Prompt disappearance and emergence of radiation belt magnetosonic waves induced by solar wind dynamic pressure variations
Prompt disappearance and emergence of radiation belt magnetosonic waves induced by solar wind dynamic pressure variations
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太阳风动压变化引起的辐射带磁声波的迅速消失和出现
DOI：
10.1002/2017gl076382
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发表时间：
2018
影响因子：
5.2
通讯作者：
Wang Shui
中科院分区：
文献类型：
--
作者：
Liu Nigang;Su Zhenpeng;Zheng Huinan;Wang Yuming;Wang Shui
磁声波是一种高度倾斜的哨声模式发射，将能量从环电流质子传递到内磁层的辐射带电子。本文首次报道了由太阳风动压变化引起的磁声波的迅速消失和出现。太阳风动压降低导致磁层膨胀，使Bernstein模不稳定性产生的环电流质子绝热减速，导致磁声波迅速消失。相反，由于太阳风动压增强对环电流质子的绝热加速，磁声波突然出现。在没有热质子脉冲注入的情况下，即使在太阳风动压增强的时间段也能观察到磁声波。结果表明，太阳风动压是模拟磁声波及其对辐射带电子影响的重要参数。
Magnetosonic waves are highly oblique whistler mode emissions transferring energy from the ring current protons to the radiation belt electrons in the inner magnetosphere. Here we present the first report of prompt disappearance and emergence of magnetosonic waves induced by the solar wind dynamic pressure variations. The solar wind dynamic pressure reduction caused the magnetosphere expansion, adiabatically decelerated the ring current protons for the Bernstein mode instability, and produced the prompt disappearance of magnetosonic waves. On the contrary, because of the adiabatic acceleration of the ring current protons by the solar wind dynamic pressure enhancement, magnetosonic waves emerged suddenly. In the absence of impulsive injections of hot protons, magnetosonic waves were observable even only during the time period with the enhanced solar wind dynamic pressure. Our results demonstrate that the solar wind dynamic pressure is an essential parameter for modeling of magnetosonic waves and their effect on the radiation belt electrons.