Electron temperature in the cusp as measured with the SCIFER‐2 sounding rocket

Abstract

It is expected that energy deposited by soft auroral electron precipitation in the ionosphere should result in heating of ionospheric electrons in that location, and this heating is an important step in the ion outflow process. We present coordinated observations from the SCIFER‐2 sounding rocket in the cusp region overflying optical observing sites in Svalbard. The rocket payload included a sensor which is designed to measure the temperature of thermal electrons. We show that elevated electron temperatures measured in situ are correlated with electron precipitation as inferred from auroral emissions during the 60–120 s preceding the passage of the rocket. This integrated “cooking time” is an important factor in determining the origin and resulting flux of outflowing ions.