Possible evidence of damped cavity mode oscillations stimulated by the January, 1997 magnetic cloud event
Possible evidence of damped cavity mode oscillations stimulated by the January, 1997 magnetic cloud event
复制标题
1997 年 1 月磁云事件激发阻尼腔模式振荡的可能证据
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
W. Lotko
中科院分区：
文献类型：
--
作者：
Jerry Goldstein;Mary Hudson;W. Lotko
太阳风动压的突变是等离子体层中激发腔模共振的一种机制。为了研究1 997年1 1 1 8 cm−3太阳风密度脉冲后发生空泡模的可能性，在偶极子网格上进行了数值模拟。将由虚拟卫星记录的模拟光谱与0228-0304UT期间的极磁时间信号产生的光谱进行了比较。在这两组光谱中，功率集中在2-5 MHz之间；在6-20 MHz范围内观察到的类似FLR的谱峰与模拟的等离子体层FLR在7-21 MHz之间大致一致。在模拟中，等离子体层的基模为3.5 MHz；对0230-0237UT区间内观测到的3.5 MHz电场和磁场信号进行的相位分析支持在该频率处存在严重衰减驻波的可能性。
A sudden drastic change in the solar wind dynamic pressure is one proposed mechanism for the excitation of cavity mode resonances in the plasmasphere. To study the possibility of cavity mode occurrence following a 180 cm−3 solar wind density pulse on January 11, 1997, a numerical MHD simulation was run on a dipole grid. The simulated spectra recorded by a virtual satellite are compared with those produced from the Polar magnetic time signals during the interval 0228–0304 UT. In both sets of spectra, power is concentrated between 2 and 5 mHz; observed FLR‐like spectral peaks in the range 6–20 mHz are in rough agreement with simulated plasmaspheric FLRs between 7–21 mHz. In the simulation, the fundamental plasmaspheric cavity mode is at 3.5 mHz; phase analysis of observed 3.5 mHz electric and magnetic field signals from the interval 0230–0237 UT supports the possibility of a heavily damped standing wave at this frequency.