The lost sunspot cycle: New support from Be10 measurements

Abstract

It has been suggested that the deficit in the number of spots on the surface of the Sun between 1790 and 1830, known as the Dalton minimum, contained an extra cycle that was not identified in the original sunspot record by Wolf. Though this cycle would be shorter and weaker than the average solar cycle, it would shift the magnetic parity of the solar magnetic field of the earlier cycles. This extra cycle is sometimes referred to as the 'lost solar cycle' or 'cycle 4b'. Here we reanalyse Be10 measurements with annual resolution from the NGRIP ice core in Greenland in order to investigate if the hypothesis regarding a lost sunspot cycle is supported by these measurements. Specifically, we make use of the fact that the Galactic cosmic rays, responsible for forming Be10 in the Earth's atmosphere, are affected differently by the open solar magnetic field during even and odd solar cycles. This fact enables us to evaluate if the numbering of cycles earlier than cycle 5 is correct. For the evaluation, we use Bayesian analysis, which reveals that the lost sunspot cycle hypothesis is likely to be correct. We also discuss if this cycle 4b is a real cycle, or a phase catastrophe, and what implications this has for our understanding of stellar activity cycles in general.

arXiv commentaccepted for publication in A&A

References in corpus (11)

• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• The connection between stellar granulation and oscillation as seen by the Kepler mission
• Reconstruction of solar activity for the last millennium using ${}^{10}$Be data
• Magnetic Activity Cycles in the Exoplanet Host Star epsilon Eridani
• A solar cycle lost in 1793--1800: Early sunspot observations resolve the old mystery
• The butterfly diagram in the 18th century
• A Bayesian approach to scaling relations for amplitudes of solar-like oscillations in Kepler stars
• The quasi-biennial periodicity as a window on the solar magnetic dynamo configuration
• Observations of intensity fluctuations attributed to granulation and faculae on Sun-like stars from the Kepler mission
• The Quasi-Biennial Periodicity (QBP) in velocity and intensity helioseismic observations

Cited by in corpus (8)

• Re-calibration of the Sunspot Number: Status Report
• Thaddäus Derfflinger's sunspot observations during 1802-1824: A primary reference to understand the Dalton Minimum
• The Origin of Parity Changes in the Solar Cycle
• Space climate and space weather over the past 400 years: 2. Proxy indicators of geomagnetic storm and substorm
• The Dalton Minimum and John Dalton's Auroral Observations
• Christian Horrebow's Sunspot Observations -- II. Construction of a Record of Sunspot Positions
• Iwahashi Zenbei's Sunspot Drawings in 1793 in Japan
• The Solar Corona during the Total Eclipse on 16 June 1806: Graphical Evidence of the Coronal Structure during the Dalton Minimum