Abstract:
We analyze the long-term behavior of the supergranule scale parameter, in active regions (ARs) and quiet regions
(QRs), using the Kodaikanal digitized data archive. This database provides century-long daily full disk
observations of the Sun in Ca II K wavelengths. In this paper, we study the distributions of the supergranular scales,
over the whole data duration, which show identical shape in these two regimes. We found that the AR mean scale
values are always higher than that of the QR for every solar cycle. The mean scale values are highly correlated with
the sunspot number cycle amplitude and also with total solar irradiance (TSI) variations. Such a correlation
establishes the cycle-wise mean scale as a potential calibrator for the historical data reconstructions. We also see an
upward trend in the mean scales, as has already been reported in TSI. This may provide new input for climate
forcing models. These results also give us insight into the different evolutionary scenarios of the supergranules in
the presence of strong (AR) and weak (QR) magnetic fields.
