Development of the electron streaming instability in magnetopause reconnection

The development of the electron streaming instability is usually very fast, making it difficult to be observed from spacecraft observations. However, with a separation of 10s of km, Magnetospheric Multiscale(MMS) spacecraft provide a good opportunity to resolve the spatial evolution of election beams and also the corresponding electron streaming instability. Here, we show such an event in the magnetopause reconnection, in which the accelerated electrons of the sheath origin become unstable at the magnetospheric side, and different MMS spacecraft captures significantly different wave activities. Interestingly, the scattered electrons may even form agyrotropic electron distributions as observed by one MMS spacecraft.