A combined uniform and long-time series of Ca-K images from the Kodaikanal Observatory, Mount Wilson Observatory and Mauna Loa Solar Observatory was used to identify and study the Ca-K small-scale features and their solar cycle variations over a century. The small scale features are classified into three distinct categories: enhanced network, active network and quiet network. All these features show that their areas vary according to the 11 yr solar cycle. The relative amplitude of the Ca-K network variations agrees with that of the sunspot cycle. The total area of these small-scale features varies from about 5% during the minimum phase of the solar cycle to about 20% during its maximum phase.
Key words: Sun: activity – Sun: chromosphere – (Sun:) sunspots
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