Evaluation of the Empirical Scaling Factor of Joule Heating Rates in TIE‐GCM With EISCAT Measurements

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 thermosphere‐ionosphere models tend to underestimate the actual Joule heating rate quite significantly. The Therm...

Full description

Bibliographic Details
Published in:Earth and Space Science
Main Authors: Florian Günzkofer, Huixin Liu, Gunter Stober, Dimitry Pokhotelov, Claudia Borries
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union (AGU) 2024
Subjects:
Joule heating
incoherent scatter radar
ionosphere model
polar plasma convection
Astronomy
QB1-991
Geology
QE1-996.5
EISCAT
Online Access:https://doi.org/10.1029/2023EA003447
https://doaj.org/article/7f209b06b7104bbd9dc2d5ab075717c6
Description
Summary: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 thermosphere‐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 2,220 hr 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 Joule heating rates calculated from measurement and model plasma parameters.

Similar Items