|Light pillars loom in the sky|
over Burlington, Vermont International
Airport early this morning. Photo
from National Weather Service,
South Burlington, Vermont.
Light pillars appear as columns of light directly upward from an unshielded light.
They form during very cold weather when plate-shaped ice crystals that normally are high up in the atmosphere float close to the ground instead. Horizontal sections of the crystals reflect the light back downward, says Atmospheric Optics.
The pillars are aren't really a physical presense. Instead, they are a collection of light beams from millions of ice crystals which are reflecting light toward your eyes. The crystals that create the pillars are about halfway between you and the lights.
The higher the crystals are in the sky the taller the light pillar will appear.
The ice crystals this morning seemed to extend pretty high up, judging from the size of the light pillars towering over the Burlington International Airport terminal in the photo.
The weather was certainly right for light pillar formation around Burlington before dawn today. The temperature was a little below zero, winds were calm, and ice crystals could just sort of float around and create the pillars.
See? Even nasty cold nights can be beautiful sometimes.