CISM

SOHO image animation (57k)
images from SOHO-EIT

Reconstruction of the Solar/Interplanetary Disturbances for the Space Weather Event on 6-10 Jan 1997

(*)
SOHO's LASCO coronagraph provided this picture of the expanding halo of bright material on 6-7 Jan 97, widely interpreted as a coronal mass ejection. The expanding halo's apparent speed is ~100-150 km/s as projected on the plane of the sky, but the associated interplanetary disturbance's arrival time at Earth indicates the ejecta attained an ultimate speed of at least ~450-490 km/s. (This image is from the Goddard Space Flight Center ISTP events web site. The halo was made visible by differencing sequential LASCO C3 coronagraph images.) Click on the image on the right to see the corresponding animation.
(*)
Potential field source surface model reconstructions of the coronal magnetic field for the 5 days centered on the day of the 6 Jan 97 coronal transient, constructed from daily updates of Wilcox Observatory synoptic maps, show modest changes in the large-scale coronal field. However, a part of the coronal magnetic field containing substantial flux becomes newly open on the day of the event (right panel), perhaps in response to the photospheric flux emergence also causing the filament disruption. Click on the two images on the right to see the corresponding animation.
(*)
The time-dependent version of the MHD coronal model using ~96 min. resolution MDI data as a photospheric boundary condition can determine whether the observed changes in the magnetic field on 6-7 Jan 97 explain the observed coronal transient and subsequent interplanetary disturbance. The projected density structure of the ejection from the model can be compared with the LASCO halo images to examine their comparative coronal behavior. Click on the image on the right to see the corresponding animation.

PREVIOUS NEXT