Other than making many of us sneeze from hay fever, pollen in the air is causing another strange phenomenon: pollen coronas.
The sun has been spotted over Finland with bizarre rainbow-like haloes around it, due to pollen floating about.
Photographer Mikko Peussa snapped several pictures of the beautiful pastel-colored sight on May 30 in Turku, Finland.
"The pollen is coming from pine trees in the area," Peussa told spaceweather.com. He also posted the images to Facebook.
These so-called pollen coronas are a result of microscopic pollen diffracting the sun's light.
Pollen is produced by flowering plants, and contains the male sex cells of the plants. They are evolved to disperse from their parent plant far and wide, floating on the wind or being carried by pollinators to the female parts of another plant of the same species.
Pollen particles usually aren't spherical, as they have tiny air sacs to assist the wind in their dispersal. This irregularity of the shape of pollen particles means that these haloes aren't exactly circular: according to Bob King of the Universe Today, due to pollen's elongated shape (as opposed to spherical water droplets), the coronas are oval-shaped. The lower down the sun is in the sky, the more elongated and oval-shaped the rings become.
Other atmospheric phenomena occur as a result of light from the sun—or moon—being refracted by objects floating in the air. Solar halos and sundogs, as well as light pillars, are caused by tiny ice crystals in the atmosphere scattering light in certain ways, while rainbows and fogbows, on the other hand, are a result of water droplets refracting light.
"Halos form whenever sunlight is reflected and refracted by tiny ice crystals in the atmosphere. The appearance of a halo is dependent on the shape and quality of the ice crystals involved in the reflection and refraction of light," Victor Ongoma, an assistant professor of climate change adaptation at Mohammed VI Polytechnic University in Morocco, previously told Newsweek.
Unlike other solar halos, pollen coronas are much smaller.
Pollen is in the air in high concentrations at the moment due to the springtime bloom. Pollen from pine, birch, spruce, and alder trees are best set to produce these coronas, so keep an eye out if there are these trees in your area: the best way to spot the colored rings is to block out the sun itself and look for any surrounding rings.
Do you have a tip on a science story that Newsweek should be covering? Do you have a question about pollen coronas? Let us know via science@newsweek.com.
Uncommon Knowledge
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Jess Thomson is a Newsweek Science Reporter based in London UK. Her focus is reporting on science, technology and healthcare. ... Read more
