What solar event caused massive aurora borealis in the mid 1960's?

Question

Living in Belleville, Ontario (north shore of Lake Ontario, about the midpoint running east-west), in the mid 1960's I recall two incidences between roughly November 1965 and February 1968 when the aurora borealis (northern lights) was so bright and high in the sky that we noticed from our living room, above the houses just across the street.

Even seeing the aurora in the vicinity of Belleville today, even in a darkness preserve, seems outrageously far fetched as it is never visible within a couple of hundred miles. The notion of detecting it from inside a lighted room, even faintly, likewise approaches absurdity for most of the populated regions of Canada.

It is updated several times hourly and of course varies with solar conditions, but here is a 30 minute Aurora Forecast projected from solar flux currently detected at Earth's L1 Lagrangian point (with a history of the past 24 hours). As is clearly apparent, the aurora is almost never visible anywhere near the locale of Belleville, Ontario.

Is it possible to identify the solar events or effects that caused the aurora to be visible so far south?

Answer 1

This was likely the major solar flare and associated geomagnetic storm of May, 1967. I saw it too! The aurora filled nearly the whole sky as seen from my home at Westport Point, Massachusetts. This was likely the night of May 25-26, 1967, when the geomagnetic storm was at its maximum. I was only a boy in second grade at the time. My parents and I were riding home after dark, and we noticed the aurora on our way. It must have been the early evening. Our home was a dark and rural site, and from there we could see that the display was spectacular and extended far past zenith toward the south.

For details, one source to check is Sky & Telescope magazine. Reporting on the aurora would have been published about two months later.

In August, 1972, I attended a summer astronomy program called Camp Uraniborg. We were thus very lucky to be watching and fully aware of another major solar event and associated geomagnetic storm early that month.

I went on to become a staff member at Sky & Telescope in the 1980s, and later I was an engineer involved for several years at National Solar Observatory. How the world turns! --John W. Briggs.

Answer 2

It is unlikely that identifying the particular event that caused the aurora is going to be possible. Solar monitoring was in its infancy in the 1960s.

However, while rare, it is certainly possible for aurorae to be visible at latitudes even further south than Belleville.

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From the Wikipedia page on Aurora:

Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere) due to Earth's magnetic field, where their energy is lost.

The first direct measurement of the strength of the solar wind was made by the spacecraft Luna 1 in 1959. You can read more about the history of our knowledge of the subject on the Solar Wind Wikipedia page.

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At least one aurora was visible even further south, from Washington DC, in the time range you remember, and was reported in the Washington Post on 27 May 1967: