Latitude and power characteristics of solar activity in the end of the Maunder minimum

TL;DR

This study analyzes sunspot latitude distributions during the end of the Maunder minimum to estimate solar activity levels, revealing higher activity than previously indicated by some indices and supporting the existence of a non-very-low solar cycle.

Contribution

It introduces a method linking sunspot latitude dispersions to solar activity, providing new estimates for the Maunder minimum period independent of direct sunspot counts.

Findings

Sunspot latitude dispersions suggest moderate solar activity during the Maunder minimum transition.

Estimated Wolf number during cycle -3 maximum is W=100±50.

Activity levels from latitude data align better with traditional indices than with GSN.

Abstract

Two important sources of information about sunspots in the Maunder minimum are the Sp\"orer catalog and observations of the Paris observatory, which cover in total the last quarter of the 17th and the first two decades of the 18th century. These data, in particular, contain information about sunspot latitudes. As we showed in previous papers, dispersions of sunspot latitude distributions are tightly related to sunspot indices, so we can estimate the level of solar activity in this epoch by a method which is not based on direct calculation of sunspots and is weakly affected by loss of observational data. The latitude distributions of sunspots in the time of transition from the Maunder minimum to the common regime of solar activity proved to be wide enough. It gives evidences in favor of, first, not very low cycle No. -3 (1712-1723) with the Wolf number in maximum W=$100\pm50$, and, second, nonzero activity in the maximum of cycle No. -4 (1700-1711) W=$60\pm45$. Therefore, the latitude distributions in the end of the Maunder minimum are in better agreement with the traditional Wolf number and new revisited indices of activity SN and GN than with the GSN; the latter provide much lower level of activity in this epoch.