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- The serial number assigned to 27-day rotation periods of solar and geophysical parameters. Rotation 1 in this sequence was assigned arbitrarily by Bartel to begin in January 1833.
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- Active Region (AR), AP Index, Central Meridian Passage (CMP), Continuum Storm (CTM), Differential Rotation, Granulation, High-Speed Stream, insolation, Magnetopause, Plage Corridor, Plagenil, Solar Coordinates, Solar Cycle, Solar Maximum, Solar Minimum, Solar Sector Boundary (SSB), SPOTNIL, Syzygy