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921.
A.L. Mishev P.I.Y. Velinov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(1):316-325
The influence of high energy particles, specifically cosmic rays, on atmospheric physics and chemistry is highly discussed. In most of the proposed models the role of ionization in the atmosphere due to cosmic rays is not negligible. Moreover, effect(s) on minor constituents and aerosols are recently observed, specifically over the polar regions during strong solar particle events. According to the recent findings for such effects it is necessary an essential increase of ion production, specifically during the winter period. The galactic cosmic rays are the main source of ionization in the Earth’s stratosphere and troposphere. Occasionally, the atmospheric ionization is significantly enhanced during strong solar energetic particles events, specifically over the polar caps. During the solar cycle 23 several strong ground level enhancements were observed. One of the strongest was the Bastille day event occurred on 14 July 2000. Using a full Monte Carlo 3-D model, we compute the atmospheric ionization, considering explicitly the contribution of cosmic rays with galactic and solar origin, focusing on high energy particles. The model is based on atmospheric cascade simulation with the PLANETOCOSMICS code. The ion production rate is computed as a function of the altitude above the sea level. The ion production rate is computed on a step ranging from 10 to 30?min throughout the event, considering explicitly the spectral and angular characteristics of the high energy part of solar protons as well as their time evolution. The corresponding event averaged ionization effect relative to the average due to galactic cosmic rays is computed in lower stratosphere and upper troposphere at various altitudes, namely 20?km, 15?km, 12?km and 8?km above the sea level in a sub-polar and polar regions. The 24h and the weekly ionization effects are also computed in the troposphere and low stratosphere. Several applications are discussed. 相似文献
922.
923.
In this report briefly presented the contemporary state of the experimental base of Radio Astrophysical Observatory (RAO) of the Institute of Solar-Terrestrial Physics (ISTP), the methodology of radioheliographic monitoring of the solar corona, the SSRT database, the RAO Web-pages, factors limiting the effective use of SSRT. Here are formulated the original results of the basic directions of the solar activity researches and the problems solutions on SSRT: (1) active regions at various development stages, morphology, modeling,signs of energy accumulation and flares buildup, forecast of powerful flares; (2) scenario, topology and the fine temporal picture of flares development, signs of primary energy release, radio emission mechanisms, scatter effects of radio emission in turbulent corona, energetic particles fluxes; (3) filaments; (4) CME with the localization of their initiation at the solar disk background, development scenario of filament activation + CME +flare; (5) coronal holes, and (6) bright coronal points. 相似文献
924.
G.Y.Smolkov 《空间科学学报》2005,25(5):338-344
In this paper, the possibility and some results of radioheliographic study of space weather solar factors are shortly described. 相似文献
925.
A preliminary model is proposed to describe quantitatively the position and movement of cusp equatorward boundary. This integrated model, consisting of an empirical model of the magnetopause and a compressed dipolar model of Open/Closed field line, connects quantitatively the solar wind conditions, subsolar magnetopause and cusp equatorward boundary. It is shown that the increasing solar wind dynamic pressure and the increasing southward Interplanetary Magnetic Field (IMF) component drive the magnetopause to move inward and the cusp equatorward. This model is adopted to interpret quantitatively the cusp movement of August 14, 2001 observed by Cluster. The results show that the subsolar magnetopause moved earthward from 10.7 He to 9.0 Re during the period of 002300-002800 UT, and correspondingly the cusp equatorward boundary shifted equatorward. The observations of Cluster C1 and C4 show the cusp equatorward boundary that Cluster Cl and C4 were crossing during same interval moved equatorward by 4.6°. The cusp equatorward boundary velocity computed in the theoretical model (10.7km/s) is in good agreement with the observed value (9.4km/s) calculated from the data of CIS of Cluster C4 and C1. 相似文献
926.
This paper gives a brief outline of the progression from the first substorm model developed in Ref.[4] and[8] based on Kennel's ideas[3], to the present views about the mechanism by which solar wind kinetic energy is converted to electromagnetic energy at the Bow Shock and by which this energy is transferred to the magnetosphere in the form of current; about the transformation of the energy of this current to gas kinetic energy of convecting plasma tubes, and, finally, the back transformation of gas kinetic energy to electromagnetic energy in secondary magnetospheric MHD generators. The questions of the formation of the magnetospheric convection system, the nature of substorm break-up, and of the matching of currents in the magnetosphere-ionosphere system are discussed. 相似文献
927.
928.
929.
应用MonteCarlo方法对太阳X射线暴(1-8?及0.5-4?)与地球大气相互作用过程进行跟踪模拟,得到了X射线暴在电离层D层产生的电子产生率,并计算了由此产生的宇宙噪声吸收值。结果与作者在南极观测得到的X射线暴期间宇宙噪声吸收值符合较好. 相似文献
930.
太阳耀斑显著的热和非热事件的统计特征 总被引:1,自引:1,他引:0
本文利用GOES卫星和SMM卫星软、硬X射线耀斑观测资料,分析耀斑中软、硬X射线辐射流量的分布,发现太阳耀斑存在着显著的热事件(PT事件)和显著的非热事件(PNT事件),它们主要特征是:(1)PT事件为缓变型耀斑,PNT事件为脉冲型耀斑;(2)PT事件的硬X射线谱较软,PNT事件能谱较硬;(3)PNT事件非热能量释放速率比PT事件快3—10倍;(4)耀斑发展趋缓慢,PT事件中软X射线峰值流量越大;(5)耀斑中PNT事件约占60%,PT事件约占40%.最后定性讨论了产生PT和PNT事件的可能机制. 相似文献