Dipolarization front (DF)—a sharp boundary separating hot tenuous plasmas from cold dense plasmas—is followed by a strong B_z region, which is termed flux pileup region (FPR) or dipolarizing flux bundle (DFB). Using 9‐year (2001‐2009) Cluster data, we show that the FPR hosts whistler waves because of the pancake distribution of electrons, whereas the DF boundary hosts lower hybrid drift waves due to the strong density and magnetic gradients statistically. Different from statistical results, we report an unexpected case: whistler waves are generated at the DF boundary rather than inside the FPR. Using Cluster data, we observed strong whistler waves at DF boundaries but no whistlers inside FPRs, although flux tubes inside the FPRs are significantly compressed and suprathermal electrons there are perpendicularly anisotropic. We calculate wave growth rates and successfully explain the generation/damping of these whistlers. We find that 1 – 4 keV electrons are responsible for generation/damping of these whistlers.

中文翻译：

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在偶极波前周围产生意外的惠斯勒波

双极化前沿（DF）（将热微弱等离子体与冷致密等离子体分离开来的尖锐边界）之后是强B _z区域，称为通量堆积区域（FPR）或双极化通量束（DFB）。使用9年（2001-2009年）的簇数据，我们显示FPR由于电子的薄饼分布而产生了吹口哨的波，而DF边界由于统计上的强密度和磁梯度而导致了较低的混合漂移波。与统计结果不同，我们报告了一个意外情况：在DF边界而不是FPR内部产生了哨声波。使用簇数据，我们在DF边界观察到了强啸叫声，但FPR内部没有啸叫声，尽管FPR内部的通量管被显着压缩并且超热电子垂直各向异性。我们计算波浪的增长率，并成功地解释了这些哨子的产生/阻尼。