Atmosphere

atmosphere

Air pollutants from "megacities" a growing problem

Megacities — cities with populations equaling or greater than 10 million people — are producing an unprecedented amount of air pollution, according to scientists at the American Chemical Society's annual meeting in Washington, D.C., on Tuesday.

21 Aug 2009

Raindrop study splashes old assumptions

Predicting the weather has been central to human civilization since the Babylonians started studying cloud patterns in 650 B.C. The key to weather predictions is making correct assumptions. Today, instruments like Doppler radar that measure rainfall work under the assumption that raindrops fall at their terminal velocity. A new study, however, shows that some raindrops fall faster than they should, indicating rainfall instruments — and by extension, weather forecasts — may need some tweaking.

23 Jul 2009

Montreal Protocol affects more than just ozone

In 1987, nearly 200 nations signed the Montreal Protocol to restrict the use of ozone-depleting chemicals. The international treaty helped keep the ozone hole over Antarctica from growing further, preventing an increase in harmful radiation reaching Earth’s surface. Twenty years later, new research suggests that the treaty helped the planet dodge more than one bullet: The Montreal Protocol also prevented significant regional climate change.

13 Nov 2008

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