Atmosphere of Earth However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft. The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about , although this altitude varies from about at the geographic poles to at the Equator, with some variation due to weather. The troposphere is bounded above by the tropopause, a boundary marked in most places by a temperature inversion (i.e. a layer of
What We Live For "we tried to take a lot of the stuff that our fans like and love about us from Oh, What a Life and take that to the next level as far as sounds go. [We] brought back some of the old instruments like mandolin and banjo, but also experimented with a lot of different sounds like vocal samples. We brought back a lot of piano [and] bigger harmonies." Lyrically, the album builds on "Oh, What a Life"s biographical themes, which followed the band's origins and journey; "What We Live For" documents the band's experiences during the present and their perspective