Ring-diagram analysis is a technique of local helioseismology
used to measure flows in the outer portions of the solar Convection Zone,
in relatively small areas. In our standard analysis the
remapped image of the Sun is divided into 189 square patches,
each covering 15 degrees in heliographic latitude and longitude and
overlapping, with the centers spaced at 7.5 degree intervals.
The image shows a mosaic of the magnetograms corresponding to the
central portion of each square, for GONG data from
2002/08/05
The colors (from blue to red) represent
the frequency of a selected mode measured in each patch,
with respect to the mean frequency for that mode over several days,
with blue representing the lowest and red the highest frequencies.
The highest frequencies are clearly associated with the squares at
the highest magnetic activity levels.
For more details see
our
SPD 2003 poster .
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