Analysis of data from the first 26 months of the mission proceeded during the SOHO summer and winter interruptions. Some of the results are seen here. Developing Spot Region Full Disk Observables MDI recommissioning images from Nov 5, 1998. Images are available both in a combined format and individually. Go To Top High Resolution Observables MDI recommissioning images from Nov 5, 1998.
Images are available both in a combined format and individually.
This view shows sound speed variations beneath a sunspot. The spot was observed in June 1998 just prior to the SOHO 4-month interruption. Three planes are shown, on top the intensity at the surface which shows the sunspot with the dark central umbra surrounded by the somewhat brighter, filamentary penumbra. The second plane is a vertical cut from the surface to a depth of 24000 km showing areas of faster sound speed as reddish colors and slower sound speed as bluish colors. The sound speed is affected both by the temperature of the gas and the magnetic field, which we know to be strong in the sunspot at the surface.