The Aspect Of The Sky In 1912 Following The Katmai Eruption

[Weather-history]

A letter by T. W Backhouse of Sunderland, written on the 21st December 1912 about the colour of the sky during 1912 following the eruption of Mt Katmai in the June of that year.

"Excess of cloud has been noted this year, but I have not seen any mention of, what has appeared to me very remarkable, the want of blueness in the sky, especially during the summer. With this seems to be connected a phenomenon of the nature of "Bishop's Ring." It may be remembered that after the eruption of Krakatoa in 1883, there appeared a large corona round the sun, the outer part of which was pink or slamon-coloured and was called "Bishop's Ring"; the interior was light blue or green; it was best seen near sunrise and sunset. In the course of many years this gradually faded and ultimately no trace of it remained; whether there was any feeble manifestation of the kind before the eruption, I am unable to say, as one's attention was naturally not directed particularly to the point. Since then, however, there has at times been a recrudescence of a large corona, which no doubt is capable of being marked, though of very feeble colours, the reddish being replaced by a dull brownish hue and the interior being bluish or greenish white, the result being an excessive glare round the sun. The corona is rather larger than in the case of the Krakatoa dust, the distance of the brownest part being perhaps 40 degrees from the sun.

It would appear from these observations that there must be some kind of film high up in the atmosphere - not so high up as the Krakatoa dust was - and that this film still remains as the corona continues, though the sky is fairly blue.

It is not only at Sunderland that these remarks apply, but also in other places where I have travelled.

There has been, however, a singularly scarcity of true cirrus and also of halos."