Ion and neutral motions observed in the winter polar upper atmosphere
Ion and neutral motions observed in the winter polar upper atmosphere
复制标题
在冬季极地高层大气中观察到的离子和中性运动
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
W. Guo
中科院分区：
文献类型：
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作者：
R. Heelis;D. Mcewen;W. Guo
[1]离子漂移的连续样品从DMSP卫星近800公里的高度，并与远程测量的F区中性风从地面在尤里卡在北方极冠。这些测量值相互比较，并与行星际磁场和太阳风的变化进行比较。在6天的时间内，国际货币基金组织的北-南分量和离子和中性漂移的正午-午夜分量之间的线性关系被用来确定气体运动的响应时间的变化，在太阳风驱动器。当IMF向南或弱向北时，离子和中性气体响应几乎立即开始于太阳风驱动器的变化。离子响应的时间常数约为20 min，而对于约5 × 105 cm−3的F峰密度，中性时间常数为75 min。虽然存在显著的变化，但响应时间之间的55 min时间差与测量时间和位置处F区域中的中性离子碰撞时间一致。在准平衡状态下，超过150 m s−1的反日离子漂移会以约60%的离子漂移速度驱动中性气体反日。
[1] Continuous samples of the ion drift are made near 800-km altitude from the DMSP satellite and compared with remote measurements of the F region neutral winds made from the ground at Eureka in the northern polar cap. These measurements are compared with each other and with variations in the interplanetary magnetic field and solar wind. Over a 6-day period, linear relationships between the north-south component of the IMF and the noon-midnight components of the ion and neutral drifts are used to determine the response times of the gas motions to changes in the solar wind driver. When the IMF is southward or weakly northward, the ion and neutral gas response begins almost immediately following a change in the solar wind driver. The time constant for the ion response is about 20 min, while for an F peak density of about 5 × 105 cm−3 the neutral time constant is 75 min. While significant variability exists, the 55-min time difference between the response times is consistent with the neutral-ion collision time prevailing in the F region at the time and location of the measurements. In the quasi-equilibrium state, antisunward ion drifts in excess of 150 m s−1 drive the neutral gas antisunward with speeds about 60% of the ion drift.