Oscillation of the ionosphere at planetary-wave periods

E x B drifts dominate at the magnetic equator, while the two sources play more equal roles between 20 degrees and 40 degrees magnetic latitudes in each hemisphere. The in situ neutral wind effect arises from vertical propagation of PW-modulated tides, whereas the ExB drifts originate from dynamo-generated electric fields produced by the E-region component of the same wind field; the former represents a new coupling mechanism for production of ionospheric oscillations at PW periods.

Roughly half the above-mentioned variability in Ne and Delta hmF2 is associated with zonally symmetric (S0) oscillations, which contribute at about half the level of low-level magnetic activity during October 2009. The thermosphere-ionosphere-electrodynamics general circulation model simulates the S0 oscillations in Ne observed from the CHAMP satellite well during this period and reveals that S0 oscillations in ExB play a significant role in driving S0 oscillations in hmF2, in addition to neutral winds.