Magnetic Oscillations at Mars During the October 2003 Solar Storm

The powerful x-class superflare which occurred on the Sun on October 28, 2003 had important effects on the plasma environments of both the Earth and Mars. We present here observations of the effects at Mars from the Mars Global Surveyor (MGS) Magnetometer/Electron Reflectometer experiment. In particular we focus on the changes in the nature of the magnetic oscillations observed during the passage of the solar storm. We find that the types of plasma oscillations observed at the MGS mapping altitude of 400 km are similar to the oscillations observed in the magnetosheath (which is normally at altitudes higher than 1000 km). This result is consistent with other observations that show that the magnetosheath altitude is lowered during the solar storm. We also observe relatively strong oscillations in the nightside tail region where such oscillations are rarely observed. Such observations have implications for atmospheric loss since they raise the possibility that large portions of the atmosphere are exposed to the solar wind and are hence subject to pickup escape during such large storm events.