Iridescent Fireworks Smoke
Like everywhere around the world, New Years Day was also welcomed with fireworks around Mt. Wendelstein. It is always a special highlight to watch the fireworks from the top of the mountain at 1838 meters above sea level. In the Leitzach Valley, about 1000 meters lower, there was a fireworks display.
Even when watching it with the naked eye, the smoke and fog of the fireworks seemed to show iridescent colours. The photographs (photo) show the iridescence more obviously. It was probably caused by the condensation nuclei from the fireworks smoke, on which small droplets condensated. As short time before an area of precipitation had passed, air humidity was still very high.
Additionally, the fireworks caused a thin layer of fog over almost the whole alpine foothills area (photo), and the big city of Munich with more than a million inhabitants, was covered by a thick layer of clouds (photo).
Similar things were reported by other observers. In Bochum, Peter Krämer observed that light graupel turned into snow during the fireworks, leaving about a centimetre of snow. On the weather radar it could be seen that a precipitation area formed right over the Ruhr area just after midnight.
Two years ago, thin fog with visibilities around 300 meters thickended after the New Years Fireworks, forming a dense layer of fog with visibilities which were less than 10 meters in some places.
Posted by Claudia Hinz
Wolfgang and I spend New Year’s Eve 2 years ago on the top of the Wendelstein Mountain. 100m lower down was the “Wendelsteinhaus” tavern with a party in full swing. After midnight the party fireworks detonated at our level in front of our eyes. The flares illuminated some fog patches from the valley and produced greenish and brownish coronas. Some of the original flares could have been green but the effect could also be due to scattering from the firework smoke particles. We wish you all a wonderful New Year and hope that you see this and plenty more atmospheric optics phenomena in 2007.
Author: Claudia Hinz, Brannenburg, Germany