RHESSI/SOHO/TRACE Workshop
[New 23-Nov-04: event list]
[New 7-Dec-04: S. Yashiro data link]
Working Group 3 - Interrelationships of Flares/CMEs in "Super" Events
The first solar flare ever observed was followed by a geomagnetic storm
within a day implying the rapid propagation of a CME to Earth [Carrington,
1859, Hodgson, 1859]. Interestingly, a CME was observed in eclipse
pictures (Spanish eclipse, 1860 July 18, Eddy, 1974), although it was recognized
only after the discovery of CMEs in the early seventies [Tousey, 1973].
The Carrington-Hodgson event was indeed a "super" event because the associated
CME shock reached Earth in a sheer 17.5 hours. Only a handful of
such super events have been recorded in the past [Cliver et al., 1990].
SOHO/LASCO observed several of these super events in a single solar cycle
(23). These extreme events help us understand the limit of free energy
available in solar active regions. Particular emphasis will be placed on
the super events that occurred in a cluster during October-November 2003.
Both CMEs and flares were well observed by SOHO, RHESSI and TRACE
during this period so we can revisit the long-standing question of CME-flare
relationship.
Questions
1. What can the super events tell us about the maximum free energy available
in the source region?
2. How can we distinguish between CME and flare onsets?
3. Is a flare precursor a precursor or a preceding flare? (Same
question for CMEs).
4. What is the relation between flare evolution and CME acceleration?
Observations
Frontside superfast CMEs (speed > 2000 km/s) observed by SOHO/LASCO will
be the starting point. Events with RHESSI and TRACE observations will be
identified and all the available measurements will be made available
online. Detailed timing analysis will be done for the chosen events. In
addition to the RST data, Wind/WAVES and Nobeyama radioheliograph and solar
energetic particle (SEP) data will be used to cross-check timing. Characteristics
of the source region will be accumulated to see if any pattern emerges
in terms of magnetic field and other physical quantities.
Theory and modeling
CME modelers generally work with slower CMEs. Modelers should identify
crucial issues that prevent them from "producing" super fast CMEs.
Events for study
General sources:
SOHO CME list from here
RHESSI event list from here
TRACE events from here
Nobeyama events from here
Wind/WAVES events from here
Workshop events list for WG3: now available here.
S. Yashiro's data link for WG3: now available
here and also
locally in Sonoma.
Literature
References & Relevant papers:
Carrington, R. C. Description of a Singular Appearance seen in the
Sun on September 1, 1859, MNRAS, 20, 13, 1859
Cliver, E. W.; Feynman, J.; Garrett, H. B., An estimate of the
maximum speed of the solar wind, 1938-1989, JGR 95, 17,103, 1990
Eddy, J., A Nineteenth-century Coronal Transient, Astron. Astrophys.,
34, 235, 1974
Hodgson, R., On a curious appearance seen in the Sun, MNRAS, 20, 15,
1859.
Tousey, R., The solar corona, Space Res., 13, 713, 1973
...
P. Gallagher, N. Gopalswamy