Tropospheric lapse rate

 E. Linacre 11/'98

Mankind has long known that temperatures fall up a mountain. In fact this knowledge was essential to the success of early civilizations in the Fertile Crescent of the Middle East. Yet it is not easy to explain this without an understanding of the connection between the pressure and the temperature of a gas, i.e. the ideal gas law (Note 1.M). This law is an extension of Charles' Law, which was first enunciated in France in 1787, and later formalized by Joseph Gay-Lussac.

Anaximenes (550 - 475 BC) thought that the explanation was that air higher up was further from the heat of the Sun's rays reflected from the ground. The paradox of temperature decrease with height and decrease of distance to the Sun was so obvious that most people, including ancient writers, believed that eventually the temperature would increase with height. We now know that this does happen, in the stratosphere, but not because of closer proximity to the Sun.