The Solar Magnetic Field in Time

The Solar Magnetic Field in Time

. These magnetograms portray the polarity and surface distribution of the magnetism of the solar photosphere. They were made with the Vacuum Tower Telescope of the National Solar Observatory at Kitt Peak from 8 January 1992, during the last maximum in the sunspot cycle (lower left) to 25 July 1999, well into the next maximum (lower left). They show opposite polarities as darker and brighter than the average tint. When the Sun is most active, the number of sunspots is at a maximum, and solar magnetism is dominated by large bipolar sunspots oriented in the east-west (left-right) direction within two parallel bands. At times of low activity (top middle), there are no large sunspots and tiny magnetic fields of different magnetic polarity can be observed all over the photosphere. The haze around the images is the inner solar corona. (Courtesy of Karel J. Schrijver, NSO, NOAO nad NSF.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University