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,
Live Earth (2007 concert) the crowd "motherfuckers". The BBC later apologised for cutting away from footage of Metallica, and both during and after the concert for the bad language. On 12 April 2008, an Ofcom broadcast was shown on BBC1, apologising again for the 'offensive language.' Intelligent Giving have attempted to find out what was happening to the proceeds from ticket sales at the concerts. Their conclusions, published in a feature "What on (Live) Earth is going on?" were that no one involved is capable of giving a clear answer. Live Earth was documented on "Live Earth: The Concerts for a Climate in Crisis",