Pollen Coronas

Pollen Coronas

 It begins with a sneeze. Pollen floating through the air tickles your nose, and your body responds by expelling the allergen. Gesundheit!

That's German for "look at the sun." Not really, but look anyway. The same pollen that makes you sneeze can also make beautiful coronas around the sun, like this one photographed May 17th by Vesa Vauhkonen of Rautalampi, Finland:

 

"The birch is strongly flowering now in Finland," says Vauhkonen. "This weekend we have seen soom very impressive pollen halos around the Sun."

Coronas appear when small particles scatter waves of light from the sun. Usually the particles are tiny droplets of water or ice crystals in high clouds. During northern spring, however, abundant grains of pollen can do the job, too.

"Unlike water droplets, pollens are non-spherical--and this adds to their magic," says atmospheric optics expert Les Cowley. "Many have air sacs to help carry them in the wind. These align the grains to give beautiful elliptical coronas with bright spots." This is why Vauhkonen's pollen corona looks egg-shaped instead of circular

So, the next time you sneeze... Gesundheit! ...look for coronas near the sun.

 

From Spaceweather.com