Catastrophic Chinese Floods Triggered By Air Pollution 59
sciencehabit writes: The worst flooding to hit China in 50 years may have been caused by air pollution, according to a new study. Soot in particular contributed to the catastrophic flooding. It prevented rainclouds from forming over the Sichuan basin, which is surrounded by mountains that trap smoke billowing from its industrial centers, and is 'notorious' for its dirty air. That in turn lead to more intense rainfall in the mountains that evening, which eventually led to the massive flooding.
Re:The converse (Score:4, Informative)
I'm not a meteorologist, but this is my understand: It depends on the size and temperature of the particles, and potentially on their shape and concentration. If the particulate matter is too hot and in the air too thick, not enough water vapor condenses on each to form droplets heavy enough to fall.
I think what they are saying in this case is once the particles cool and thin a bit, they end up carrying that moisture with them until the condensation is complete. Hitting a mountainside and mixing with the cool air above is a perfect trigger to release the rain.
Large rain events often happen when a warm, wet mass of air mixes with a cooler, dryer mass of air that can't hold that level of moisture. The particulate matter is just one of a number of variables.
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My take was that the pollution "moved" the rain to fall faster, on harder ground (mountainsides).
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FTFA (Score:5, Informative)
Fan and her co-authors ran two forecasts for the weather system that passed over the Sichuan basin during the peak of the floods: one with the thick blanket of smoke that covered the region and one with the kind of clean air that existed 40 years ago, before the Chinese economic boom. In the clean air model, moist air at Earth’s surface was heated by the daytime sun, became buoyant, and rose to great heights, triggering a convective cycle that led to storm clouds and mild daytime rainfall. But in the dirty air model, the dark veil over the plain soaked up much of the sun’s warmth high in the atmosphere, while simultaneously cooling the streets and fields below. This altered thermal structure stabilized the daytime atmosphere and suppressed rainfall. But as night fell, the moist air mass moved northward toward the Longmen Mountains, which tower some 2000 meters above the basin. The weather system that had been building energy over the plains for 12 hours was driven upward as it collided with the range’s steep contours, triggering the postponed convection. A day’s worth of rainfall from the plains was focused into a few hours over a handful of mountain valleys.
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My theory says X is responsible for Y, except when it's responsible for NOT "Y".
My theory accounts for all outcomes!
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If you're referring to YYZ, then yes.
If you're NOT referring to YYZ, then yes.
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But in the dirty air model, the dark veil over the plain soaked up much of the sun's warmth high in the atmosphere, while simultaneously cooling the streets and fields below. This altered thermal structure stabilized the daytime atmosphere and suppressed rainfall.
But as night fell, the moist air mass moved northward toward the Longmen Mountains, which tower some 2000 meters above the basin. The weather system that had been building energy over the plains for 12 hours was driven upward as it collided with th
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It actually is both. Perception is all there is.
Misread the title (Score:2)
Catastrophic Chinese FOODS triggered by air pollution.
I could believe that.
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That makes at least three of us.
But now I want noodles anyway.
I am pretty sure the actual cause of the floods... (Score:2, Funny)
I am pretty sure the actual cause of the floods... was water.
Also, if they'd just let it float across the Pacific to California, like it used to, it'd solve a lot of problems for everyone.
Inversion layer (Score:3)
Re:Inversion layer (Score:4, Funny)
If the capping inversion layer or "cap" is too strong (too close to the surface), it will prevent thunderstorms from developing.
Perhaps the soot is increasing the effect of the capping inversion? But I'm sure it's just more scientists so colossally ignorant that they failed to check Slashdot first.
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Sadly this phenomenon isn't limited to just Slashdot. Most forums seem to be the same. I bet it goes back to the dawn of time too. There was probably some caveman rubbing two sticks together, and another couple watching from their armchairs and commenting that the fiction would never be enough to enable combustion.
Re:Inversion layer (Score:4, Interesting)
I grew up in Los Angles, and the first thing I thought of when I RTFM
Wait a minute, the give you a manual on how to live in Los Angeles? That actually makes a lot of sense.
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Chinese Catastrophic FOODS?!? (Score:2)
I thought "Yeah, I didn't feel too well after eating at the Chinese Buffet the other day; but WTF?!?"
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+5
I am not suggesting your moderation. I am counting the people who can not read. ;) (Ctrl + F; food; enter == You are slow on the uptake and did not even read to the bottom before posting.)
The number one cause (Score:4, Informative)
The number one cause of flooding in China is, and has been for a long time, that the ability of the watershed to retain water and let it move through slowly has been degraded by some of the longest-term use of the plow on the face of the planet. The Loess Plateau, the original homeland of the Han people, shows some of the most horrific erosion ever. It's been reduced to near-desert conditions, and rainwater washes off from it unabsorbed, carrying silt, right into the river that's called Yellow because of just that.
Air pollution just adds to this.
https://www.youtube.com/watch?... [youtube.com]
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"the ability of the watershed to retain water and let it move through slowly. [The land] has been degraded by "
Darn touchpads.
Anyone else? (Score:1)
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+6
Your rush to seem witty resulted in your failure to read the thread. You are the sixth person to state this.
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You should thank your lucky stars then. Sheesh. I have to do everything around here.