Vibrationally excited nitrogen in stable auroral red arcs and its effect on ionospheric recombination
Vibrationally excited nitrogen in stable auroral red arcs and its effect on ionospheric recombination
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稳定极光红弧中的振动激发氮及其对电离层复合的影响
DOI：
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发表时间：
1974
期刊：
影响因子：
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通讯作者：
P. Meijer
中科院分区：
文献类型：
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作者：
G. Newton;James C. G. Walker;P. Meijer
与时间相关的连续性方程，包括扩散，解决了前六个能级的氮分子的条件下，在热层对应于稳定的极光红（SAR）弧。氮分子激发的主要来源是热电子与氮分子之间的亚激发非弹性碰撞。该过程的反应速率来自已发表的横截面计算。振动能的损失过程是电子和原子氧的猝灭。结果表明，分子氮被振动激发的程度，电离层损失过程，O+ + N2 → NO+ + N的速率常数，增加了多达7.6倍，在F2区的高度。结果发现，偏离能量等效玻尔兹曼分布是大的，导致的速率常数是多达1.6倍的速率常数计算的玻尔兹曼分布。这些结果表明，合成孔径雷达弧强度小至58 R可以产生显着增加电离层离子原子交换反应率，从而在电离层电子的损失率。有人建议，所观察到的SAR弧中F2区域的电子密度的降低可能可以解释由电子碰撞引起的分子氮的振动激发的O+和N2之间的离子-原子交换的增强的反应速率。
The time-dependent continuity equations, including diffusion, were solved for the first six energy levels of molecular nitrogen for conditions in the thermosphere corresponding to stable auroral red (SAR) arcs. The primary source of molecular nitrogen excitation was subexcitation inelastic collisions between thermal electrons and molecular nitrogen. The reaction rates for this process were derived from published cross-section calculations. The loss processes for vibrational energy were quenching by electrons and atomic oxygen. The results show that molecular nitrogen is excited vibrationally to the degree that the rate constant for the ionospheric loss process, O+ + N2 → NO+ + N, is increased by as much as a factor of 7.6 at F2 region altitudes. It was found that deviations from the energetically equivalent Boltzmann distribution were large, causing the rate constant to be as much as 1.6 times the rate constant calculated for the Boltzmann distribution. These results indicate that SAR arc intensities as small as 58 R can produce noticeable increases in the ionosphere ion-atom interchange reaction rate and hence in the rate of loss of ionospheric electrons. It is suggested that the observed decrease of electron density in the F2 region in SAR arcs can probably be explained by enhanced reaction rates for ion-atom interchange between O+ and N2 caused by vibrational excitation of molecular nitrogen by electron impact.