Atmosphere of Earth (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. From highest to lowest, the five main layers are: The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at
Where We Are Tour: Live from the O2 ‘What About Now’ video. In addition, the Blu-ray will feature a full hour and a half exclusive commentary where the boys discuss the show in detail and talk about what we can expect from the next tour. It is simply essential viewing for any Westlife fan. 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.