Corection of the Jicamarca electron‐ion temperature ratio problem: Verifying the effect of electron Coulomb collisions on the incoherent scatter spectrum
Corection of the Jicamarca electron‐ion temperature ratio problem: Verifying the effect of electron Coulomb collisions on the incoherent scatter spectrum
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吉卡马卡电子离子温度比问题的修正：验证电子库仑碰撞对非相干散射光谱的影响
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
S. González
中科院分区：
文献类型：
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作者：
N. Aponte;M. Sulzer;S. González
自从20世纪70年代首次尝试使用完全非线性最小二乘分析拟合Jicamarca自相关函数（ACF）测量以来，对于大部分F区域数据，已经推导出低于1的表观电子-离子温度比。直到最近，Sulzer和González [1999]（以下简称SG）解释了电子库仑碰撞如何扭曲或缩小非相干后向散射光谱，并且这种缩小必须满足两个条件。首先，雷达k矢量必须位于接近垂直于磁场的小范围内，其次，雷达波长必须足够长。这两种情况在Jicamarca都是真实的。SG理论的精确计算现在可以在一个紧凑的图书馆，我们已经纳入了非相干散射最小二乘拟合代码。使用这个代码，我们已经减少了Jicamarca ACF数据与法拉第双脉冲模式，并发现SG理论正确解释ACF数据从Jicamarca，从而解决了长期的Te/Ti比的问题，从而允许精确的电子和离子温度测量。
Ever since the first attempts to fit Jicamarca autocorrelation function (ACF) measurements in the 1970s using a full nonlinear least squares analysis, an apparent electron‐ion temperature ratio below unity has been deduced for a large portion of the F region data. The cause of this unexpected and geophysically unreasonable result has been a mystery until recently, when Sulzer and González [1999] (herein SG) explained how electron Coulomb collisions can distort, or narrow, the incoherent backscatter spectrum, and that for this narrowing to be observable two conditions must be met. First, the radar k vector must lie in a small range near perpendicular to the magnetic field, and second, the radar wavelength must be sufficiently long. Both of these conditions are true at Jicamarca. The accurate calculations from the SG theory are now available in a compact library, which we have incorporated into an incoherent scatter least squares fitting code. Using this code, we have reduced Jicamarca ACF data taken with the Faraday double‐pulse mode, and find that the SG theory correctly interprets the ACF data from Jicamarca, thereby solving the longstanding Te/Ti ratio problem and thus allowing accurate electron and ion temperature measurements.