A solar halo aroused the curiosity of Madeirans and Porto Santo today.
Several photos of this optical phenomenon were published on social networks, one of which was by a member of the Porto Santo Parish Council.
According to the Portuguese Institute of Atmosphere and Sea (IPMA), the halo “is a ring-shaped or arc-shaped optical phenomenon, caused by the refraction of light, by ice crystals suspended in the atmosphere.”
The solar halo adds the same source, “happens when the Sun’s rays encounter the tiny ice crystals existing in Cirrus (made of ice crystals and commonly known as ‘Mare’s Tails, due to their shape and formation), and Cirrostratus clouds (again made of ice crystals, formed at high altitude and usually forewarn of an approaching storm) refract their light giving rise to a ring.”
This phenomenon can also occur at night around the moon.
Samantha Gannon
info at madeira-weekly.com
Photo: Porto Santo Parish Council
