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311.
L.V. Tverskaya T.A. Ivanova N.N. Pavlov S.Ya. Reizman I.A. Rubinstein E.N. Sosnovets N.N. Vedenkin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2005,36(12):2392-2400
An empirical formula relating the strength of a storm given by its |Dst|max with the L-coordinate of the peak of storm-injected relativistic electrons is one of a few well-confirmed quantitative relations found in the magneto-spheric physics. We successively extended a dataset of the formula’s basic storms with several events of high Dst-amplitude up to the highest observed |Dst|max = 600 nT. Possible applying of the formula to the predicting of the ring-current plasma-pressure distribution and the lowest westward electrojet position for a storm are discussed. We have also analyzed the 2000–2001 years’ data on relativistic electrons from our instruments installed on EXPRESS-A (geosynchronous orbit; Ee = 0.8–6 MeV), Molniya-3 (h = 500 × 40 000 km, i = 63°; Ee = 0.8–5.5 MeV) and GLONASS (h = 20 000 km, i = 64°; Ee l MeV) along with other correlated measurements: GOES series (Ee > 2 MeV), geomagnetic indices (Dst, AE, AL) and interplanetary parameters (solar wind, IMF). The goal is to investigate which outer conditions are most responsible for the high/low output of the storm-injected relativistic electrons. For the geosynchronous orbit, two factors are found as the necessary condition of the highest electron output: high and long-lasting substorm activity on a storm recovery phase and high velocity of solar wind. On the contrary, extremely low substorm activity surely observed during whole the storm recovery phase constitutes a sufficient condition of the non-increased after-storm electron intensity. For the first time found cases of the increased after-storm electron intensity observed at the inner L-shells with no simultaneously seen increase in the geosynchronous distances are presented. 相似文献
312.
Maha Ashour-Abdalla Jean-Michel Bosqued Mostafa El-Alaoui Vahé Peroomian Takayuki Umeda Raymond J. Walker 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(10):1598-1610
On October 8, 2004, the Cluster and Double Star spacecraft crossed the near-Earth (12–19 RE) magnetotail neutral sheet during the recovery phase of a small, isolated substorm. Although they were separated in distance by ∼7 RE and in time by ∼30 min, both Cluster and Double Star observed steady, but highly structured Earthward moving >1000 km/s high speed H+ beams in the PSBL. This paper utilizes a global magnetohydrodynamic (MHD) simulation driven by Wind spacecraft solar wind input to model the large-scale structure of the PSBL and large-scale kinetic (LSK) particle tracing calculations to investigate the similarities and differences in the properties of the observed beams. This study finds that the large-scale shape of the PSBL is determined by the MHD configuration. On smaller scales, the LSK calculations, in good qualitative agreement with both Cluster and Double Star observations, demonstrated that the PSBL is highly structured in both time and space, on time intervals of less than 2 min, and spatial distances of the order of 0.2–0.5 RE. This picture of the PSBL is different from the ordered and structured region previously reported in observations. 相似文献
313.
Valery M. Nakariakov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2007,39(12):1804-1813
Wave and oscillatory activity is observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands in all parts of the solar corona. Magnetohydrodynamic (MHD) wave theory gives satisfactory interpretation of these phenomena in terms of MHD modes of coronal structures. The paper reviews the current trends in the observational study of coronal oscillations, recent development of theoretical modelling of MHD wave interaction with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasmas is discussed. In particular, the applicability of this method to the estimation of the coronal magnetic field is demonstrated. 相似文献
314.
S.S. Rossolenko E.E. Antonova Yu.I. Yermolaev I.P. Kirpichev N.L. Borodkova E.Yu. Budnik 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(10):1545-1550
Characteristics of low latitude boundary layer (LLBL) of the Earth’s magnetosphere are investigated using data of Interball/Tail probe observations. The role of different processes of LLBL formation is discussed. The high level of magnetosheath turbulence is taken into account. It is shown that the turbulent nature of magnetic field and plasma fluctuations in the magnetosheath is one of the main factors determining the structure of LLBL. The results of Interball/Tail probe observations of the event 9 March 1996 are analyzed. The thickness of LLBL is determined for the number of cases. The change of LLBL thickness under the influence of the changes of solar wind parameters is investigated. It is shown that variability of solar wind conditions can be the important factor controlling LLBL thickness. Results of observations are compared with the theory which explains the value of LLBL thickness as the result of plasma transport inside the magnetosphere. It is shown that the theory gives the qualitative explanation of the observed dependence of LLBL thickness on solar wind parameters. 相似文献
315.
P. Muralikrishna 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
A Brazilian SONDA III rocket carrying plasma diagnostic experiments was launched from the Brazilian rocket launching stations in Alcântara (2.31°S, 44.4°W Geog. Lat.) to measure the height profiles of electron density, electron temperature and the ambient electric field. High frequency capacitance probe was used to measure the height profile of the electron density and the Langmuir probe was used to measure the electron density and the spatial structures of plasma irregularities. An electric field double probe was used to measure the electric field fluctuations associated with the F-region plasma irregularities. Spectral analysis of the fluctuations in electron density and electric field indicated the presence of propagating waves in the night time F-region over a large height range. The electron temperatures estimated from the LP data showed abnormally high values in the base of the F-region during the upleg of the rocket and practically normal values in the same height region during the downleg. A brief study of the characteristic features of the spectra of electron density and electric field fluctuations and the associated electron temperature variations are presented and discussed here. 相似文献
316.
317.
霍尔推力器振荡问题的研究综述 总被引:1,自引:0,他引:1
自前苏联1971年将霍尔推力器成功地应用以来,霍尔推力器以其优异的性能,在卫星 轨道保持和变轨运行过程中成为最佳动力装置之一,由于霍尔推力器自身工作原理所产生的 等离子体振荡,其频率从几十kHz到几GHz,包含推力器中各种物理现象、与推力器中粒子电 离、加速、传导等等离子体微观物理过程息息相关,一直是该领域的研究热点和焦点问题。 系统总结了各国主要研究机构对于霍尔推力器振荡问题的理论和实验研究成果,结合自 身对霍尔推力器等离子体振荡物理过程的认识,分析了目前尚待解决的振荡问题,对于进一 步深入研究霍尔推力器的等离子体振荡问题具有一定借鉴意义。 相似文献
318.
319.
320.
针对具有金属反射面的非均匀等离子体对电磁波的反射、吸收问题,采用求解波动方程的方法构造相应的边界条件,详细研究各种参数等离子体对电磁波的吸收特性,讨论对等离子体参数及波动方程进行归一化的方法,得到归一化条件下的等离子体宽频带吸收特性。计算分析表明,对于电子密度为某种渐进分布的有碰撞的低温等离子体,当碰撞频率与最大电子密度处的等离子体频率相近或略大,且等离子体层的厚度足够大时,在一个较宽的频带内,等离子体对电磁波有较强的吸收作用。研究结论可以用于等离子体参数的选择,及等离子体隐身的参数设计。 相似文献