Occurrence of great magnetic storms on 6–8 March 1582

Abstract

Although knowing the occurrence frequency of severe space weather events is important for a modern society, it is insufficiently known due to the lack of magnetic or sunspot observations, before the Carrington event in 1859 known as one of the largest events during the last two centuries. Here, we show that a severe magnetic storm occurred on 8 March 1582 based on auroral records in East Asia. The equatorward boundary of auroral visibility reached 28.8° magnetic latitude. The equatorward boundary of the auroral oval is estimated to be 33.0° invariant latitude (ILAT), which is comparable to the storms on 25/26 September 1909 (~31.6° ILAT, minimum Dst of −595 nT), 28/29 August 1859 (~36.5° ILAT), and 13/14 March 1989 (~40° ILAT, minimum Dst of −589 nT).Assuming that the equatorward boundary is a proxy for the scale of magnetic storms, we presume that the storm on March 1582 was severe. We also found that the storm on March 1582 lasted, at least, for three days by combining European records. The auroral oval stayed at mid-latitude for the first two days and moved to low-latitude (in East Asia) for the last day. It is plausible that the storm was caused by a series of ICMEs (interplanetary coronal mass ejections). We can reasonably speculate that a first ICME could have cleaned up interplanetary space to make the following ICMEs more geo-effective, as probably occurred in the Carrington and Halloween storms.

Portuguese eyewitness accounts of the great space weather event of 1582

“…Hattori et al (2019), based on auroral records in East Asia, estimated that this severe storm occurred on 8 March 1582 and was comparable with other more recent magnetic storms as, for example, those in 1909 (Hayakawa et al, 2019a) and 1989 (Allen et al, 1989). Hattori et al (2019) also indicated that the duration of this storm could be three days. Very few records from South Europe are available for this event.…”

“…According to both documentary sources reported in this work, the aurora observed in March 1582 was sighted in Lisbon. Figure 1 depicts the European places where aurora was recorded according to Hattori et al (2019) in addition to the records made in Lisbon reported here. It implies that the records made in Lisbon were the southernmost observation recorded in Europe about the aurora of 1582.…”

“…We have found two texts containing descriptions of the great aurora sighted in March 1582 in Lisbon (Portugal). We present a discussion of these records in order to complement the work about this space weather event made by Hattori et al (2019). Lisbon would represent the southernmost European V.M.…”

“…In fact, the only record made in the Iberian Peninsula corresponds to one auroral record made in Madrid on 6 March 1582 (Hattori et al, 2019). We here present two auroral records made in Portugal of this severe space weather event in order to complement the space-time distribution of the study made by Hattori et al (2019). Section 2 includes the original records and a brief discussion is given in Section 3, and conclusion in Section 4.…”

“…Another example of an extreme space weather event occurred in 1582 (Kentaro et al, 2019). Hattori et al (2019), based on auroral records in East Asia, estimated that this severe storm occurred on 8 March 1582 and was comparable with other more recent magnetic storms as, for example, those in 1909 (Hayakawa et al, 2019a) and 1989 (Allen et al, 1989).…”