Lidar observations and formation mechanism of the structure of stratospheric and mesospheric aerosol layers over Kamchatka

Lidar observations during 2007–2008 in Kamchatka revealed aerosol layers in the upper stratosphere at heights of 35–50 km and in the mesosphere at heights of 60–75 km. It is well known that forces of gas-kinetic nature, i.e., photophoretic forces, act on aerosol particles that absorb solar radiation and terrestrial IR radiation; these forces can counteract the gravitational force and even lead to the levitation of these particles at particular heights. The accumulation of particles at these heights may lead to the formation of aerosol layers. We calculated these forces for the conditions of lidar observations in Kamchatka. Aerosol layers were observed at heights where particle levitation can occur. Thus, the stratospheric and mesospheric aerosol layers, detected at heights of 30–50 and 60–75 km, respectively, may be due to the effect of the photophoretic force on aerosol particles.     

Connections between geophysical and meteorological processes

Summary The purpose of this paper is to contribute to the elucidation of the individual phases of the proposed mechanism of solar-terrestrial relations and changes of wheather [1–3], to point out mutually associated consequential events directly, using observed geophysical and meteorological data and to give proof, using concrete examples, of the effects of corpuscular radiation on the increase of temperature in the region of the auroral oval and on marked changes in the atmospheric circulation in the Northern Hemisphere.     

Modeling and forecasting the aftershock processes in Kamchatka

The aftershock processes that occurred in 1990?C2008 on the Kamchatka Peninsula and in the adjacent water area are numerically modeled with the aim of forecasting the aftershock activity. The aftershocks are identified by the Molchan-Dmitrieva algorithm followed by the analysis of spatiotemporal distribution of the earthquakes, which gives the final aftershock sequences. The simulations are based on the relaxation and triggering models of the aftershock processes. The studied models adequately describe and reliably simulate the temporal behavior of the aftershock sequences. An attempt is made to forecast the aftershock processes in Kamchatka using the ETAS model. It is shown that forecasting based on the data observed during the preceding time intervals is quite accurate. This approach can be applied in the centers of seismological monitoring for estimating the aftershock activity within the first days after a strong earthquake.     

Modeling and forecasting the aftershock processes in Kamchatka

The aftershock processes that occurred in 1990–2008 on the Kamchatka Peninsula and in the adjacent water area are numerically modeled with the aim of forecasting the aftershock activity. The aftershocks are identified by the Molchan-Dmitrieva algorithm followed by the analysis of spatiotemporal distribution of the earthquakes, which gives the final aftershock sequences. The simulations are based on the relaxation and triggering models of the aftershock processes. The studied models adequately describe and reliably simulate the temporal behavior of the aftershock sequences. An attempt is made to forecast the aftershock processes in Kamchatka using the ETAS model. It is shown that forecasting based on the data observed during the preceding time intervals is quite accurate. This approach can be applied in the centers of seismological monitoring for estimating the aftershock activity within the first days after a strong earthquake.

     

夏季西北太平洋大气环流异常及其与热带印度洋—太平洋海温变化的关系

本文分析了夏季西北太平洋大气环流异常特征及其与海温变化的关系,发现夏季西北太平洋异常反气旋/气旋(WNPAC/WNPC)是西北太平洋地区对流层中低层存在的重要大气环流异常现象,与东亚—西北太平洋低纬度至高纬度的经向PJ波列及欧亚中高纬度东西纬向波列的变化有关,通过与中高纬度环流变化的联系,对东亚及欧亚中高纬度气候有重要影响.夏季WNPAC/WNPC与热带海温变化的关系存在明显的不对称性,显著的WNPAC一般出现在El Niño衰减年夏季,与前期El Niño成熟年冬季的赤道东太平洋暖海温异常和El Niño衰减年春夏季印度洋海盆尺度的暖海温异常有明显的正相关关系,进一步表明了WNPAC在El Niño事件影响夏季气候中的重要桥梁作用;而夏季显著的WNPC与前期和同期热带海温变化的关系存在明显的不确定性,主要与夏季热带印度洋和赤道中东太平洋之间东暖西冷的热力差异异常引起的孟加拉湾—赤道西太平洋西风异常有关.进一步分析WNPAC/WNPC与海温变化关系不对称的可能原因,发现El Niño和La Niña衰减年夏季热带印度洋和太平洋海温变化所引起的印—太之间海温(热力)差异的一致性特征可能是导致WNPAC/WNPC与海温变化关系不对称的主要原因.     

Vertical dynamic and thermodynamic characteristics of urban lower boundary layer and its relationship with aerosol concentration over Beijing

By utilizing observational data from a 325 m tower of the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS) on March 19-29, 2001 and August 11-25, 2003, a comprehensive study was conducted on the vertical dynamical and thermodynamic characteristics of the urban lower boundary layer (ULBL) and its relationship with aerosol concentration over Beijing. Firstly, a comparative analysis was made on the gradient data (wind, temperature and humidity), ultrasonic data (atmospheric turbulences) and air-quality observations at different tower heights (47, 120 and 280 m). Secondly, a diagnosis was made to reveal the major features of normalized variances of velocity and temperature, turbulence kinetic energy as well as their relationship with aerosol concentrations. Furthermore, the characteristics of the ULBL vertical structure and the TSP concentration/distribution variations during a sand/dust weather process were also analyzed. The outcome of the study showed that under unstable stratification, the normalized variances of velocity (σu/u*, σv/u*, σw/u*) and temperature (σT/T*) at 47 and 120 m heights fit the Monin-Obukhov similarity (MOS) framework and the fitting formulas were given out accordingly. According to the stratification parameter (z′/L), the stable ULBL could be divided into 2 zones. With z′/L<0.1, it was a weakly stable zone and MOS framework was applicable. The other was a highly stable zone with z′/L>0.1 and the normalized velocity variances tended to increase along with higher stability, but it remained constant for normalized temperature variances. At daytime, the near-surface layer includes two heights of 47 and 120 m, while 280 m has been above it. The ULBL analysis in conjunction with a sand/dust weather process in Beijing in March 2001 indicated that the maximum concentration of Total Suspended Particulates (TSP) at 320 m reached 913.3 μg/m3 and the particles were transported from the upper to lower ULBL, which was apparently related to the development process of a low-level jet and its concomitant strong sinking motion.     

Electric and electromagnetic processes in the near-Earth atmosphere before earthquakes on Kamchatka

Simultaneous records of the diurnal variations in the quasistatic electric field in the near-Earth atmosphere, fluxes of discrete electromagnetic pulses in the VLF band, source azimuths, narrowband filter output emission intensity at frequencies of 4.65 and 5.3 kHz, and time forms and spectra of VLF pulses have been analyzed. The anomalous behavior of these parameters in October 2002 and August 2004 with different time delay was accompanied by earthquakes near the southeastern coast of Kamchatka at distances of 250–400 km from the registration points. Based on the results of a fine frequency-time analysis of the broadband records of VLF signals, it has been indicated for the first time that discrete electromagnetic pulses observed in anomalous fluxes before earthquakes were signals of local thunderstorm processes.     

High resolution aerosol optical thickness retrieval over the Pearl River Delta region with improved aerosol modelling

Aerosol retrieval algorithms for the MODerate Resolution Imaging Spectroradiometer (MODIS) have been developed to estimate aerosol and microphysical properties of the atmosphere, which help to address aerosol climatic issues at global scale. However, higher spatial resolution aerosol products for urban areas have not been well researched mainly due to the difficulty of differentiating aerosols from bright surfaces in urban areas. Here, a new aerosol retrieval algorithm using the MODIS 500 m resolution image...     

Asperity Distribution of the 1952 Great Kamchatka Earthquake and its Relation to Future Earthquake Potential in Kamchatka

—The 1952 Kamchatka earthquake is among the largest earthquakes of this century, with an estimated magnitude of M _w = 9.0. We inverted tide gauge records from Japan, North America, the Aleutians, and Hawaii for the asperity distribution. The results show two areas of high slip. The average slip is over 3 m, giving a seismic moment estimate of 155×10²⁰Nm, or M _w = 8.8. The 20th century seismicity of the 1952 rupture zone shows a strong correlation to the asperity distribution, which suggests that the large earthquakes (M > 7) are controlled by the locations of the asperities and that future large earthquakes will also recur in the asperity regions.     

Geocenter motion and its geodetic and geophysical implications

The horizontal transport of water in Earth's surface layer, including sea level change, deglaciation, and surface runoff, is a manifestation of many geophysical processes. These processes entail ocean and atmosphere circulation and tidal attraction, global climate change, and the hydrological cycle, all having a broad range of spatiotemporal scales. The largest atmospheric mass variations occur mostly at synoptic wavelengths and at seasonal time scales. The longest wavelength component of surface mass transport, the spherical harmonic degree-1, involves the exchange of mass between the northern and southern hemispheres. These degree-1 mass loads deform the solid Earth, including its surface, and induce geocenter motion between the center-of-mass of the total Earth system (CM) and the center-of-figure (CF) of the solid Earth surface. Because geocenter motion also depends on the mechanical properties of the solid Earth, monitoring geocenter motion thus provides an additional opportunity to probe deep into Earth's interior. Most modern geodetic measurement systems rely on tracking data between ground stations and satellites that orbit around CM. Consequently, geocenter motion is intimately related to the realization of the International Terrestrial Reference Frame (ITRF) origin, and, in various ways, affects many of our measurement objectives for global change monitoring. In the last 15 years, there have been vast improvements in geophysical fluid modeling and in the global coverage, densification, and accuracy of geodetic observations. As a result of these developments, tremendous progress has been made in the study of geocenter motion over the same period. This paper reviews both the theoretical and measurement aspects of geocenter motion and its implications.     

我国近海地震活动特征及其与地球物理场的关系

对我国近海海域有历史记载以来的地震的震级、震中参数进行了整理分析,并分析了各海域地震活动的时、空分布规律,根据历史地震资料,确定海域受历史地震影响的最大影响烈度,然后初步分析了地震活动与现代构造应力场、地球物理场的关系.研究发现:(1)近海海域历史地震资料的精度较低,中强地震存在明显的遗漏.(2)渤海、台湾海峡、南海北部地震活动性较强,黄海次之,东海最弱.(3)近海海域的震害主要来自海域地震和近岸陆地强震的影响,影响强弱依次为:渤海、黄海、东南沿海、东海.(4)现代构造应力场以水平向构造应力场作用下的走滑运动为主,最大主应力方向受印度板决和太平洋板块、菲律宾海板块的俯冲挤压方向影响.(5)海域地球物理场,特别是布格重力异常、地壳厚度分布与强震构造带的空间分布关系的相关性较好.本文的研究结果可为我国海域及滨海重要工程的抗震设防、海域地震危险性区划提供一定的基础.     

印尼地震海啸及其相关的地球物理现象

地震海啸的产生是地球表面固体层和流体层相互作用的结果.本文介绍了这种相互作用的物理过程,讨论了海啸的大小、能量、传播速度,展示了与印尼地震相关的地球物理现象,指出：建立早期预警系统是减少海啸灾害的重要措施,目前的预警系统虚报率很高的问题,仍需要通过加强地球表层系统相互作用的研究来解决,这是地球科学家面临的重要科学课题.     

The Chandler annual resonance and its possible geophysical significance

The secular decrease of the earth's rotation rate has caused the Chandler and annual modes of the earth's wobble to resonate in the past. The physics of the resonance is discussed as well as its thermal impact on the mantle. Energy of the order of 10²⁶ erg/year were dissipated in the upper mantle during the resonance. Estimates of the epoch and duration of the resonance place them at about 185 m.y. ago and about 10 m.y., respectively. The possibility of a causal connection between the resonance and the onset of continental drift is suggested.     

发展技术,增强基础-地球物理仪器国际化与地球物理技术在工程上的应用研讨会综述

2004年,中国地球物理学会仪器专业委员会在北京召开了“地球物理仪器国际化问题”(4月)和“地球物理技术在工程上的应用”(8月)两个研讨会。会议发表了大量论文,展示了目前我国先进的地球物理仪器和地球物理技术在工程方面的应用成就．承《地球物理学进展》编辑部支持,决定在2004年第四期和2005年第一期,连续刊载经专家审查和推荐的地球物理仪器和技术方面的部分优秀论文,     

Vegetation dynamics and ecological consequences of the 1996 eruption in Karymsky Volcanic Center, Kamchatka

This paper provides an assessment of the degree and character of vegetation damage due to the 1996 phreatomagmatic eruption in Akademii Nauk Caldera and considers the mechanisms of posteruptive vegetation recovery. Key features of the primary succession at the Novogodnii Peninsula have been revealed. The vegetation cover prior to the 1996 eruption is reconstructed, and the effect of minor ashfalls that occurred in 1996–2003 is examined.     

On the association of aerosol optical depth and total ozone fluctuations with recent earthquakes in Greece

A number of recent studies suggest that atmospheric changes that precede an earthquake might offer the hope of providing early warning. This study attempts to examine seismo-atmospheric anomalies around the time and the location of some of the major earthquakes in Greece in the period 2001–2015. Daily values of aerosol optical depth (AOD) and total ozone column (TOZ) obtained from satellite observations are used, in the time window between 25 days before and 14 days after each of these events, in a 1° × 1° area centred on the epicentre of each earthquake. For some of these earthquake events, abnormal increases in time series of AOD and TOZ data were detected before and after the occurrence of the earthquake. Nevertheless, in other cases, no clear anomalies were observed around the earthquake date. In addition, examining the statistics of AOD and TOZ daily values, there were many cases of prominent abnormal variations, without, however, being associated with an earthquake event. Therefore, no clear association was found between AOD and TOZ fluctuations and recent earthquakes in Greece.     

The andesite extrusion of Mount Mishennaya, Kamchatka, and its age

The hornblende andesite extrusion of Mount Mishennaya belongs to the andesite subcomplex of the Avacha Neopleistocene-Holocene basalt-andesite volcanic complex. The Mishennaya dome belongs to the extrusive areal field found on the north bank of Avacha Creek. It is believed that the subcomplex took a long time to develop from the Early to Late Neopleistocene. Three K-Ar age determinations of the Mishennaya andesites have been made using a hornblende monofraction for one determination and the nonmagnetic fraction of the rocks for the other two. The resulting age values are 0.60, 0.57, and 0.59 Myr. These are consistent with previous paleomagnetic determinations and with results from fission track analysis (0.7 Myr).     

地球物理资料群体智能反演(英文)

复杂地球物理资料的反演问题往往是一个求解多参数非线性多极值的最优解问题。而鸟和蚂蚁等群体觅食的过程,正好与寻找地球物理反演最优解的过程相似。基于自然界群体协调寻优的思想,本文提出了交叉学科的群体智能地球物理资料反演方法,并给出了其对应的数学模型。用一个有无限多个局部最优解的已知模型对该类方法进行了试验。然后,将它们应用到了不同的复杂地球物理反演问题中:(1)对噪声敏感的线性问题;(2)非线性和线性同步反演问题;(3)非线性问题。反演结果表明,群体智能反演是可行的。与常规遗传算法和模拟退火法相比,该类方法有收敛速度相对快、收敛精度相对高等优点;与拟牛顿法和列文伯格一马夸特法相比,该类方法有能跳出局部最优解等优点。     

海洋地球物理测量中GPS数据问题与处理

海上走航式地球物理测量的精度在很大程度上依赖于GPS（全球导航定位授时系统）数据观测的精度.由于各种原因,船载GPS测量会遇到多种问题.对记录到的GPS数据进行处理是获得高质量GPS数据一个不可缺少的环节.本文通过对多个海洋重磁调查航次的GPS观测数据进行处理,介绍了船载GPS测量中遇到的一些典型问题,以及相应的数据处理方法.本文指出,为保证数据采集的质量,船载GPS测量一般应使用两台GPS接收机同时进行测量.在数据处理时,将其中记录较稳定、可靠的一台GPS接收机作为主机,而另一台作为辅机.数据处理时,以主机记录的数据为主,当主机数据缺失时,则使用附机的数据作为补充.我们的长期观测结果表明,主机和附机之间总是存在时间差,目前我们没有发现时间差出现的规律和这种时间差出现的确切原因.用附机的数据来补充主机数据时,应该进行时间差调整.对于同一台GPS接收机的数据,本文介绍了野值、零值、重复值、时间间断和航迹间断等现象.同时文章中介绍了对于野值、零值、重复值、时间间断和航迹间断等数据,在进行数据处理时,可用剔除、插值、补遗等办法对上述出现的问题进行处理.本文认为,天气状况、卫星分布、天线运动姿态、接收机工作的稳定性、解码模块、运算〖JP3〗速度、多路径效应等都可能对GPS观测造成影响,但目前我们还并不能确定造成海上GPS测量出现问题的确切原因.