|Solar halos seen in Tambopata.|
Image by Phil Torres
A boat ride down the Tambopata River in Peru this September took an incredible turn when rare optical phenomena, known as high altitude solar halos, were seen and photographed with what are being considered the best images of the halos ever recorded.
What appeared to be an upside-down rainbow at first glance out the side of the canoe ended up being part of the rainbow-filled display seen here. Biologist Phil Torres and photographer Jeff Cremer were there to document it in the images and video seen here while on a photo tour at the Tambopata Research Center.
What are high altitude solar halos?
According the atmospheric optics expert Les Cowley, these solar halos are caused by a very specific reflections and refractions of the sun's light with ice crystals located in cirrus clouds high in the atmosphere. Normal rainbows are created by interactions of the sunlight with low level rain drops rather than high altitude hexagonal crystals of ice.
Cowley also mentioned that after first sharing the photos with others in the field of study, the consensus was that these images are considered "the best high sun halo images seen" and are strikingly clear compared to other images of this phenomenon, possibly because of the tropical origin opposed to a more temperate one typically associated with the halos.
|Image by Steve Gettle|
No- many consider all 'rainbows around the sun' like these to be sun dogs, they are not. Sun dogs are a specific type of ice halo found closer to the horizon with paired glowing refractions horizontal with the sun, as seen here. The halos seen in Tambopata were considerably higher in the sky than a sun dog.
While many think these ice halos are found only in colder climates, Cowley says that they are actually present throughout the world.
A full analysis of the display can be seen on Optics Picture of the Day.
|Simulation of the phenomenon with names of corresponding ice halos seen in the images.|
Image created by Les Cowley with HaloSim.
|Image by Phil Torres.|