News about the wildfires in San Francisco, U.S. dominated headlines in the first weeks of September 2020. The fires were raging, and the damage that went along with it was huge. And then, one morning, residents of the famed San Francisco Bay Area woke up to skies that were orange and red.
Not apocalypse
While those on social media quickly snapped pictures and captioned them in many ways, U.S.’ National Weather Service (NWS) and NASA tried to reassure people that apocalypse hadn’t arrived. And how did they do this? By explaining the science behind the phenomenon of course.
It was pretty clear to almost everyone that the skies’ strange hues were the result of the wildfire. What wasn’t well-known, however, was how exactly this was happening.
NWS went about their explanation by tweeting a picture of a satellite image that showed a thick layer of smoke above California. This smoke was filtering the energy coming from the sun. as a result, the temperatures were much cooler and the dark and dreary skies were the product of the skies shifting towards the red end of the spectrum.
Smoke blocks shorter wavelengths
NASA helped by going into more detail. They added that smoke particles block sunlight’s shorter wavelength colours – yellow, blue and green. They do, however, allow the longer wavelengths to pass through. As red and orange have longer wavelengths, they pass through the smoke and the skies therefore appear in these colours.
Picture Credit : Google