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Evaluation of the Empirical Scaling Factor of Joule Heating Rates in TIE-GCM with EISCAT Measurements
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  • Florian Ludwig Günzkofer,
  • Huixin Liu,
  • Gunter Stober,
  • Dimitry Pokhotelov,
  • Claudia Borries
Florian Ludwig Günzkofer
German Aerospace Center (DLR)

Corresponding Author:[email protected]

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Huixin Liu
Earth and Planetary Science Department, Kyushu University
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Gunter Stober
University of Bern
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Dimitry Pokhotelov
Institute of Physics, University of Greifswald
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Claudia Borries
German Aerospace Center
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Abstract

Joule heating is one of the main energy inputs into the thermosphere-ionosphere system. Precise modeling of this process is essential for any space weather application. Existing ionosphere models tend to underestimate the actual Joule heating rate quite significantly. The Thermosphere-Ionosphere-Electrodynamics General-Circulation-Model applies an empirical scaling factor of 1.5 for compensation. We calculate vertical profiles of Joule heating rates from approximately 2220 h of measurements with the EISCAT incoherent scatter radar and the corresponding model runs. We investigate model runs with the plasma convection driven by both the Heelis and the Weimer model. The required scaling of the Joule heating profiles is determined with respect to the Kp index, the Kan-Lee merging electric field EKL, and the magnetic local time. Though the default scaling factor of 1.5 appears to be adequate on average, we find that the required scaling varies strongly with all three parameters ranging from 0.46 to ∼20 at geomagnetically disturbed and quiet times, respectively. Furthermore, the required scaling is significantly different in runs driven by the Heelis and Weimer model. Adjusting the scaling factor with respect to the Kp index, EKL, the magnetic local time, and the choice of convection model would reduce the difference between measurement and model results.
28 Nov 2023Submitted to ESS Open Archive
01 Dec 2023Published in ESS Open Archive