Quiet variability of equatorial E x B drifts during a sudden stratospheric warming event

We present strong evidence that during the January 2008 minor sudden stratospheric warming (SSW) event, the equatorial vertical x drifts exhibit a unique and distinctive daytime pattern. We do not think one event causes the other, however both events might be related through the global effects of planetary waves. The drifts were measured by the Jicamarca Incoherent scatter radar located under the magnetic equator. We have observed an anomalous temporal variation of the vertical x drifts during the minor SSW event, showing a semidiurnal variation with very large amplitudes lasting for several days. Large differences in the x drifts were observed during a period of large increase of temperature and a large decrease of mean zonal wind, in the high latitude stratosphere (60 deg - 90 deg N). This high correlation is an unexpected finding which might shed new light on sources and mechanisms of quiet-time ionospheric variability.