* The author is part of the community of readers of La Vanguardia
In The Photos of the Readers of La Vanguardia we can contemplate the solar corona and the iridescences that could be observed yesterday in the Coll de Pal (Barcelona).
Coll de Pal is a mountain pass located at 2106 meters of altitude. It belongs to the municipality of Bagà, in the Berguedà region.
We are already in summer, but with the cold dawn and the clouds pushed by the wind, this optical effect has been produced that has not lasted long.
The solar corona is an effect that is produced by the diffraction of light and the small drops or ice crystals that are in the thin clouds.
For its part, iridescence is caused by multiple reflections of light on multiple semitransparent surfaces, where the subsequent phase changes and interference of the reflections modulate the light by amplifying or attenuating the different wavelengths. Depending on the angle from which the surface is illuminated, it will appear in different colors. Iridescence is very common in nature.
In the video recorded without acceleration, you can see how quickly the clouds changed with the wind. We can see it below: