Alarming videos show Indonesian villages blanketed in a blood-red haze.
Chronic forest fires in the Jambi region have transformed a normal afternoon into an alien landscape. Footage uploaded to social media has gone viral, with thousands equally amazed and horrified by the scene.
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A phenomenon known as Rayleigh scattering is responsible for the crimson air seen in Jambi, the BBC reports. This refers to the scattering of light radiation by particles smaller than the radiation's wavelength. The thick blanket of smoke scattered the sunlight from above, and as red light has a longer wavelength more of it was let through than blue light.
It's also why the sky looks blue from Earth.
The most widely-shared video of the red haze was filmed at 1pm, which meteorologists say would have enhanced the intensity of the colour due to the sun being directly overhead.
The fires, largely caused by farmers engaging in illegal slash-and-burn land clearing, have been ongoing on the islands of Sumatra and Borneo since July. Indonesia's national disaster agency reports about 328,724 hectares of land have already been burned this year.
Rising global temperatures mean this summer has been particularly dry and hot, causing more destructive fires.
The haze has drifted as far as the Philippines, where residents have been warned to wear protective masks when going outside because of unsafe levels of air pollutants. Borneo's native orangutans are suffering respiratory problems because of the smoke.
The Washington Post reports the emissions from this year's Indonesian blazes are almost on par with the devastating fire season of 2015. At least 185 people have so far been arrested on arson charges relating to the fires, according to the Associated Press.
Zuni Shofi Yatun Nisa was one of several people to upload videos of the red Jambi haze, adding (translated): "This is afternoon, not night. This is Earth, not planet Mars. This is Jambi, not outer space. This is what we breathe with lungs, not with gills. We humans need air that is clean, not smoke-filled."
Others on Twitter were similarly horrified, with some drawing comparisons to dystopian films like Blade Runner 2049.
"This is sad and all but it looks cool as s**t I won't even lie," one Twitter user admitted.