Presentation on theme: "Rainer Schwenn Max-Planck-Institut für Aeronomie Katlenburg-Lindau International Solar Cycle Studies 2001 (ISCS), June 13-16, 2001 Longmont, Colorado CME."— Presentation transcript:
Rainer Schwenn Max-Planck-Institut für Aeronomie Katlenburg-Lindau International Solar Cycle Studies 2001 (ISCS), June 13-16, 2001 Longmont, Colorado CME Mythology: Do Global CMEs or Sympathetic CMEs Exist?
A classical “halo” CME, observed by LASCO-C2 on 4.11.1998 Towards or away from Earth? That knowledge would grant space weather predictions a new quality Halo CMEs: a new quality from SOHO
A pressure wave (EIT Wave) in the solar atmosphere, pushed by a flare on 7.4.1997. A halo CME was launched towards Earth that caused a geomagnetic storm on 10.4.97. Front or backside: a new quality from SOHO
This CME began as a “global” CME, i.e. in two parts simultaneously on both limbs. Later, the envelope turned into a full halo. Note: the source “axis” was about parallel to the lobes’ axis
Another apparent halo CME, also from two parts on opposite limbs This was the obvious source, on the front side. The bright flash occurred at 05:58 UT, and the axes were parallel. However…
…close inspection of C2 images proves: the east limb event started more than one hour ahead of time! An independent backside source? Morale: better look twice, in particular if you are about to create a myth…
No: two lobes contained in one single halo CME, a “split halo” The typical “global” CME?
The same event: the source axis was perpendicular to the lobes’ axis!
No “global “ event, just two lobes contained in a halo CME, a backside event by the way
In this “butterfly type” halo CME, the axis was about 45 0 off
2 lobes under a common halo envelope. The source was oriented almost parallel to the lobes’ axis.
The source axis is perpendicular to the lobes’ axis
One more example: a “butterfly- type” halo CME, on the backside
A perfect halo, originating close to to disc center
A halo CME, “cannibalizing” a limb CME Close relatives of “global” CMEs: Cannibals! Gopalswamy, 2000
A halo CME, “cannibalizing” a limb CME Close relatives of “global” CMEs: Cannibals! Note: the “light bulb” CME had occurred behind the limb Gopalswamy, 2000
2 succeeding halo CMEs, “cannibalizing” a limb CME Close relatives of “global” CMEs: Cannibals! Gopalswamy, 2000
Suggestion: “…the chains are visible manifestations of separators or quasi-separatrix layers formed between different interacting large- scale magnetic flux systems in the evolving global magnetic solar atmosphere” Chertok, 1997 ff Other suspects in context with global CMEs: magnetic chains
Bothmer and Schwenn, 1998 Sketch showing the possible large-scale topology of a flux-rope magnetic cloud Alternative explanation of “global” CMEs: new perspective on flux ropes
Erupting flux rope with its legs connected to the sun Alternative explanation of “global” CMEs: new perspective on flux ropes Chen et al., 1993 ff
This CME (on September 9 th, 1997) was well observed by the Mark 3 and LASCO coronagraphs. It fits well to the erupting flux rope model Chen et al., 2000
This is what the flux rope model would predict how this CME should look like Chen et al., 2000
1. A typical flux rope CME seen from the side, I.e. above one limb Different perspectives of flux rope CMEs
2. An extended flux rope CME seen from the front or back side. Note the 2D rope structure and the engulfing 3D halo CME structure. “Global” CMEs: a projection effect!
Rainer Schwenn Max-Planck-Institut für Aeronomie Katlenburg-Lindau CME Mythology: Do Global CMEs or Sympathetic CMEs Exist? My answer is: No. They are probably just head-on (or head off…?) flux rope halo CMEs. Let’s see what they look like from different perspectives, i.e., STEREO and Solar Orbiter. STAY TUNED!