Numerical Modeling of Ion Contributions in Ionospheric Sporadic-E Layerormalsize
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摘要: 从离子连续性方程和动量方程出发,比较全面地考虑了太阳光电离、星光电离、地冕电离、星际背景电离和流星离子流等电离源,综合分析Es层的主要动力学过程和光化学过程,以风剪切理论为基础,研究中性成分碰撞、电场作用、金属离子作用和分子离子作用等机制对离子分布的影响,建立了一维时变电离层Es物理模型.对离子产生率、垂直方向的离子速度在高度和时间上的变化进行仿真和计算,得到了在电场及风剪切作用下的离子密度剖面24h内的变化规律.根据建立的模型,以昆明相干散射雷达观测的径向风结果作为模型输入参考,仿真并得到了电离层Es电子密度的时空分布,据此反演出电离层Es临界频率f0Es.与昆明站电离层测高仪同时间观测的情况进行对比,结果比较一致,验证了建立的Es层物理模型正确性.Abstract: The ionospheric kinetic numerical model is expressed as the solution to the temporal evolution of the electron density profile. The ion continuity and the momentum equations, the solar ionization, star ionization, coronal ionization, interstellar background ionization and meteor ion flow are all considered. The main kinetic process and photochemical process of Es layer are analyzed synthetically. The effects of neutral component collision, electric field, metal ion and molecular ion on the ion distribution are also included. In the paper, a one-dimensional time-dependent model of the ionospheric Es has been developed on the basis of the wind shear theory. The ion production rate and the distribution of the vertical ion velocity in height and time are simulated by the model. The variations of ion density profile in 24 hours are also obtained. According to the observation results of winds by coherent scattering radar in Kunming station, the time and space dependent of electron density of Es (Ne) is acquired by the model. Then the f0Es are given by the conversion of Ne, and the retrieval results are in good agreement with the contemporaneous ionosonde data in Kunming.
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Key words:
- Ionospheric sporadic-E /
- Ions contributions /
- Ions production rates /
- Ionization sources
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[1] MACLEOD M A, KENESHEA T J, NARCISI R S. Numerical modelling of a metallic ion sporadic-E layer[J]. Radio Sci., 1975, 10(3):371-388 [2] RØYRVIK O. Midlatitude sporadic-E layers and vertical metallic ion drift profiles[J]. Planet. Space Sci., 1983, 31(2):253-264 [3] CARTER L N, FORBES J M. Global transport and localized layering of metallic ions in the upper atmosphere[J]. Ann. Geophys., 1999, 17(2):190-209 [4] TAN Hui. Simulation and Statistic Analysis on Mid-Latitude Sporadic E-Layers[D]. Wuhan:Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 2004(谭辉. 中纬电离层突发E层的统计特性及模拟研究[D]. 武汉:中国科学院武汉物理与数学研究所, 2004) [5] GLEESON L J, AXFORD W I. Electron and ion temperature variations in temperate zone sporadic-E layers[J]. Planet. Space Sci., 1967, 15(1):123-136 [6] TITHERIDGE J E. Modelling the peak of the ionospheric E-layer[J]. J. Atmos. Solar Terr. Phys., 2000, 62(2):93-114 [7] SCHUNK R W, NAGY A F. Ionospheres:Physics, Plasma Physics and Chemistry[M]. Cambridge:Cambridge University Press, 2000 [8] RICHARDS P G, FENNELLY J A, TORR D G. EUVAC:a solar EUV flux model for aeronomic calculations[J]. J. Geophys. Res., 1994, 99(A5):8981-8992 [9] STROBEL D F, OPAL C B, MEIER R R. Photoionization rates in the night-time E-and F-region ionosphere[J]. Planet. Space Sci., 1980, 28(11):1027-1033 [10] STROBEL D F, YOUNG T R, MEIER R R, et al. The nighttime ionosphere:E region and lower F region[J]. J. Geophys. Res., 1974, 79(22):3171-3178 [11] XU Tong. Study on modeling of mid/low-latitude ionosphere and its relative anomalous phenomenon[D]. Xi'an:Xidian University, 2009(徐彤. 中低纬电离层模型及其异常现象相关研究[D]. 西安:西安电子科技大学, 2009) [12] THOMAS G E. The interstellar wind and its influence on the interplanetary environment[J]. Ann. Rev. Earth Planet. Sci., 1978, 6:173-204 [13] WELLER C S, MEIER R R. Observations of helium in the interplanetary/interstellar wind-The solar-wake effect[J]. Astrophys. J., 1974, 193:471-476 [14] WHITEHEAD J D. Production and prediction of sporadic E[J]. Rev. Geophys., 1970, 8(1):65-144 [15] MACDOUGALL J W. 110 km neutral zonal wind patterns[J]. Planet. Space Sci., 1974, 22(4):545-558 [16] ŠAULI P, BOURDILLON A. Height and critical frequency variations of the sporadic-E layer at midlatitudes[J]. J. Atmos. Solar Terr. Phys., 2008, 70(15):1904-1910 [17] HALDOUPIS C, PANCHEVA D, SINGER W, et al. An explanation for the seasonal dependence of midlatitude sporadic E layers[J]. J. Geophys. Res., 2007, 112(A6):A06315, doi: 10.1029/2007JA012322
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