Recurrent Flare/CME Events from an Emerging Flux Region


We basically have two items of compelling interest in these November 2000 flare/CME events that are the subject of the paper published in Geophysical Research Letters, 28, 3801 (2001).

First, it's well-known that CMEs (Coronal Mass Ejections) correlate with long-duration solar flares. This is important because CMEs play the biggest role in "space weather", i.e. solar disturbances out in our human part of the solar system. We would like to use those long-duration flares as a guide to the occurrence of a CME. These events from November, 2000, stand this correlation on its ear.

Second, these events were "homologous", meaning that they looked quite similar to one another. This is difficult to comprehend, because a CME re-structures the coronal magnetic field in an irreversible manner. This nugget shows clear evidence that magnetism boiling up through the photosphere from deep inside the Sun can feed a chain of quite similar events, if it boils up fast enough.

The discovery? The data strongly suggest that the emerging flux has a coherent pattern extending over the three days of homologous flaring. This pattern apparently persists in such detail that extraordinarily similar flares and CMEs can occur repeatedly, with the new magnetism re-creating the coronal structures as fast as necessary. This is perhaps the best-observed example of this kind of coherence and is a big deal because of its implications for the organization of magnetism beneath the surface of the Sun.

Spectacular movies

Yohkoh movie (Small version, half resolution), showing each of the November 2000 events in the context of images of the full solar disk. Erupting material can be seen, as well as the saturation of the CCD detector during the brightest part of the flares. (824 kbyte MPEG)

Yohkoh movie (CPU/Memory killer version, full resolution) (37 Mbyte animated GIF)

MDI movie, showing the continued coherent pattern of emergence of new magnetic fields from beneath the solar surface.

LASCO movie, showing the Coronal Mass Ejections associated with the November 2000 flares.

Useful links

SXT Nugget "Big Flares Associated with Halo CMEs"

Preprint of published paper in GRL

NASA GSFC press release

Local copy of press release