Fiery 'ribbon' on St Louis's Gateway arch 'finally' caught on video
September appears to be one of the best times to observe the phenomenon.
A ribbon of fire-orange light from the sunrise reflected off the stainless-steel-clad Gateway Arch in St Louis, Missouri, on September 25 -- and the phenomenon was "finally" caught on camera, according to a statement on the national park's Facebook page.
"The Gateway Arch, in St. Louis, Missouri, has stood on the western shores of the Mississippi River for over 50 years," explains Weather Network science writer Scott Sutherland.
"When the weather is just right - clear and calm - residents can catch a spectacular morning sight."
When someone is standing at the base of the arch and looking east across the Mississippi towards the rising sun, the orange sunrise can be seen reflected off the surface of the river in as bright, fiery line.
"If they turn around and look at the Arch, catching it at just the right angle, they will see that fiery orange line reflected in the polished stainless steel panels of the Arch, stretching upwards into the sky," Sutherland explains.
The illusion of the fiery line stretching up the entire side of the monument is the result of the angles of the stainless steel panels, all of which reflect nearly the exact same view back down to the viewer at the base.
While the phenomenon can be observed at different times of the year, Sutherland says, the best time appears to be in March and September, near the Equinoxes, when sunrise is directly across the river from the arch.
The Gateway Arch National Park employee that took the video above told Storyful it was captured around 6:55 a.m. local time on a day when the sun looked like a “big orange orb” that was unobstructed by clouds.
