F region ion temperature enhancements resulting from Joule heating
F region ion temperature enhancements resulting from Joule heating
复制标题
焦耳热导致 F 区离子温度增强
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
R. Wand
中科院分区：
文献类型：
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作者：
M. Baron;R. Wand
F区离子温度测量是由Chatanika和Millstone Hill非相干散射雷达进行的，这是磁层-电离层-热层雷达研究协调高纬度观测方案的一部分。在这两个雷达，增强离子温度与焦耳加热事件的周期进行了检测。观测的一个常规特征是，在电场强度相当的时期内，与晚间部分相比，早晨部分存在更大和更持久的温度增强。由于离子温度与离子和中性速度之间的矢量差的平方成比例地增加，因此早晨/傍晚温度增强不对称意味着早晨/傍晚中性风不对称。晚上的中性风必须更紧密地对准离子流矢量。这可能是由于夜晚扇区的等离子体密度较高，使离子能够使中性空气运动。同时等离子体密度和离子速度测量与离子温度数据的比较支持上述解释所观察到的更大的早晨扇区温度增强。
F region ion temperature measurements were made by the Chatanika and Millstone Hill incoherent scatter radars as part of the Magnetosphere-Ionosphere-Thermosphere Radar Studies program of coordinated high-latitude observations. At both radars, periods of enhanced ion temperature associated with Joule heating events were detected. A regular feature of the observations was the existence of larger and longer lasting temperature enhancements in the morning sector as contrasted with the evening sector during periods of comparable electric field magnitudes. Because the ion temperature increases in proportion to the square of the vector difference between the ion and neutral velocities, the morning/evening temperature enhancement asymmetry implies a morning/evening neutral wind asymmetry. The neutral wind in the evening must be more closely aligned to the ion flow vector. This might arise as a consequence of the higher plasma density in the evening sector, enabling the ions to set the neutral air in motion. Comparison of the simultaneous plasma density and ion velocity measurements with the ion temperature data supports the foregoing explanation for the observed greater morning sector temperature enhancements.