Observations of EIT Waves with the Recent STEREO Mission
|Yu Dai |
"Observations of EIT Waves with the Recent STEREO Mission"
Since EIT waves were for the first time observed by the Extreme-ultraviolet Imaging Telescope (EIT)
on board the SOHO satellite, their nature has been intensely debated. Some authors have modeled
EIT waves as a fast-mode MHD wave in the corona, with its skirt sweeping through the chromosphere,
behaving as a Moreton wave. However, the non-wave interpretations consider them as propagating
disturbances related to magnetic field line opening and restructuring associated with the coronal mass
ejection (CME)-liftoff. The improvements in temporal resolution and spatial coverage of the recent
Solar Terrestrial Relations Observatory (STEREO) mission give us an unprecedented opportunity to
better study EUV waves (In STEREO period, the term "EIT waves" may be somewhat obsolete).
Our EUVI-COR1 composite observations of a limb CME and the associated EUV disturbances support
a new non-wave model recently proposed by Attrill et al., while on-disk observations of another event
with the high cadence in 171 A bandpass are in favor of the wave models. With the increasing separation,
the STEREO twin spacecraft will enable us to observe both limb and on-disk signatures of an "EUV wave"
if the source region is appropriately located. A synthesis of the stereoscopic observations may give a
full view of such wave-like disturbances.