On the Excitation of ULF Waves after Interplanetary Shock-induced Impulses
Abstract
We study the generation of the ULF wave during shock-related sudden impulse in the Earth magnetosphere using Van Allen Probes measurement. Among the 63 shock-related sudden impulses, there are 39 cases with ULF wave induced and we find that in strong wave cases the impulse frequency appears correlated to the induced wave frequency which, at the same time, appears correlated to the local eigen frequency. Our results show that the shock-related ULF wave can be excited in the magnetosphere on condition that the shock-induced impulse frequency matches the local eigen frequency. We also find that the frequency of the first period of shock-related impulse is likely determined by the local fast-mode speed instead of local eigen frequency, which shows that the characteristic of the first impulse period is more likely related to a propagation mechanism rather than field-line resonance. A more detailed study using MMS measurement on how shock impulse propagates from solar wind into magnetosphere is in process.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSM51C3203Z
- Keywords:
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- 2139 Interplanetary shocks;
- INTERPLANETARY PHYSICS;
- 2740 Magnetospheric configuration and dynamics;
- MAGNETOSPHERIC PHYSICS;
- 2784 Solar wind/magnetosphere interactions;
- MAGNETOSPHERIC PHYSICS;
- 7811 Discontinuities;
- SPACE PLASMA PHYSICS