Large-scale auroral-zone electron precipitation event, briefly interrupted during a negative magnetic impulse

Multiple balloon recordings of bremsstrahlung X-rays from a large scale auroral-zone electron precipitation event are presented. Additional riometer recordings show that it extended from noon, via dusk, to midnight. The X-ray observations show electron precipitation over a range of L -values from ∼− 5.5 to 7.5. This was briefly interrupted during a negative sudden impulse in the geomagnetic field. A close similarity between variations in the X-ray fluxes and locally recorded variations in the geomagnetic field was observed. Magnetic records from around the auroral zone suggest that the precipitation was related to an asymmetric magnetospheric convection system.