Sky above San Francisco was the color of television, corresponding to the president.
To be fair, I stole it Punch line Vaguely published from Twitter, and vaguely published about Donald Trump’s alleged clear choices of his makeup, will not fix North America’s worst fire season on record. About 100 fires are burning in a westerly direction, driven by lightning sieges and driven by dry wind eruptions through drought-stricken, beetle-eating forests and chaparrals. So far the flames have consumed 4. entire million acres, including entire towns and more than 1,000 homes. But none of this explains what happened to the sky. Residents of the Bay Area of California didn’t think it was funny to paint the Golden Gate Bridge in the sunless sky on Wednesday morning. The street lights did not go off; The big sutra cleared the broadcast antenna from the fog like the mechatronic eye of a surfer; And the angry-magma glow fed everything, like being trapped in just one strip of a fabulous sunset. Between the nuisance of darkness, the twilight at noon, and the depressing half-jokes about the news in the city Blade Runner 2049, People in the West wonder: No, but really, why is the sky color?
The reason for the orange – and then the hair and the sick gray that is caused by a combination of atmospheric chemistry and the physics of small things.
To a greater extent, cause, grief, was fire. Many are so big and hot that they make Pyrocumulonimbus clouds, Or “fire storms,” which formula and smoke all the way to the atmospheric column, in a 50,000-foot stratosphere. The heat also produced unusual winds blowing from the Sierra Nevada to the coast. All those guns literally blocked the sun. At least, Some There were sun-devil-colored details. “I have never seen anything like it. I’ve lived in polluted cities, but you never get that deep orange, ominous color, ‘says Sanaz Wahidinia, a physicist at NASA’s Ames Research Center, who studies aerosols and light scattering. “In normally polluted cities, this is a husky color, more like a sepia color right now, I can be a little dimmer. It was really interesting. “
First, the chemistry side. Smoking is the reduction of particles that are left after something is burned; It can be hydrocarbon molecules or soot, which is just black carbon. Now, the thing to remember here is that sunlight appears approximately white or white-yellow at dusk noon, it actually contains exactly the same amount of light for each wavelength of light, from the red end of the visible spectrum to the dull, all mixed subatomic pointlist spray. And yet you can likely associate carbon-heavy things like oil or coal with colored black – really like carbon atoms that absorb light from the visible spectrum. They absorb more long-wavelength red than short-wavelength blues and are also scattered. “Soot particles absorb blue light from the sun, and we don’t see that,” says Mark Marley, a researcher at NASA’s AIIMS research center who studies the atmosphere of planets outside the Earth’s solar system. Those particles absorb the blue or scatter – but let the mordorish turn reddish-orange.
The smoke was not the only layer in the sky. A sea level of moist air beneath it. San Francisco’s famous Carl the Fog, the third wave dissipates like boiled milk under Latte’s foam. Some physics also forms here. Unlike carbon, water vapor is generally more absorbed on the red-orange side of the visible spectrum. But those water molecules, just two hydrogen and oxygen, are even larger than most particles of smoke. And in the physics of light scattering, matters of size. On an atom or two scale, some hundreds of nanometers, light can change direction around a particle and change direction or bounce it and reverse the way it comes depending on its wavelength. That is to say, particles of different sizes interact differently with different colors of light.
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