Atmosphere of Earth

The atmosphere of Earth is the layer of gases surrounding the planet Earth that is retained by Earth's gravity. 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 (the diurnal temperature variation).

The common name air (English pronunciation: /ɛər/) is given to the atmospheric gases used in breathing and photosynthesis. By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air content and atmospheric pressure vary at different layers, and air suitable for the survival of terrestrial plants and terrestrial animals is found only in Earth's troposphere and artificial atmospheres.

The atmosphere has a mass of about 5.15×10¹⁸ kg, three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km (62 mi), or 1.57% of Earth's radius, is often used as the border between the atmosphere and outer space. Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km (75 mi). Several layers can be distinguished in the atmosphere, based on characteristics such as temperature and composition.

Sora

Sora may refer to:

People

Places

Acronyms

Other uses

Air Gear

Air Gear (Japanese: エア・ギア, Hepburn: Ea Gia) is a shōnen manga written and illustrated by Ito "Oh Great" Ōgure. Air Gear revolves around the life of Itsuki Minami "Ikki or Crow", also known as "Baby Face", "Lil (and Little) Crow", and his friends. The story follows their use of Air Treks, an in-universe invention derived from inline skates. Initial sections of the plot carries out the introduction of characters that eventually join Ikki. As the story progresses, it focuses on their roles as Storm Riders and their quest to be on the top of the Trophaeum Tower. Air Gear won the 2006 Kodansha Manga Award in the shōnen category. The series concluded on May 28, 2012 with Chapter 357, but was continued with a new chapter. At the end of Chapter 358, the author of the manga told readers to look forward to more Air Gear.

Plot

A new fad by the name of 'Air Treks' (a futuristic evolution of aggressive skating) has swept the nation's youth and all over gangs are being formed that compete in various events using their A-T's. Ikki is a middle-school boy who is the toughest street-fighting punk on the east side of town, on top of that he lives with 4 gorgeous sisters that took him in when he was a kid. But what Ikki doesn't know is that the girls are part of one of the most infamous A-T gangs, 'Sleeping Forest'. It doesn't take long before Ikki finds out about the world of Air Treks and is propelled into a fate he had not foreseen.