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A comparison of auroral oval proxies with the boundaries of the auroral electrojets
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  • Simon James Walker,
  • Karl Laundal,
  • Jone Peter Reistad,
  • Anders Ohma,
  • Spencer Mark Hatch,
  • Gareth Chisham,
  • Margot Decotte
Simon James Walker
Univerisity of Bergen

Corresponding Author:[email protected]

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Karl Laundal
University in Bergen
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Jone Peter Reistad
Birkeland Centre for Space Science, University of Bergen
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Anders Ohma
Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen
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Spencer Mark Hatch
Birkeland Centre for Space Science
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Gareth Chisham
British Antarctic Survey
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Margot Decotte
University of Bergen
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The boundaries of the auroral oval and auroral electrojets are an important source of information for understanding the coupling between the solar wind and the near-earth plasma environment. Of these two types of boundaries the auroral electrojet boundaries have received comparatively little attention, and even less attention has been given to the connection between the two. Here we introduce a technique for estimating the electrojet boundaries, and other properties such as total current and peak current, from 1-D latitudinal profiles of the eastward component of equivalent current sheet density. We apply this technique to a preexisting database of such currents along the 105◦ magnetic meridian producing a total of eleven years of 1 minute resolution electrojet boundaries during the period 2000–2020. Using statistics and conjunction events we compare our electrojet boundary dataset with an existing electrojet boundary dataset, based on Swarm satellite measurements, and auroral oval proxies based on particle precipitation and field aligned currents. This allows us to validate our dataset and investigate the feasibility of an auroral oval proxy based on electrojet boundaries. Through this investigation we find the proton precipitation auroral oval is a closer match with the electrojet boundaries. However, the bimodal nature of the electrojet boundaries as we approach the noon and midnight discontinuities makes an average electrojet oval poorly defined. With this and the direct comparisons differing from the statistics, defining the proton auroral oval from electrojet boundaries across all local and universal times is challenging.
03 Jan 2024Submitted to ESS Open Archive
13 Jan 2024Published in ESS Open Archive