Fine Structure of Chorus Wave Packets: Comparison Between Observations and Wave Generation Models
Fine Structure of Chorus Wave Packets: Comparison Between Observations and Wave Generation Models
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DOI：
10.1029/2021ja029330
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发表时间：
2021-08
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影响因子：
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通讯作者：
X.‐J. Zhang;A. Demekhov;Y. Katoh;D. Nunn;X. Tao;D. Mourenas;Y. Omura;A. Artemyev;V. Angelopoulos
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作者：
X.‐J. Zhang;A. Demekhov;Y. Katoh;D. Nunn;X. Tao;D. Mourenas;Y. Omura;A. Artemyev;V. Angelopoulos
强烈的低频合唱波在内磁层中是普遍存在的。它们的特性已经被各种代码建模，并使用许多航天器任务的测量进行了研究。本研究的目的是比较模拟和观测到的合唱波的特性。我们提出了详细的比较结果从四个不同的代码的非线性合唱波的产生和统计观测卫星，专注于这样的合唱波的精细结构。我们表明，这些不同的代码进行的模拟很好地再现所观察到的波包特性，虽然在有些互补的参数域的波包的大小，幅度和频率扫描速率。特别是，模拟生成频繁观察到的短波包具有高的正和负频率扫描速率，和更罕见的长和强烈的数据包，主要是上升的音调。此外，模拟再现定量的增加所观察到的合唱波包的大小与它们的峰值幅度，和它们的频率扫描速率的快速下降，因为它们的大小增加。这证实了现有的主要代码的可靠性，准确建模合唱波的产生，虽然我们发现，初始条件应仔细选择重现给定的参数范围。
Intense lower band chorus waves are ubiquitous in the inner magnetosphere. Their properties have been modeled by various codes and investigated using measurements of many spacecraft missions. This study aims to compare simulated and observed properties of chorus waves. We present detailed comparisons between results from four different codes of nonlinear chorus wave generation and statistical observations from satellites, focusing on the fine structure of such chorus waves. We show that simulations performed with these different codes well reproduce the observed wave packet characteristics, although in somewhat complementary parameter domains as concerns wave packets sizes, amplitudes, and frequency sweep rates. In particular, simulations generate both the frequently observed short wave packets with high positive and negative frequency sweep rates, and the more rare long and intense packets with mainly rising tones. Moreover, simulations reproduce quantitatively both the increase of the size of the observed chorus wave packets with their peak amplitude, and the fast decrease of their frequency sweep rate as their size increases. This confirms the reliability of the main existing codes for accurately modeling chorus wave generation, although we find that initial conditions should be carefully selected to reproduce a given parameter range.