3. Case study observations and results
This study uses simultaneous chorus, microburst, and electron flux observations made from 5 December 2017 00:00 UT to 6 December 2017 06:00 UT. Geomagnetic activity prior to December 5th was relatively low until a weak (Dst ~ -45 nT) storm late on December 4th. This was accompanied by enhanced electron fluxes, as observed on MagEIS, in association with substorm activity (peaks in AE from 600 to 900 nT), which continued for several days. After December 6th, there was a gradual recovery, with no storms for the next few days.
There were four magnetic conjunction events (with RBSP and FIREBIRD within 1 MLT and 1 L shell of each other on 5 December 2017) during which FIREBIRD obtained high resolution data. Since we focus on the overall extent of the microburst-producing chorus source region, we include observations taken throughout the interval of interest. RBSP and Arase made multiple passes through the dawn-to-dusk MLT sectors across noon. FIREBIRD and AC6-A also made multiple microburst observations in these same regions.