天气预报模式中予以考虑.     

汶川8级地震的调制背景研究

一些研究表明中强以上地震的发生可能与水平引潮力极值状态有关。如1966年邢台、1967年河间和1976年唐山等几次强地震的发震时间都在朔、望的半日潮水平引潮力极大值时刻附近。而当处于朔、望大潮时,半日潮水平引潮力的极大值时刻即总的水平引潮力极大值时刻。有学者对上世纪全球的7级强震统计也表明许多大震都发生在日、月对震中区水平引潮力的极值附近。     

基于行星会合指数对太阳系结构变化的自禀赋特征的辨析

基于太阳系质心坐标系论证了太阳和行星系质心同步绕太阳系质心运动的命题.对K指数的研究发现,太阳系结构演变可导致选定的太阳质心坐标系的性质具有周期性变化的特征.太阳系结构变化可以从K指数的量值上予以区分.当行星系统处在K=Kmax和K=Kmin分布状态时,所揭示的正是整个太阳系结构演变的两种性质相反的极端状态.太阳轨道运动的复杂性主要是指太阳轨道运动具有向太阳自转运动转变的周期性变化特征.K指数除了具有指代太阳轨道运动极半径的变化特征之外,还近似具有与木星同步绕转的方向周期.理论分析获得:太阳轨道运动角动量的变化可导致太阳自转角动量和行星系统轨道角动量的变化,这对进一步探讨地球轨道运动扣自转运动的变化机制具有重要的参考价值.     

行星会合运动与太阳引潮力的周期性分析

行星会合指数和太阳引潮力指数是行星系统相对于太阳的两个重要指标,在分析行星系统对太阳影响方面具有重要意义.为探究行星系统会合运动及其引发太阳引潮力的周期吻合性,本文对行星会合指数和太阳引潮力指数两指标进行数值模拟,提供了百年、千年尺度的时间序列.对1450—2000AD期间的行星会合指数和太阳引潮力指数进行索周分析,显示行星会合指数存在显著的准19.88年、39.37年、12.94年、25.54年的周期规律,其中19.88年、39.37年的周期性较强、12.94年、25.54年的周期性较弱;太阳引潮力指数存在准11.99年、24.04年、35.99年、48.03年的强周期和4.0年、5.97年、7.98年、16.01年的弱周期.同时,利用功率谱和Morlet小波分别对行星会合指数和太阳引潮力指数进行周期性分析,分析结果与索周分析结果一致.行星会合指数和太阳引潮力指数存在相近的周期性规律又存在不同的周期性特征,反映了两指标的变化特征;行星对太阳正、反垂点产生大小近似相等、方向相反的引潮力,当行星会合指数处于极大或极小值时太阳引潮力指数都将达到极大值.行星对太阳引潮力的复杂性导致太阳引潮力...     

27.3-day and 13.6-day atmospheric tide

An analysis of time variations in the earth's length of day (LOD) for 25 years (1973-1998) versus at- mospheric circulation changes and lunar phase is presented. It is found that, on the average, there is a 27.3-day and 13.6-day period oscillation in global zonal wind speed, atmospheric geopotential height, and LOD following alternating changes in lunar phase. Every 5-9 days (6.8 days on average), the fields of global atmospheric zonal wind and geopotential height and LOD undergo a sudden change in rela- tion to a change in lunar declination. The observed atmospheric oscillation with this time period may be viewed as a type of atmospheric tide. Ten atmospheric tidal cases have been analyzed by comparing changes in LOD, global zonal wind speed and atmospheric geopotential height versus change in lunar declination. Taken together these cases reveal prominent 27.3-day and 13.6-day tides. The lunar forcing on the earth's atmosphere is great and obvious changes occur in global fields of zonal wind speed and atmospheric geopotential height over the equatorial and low latitude areas. The driving force for the 27.3-day and 13.6-day atmospheric tides is the periodic change in lunar forcing during the moon's revolution around the earth. When the moon is located on the celestial equator the lunar declination equals zero and the lunar tidal forcing on the atmosphere reaches its maximum, at this time the global zonal wind speed increases and the earth's rotation rate decreases and LOD increases. Conversely, when the moon reaches its most northern or southern positions the lunar declination is maximized, lunar tidal forcing decreases, global zonal wind speed decreases, earth's rotation rate increases and LOD decreases. 27.3-day and 13.6-day period atmospheric tides deserve deeper study. Lunar tidal forcing should be considered in models of atmospheric circulation and in short and medium range weather forecasting.     

Simulation of tides in hydrocarbon lakes on Saturn’s moon Titan

Numerous hydrocarbon lakes have recently been detected on Saturn’s largest moon Titan, representing the only known large bodies of liquids on a planetary surface outside the Earth. In the context of comparative oceanography, tides and tidal currents in two representative lakes on Titan (Kraken Mare and Ontario Lacus) are simulated by a three-dimensional baroclinic ocean circulation model. Since the tide-generating force on Titan is an order of magnitude larger than on Earth and the gravitational acceleration is small, tides and currents are substantially larger than in Earth’s lakes and are more comparable with those in Earth’s oceans. The predicted maximum tidal range in Kraken Mare is 4 m. The tidal wave propagates around the basin of Kraken Mare, while a nearly standing tidal wave is excited in Ontario Lacus. Titan’s rotation is too slow to affect the tidal flow in any Titan’s lake. The tidal current velocity in Kraken Mare amounts to a few centimeters per second except in the vicinity of a narrow strait, where it is enhanced by an order of magnitude. In summer, when the lake is stratified, internal tides can develop. Seiches cannot be caused by tide. In the largest lakes, atmospheric tide may cause additional lake surface displacements.     

Global tidal parameters

Summary Global tidal parameters are shown to have recently increased in accuracy, after more than twenty years of LLR and a decade of superconducting gravimetry, whereas the numerical values for the Earth have not changed substantially. Numerical values of Love numbers for terrestrial planets and the moon are also given for degrees higher than four as load numbers are basically linear combinations of Love numbers, at least for spherical non-rotation approximations. Numerical values for planetary moons, as far as they are known, have also been included in the paper. The static and dynamic behaviour of long-period and pole tide is discussed. Inner solid and outer fluid core effects are critically reviewed, also in view of a century of terrestrial tide observations of the classical type. The separation of long-period tides from secular effects (on a rotating Earth) such as J_n (n<5), is considered.Dedicated to the Memory of M. S. Molodensky     

Lunar Laser Ranging: Glorious Past And A Bright Future

Lunar Laser Ranging (LLR), a part of the NASA Apollo program, has beenon-going for more than 30 years. It provides the grist for a multi-disciplinarydata analysis mill. Results exist for solid Earth sciences, geodesy and geodynamics,solar system ephemerides, terrestrial and celestial reference frames, lunar physics,general relativity and gravitational theory. Combined with other data, it treatsprecession of the Earth's spin axis, lunar induced nutation, polar motion/Earthrotation, Earth orbit obliquity to the ecliptic, intersection of the celestial equatorwith the ecliptic, luni-solar solid body tides, lunar tidal deceleration, lunar physicaland free librations, structure of the moon and energy dissipation in the lunar interior.LLR provides input to lunar surface cartography and surveying, Earth station and lunar retroreflector location and motion, mass of the Earth-moon system, lunar and terrestrial gravity harmonics and Love numbers, relativistic geodesic precession, and the equivalence principle of general relativity. With the passive nature of the reflectors and steady improvement in observing equipment and data analysis, LLR continues to provide state-of-the-art results. Gains are steady as the data-base expands. After more than 30 years, LLR remains the only active Apollo experiment. It is important to recognize examples of efficient and cost effective progress of research. LLR is just such an example.     

Correlation of variations in the thermal neutron flux from the Earth’s crust with the Moon’s phases and with seismic activity

The results of the long-term recording of thermal neutron flux near the Earth’s surface with the use of an unshielded scintillation thermal-neutron detector are presented. The data obtained indicate the presence of periodic variations in the thermal neutron flux with the lunar diurnal and the lunar monthly periods. A hypothesis about the existence in the Earth’s crust of radon-neutron tidal variations in the concentration of thermal neutrons, correlated with the Moon’s phases and which have the gravitational origin, is formulated and confirmed experimentally. A simple mathematical model is proposed, which satisfactorily describes the observed variations. The case of the anomalous behavior of thermal neutrons is presented, which correlates with the high local seismic activity.     

The synodic periods of planets in the solar system and synchronization of the timing of large earthquakes

We report the results from a search for statistically significant (at a significance level of <0.05) periodicities that synchronize the occurrence of large shallow (h ≤ 100 km) earthquakes in the eight world regions with the highest level of seismicity. The periodicities in question include the synodic periods of planets of the solar system (Mercury, Venus, Mars, and Jupiter), as well as the precession period of the lunar orbit. In five of the eight regions we have found statistically significant results for the period T ≈ 780 days, corresponding to the synodic period of Mars. The lunar cycle and the period of Mercury were significant in two regions. These results cannot be accounted for by invoking the disturbing influence of gravitational and tidal forces due to planets other than the Earth. The significant periodicities were used to develop a forecast (for the period 2004–2009) of the most probable time intervals for the occurrence of large earthquakes in four regions: Kamchatka, the South Kurils, northeastern Japan, and the Nankai trough.     

中国大陆精密重力潮汐改正模型

利用理论和实验重力固体潮模型,充分考虑全球海潮和中国近海潮汐的负荷效应,建立了中国大陆的精密重力潮汐改正模型.结果表明,采用不同的固体潮模型会对重力潮汐结果产生相对变化幅度小于0.06％的差异;在沿海地区海潮负荷的影响约为整个潮汐的4％,而中部地区约为1％,其中中国近海潮汐模型的影响约占整个海潮负荷的10%,内插或外推潮波的负荷约占海潮负荷的3％.通过比较实测的重力数据表明,本文给出的重力潮汐改正模型的精度远远优于0.5×10^-8 m·s^-2,说明了本文构建的模型的实用性,可为中国大陆高精度重力测量提供有效参考和精密的改正模型.     

Ocean tidal effects on Earth rotation

Tidal forces due to the tide-raising potential deform the solid and fluid regions of the Earth, causing the Earth's inertia tensor to change, and hence causing the Earth's rate of rotation and length-of-day to change. Because both the tide-raising potential and the solid Earth's elastic response to the tidal forces caused by this potential are well-known, accurate models for the effects of the elastic solid body tides on the Earth's rotation are available. However, models for the effect of the ocean tides on the Earth's rotation are more problematic because of the need to model the dynamic response of the oceans to the tidal forces. Hydrodynamic ocean tide models that have recently become available are evaluated here for their ability to account for long-period ocean tidal signals in length-of-day observations. Of the models tested here, the older altimetric data-constrained model of Kantha et al. (1998) is shown to still do the best job of accounting for ocean tidal effects in length-of-day, particularly at the fortnightly tidal frequency. The model currently recommended by the IERS is shown to do the worst job.     

Apparent tidal influence on magmatic activity at Oldoinyo Lengai volcano,Tanzania, as observed in Moderate resolution Imaging Spectroradiometer (MODIS) data

This paper investigates the relative timing of solid Earth tides and thermal anomalies associated with volcanic activity at Oldoinyo Lengai (OL), Tanzania, from 2000 to 2008. The low viscosity of OL's carbonatite magmas may make it particularly susceptible to tidal stresses. Thermal data from the Moderate resolution Imaging Spectroradiometer (MODIS) were filtered using the MODLEN algorithm and Earth tides were modeled using TSoft. Application of the Schuster and Chi-squared tests resulted in apparent correlations between times of thermal anomalies and the phase of the semi-diurnal and biannual solid Earth tides. However, for semi-diurnal and biannual tides limited acquisition times of the MODIS data account for the apparent correlations. Re-examining the data while accounting for the bias introduced by the limited acquisition times, correlations are no longer found. Onset times of eruptive events and times of thermal anomalies show no statistically significant correlation with the fortnightly tide, indicating this is not an influence on activity at OL. Tidal influences on magmatic activity, if at all present, cannot be observed in coarse resolution thermal data on semi-diurnal and fortnightly time scales. Based on the available data, correlations on biannual timescales cannot be ruled out.     

Cycles in the scaling properties of length-of-day variations

Variations in the length-of-day (LOD) reflect the effects of several mechanisms in the Earth's rotation dynamics, including Earth–Sun and Earth–Moon line-up, geomagnetic effects and gravitational changes. Several studies showed that signatures of cycles occurring over a wide range of time scales are present in the LOD variations. The present work uses a fractal scaling study based on detrended fluctuation analysis (DFA) to study persistence of LOD variations and to provide insights in the different cycling mechanisms. The results showed that that the LOD variations are persistent over a wide range of time scales, meaning that an increment (resp., decrement) is more likely to be followed by an increment (resp., decrement). The temporal variation of the scaling exponent obtained from the DFA showed that several cycles already reported from the direct LOD variations analysis are inherited by the scaling properties. Inter-annual cycles, including 4.3 and 18.6 years cycles, are linked to the variations of the stochastic dynamics of LOD fluctuations. In this way, the 18.6 years cycle attains a period where variations are mostly affected by white noise effects, reducing the predictability of the LOD anomalies. The results are discussed in terms of the different lunar tidal and core–mantle mechanisms and related to recent results in the literature.