Abstract Details
| Name: Subhamoy Chatterjee Affiliation: IIA, Bengaluru Conference ID: ASI2019_152 Title : Signature of Extended Cycles from Digitised Ca II K Data of Kodaikanal Observatory Authors and Co-Authors : Subhamoy Chatterjee, Dipankar Banerjee, Scott W. McIntosh, Robert J. Leamon, Mausumi Dikpati, Abhishek K. Srivastava Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : Kodaikanal Solar Observatory (KoSO) has archived 100 years of full-disc Ca II K spectroheliograms which have been digitised recently. From the Carrington maps generated from calibrated Ca II K we detected supergranule boundaries called the network. Subsequently we excluded the plages areas to consider only quiet sun (QS) and detected small scale bright feature through intensity thresholding over the QS network. Those features we named as `network bright elements'. Latitudinal density of network bright elements could clearly depict the existence of overlapping cycles with equatorward branches starting at latitude ~ 55 degrees and taking about 16-17 years to reach the equator. We performed superposed epoch analysis to depict the similarity of those extended cycles. We believe the clear temporal overlap between two equatorward branches and its correlation with sunspot cycles starting at about 40 degree latitude can provide vital inputs to dynamo theory. |