Observations and simulations of quasiperiodic ionospheric oscillations and large-scale traveling ionospheric disturbances during the December 2006 geomagnetic storm

A prominent northward propagating large-scale traveling ionospheric disturbance (LSTID) during daytime, seen by the GEONET total electron content (TEC) data, was captured by the CMIT model. Two southward LSTIDs observed by GEONET GPS network were also reproduced by the CMIT model. However, the model gave faster phase speeds for the southward propagating LSTID occurred during 0620-0800 UT and the northward propagating LSTID; furthermore, the model missed the LSTID seen in the TEC perturbation data during 0140-0220 UT.

Finally, both observations and simulations showed a strong hemispheric asymmetry for the TAD propagation that occurred during 0000-0400 UT, which may be associated with the hemispheric asymmetry of the change of Joule heating at high latitude.