Fogbow south east of Newfoundland imaged by Juerg Alean (site, more voyage images, Stromboli online) from the stern of a container ship as it thundered across 'Titanic waters'. ©Juerg Alean, shown with permission. Fogbow form like rainbows by sunlight refraction and reflection in water drops. Fog droplets are much smaller than raindrops and another process becomes important. Diffraction - interference between light waves - broadens the bow and renders the colours more pastel. Fogbows    Droplets & diffraction    Fogbows & rainbows