Add it to the list: Pollution in thunderclouds
A thunderstorm (Photo credit: Wikipedia)
It seems as if a day doesn't go by where new computer "simulations" don't add another item to the ever-growing list of what causes global warming. Turns out pollution in thunder-bangers fits right into computer models developed to show they increase global warming not taken into account in those other computer models. From TG Daily [emphasis added]:
Pollution is leading thunderstorm clouds to capture heat, increasing global warming in a way that climate models have failed to take into account.
It strengthens them, causing their anvil-shaped tops to spread out high in the atmosphere and capture heat, especially at night, says Jiwen Fan of the Department of Energy's Pacific Northwest National Laboratory.
"Global climate models don't see this effect because thunderstorm clouds simulated in those models do not include enough detail," says Fan. "The large amount of heat trapped by the pollution-enhanced clouds could potentially impact regional circulation and modify weather systems."
To find out which factors contribute the most to this invigoration effect, the team set up computer simulations for two different types of storm systems: warm summer thunderstorms in southeastern China and cool, windy frontal systems on the Great Plains of Oklahoma.
The simulations had a resolution that was high enough to allow the team to see the clouds develop. The researchers then varied conditions such as wind speed and air pollution.
And they found that for the warm summer thunderstorms, pollution led to stronger storms with larger anvils. Compared to cloud anvils that develop in clean air, the larger anvils both warm more, by trapping more heat, and cool more, by reflecting additional sunlight back to space. On average, however, the warming effect dominates.