Immediate Impact of Solar Wind Dynamic Pressure Pulses on Whistler‐Mode Chorus Waves in the Inner Magnetosphere
Yuyue Jin, Nigang Liu, Zhenpeng Su, Huinan Zheng, Yuming Wang, Shui Wang
Abstract
Abstract Solar wind‐magnetosphere coupling is a key link of the space weather chain. There have been increasing reports of solar wind dynamic pressure pulses influencing the whistler‐mode chorus wave growth in the inner magnetosphere, but the response conditions and mechanisms of chorus growth remain under debate. Here we present a statistical study of the immediate impact of solar wind dynamic pressure pulses on inner magnetospheric chorus waves using Van Allen Probes data from 2012 to 2019. A stronger pulse is found to have a greater likelihood to change the chorus amplitude particularly on the dayside. Positive pulses can significantly enhance chorus amplitudes, while negative ones result in a weakening in chorus amplitudes. As supported by direct observations, these pulses alter the linear growth of waves by modifying energetic electron distributions; in contrast, geomagnetic field modeling indicates no significant changes in the geomagnetic field inhomogeneity controlling the nonlinear growth threshold of waves.