Weather, twilight, and auroral observing from Spitsbergen in the polar winter

Abstract

ABSTRACTDespite the harshness of the weather, the winter months on Spitsbergen provide good opportunities for auroral observing. December is usually the cloudiest month, but it also has many short-lived periods of post-cyclonic clearing of excellent clarity. January, however, is the most favourable month, with long periods of clear, dark skies due to the dominance of anticyclonic systems over the polar cap. February is also a very good month from the meteorological point of view, but observing opportunities are much more restricted by increasing twilight, especially in the latter half of the month. The most frequently observed types of aurora are patchy prenoon aurora, noontime or cusp aurora, discrete postnoon arcs, discrete polar-cap aurora, and substorm aurora. Diffuse polar-cap (polar glow) aurora and storm-type aurora are also seen occasionally but only at times of great geomagnetic disturbance.