De sublimes images de ce Soleil à l'horizon ! Les captures vidéo des oiseaux passant devant le disque solaire déformé sont merveilleuses ! Merci Adrien pour ce partage qui nous fait voyager au pays où le Soleil ne se couche pas en été.
A correction, the green and red flashes are NOT caused by diffraction, but by wavelength dependence of the refractive index (dispersion). The refractive index of air is higher for blue light than for red light. Thus the suns lower limb is lower and the upper limb is higher than the main body. Temperature variations (thus refraction variations) in the upper atmosphere cause the bars in the image. The blue light is scattered more than the red, this accounts for the rarity of blue or green flashes. When the apparent lower limb of the sun touches the sea horizon the geometric sun is completely under the horizon. A very good book was published by the Vatican Observatory in 1958, "The Green Flash and other Low Sun Phenomena", it has 80 photos, may be available as a PDF file PS I've never seen a green flash
