Arc de fog - Fogbow - Arc de brume observed in Brittany on February 23,...

Arc de fog - Fogbow - Arc de brume observed in Brittany on February 23, 2008. A haze arc is formed in the way of a rainbow. The light of the Sun is reflected in the water drops of the mist, but unlike raindrops, the mist droplets are much smaller: about a millimetre for the rain versus a few centiemes for the mist. As a result, the diffraction in the mist droplets is preponderant, which results in colour refracting at random angles, between 30 and 45* around the anti-sun point (opposite the Sun). Thus, all colours blend and one sees a white arch of light, sometimes slightly bluish on the inside and red on the outside, wider than a rainbow. Fogbow seen in Brittany on Feb 23, 2008. A fogbow is forming like a rainbow. The sunlight reflects in the fog droplets, but thoses droplets are much more smaller than the raindrops: about hundredths millimeters for the fog instead of about one millimeter for the rain. Thus, the diffraction in the fog droplets is leading, then the colors are refracted under angles between 30 and 45* around the antisolar point (at the opposite of the Sun). Then the colors mixe and one can see a white light bow, with sometime blue in the interior and red in the exterior, larger than a rainbo