Paper Title:
TRACE Observations of Many Active Regions with X-flares and Rotating
Sunspots in the Current Solar Cycle

Author List:
Nightingale, R., Metcalf, T.

Abstract:
The TRACE instrument in its 7 UV and EUV wavelength channels has
observed approximately 55 X-flares throughout its mission so far in
solar cycle 23 from launch in April 1998 through August 2004. About 40
of those X-flares (73%) can be associated with 17 solar active regions
that contain rotating sunspots, which have been observed by TRACE in its
white light channel. These sunspots, rotating about the center of their
umbras, appear to be manifestations of the twist and/or writhe, i.e.,
the helicity, instilled in the rising active region omega loops as they
travel through the convection region below the photosphere.  Of the 40
X-flaring active regions observed, 26 (65%) can be further associated
with large, fast Coronal Mass Ejections (CMEs) leaving the sun, as
recorded by the LASCO instrument on SoHO. Furthermore, 24 of these 26
events appear to be geo-effective because the  energetic proton fluxes,
observed by instruments on the GOES  geosynchronous spacecraft,
increased by several orders of magnitude shortly after the solar events
occurred. The data and the importance of such a high percentage of
rotating sunspots being associated with X-flaring active regions and
CMEs will be discussed.    This work was supported by NASA under the
TRACE contract NAS5-38099.

Poster:
Yes