The Maunder minimum (1645–1715) was indeed a grand minimum: A reassessment of multiple datasets

By I. Usoskin, R. Arlt, E. Asvestari, Ed Hawkins, M. Kapyla, G. Kovaltsov, N. Krivova, M. Lockwood, K. Mursula, J. O’Reilly and 6 more. 2015

206 citations recorded by the source corpus.

Aims. Although the time of the Maunder minimum (1645–1715) is widely known as a period of extremely low solar activity, it is still being debated whether solar activity during that period might have been moderate or even higher than the current solar cycle #24. We have revisited all existing evidence and datasets, both direct and indirect, to assess the level of solar activity during the Maunder minimum. Methods. We discuss the East Asian naked-eye sunspot observations, the telescopic solar observations, the fraction of sunspot active days, the latitudinal extent of sunspot positions, auroral sightings at high latitudes, cosmogenic radionuclide data as well as solar eclipse observations for that period. We also consider peculiar features of the Sun (very strong hemispheric asymmetry of the sunspot location, unusual differential rotation and the lack of the K-corona) that imply a special mode of solar activity during the Maunder minimum. Results. The level of solar activity during the Maunder minimum is reassessed on the basis of all available datasets. Conclusions. We conclude that solar activity was indeed at an exceptionally low level during the Maunder minimum. Although the exact level is still unclear, it was definitely lower than during the Dalton minimum of around 1800 and significantly below that of the current solar cycle #24. Claims of a moderate-to-high level of solar activity during the Maunder minimum are rejected with a high confidence level.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/024baa5fc4d801f9e95610bd84597f28d6352d02

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. I. Usoskin
2. G. Kovaltsov
3. S. Solanki
4. M. Lockwood
5. M. Owens
6. K. Mursula
7. L. Svalgaard
8. F. Clette

Citations in the corpus

• A Revised Collection of Sunspot Group Numbers (2016, methodology): “Finally, consulting the original documents, Usoskin et al. (2015) concluded that the sunspot observation assigned to Kircher in 1667 is erroneous and needs to be removed from the HS98 database.”
• A New Calibrated Sunspot Group Series Since 1749: Statistics of Active Day Fractions (2015, methodology): “…Hathaway, 2015) that solar activity varies between very low activity, called grand minima, such as the Maunder Minimum during 1645 – 1715 (Eddy, 1976; Usoskin et al. , 2015), and grand maxima such as the recent period of high activity in the second half of the twentieth century, called the Modern…”