Atmosphere of Earth relatively warm air above a colder one), and in others by a zone which is isothermal with height. Although variations do occur, the temperature usually declines with increasing altitude in the troposphere because the troposphere is mostly heated through energy transfer from the surface. Thus, the lowest part of the troposphere (i.e. Earth's surface) is typically the warmest section of the troposphere. This promotes vertical mixing (hence, the origin of its name in the Greek word τρόπος, "tropos", meaning "turn"). The troposphere contains roughly 80% of the mass of Earth's atmosphere. The troposphere is denser than all its overlying atmospheric
What We Live For We Live For" and "I'm Born to Run". To promote the album, the band went on a U.S. tour to promote the record ahead of its release. In March 2014, American Authors released their debut studio album, "Oh, What a Life", after many years releasing extended plays under the moniker The Blue Pages. American Authors enjoyed considerable success with the album, gaining significant exposure, especially through adult contemporary radio. Their success is largely due to the commercial boom of their hit single, "Best Day of My Life", which by April 2015 had been certified triple platinum by the Recording Industry