Discovery of very large amplitude whistler-mode waves in Earth's radiation belts
Discovery of very large amplitude whistler-mode waves in Earth's radiation belts
复制标题
DOI：
10.1029/2007gl032009
复制
发表时间：
2008-01-12
影响因子：
5.2
通讯作者：
Russell, C. T.
中科院分区：
文献类型：
--
作者：
Cattell, C.;Wygant, J. R.;Russell, C. T.
STEREO S/ waves仪器在穿过地球黎明侧外辐射带时，观测到振幅高达240 mV/m以上的哨声模式波。这些波比以前在辐射带中观察到的哨子波要大一个数量级。虽然峰值频率与口哨声合唱相似，但除了振幅更大之外，与合唱有明显的区别，包括频率上没有漂移，纵向电场分量大的斜传播。模拟结果表明，这些振幅较大的波可以在不到0.1s的时间内使电子获得1兆电子伏数量级的能量，这解释了在此事件中STEREO-B和STEREO-A通道之间观察到的电子强度的快速增强。我们的研究结果表明，通常的小振幅波的电子能量和散射理论模型，以小时到天的时间尺度，可能不足以理解辐射带动力学。
During a passage through the Earth's dawn-side outer radiation belt, whistler-mode waves with amplitudes up to more than similar to 240 mV/m were observed by the STEREO S/WAVES instrument. These waves are an order of magnitude larger than previously observed for whistlers in the radiation belt. Although the peak frequency is similar to whistler chorus, there are distinct differences from chorus, in addition to the larger amplitudes, including the lack of drift in frequency and the oblique propagation with a large longitudinal electric field component. Simulations show that these large amplitude waves can energize an electron by the order of an MeV in less than 0.1s, explaining the rapid enhancement in electron intensities observed between the STEREO-B and STEREO-A passage during this event. Our results show that the usual theoretical models of electron energization and scattering via small-amplitude waves, with timescales of hours to days, may be inadequate for understanding radiation belt dynamics.