共查询到20条相似文献，搜索用时 218 毫秒
1.
The effect of sunrise in time variations in the electric field in the near-Earth atmosphere at the Kamchatka Paratunka observatory has been studied. Twenty-nine records under fair-weather conditions have been selected. It has been indicated that the estimated effect parameters—the times of the effect’s onset and field strength maximum relative to the sunrise time, as well as the ratio of the strength maximum to its value before sunrise and the effect duration—coincide with the previously published data. Thereby, the conclusion is confirmed that the sunrise effect in diurnal variations in the electric field in the near-Earth atmosphere is related to the turbulence and convection processes in the atmospheric boundary layer at a change in atmospheric temperature. 相似文献
2.
3.
《Journal of Atmospheric and Solar》1999,61(10):745-750
ELF magnetic field measurements from 10 to 135 Hz at Arrival Heights, Antarctica, are used as a proxy measure of global cloud-to-ground lightning activity. Simultaneous hourly recordings of the atmospheric electric field on the surface of the Earth at South Pole during December 1992 make possible a detailed comparison between global cloud-to-ground lightning activity and the atmospheric electric field. Although the mean diurnal variation of the ELF magnetic field and the atmospheric electric field exhibit a remarkable similarity in shape and phase, the hourly departures from their mean diurnal variations are poorly correlated. We quantify the variability of the atmospheric electric field which can be explained by global cloud-to-ground lightning activity through linear regression analysis. To estimate an accuracy of this method, it is applied to simultaneous measurements of the ELF magnetic field at Søndrestrømfjord, Greenland, for comparison. The resulting hourly contribution of global cloud-to-ground lightning activity to the atmospheric electric field in the Antarctic during December 1992 is ∼40±10%, and the contribution of global cloud-to-ground lightning activity to hourly departures from the mean diurnal variation of the atmospheric electric field is ∼25±10%. 相似文献
4.
The measurement of the atmospheric electric field was carried out with a field mill at a small island in a bay on the Pacific coast of Japan. The data obtained during 80 months from 1971 to 1977 were analysed. It was found that characteristically the diurnal variation regularly alters with the seasons. Whereas the electric field in winter has the same diurnal pattern as that observed at globally representative stations, it exhibits in summer a pattern depending on the variation of the local electric conductivity. The alteration is inferred to be associated with regional atmospheric conditions surrounding the observation site. 相似文献
5.
The effects of the geomagnetic storms of November 8 and 10, 2004, in variations in the strength and power spectra of the electric field in the near-Earth’s atmosphere in Kamchatka were studied, together with the meteorological and geophysical phenomena observed simultaneously. A sequence of strong solar flares was shown to cause an anomalous increase in air temperature and humidity. This resulted in the excitation of anomalously strong thunderstorm processes in the atmosphere during the storm of November 8 and made it impossible to distinguish the effects associated with cosmic rays on this background. During the storm of November 10, on the background of weak variations in meteorological parameters, an increase in the strength and intensity of power spectra of the electric field on the day before the storm of November 10 was detected; it was followed by an attenuation of these parameters on the date of the storm. These effects were supposed to be associated with the action of cosmic rays on currents of the global electric circuit. It was shown that the influence of the Forbush effect of galactic cosmic rays in the power spectrum of the electric field first of all shows as the amplification of the component with the period T ～ 48 h; in variations in humidity, the effect shows as the amplification of the component with T ～ 24 h. Cause-and-effect relationships between variations in the electric field strength and the horizontal component of the geomagnetic field were shown to be absent both under the conditions of “fair weather” and during the storm of November 10. A diurnal negative-difference atmospheric pressure was detected on the second day after the geomagnetic storms of November 8 and 10. 相似文献
6.
The diurnal variations in the electric conductivity, electric-field strength, and meteorological parameters in the near-Earth’s atmosphere during the solar events in October 21–31, 2003, have been studied. It has been indicated that the conductivity and electric-field strength strongly depend on the air temperature and humidity. It has been found that the conductivity increased for 2 days before the geomagnetic storm on October 29–30 as a result of the effect of solar cosmic rays and decreased during a Forbush decrease in galactic cosmic rays, which was accompanied by a corresponding increase in the electric-field strength. It has been found that the air temperature and humidity anomalously increased in the process of solar activity, which resulted in the formation of different clouds, including thunderclouds accompanied by thunderstorm processes and showers. Simultaneous disturbances of the regular meteorological processes, solar flare series, and emission intensification in the near ultraviolet band, and visible and infrared spectral regions make it possible to consider these processes as a source of additional energy inflow into the lower atmosphere. 相似文献
7.
《Journal of Atmospheric and Solar》2008,70(17):2144-2158
The results from the numerical calculations of the global distribution of topside ionospheric parameters such as H+ ions and ion and electron temperatures up to 1500 km height are presented for equinoctial conditions at solar minimum. Calculations are carried out using the Global Self-consistent Model of Thermosphere, Ionosphere and Protonosphere (GSM TIP) developed in WD IZMIRAN, and using a new calculation block for electric fields due to dynamo and of magnetospheric origin. A comparison of two sets of calculations of magnetospheric convection electric field for a given potential difference is carried out, one through polar caps and other through field aligned currents of first zone. It is shown that the distribution of the electric potential obtained through field aligned currents of first zone is more self-consistent than that through polar caps. The light ion trough in H+ ions is deeper and occupies larger region for the potential difference through polar cap. For a given potential difference through field aligned current, at 1500 km, the maximum ion temperature is 150 K higher, minimum ion temperature is 200 K lower and maximum electron temperature is 100 K higher than those obtained for the same potential difference through polar caps. It is concluded that for modeling the electric field of magnetospheric origin, it is necessary to use the potential difference through field aligned current of first zone instead of through polar caps. 相似文献
8.
M. B. Gokhberg N. I. Kolosnitsyn V. M. Lapshin 《Izvestiya Physics of the Solid Earth》2009,45(8):633-639
The electric field in the near-surface layers of a spherically symmetrical Earth was calculated. This electric field is generated by electrokinetic processes in a water-saturated porous medium deformed by lunisolar tides. An exact analytical solution of the Frenkel’ equations describing electrokinetic phenomena is found. Data of observations of the horizontal components of the electric field are processed. The main harmonics of diurnal and semidiurnal tides are identified in accordance with the theory. 相似文献
9.
We perform spectral analysis of records of meteorological (temperature, humidity, pressure of the atmosphere) and electrical (strength of quasi-static electric field and electric conductivity of air) parameters observed simultaneously at the Paratunka observatory during the solar events of October 21–31, 2003. Also, we use simultaneous records of X-ray fluxes of solar radiation, galactic cosmic rays, and the horizontal component of the geomagnetic field. We show that the power spectra of the meteorological parameters under fine weather conditions involve oscillations with a period of thermal tidal waves (T ～ 12 and 24 h) caused by the influx of thermal radiation of the Sun. During strong solar flares and geomagnetic storm of October 29–31 with a prevailing component of T ～ 24 h, their spectra involve an additional component of T ～ 48 h (the period of planetary-scale waves). With the development of solar and geomagnetic activities, the power spectra of atmospheric electric conductivity and electric field stress involve components of both thermal tidal and planetary-scale waves, which vary highly by intensity. In the power spectra of galactic cosmic rays accompanying the strong solar flares, components with T ～ 48 h were dominant with the appearance of additional (weaker by intensity) components with T ～ 24 h. The simultaneous amplification of components with T ～ 48 h in the power spectra of electric conductivity and electric field strength provides evidence of the fact that the lower troposphere is mainly ionized by galactic cosmic rays during strong solar flares and geomagnetic storms. The specified oscillation period with T ～ 48 h in their spectra, as well as in the spectra of X-ray radiation of the sun, is apparently caused by the dynamics of solar and geomagnetic activities with this time scale. 相似文献
10.
S. E. Smirnov G. A. Mikhailova Yu. M. Mikhailov O. V. Kapustina 《Geomagnetism and Aeronomy》2017,57(5):610-617
The diurnal variations in electrical (quasistatic electric field and electrical conductivity) and meteorological (temperature, pressure, relative humidity of the atmosphere, and wind speed) parameters, measured simultaneously before strong earthquakes in Kamchatka region (November 15, 2006, М = 8.3; January 13, 2007, М = 8.1; January 30, 2016, М = 7.2), are studied for the first time in detail. It is found that a successively anomalous increase in temperature, despite the negative regular trend in these winter months, was observed in the period of six–seven days before the occurrences of earthquakes. An anomalous temperature increase led to the formation of “winter thunderstorm” conditions in the near-surface atmosphere of Kamchatka region, which was manifested in the appearance of an anomalous, type 2 electrical signal, the amplification of and intensive variations in electrical conductivity, heavy precipitation (snow showers), high relative humidity of air, storm winds, and pressure changes. With the weak flow of natural heat radiation in this season, the observed dynamics of electric and meteorological processes can likely be explained by the appearance of an additional heat source of seismic nature. 相似文献
11.
A normal electromagnetic field of the high-frequency horizontal electric dipole is analyzed with allowance for the displacement currents in the earth and air. The components of the field are calculated by the method of partial integration for nonsmooth behavior of the integrand. The boundary between the quasistationary and wave zone of the source is established according to the results of calculations. The effects arising in the wave zone due to the displacement currents in the air are considered. The results of the calculations are confirmed by field experiments. 相似文献
12.
江苏地区地电场变化特征与差异性分析 总被引：1，自引：0，他引：1
处理、分析了江苏省4个台的地电场日变化资料,结合地磁场水平分量H、线应变理论固体潮,研究了地电场日变化特征和差异,得到：（1）4个台地电场日变化明显,主要以12小时的半日波成分最强,8小时周期和全日波成分次之;（2）地电场日变化存在地磁场和固体潮影响。靠近海边及湖泊的台站,受固体潮的影响较为明显,各方向还具有明显的固体潮半月波,但没有像固体潮一样大小的波;而远离江、海、湖的一些台站观测到的地电场日变与地磁水平分量比较相关,其差异性与台站的位置、电性结构有关系。 相似文献
13.
本文利用1993～1994年日本国家农业环境研究所与中国科学院沙漠研究所合作在内蒙古奈曼地区实测的7种不同生态系统（沙丘、轻度放牧草原、中度放牧草原、重度放牧草原、无放牧草原、玉米田和大豆田）的净辐射、土壤热通量、两个高度的CO2浓度、温度、湿度和风速等资料，采用空气动力学方法，计算了CO2通量及其与环境和人为干扰因子的关系，并分析了不同下垫面的光合作用特征. 结果表明：各种下垫面CO2通量的共同特点是：在白天，CO2通量和梯度的输送方向是从大气向植被，在中午（11～13时）输送达到负的最大值； 在夜间，CO2通量和梯度输送方向与白天相反，是从植被向大气，在早晨（3～5时）达到正的最大值. 植被覆盖率及生物量不同的下垫面光合作用强度有明显差异，天气状况对光合作用也有一定影响. 相似文献
14.
Common studies on the static electric field distribution over a conductivity anomaly use the self-potential method. However, this method is time consuming and requires nonpolarizable electrodes to be placed in the ground. Moreover, the information gained by this method is restricted to the horizontal variations of the electric field. To overcome the limitation in the self-potential technique, we conducted a field experiment using a non conventional technique to assess the static electric field over a conductivity anomaly. We use two metallic potential probes arranged on an insulated boom with a separation of 126 cm. When placed into the electric field of the free air, a surface charge will be induced on each probe trying to equalize with the potential of the surrounding atmosphere. The use of a plasma source at both probes facilitated continuous and quicker measurement of the electric field in the air. The present study shows first experimental measurements with a modified potential probe technique (MPP) along a 600-meter-long transect to demonstrate the general feasibility of this method for studying the static electric field distribution over shallow conductivity anomalies.Field measurements were carried out on a test site on top of the Bramsche Massif near Osnabrück (Northwest Germany) to benefit from a variety of available near surface data over an almost vertical conductivity anomaly. High resolution self-potential data served in a numerical analysis to estimate the expected individual components of the electric field vector.During the experiment we found more anomalies in the vertical and horizontal components of the electric field than self-potential anomalies. These contrasting findings are successfully cross-validated with conventional near surface geophysical methods. Among these methods, we used self-potential, radiomagnetotelluric, electric resistivity tomography and induced polarization data to derive 2D conductivity models of the subsurface in order to infer the geometrical properties and the origin of the conductivity anomaly in the survey area. The presented study demonstrates the feasibility of electric field measurements in free air to detect and study near surface conductivity anomalies. Variations in Ez correlate well with the conductivity distribution obtained from resistivity methods. Compared to the self-potential technique, continuously free air measurements of the electric field are more rapid and of better lateral resolution combined with the unique ability to analyze vertical components of the electric field which are of particular importance to detect lateral conductivity contrasts. Mapping Ez in free air is a good tool to precisely map lateral changes of the electric field distribution in areas where SP generation fails. MPP offers interesting application in other geophysical techniques e.g. in time domain electromagnetics, DC and IP.With this method we were able to reveal a ca. 150 m broad zone of enhanced electric field strength. 相似文献
15.
The work is devoted to the numerical simulation of the dynamo electric field and its effects in the Earth’s ionosphere within the scope of the thermosphere-ionosphere-protonosphere global self-consistent model developed at WD IZMIRAN. The new electric field calculation block, which was used to obtain results of the self-consistent calculations of the electric field potential generated by the dynamo effect of the thermospheric winds (the dynamo field) and the equatorial electrojet for March 22, 1987, is briefly described in this work. A comparison of the obtained results with the experimental data showed a satisfactory agreement. Moreover, the proposed model was used to calculate the diurnal variations in the ionospheric parameters for Jicamarca equatorial station under the same conditions with the help of the new block of the electric field. The results of these calculations are also presented and discussed in this work. It has been indicated that the new model satisfactorily describes the specific features of electric field distribution at the geomagnetic equator and the well-known phenomenon of equatorial electrojet. 相似文献
16.
The distribution of the electric potential, generated by the magnetospheric field-aligned currents flowing along the auroral oval and in the dayside cusp region at the upper atmospheric boundary in the polar ionosphere, is calculated. The obtained electric potential distributions are used to calculate the electric field strength near the Earth’s surface. The results of the model calculations are in good agreement with the electric field measurements at Vostok Antarctic station. It has been indicated that large-scale magnetospheric fieldaligned currents, related to IMF variations, can affect variations in the electric field strength in the polar regions via changes in the electric potential in the polar ionosphere, associated with these currents. 相似文献
17.
18.
作为地电场最重要的背景变化组成成分之一,地电场日变化普遍存在。本文选取中国大陆10个地电场台站观测数据,应用时序迭加和谐波分析方法,研究地电场日变化的时间域和空间域基本特征。地电场日变化大多呈现"两峰一谷"或"两谷一峰"的变化特征,日变化特征一年四季基本相同,但是幅度、相位略有差异。此外,利用地磁、地貌、电性结构等资料,对地电场日变化的复杂性及与空间电磁活动、地下电性结构及潮汐相关性进行分析,认为地电场日变化特征本质是受空间电磁活动和地下介质电性结构、水文、地质等因素共同作用的结果。 相似文献
19.
Stream temperature will be subject to changes because of atmospheric warming in the future. We investigated the effects of the diurnal timing of air temperature changes – daytime warming versus nighttime warming – on stream temperature. Using the physically based model, Heat Source, we performed a sensitivity analysis of summer stream temperatures to three diurnal air temperature distributions of +4 °C mean air temperature: i) uniform increase over the whole day, ii) warmer daytime and iii) warmer nighttime. The stream temperature model was applied to a 37‐km section of the Middle Fork John Day River in northeastern Oregon, USA. The three diurnal air temperature distributions generated 7‐day average daily maximum stream temperatures increases of approximately +1.8 °C ± 0.1 °C at the downstream end of the study section. The three air temperature distributions, with the same daily mean, generated different ranges of stream temperatures, different 7‐day average daily maximum temperatures, different durations of stream temperature changes and different average daily temperatures in most parts of the reach. The stream temperature changes were out of phase with air temperature changes, and therefore in many places, the greatest daytime increase in stream temperature was caused by nighttime warming of air temperatures. Stream temperature changes tended to be more extreme and of longer duration when driven by air temperatures concentrated in either daytime or nighttime instead of uniformly distributed across the diurnal cycle. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
本文以电磁环境、装置系统、日变波形均具有代表性的海安、平凉、瓜州等7个台站为对象,基于大地电场潮汐机理和裂隙水(电荷)渗流(移动)模型,应用快速傅里叶变换和矢量分析方法,研究这7个台站在2009—2015年多个时段、多个测向的地电场日变波形的相位关系及影响因素.结果显示:多方位地电场观测的日变波形之间具有同相或反相的相位关联特征; 当观测地电场的电极与仪器的连接方式确定后,不同测向地电场日变波形的相位关联即由场地岩体裂隙优势方位所决定,且这种相位关联特征具有相对稳定性. 相似文献