Tuesday, 21 February 2017
Split spectrum in Schulthess arcs
It has been evident in many a spotlight display, but in this case it is particularly striking: the other Schulthess arc is completely blue while the other one is predominantly red.
This is not something we see in simulations, where both components are equally coloured. In the blue-red processed image above it looks like these two arcs split the spectrum of parhelia/subparhelia in two.
I have of course no idea what is going on. Below is a more traditional version of the photo with heavily saturated colours. The display was photographed in Rovaniemi on the night of 28/29 November, 2016.