While significant strides have been made in improving air quality in China through regulations like the Clean Air Act issued in 2013, air pollution has become increasingly complex. Despite notable improvements, the development ...
Environment
6 hours ago
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With dancing ribbons of light visible in the sky, a team of researchers flew on a series of scenic and sometimes stormy flights into the cold unknown, trying to learn more about why one of the most frigid places on Earth ...
Earth Sciences
May 3, 2024
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The Earth's atmosphere is a layer of gases surrounding the planet Earth that is retained by the Earth's gravity. It has a mass of about five quadrillion metric tons. Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and trace amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night.
There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. An altitude of 120 km (75 mi) marks the boundary where atmospheric effects become noticeable during atmospheric reentry. The Kármán line, at 100 km (62 mi), is also frequently regarded as the boundary between atmosphere and outer space. Three quarters of the atmosphere's mass is within 11 km (6.8 mi; 36,000 ft) of the surface.
This text uses material from Wikipedia, licensed under CC BY-SA
