Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Saha, Chitradeep, Mukhopadhyay, Suprabha, Nandy, Dibyendu
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:https://arxiv.org/abs/2504.16681
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866913805843300352
author Saha, Chitradeep
Mukhopadhyay, Suprabha
Nandy, Dibyendu
author_facet Saha, Chitradeep
Mukhopadhyay, Suprabha
Nandy, Dibyendu
contents One of the most striking manifestations of orderly behavior emerging out of complex interactions in any astrophysical system is the 11-year cycle of sunspots. However, direct sunspot observations and reconstructions of long-term solar activity clearly exhibit amplitude fluctuations beyond the decadal timescale -- which may be termed as supradecadal modulation. Whether this long-term modulation in the Sun's magnetic activity results from nonlinear mechanisms or stochastic perturbations remains controversial and a matter of active debate. Utilizing multi-millennial scale kinematic dynamo simulations based on the Babcock-Leighton paradigm -- in the likely (near-critical) regime of operation of the solar dynamo -- we demonstrate that this supradecadal modulation in solar activity cannot be explained by nonlinear mechanisms alone; stochastic forcing is essential for the manifestation of observed long-term fluctuations in the near-critical dynamo regime. Our findings substantiate some independent observational and theoretical investigations, and provide additional insights into temporal dynamics associated with a plethora of natural phenomena in astronomy and planetary systems arising from weakly nonlinear, non-deterministic processes.
format Preprint
id arxiv_https___arxiv_org_abs_2504_16681
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the origin of long-term modulation in the Sun's magnetic activity cycle
Saha, Chitradeep
Mukhopadhyay, Suprabha
Nandy, Dibyendu
Solar and Stellar Astrophysics
One of the most striking manifestations of orderly behavior emerging out of complex interactions in any astrophysical system is the 11-year cycle of sunspots. However, direct sunspot observations and reconstructions of long-term solar activity clearly exhibit amplitude fluctuations beyond the decadal timescale -- which may be termed as supradecadal modulation. Whether this long-term modulation in the Sun's magnetic activity results from nonlinear mechanisms or stochastic perturbations remains controversial and a matter of active debate. Utilizing multi-millennial scale kinematic dynamo simulations based on the Babcock-Leighton paradigm -- in the likely (near-critical) regime of operation of the solar dynamo -- we demonstrate that this supradecadal modulation in solar activity cannot be explained by nonlinear mechanisms alone; stochastic forcing is essential for the manifestation of observed long-term fluctuations in the near-critical dynamo regime. Our findings substantiate some independent observational and theoretical investigations, and provide additional insights into temporal dynamics associated with a plethora of natural phenomena in astronomy and planetary systems arising from weakly nonlinear, non-deterministic processes.
title On the origin of long-term modulation in the Sun's magnetic activity cycle
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2504.16681