Solar Cycle Observations

2023/05/31 by A. A. Norton, Norton, Aimee, R. Howe +5 · 4 citations
Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.2305.19803

openalex publication_date 2023/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We describe the defining observations of the solar cycle that provide constraints for the dynamo processes operating within the Sun. Specifically, we report on the following topics: historical sunspot numbers and revisions; active region (AR) flux ranges and lifetimes; bipolar magnetic region tilt angles; Hale and Joy's law; the impact of rogue ARs on cycle progression and the amplitude of the following cycle; the spatio-temporal emergence of ARs that creates the butterfly diagram; polar fields; large-scale flows including zonal, meridional, and AR in-flows; short-term cycle variability; and helioseismic results including mode parameter changes.

Cited by

• Helicity Fluxes and Hemispheric Helicity Rule of Active Regions Emerging from the Convection Zone Dynamo
• Latitudinal dependence of the solar wind during periods of high and low activity through interplanetary scintillation
• Multitaper magnitude-squared coherence for time series with missing data: Understanding oscillatory processes traced by multiple observables
• Resolution of the Solar Convective Conundrum? New Results Using the Time-Distance Deep-Focus Method

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