Related topics: air pollution · air quality · pollution

Air pollution fell sharply during lockdown

The far-reaching mobility restrictions at the beginning of the COVID pandemic in March 2020 created a unique situation for atmospheric sciences: "During the 2020 lockdown, we were able to directly investigate the actual effects ...

Bioinspired materials from dandelions

Fields are covered with dandelions in spring, a very common plant with yellow-gold flowers and toothed leaves. When they wither, the flowers turn into fluffy white seed heads that, like tiny parachutes, are scattered around ...

Simply speaking while infected can potentially spread COVID-19

COVID-19 can spread from asymptomatic but infected people through small aerosol droplets in their exhaled breath. Most studies of the flow of exhaled air have focused on coughing or sneezing, which can send aerosols flying ...

A sponge to soak up carbon dioxide in the air

Human activity is now leading to the equivalent of 40 billion tons of carbon dioxide emitted into the atmosphere each year, putting us on track to increase the planet's temperature by 1.5 degrees Celsius over pre-industrial ...

How outdoor pollution affects indoor air quality

Just when you thought you could head indoors to be safe from the air pollution that plagues the Salt Lake Valley, new research shows that elevated air pollution events, like horror movie villains, claw their way into indoor ...

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Earth's atmosphere

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