Blog Archives

Fogbow with supernumeraries and Glory

This fogbow and glory was photographed by Ken Tape on May 12, 2006 while descending to a place called “Isachsen” located at 79 degrees North in the Canadian archipelago. The display and descent lasted for about 10 minutes, and the strength of the bows was fairly constant throughout. The intensity of the fogbow supernumeraries was strengthened by the use of a polarization filter. Note that the color sequence in the supernumeraries – blue outside – is reversed compared to that in the main maximum. The shadow in the glory is of a Twin Otter on skis. Nikon D70 with old 20mm lens (effective 30mm).

Posted by Ken Tape, edited by Günther Können

Cloud droplet phenomena

This image shows how light scattering by small cloud droplets produces multiple effects that are actually all part of the same phenomena. The scene was taken by Leigh Hilbert in Washington State in January ’06. The shadow of the descending aircraft is surrounded by a bright glory (1, 2) centred just behind the wing where Leigh was seated. Much further from the aircraft shadow is a circular cloud bow (1, 2), a form of fogbow (1, 2), produced also by scattering by cloud water droplets. The classical light paths producing it are those of the rainbow (1,2,3) but diffraction by the small droplets produces something much broader and almost lacking in colour. Inside the main cloudbow is a supernumerary arc that, characteristically for cloudbows and fogbows, has more colour saturation than the primary. The more distant clouds at the image top have produced a narrower cloudbow indicating that their droplets were larger.

Posted by Les Cowley

Bright Fogbow with serveral supernumerary arcs

On October 3, 2005, on the Wendelstein mountain (1834 m) a very bright fogbow with several supernumerary arcs appeared during the partial solar eclipse. In the centre of the fogbow there also appeared the spectre of the Brocken in variable intensity and size, according to the distance to the clouds. The spectre was also surrounded by a bright glory. Using a polarization filter, Carolin Baumann made this impressive photograph.