SUNSPOT REGION HISTORIES ------------------------------------------------------
This collection of daily sunspot region measurements was taken from Table II in
the SOLAR PHENOMENA bulletins published by the Rome Astronomical Observatory.
Each 80-character record includes the heliographic position, classification,
area, and region number of a particular spot group on the sun's disk.  Records
are grouped into files by year.  Within each file, records are sorted first by
region number and then by date and time to provide an evolutionary history of
every group.  Each file contains two kinds of records--a standard report and a
summary.  Standard records give the characteristics of either the LEADING or
FOLLOWING portion of a group; summary records contain values pertaining to the
whole group.  A second series of files gives the daily sum of the areas of all
spot groups; Rome publishes these listings as Table I in their bulletin.

  CONTENTS  -organization of disk files
   RGN_FMT  -definition of fields contained in each sunspot group record
   RGN19yy  -sunspot region reports for 1 year; areas (as observed) are given
               in millionths of the area of the solar disk; areas corrected for
               foreshortening are expressed in millionths of solar hemisphere.
   DLY_FMT  -definition of fields contained in each daily sunspot area record
   DLY19yy  -daily summed area of all spot groups on face of sun for 1 year
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NATIONAL GEOPHYSICAL DATA CENTER                         Phone:  (303) 497-6346
Solar-Terrestrial Physics Div (E/GC2)     325 Broadway, Boulder, Colorado 80303