Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/7072
Title: Association of Plages with Sunspots: A Multi-Wavelength Study Using Kodaikanal Ca ii K and Greenwich Sunspot Area Data
Authors: Mandal, Sudip
Chatterjee, Subhamoy
Banerjee, D
Keywords: Sunspots;Sun: activity;Sun: oscillations
Issue Date: 1-Feb-2017
Publisher: IOP Publishing
Citation: The Astrophysical Journal, Vol. 835, No. 2, 158
Abstract: Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 Å). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of plages are also similar to those of sunspots. Different area thresholdings on the "butterfly diagram" reveal that plages of area ≥4 arcmin2 are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.
Description: Restricted Access
URI: http://hdl.handle.net/2248/7072
ISSN: 0004-637X
???metadata.dc.rights???: © The American Astronomical Society
???metadata.dc.relation.uri???: https://doi.org/10.3847/1538-4357/835/2/158
Appears in Collections:IIAP Publications

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