Journal or Publication Title:

Բյուրականի աստղադիտարանի հաղորդումներ: Երևանի աստղադիտարանի բյուլետեն = Сообщения Бюраканской обсерватории. Бюллетень ереванской Астрономической обсерватории = Contributions from the Burakan observatory. Bulletin of the Erevan astronomical observatory

Date of publication:

2025

Volume:

72

Number:

1

ISSN:

2579-2276

Coverage:

19-22

Abstract:

Solar periodicity is discovered in many magnetic activity indices (11 years, Rieger type 155-165 days, hundreds, and thousands of years). This research investigates multi-periodic variations in solar activity during Solar Cycles 23–24 and estimates the dynamo field strength. Daily sunspot area data from the Greenwich Royal Observatory were analyzed using Lomb-Scargle and Wavelet methods. These reveal multi-periodic variations (40–600 days) across the Sun’s full disk. The observed periods likely originate from magneto-Rossby waves in the solar dynamo layer. We estimate dynamo field strengths of 25–31 kG for Cycle 23 and 23–30 kG for Cycle 24 using wave dispersion relations.

Format:

pdf

Identifier:

oai:arar.sci.am:425908

General note:

Communications of the Byurakan Astrophysical Observatory (ComBAO) is a peer-reviewed scientific journal, which publishes research in observational and theoretical astronomy/astrophysics and presents recent advances in these fields. It is being published by the NAS RA V. Ambartsumian Byurakan Astrophysical Observatory (BAO) in English in electronic form. The journal publishes original papers, review papers, brief reports, book reviews, special communications, observational and theoretical results in various fields of astronomy and related sciences, and some editorial notes, including anniversaries and obituaries. Under the heading “Legacy”, the renewed magazine will republish some old articles of high value in English. The heading “Guest articles” will bring to the attention of readers the articles of researchers who are not employees of BAO. ComBAO was founded in 1946 and regularly published in 1946-1990. However, the publication was interrupted because of the economic situation after the disintegration of the Soviet Union in 1991.

Location of original object:

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