Using an Inversion Method to Estimate Precipitating Energy Flux of Pulsating Aurora

Jodie McLennan

To better understand energy flow from the magnetosphere into the ionosphere, we seek to quantify the energy input of pulsating aurora, a common, long-lasting, and energetic type of aurora. Its precipitating electrons typically have energies from a few to 100s keV and are associated with MeV microburst precipitation. These energetic electrons can deposit energy into the D region and are associated with ozone loss in our atmosphere. One method to measure its precipitating electron energy flux is to use an inversion method that utilizes ground-based observations from an incoherent scatter radar (ISR). Here we validate an inversion outlined by Semeter and Kamalabadi (2005) with in-situ spacecraft data from the Electron Losses and Fields Investigation (ELFIN) spacecraft for an energetic pulsating aurora event. This method uses electron density vs altitude measurements from the Poker Flat ISR (PFISR) and calculates the precipitating energy flux spectra. It uses both an atmospheric chemistry model that finds the recombination coefficient, and an ionization rate model. We seek to validate a selection of these model inputs by comparing the inverted flux to the in-situ measurements of the bounce loss cone flux. Additionally, we utilize this method to estimate the evolution of electron energy flux spectra during active substorm periods that also exhibit pulsating aurora activity.

To participate in this event virtually via Zoom, go to https://uiowa.zoom.us/j/97966965677?pwd=QXbiQaiaCRCefviFhi43CJILttoKTy.1&from=addon.