Fig. 2

Time evolution of Rio de Janeiro’s magnetic latitude computed with the geomagnetic field model GUFM1 (Jackson et al. 2000). The light purple bar shows the period corresponding to Sanches Dorta’s magnetic and aurora observations in Rio de Janeiro during the period 1781–1788 (Vaquero and Trigo 2005, 2006). The green and brown vertical lines mark the Carrington event (e.g., Green and Boardsen 2006; Hayakawa et al. 2018b, 2019b) and the eventual sporadic aurora observation here reported