Temporal and Latitudinal Variation in Penumbra-Umbra Ratios of the Sunspots: Analyses of RGO, Kodaikanal and Debrecen Databases

Abstract

We study the latitudinal distribution and temporal evolution of the sunspot penumbra-umbra ratio (q ) for the even and odd Solar Cycles 12 - 24 of RGO sunspot groups, SC21 - SC24 of Debrecen sunspot groups and Kodaikanal sunspot dataset for SC16 - SC24. We find that RGO even (odd) Cycles have q -values 5.20 (4.75), Kodaikanal even (odd) cycles have q -values 5.27 (5.43), and Debrecen cycles have q -value 5.74 on the average.