Plasma environment of Venus: Comparison of Venus Express ASPERA‐4 measurements with 3‐D hybrid simulations
Plasma environment of Venus: Comparison of Venus Express ASPERA‐4 measurements with 3‐D hybrid simulations
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DOI：
10.1029/2008je003174
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发表时间：
2007-12
影响因子：
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通讯作者：
C. Martinecz;A. Boesswetter;M. Fränz;E. Roussos;J. Woch;N. Krupp;E. Dubinin;U. Motschmann;S. Wie
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文献类型：
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作者：
C. Martinecz;A. Boesswetter;M. Fränz;E. Roussos;J. Woch;N. Krupp;E. Dubinin;U. Motschmann;S. Wie
[1]我们利用金星快车搭载的ASPERA - 4离子和电子能谱仪的数据来确定金星上等离子体边界（弓形激波、离子成分边界和幔）的位置和形状。我们还研究了终端弓形激波位置随太阳风动压和太阳极紫外通量的变化。我们将结果与三维混合模拟进行了比较。在混合模型中，离子被视为在自洽产生的电磁场中运动的单个粒子，电子被建模为无质量的电荷中和流体。行星重离子等离子体是由适应于一个剖面的氧电离层和外逸层产生的，该剖面取决于太阳天顶角（查普曼层）。观测结果和模拟之间的比较表明，混合模型能够对金星的全球等离子体环境产生足够的描述。该模型很好地再现了等离子体边界的位置，但在所考虑参数的绝对值上出现了显著差异。
[1] We use data of the ASPERA-4 ion and electron spectrometers onboard Venus Express to determine the locations and shapes of the plasma boundaries (bow shock, ion composition boundary, and mantle) at Venus. We also investigate the variation of the terminator bow shock position as a function of the solar wind dynamic pressure and solar EUV flux. We compare the results with a 3-D hybrid simulation. In the hybrid model, ions are treated as individual particles moving in self-consistently generated electromagnetic fields and electrons are modeled as a massless charge neutralizing fluid. The planetary heavy ion plasma is generated by an oxygen ionosphere and exosphere adapted to a profile, which depends on the solar zenith angle (Chapman layer). A comparison between observations and simulations indicates that the hybrid model is able to produce an adequate picture of the global plasma environment at Venus. The positions of the plasma boundaries are well reproduced by the model but a significant disagreement appears in the absolute values of the considered parameters.