Browsing by Author "Pitzel, Jared Colton"

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    Estimating Electron Precipitation using the Total Radiation Belt Electron Content
    (2022-08-18) Pitzel, Jared Colton; Cully, Christopher; Donovan, Eric; Spanswick, Emma; Stil, Jeroen
    In the near-Earth space environment charged particles, mainly electrons and protons, are heavily influenced by Earth's magnetic field and can be captured for years and more. The number of particles with trapped trajectories accumulates over time to create regions of high-intensity radiation that are known as the Van Allen radiation belts. External forces can alter these trajectories such that particles are lost from the radiation belts and enter Earth's atmosphere where they deposit energy via collisions. The transfer of energy from particles that precipitate into the atmosphere triggers changes to the chemistry of the upper atmosphere that play a role in the destruction of ozone. This may engender long-term climate effects, but the extent of these changes has been difficult to quantify given that the flux and spectrum of precipitating particles is inherently difficult to estimate from limited point measurements of in-situ spacecraft. This thesis uses a globally integrated quantity, the Total Radiation Belt Electron Content (TRBEC), to quantify the rates of Energetic Electron Precipitation (EEP). The TRBEC is a single value that indicates the number of electrons in a given population in the radiation belts and its time rate of change is used to estimate the number of particles that are lost due to precipitation. The necessary framework of the TRBEC is first derived extensively followed by a demonstration of its ability to infer EEP by utilizing observations from the Van Allen Probes during a geomagnetically quiet interval in 2013. It is determined that the total number of electrons in the radiation belts has been overestimated in recent literature during the same period, at least by a factor of about 250. Simultaneously, a well-regarded EEP model underestimates precipitation rates compared to that from the TRBEC method, at least by an order of magnitude and generally much more.