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Automated Identification of Electron Microinjections in MMS/FEEPS Measurements: Initial Results
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  • Seth Claudepierre,
  • Joseph Fennell,
  • Ananya Sengupta,
  • Craig Kletzing
Seth Claudepierre
Aerospace Corporation Santa Monica

Corresponding Author:[email protected]

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Joseph Fennell
The Aerospace Corp
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Ananya Sengupta
University of Iowa
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Craig Kletzing
University of Iowa
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The MMS spacecraft routinely observe electron “microinjections” at energies in the 10s-100s keV range across the nightside magnetosphere at distances <20 Re. Microinjections are typically observed in clusters where multiple dispersed injection signatures are recorded in succession over a short time interval (e.g., ~10 in one hour) and may be related to surface wave activity at the magnetopause. Recent work has shown that microinjections have distinctive features in the angular distributions, where field-aligned distributions are observed near dusk, while trapped distributions are observed near dawn. Due to their recent discovery, the origin and generation of microinjections has yet to be conclusively identified and detailed studies thus far have largely been done on a case-by-case basis. In an effort to elucidate more general properties and characteristics of microinjections, we describe an automated routine designed to identify microinjection signatures in the MMS/FEEPS measurements. The algorithm uses image processing techniques (the radon transform) and is based on a similar method developed to identify whistler-mode chorus elements in Van Allen Probes wave observations (Sen Gupta et al., [2017]). We present an initial set of results from a statistical database of microinjection events obtained from the automated algorithm to further our understanding of this intriguing phenomenon.