Atmosphere of Earth surface. The refractive index of air depends on temperature, giving rise to refraction effects when the temperature gradient is large. An example of such effects is the mirage. "Atmospheric circulation" is the large-scale movement of air through the troposphere, and the means (with ocean circulation) by which heat is distributed around Earth. The large-scale structure of the atmospheric circulation varies from year to year, but the basic structure remains fairly constant because it is determined by Earth's rotation rate and the difference in solar radiation between the equator and poles. The first atmosphere consisted of gases in the solar nebula,
Where We Are Tour: Live from the O2 Where We Are Tour: Live from the O2 Where We Are Tour: Live from the O2 is a concert DVD by Irish boy band Westlife from their Where We Are Tour. During the group's Where We Are Tour, it was confirmed that their May 14 concert at the O2 Arena, London, England was recorded. The release date was then set as 29 November 2010 for both DVD and Blu-ray formats, making it the band's first release on Blu-ray. Pre-order links were set up by Play.com on 12 October 2010. The album includes an unseen backstage documentary during said tour and