Published online by Cambridge University Press: 27 October 2009
A comprehensive visual and photographic record of a wide variety of auroral events was made from Spitsbergen during a prolonged period of clear weather that coincided with a remarkable resurgence in solar activity close to sunspot minimum. Using colour and interference-filter photography, the nature of the different auroral types was established and tentatively correlated with major flare events on the sun. At least three outstanding auroral substorms and three diffuse polar cap glows were generated by four large solar flares in the first half of February 1986. Many discrete polar cap aurorae were also observed in the same period.