Events Calendar

Determining the Energy Content and Size of a Pulsating Aurora Event

Jodie McLennan; University of Iowa

Studying aurora helps us understand the dynamics and the energy flow of energetic particles that move from the earth's magnetosphere into our upper atmosphere. What we observe as aurora are energetic particles that enter into our upper atmosphere and interact with the neutral particles resulting in light emission. One type of aurora, pulsating aurora, is considered to be more energetic, and we are interested in characterizing the energy of its precipitating electrons since it has been tied to loss of ozone (Verronen et al., 2021). Using an inversion method outlined in Semeter and Kamalabadi (2005), we can estimate the energy flux spectra of the precipitating electrons. This inversion method uses electron density over altitude measurements that are found with a radar instrument called the Poker Flat Incoherent Scatter Radar (PFISR). The inversion method also takes several other inputs, including differing chemistry and ionization models, and we seek to validate which combination of model inputs give the closest results to data. We use electron flux measurements from a low earth orbiting satellite, ELFIN, when it flies overhead PFISR as our "ground truth" data in our validations. Additionally, we analyze subionosphere propagating very low frequency (VLF) radio waves observed by several receivers, whose paths criss-cross the area of the event, to determine an approximate area of the pulsating aurora precipitation event during the LAMP rocket launch. With the size of the pulsating aurora precipitation area and the energy flux results from PFISR we can better understand the total energy input during the event. 

Anyone wishing to join the seminar virtually can do so via Zoom - https://uiowa.zoom.us/j/93816357338