English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The solar activity is asymmetric in both hemispheres in almost all cycles.This asymmetry is observed both in cycle amplitude and period. We have usedabout 90~years of sunspot-area data from the Kodaikanal Solar Observatory tostudy the North--South asymmetry in sunspot activity. The monthly meansunspot-area showed the northern hemisphere dominated in Solar Cycles 16, 19,and 20, and the southern hemisphere dominated in Cycles 18, 22, and 23. The13-months smoothed data indicated that in Cycle 17 and 21, the northern andsouthern hemisphere showed equal amplitude. Cumulative sunspot area showed thatthe northern hemisphere dominated in Cycles 18, 19, 20, and 21, with a largedifference between the two hemispheres in Cycles 19 and 20. The northernhemisphere activity led by 12, 15, and 2 months in Cycles 20, 21, and 22,respectively. No significant phase difference is found between the twohemispheres in Cycles 16, 17, 18, 19, and 23. The wavelet technique is used tofind Rieger-type periodicities in the sunspot cycles. The cross-waveletanalysis of these data sets showed several statistically significant commonperiodicities like the Rieger-type periodicities and Quasi-biennialoscillations. The Gnevyshev gap was found in both the hemispheric data inCycles 16, 18, 21, 22, and 23. These results are consistent with the earlierreported characteristics of North--South asymmetry in sunspot-area data. Theseresults suggest that the Kodaikanal Observatory data complement the existingsunspot data from other observatories to study solar activity over long andshort periods.

Solar-Cycle Characteristics in Kodaikanal Sunspot Area: North--South Asymmetry, Phase Distribution and Gnevyshev Gap