Editing Alpine climate (section)

==Cause==
The temperature profile of the atmosphere is a result of an interaction between [[radiation]] and [[convection]]. Sunlight in the [[visible spectrum]] hits the ground and heats it. The ground then heats the air at the surface. If [[radiation]] were the only way to transfer heat from the ground to space, the [[greenhouse effect]] of gases in the atmosphere would keep the ground at roughly {{convert|333|K|C F}}, and the temperature would decay exponentially with height.<ref name=goodywilson>{{cite book|first1=Richard M.|last1=Goody|first2=James C.G.|last2=Walker|title=Atmospheres|chapter=Atmospheric Temperatures|chapter-url=http://lasp.colorado.edu/~bagenal/3720/GoodyWalker/AtmosCh3sm.pdf|publisher=Prentice-Hall|year=1972|access-date=2016-05-02|archive-date=2016-07-29|archive-url=https://web.archive.org/web/20160729075851/http://lasp.colorado.edu/~bagenal/3720/GoodyWalker/AtmosCh3sm.pdf|url-status=dead}}</ref>

However, when air is hot, it tends to expand, which lowers its density. Thus, hot air tends to rise and transfer heat upward. This is the process of [[convection]]. Convection comes to equilibrium when a parcel of air at a given altitude has the same density as its surroundings. Air is a poor conductor of heat, so a parcel of air will rise and fall without exchanging heat. This is known as an [[adiabatic process]], which has a characteristic pressure-temperature curve. As the pressure gets lower, the temperature decreases. The rate of decrease of temperature with elevation is known as the [[adiabatic lapse rate]], which is approximately 9.8&nbsp;°C per kilometer (or 5.4&nbsp;°F per 1000&nbsp;feet) of altitude.<ref name=goodywilson/>

The presence of water in the atmosphere complicates the process of convection. Water vapor contains latent [[heat of vaporization]]. As air rises and cools, it eventually becomes [[Dew point|saturated]] and cannot hold its quantity of water vapor. The water vapor condenses (forming [[cloud]]s), and releases heat, which changes the lapse rate from the [[dry adiabatic lapse rate]] to the [[moist adiabatic lapse rate]] (5.5&nbsp;°C per kilometre or 3&nbsp;°F per 1000&nbsp;feet).<ref>{{cite web|url=http://meteorologytraining.tpub.com/14312/css/14312_47.htm |title=Dry Adiabatic Lapse Rate |publisher=tpub.com |access-date=2016-05-02 |url-status=dead |archive-url=https://web.archive.org/web/20160603041448/http://meteorologytraining.tpub.com/14312/css/14312_47.htm |archive-date=2016-06-03 }}</ref> The actual lapse rate, called the [[environmental lapse rate]], is not constant (it can fluctuate throughout the day or seasonally and also regionally), but a normal lapse rate is 5.5&nbsp;°C per 1,000&nbsp;m (3.57&nbsp;°F per 1,000&nbsp;ft).<ref>{{cite book
  | chapter-url=http://goldbook.iupac.org/A00144.html
  | chapter=Adiabatic Lapse Rate
  | publisher=[[IUPAC]]| doi=10.1351/goldbook.A00144
  | year=2009
  | isbn=978-0-9678550-9-7
  | title=The IUPAC Compendium of Chemical Terminology
 }}</ref><ref>{{Cite book|last=Dommasch|first=Daniel O.|title=Airplane Aerodynamics (3rd ed.)|publisher=Pitman Publishing Co.|year=1961|page=22}}</ref> Therefore, moving up {{convert|100|m}} on a mountain is roughly equivalent to moving 80&nbsp;kilometres (50&nbsp;miles or 0.75° of [[latitude]]) towards the pole.<ref>{{cite web
  | title= Mountain Environments
  | url= http://quin.unep-wcmc.org/mountains/mountain_watch/pdfs/mountainEnvironments.pdf
  | archive-url= https://web.archive.org/web/20110825113735/http://quin.unep-wcmc.org/mountains/mountain_watch/pdfs/mountainEnvironments.pdf
  | archive-date=2011-08-25
  | publisher = United Nations Environment Programme World Conservation Monitoring Centre}}</ref> This relationship is only approximate, however, since local factors, such as proximity to [[ocean]]s, can drastically modify the climate.<ref>{{cite web
  | url=http://www.ecn.ac.uk/Education/factors_affecting_climate.htm
  | archive-url=https://web.archive.org/web/20110716163841/http://www.ecn.ac.uk/Education/factors_affecting_climate.htm
  | archive-date=2011-07-16
  | title=Factors affecting climate
  | publisher=The United Kingdom Environmental Change Network}}</ref> As the altitude increases, the main form of [[precipitation (meteorology)|precipitation]] becomes [[snow]] and the [[wind]]s increase. The temperature continues to drop until the [[tropopause]], at {{convert|11000|m|ft}}, where it does not decrease further. This is higher than the highest [[summit]].