Reconciliation of rocket‐based magnetic field measurements in the equatorial electrojet with classical collision theory

Abstract

[1] We provide an explanation for a long-standing (more than 35 years) discrepancy between theory and rocket experiments concerning the peak height of the electrojet current and the magnitude of magnetic field perturbation. The arbitrary correction of the electron-neutral collision frequency by a factor of 4, which has been used to explain these problems, is not necessary if the field line-integrated conductivities are used. Recent research using ground-based magnetometers and CHAMP have also used this constant connection to classical collision theory. These methods arbitrarily change the electron-neutral collision frequency. A field line-integrated theoretical study of the electrojet by G. Haerendel and J. V. Eccles, implemented in this paper, explains the height of the electrojet using classical collision frequency. Furthermore, we argue that since the correction factor is independent of the driving electric field, it is unlikely that anomalous electron collision frequency due to a nonlinear plasma instability (gradient drift) is involved.Citation: Kelley, M. C., R. R. Ilma, and V. Eccles (2012), Reconciliation of rocket-based magnetic field measurements in the equatorial electrojet with classical collision theory,

Latitude-dependent delay in the responses of the equatorial electrojet and <i>S</i><sub><i>q</i></sub> currents to X-class solar flares

“…A rapid rise in the conductivity marks the sunrise, which is followed by the daytime increase in its values that peak at midday (UT−3). In its height variation the C peaks in the region of 105-107 km, which is in accordance with results from many observational and theoretical studies (Richmond, 1973;Haerendel and Eccles, 1992;Kelley et al, 2012). In the right panels, where the time variation of the solar flux is considered, we can clearly note the sensibility of the integrated Cowling conductivity to small changes in the EUV flux variation.…”