Editing FlightGear (section)

==== Atmospheric and environmental physics ====
''FlightGear'' can simulate the atmosphere ranging from [[Earth's energy budget#Energy budget|energy inputs/outputs]] to the system, like energy from the Sun or volcanic sources, through to fluid flow on various scales and changes of state. ''FlightGear'' is able to model different surface characteristics such as heating or cooling, and the exchange of heat and moisture with the atmosphere depending on factors like windflow or dew point. ''FlightGear'' models the continuously evolving life-cycle of phenomena on various scales, driven by interaction of fluid with terrain. They range from turbulence on different scales to, individual thermals, thunderstorms, through to moving air layers, and depicting air-masses on the scale of thousands of kilometers. Atmospheric water is modeled by ''FlightGear'' ranging from state changes such as condensing into cloud or haze layers, along with energy provided from latent heat to drive convective fluid flow, through to precipitation as rain droplets, snow, or hail.<ref name=":022">{{Cite web|last=|first=|date=June 25, 2013|title=The art of cloud and weather rendering – FlightGear Flight Simulator|url=https://www.flightgear.org/tours/the-art-of-cloud-and-weather-rendering/|url-status=live|archive-url=https://web.archive.org/web/20201031172624/https://www.flightgear.org/tours/the-art-of-cloud-and-weather-rendering/|archive-date=31 October 2020|access-date=2019-07-23|website=FlightGear.org|language=en-US}}</ref><ref name=":232">{{Cite web|last=|first=|date=December 17, 2014|title=The magic of light and haze – FlightGear Flight Simulator|url=https://www.flightgear.org/tours/the-magic-of-light-and-haze/|url-status=live|archive-url=https://web.archive.org/web/20201205092108/https://www.flightgear.org/tours/the-magic-of-light-and-haze/|archive-date=5 December 2020|access-date=2019-08-31|website=FlightGear.org|language=en-US}}</ref><ref name=":32">{{Cite web|last=|first=|date=November 30, 2014|title=A preview of features for Flightgear 3.4 – FlightGear Flight Simulator|url=https://www.flightgear.org/info/a-preview-of-features-for-flightgear-3-4/|url-status=live|archive-url=https://web.archive.org/web/20210119222757/https://www.flightgear.org/info/a-preview-of-features-for-flightgear-3-4/|archive-date=19 January 2021|access-date=2019-08-31|website=FlightGear.org|language=en-US}}</ref><ref name=":03">{{Cite web|last=|first=|date=February 24, 2012|title=Advanced Weather v1.4 in Flightgear 2.6+ – FlightGear Flight Simulator|url=https://www.flightgear.org/tours/advanced-weather-v1-4-in-flightgear-2-6/|url-status=live|archive-url=https://web.archive.org/web/20190831105119/https://www.flightgear.org/tours/advanced-weather-v1-4-in-flightgear-2-6/|archive-date=31 August 2019|access-date=2019-08-31|website=FlightGear.org|language=en-US}}</ref>

The process of generating lift creates turbulence with vortices, and ''FlightGear'' models wake turbulence with [[Vortex shedding|shedding]] of wingtip vortices by flown craft as well as AI craft.<ref>{{Cite web|title=AI wake turbulence - FlightGear wiki|url=http://wiki.flightgear.org/AI_wake_turbulence|access-date=2019-09-04|website=FlightGear wiki}}</ref><ref>{{Cite web|title=Changelog 2017.3 - FlightGear wiki|url=https://wiki.flightgear.org/Changelog_2017.3#JSBSim|url-status=live|archive-url=https://web.archive.org/web/20200705062057/https://wiki.flightgear.org/Changelog_2017.3#JSBSim|archive-date=5 July 2020|access-date=2021-03-15|website=FlightGear wiki}}</ref>

FlightGear also has a less physically accurate model that uses [[METAR]] weather updates of differing frequency, designed for safe operation of [[aerodromes]], to [[Classification of discontinuities#Jump discontinuity|dis-continuously]] force atmosphere based on attempted guesses of processes that are fundamentally constrained by the closeness or density of observation stations, as well as the [[Meteorology#Spatial scales|small-scale]], limited, rounded off, [[Quantization (signal processing)#Types|non-smoothly varying]], and need-to-know precision of information.<ref>{{Cite web|title=Weather - FlightGear wiki|url=http://wiki.flightgear.org/Weather#Scenarios_and_METAR|access-date=2019-09-04|website=FlightGear wiki}}</ref> Aloft waypoint settings modelling high altitude behaviors of wind can be synced to updates from Jeppeson.<ref>{{Cite web|last=|first=|date=|title=Weather - FlightGear wiki|url=http://wiki.flightgear.org/Howto:Fetch_live_aloft_data|url-status=live|archive-url=https://web.archive.org/web/20190904073627/http://wiki.flightgear.org/Howto:Fetch_live_aloft_data|archive-date=2019-09-04|access-date=2019-07-23|website=FlightGear wiki}}</ref>

''Flightgear'' has a simulation of planetary bodies in the [[Solar System]] which is used for purposes like driving latitude dependent weather from solar radiation, as well as the brightness and position of stars for [[celestial navigation]]. There is a model of gravity based on a non-spherical Earth, and craft can even experience differing gravity across their bodies which will exert [[Torque|twisting force]].<ref name=":732">{{Cite web|last=|first=|date=December 18, 2015|title=An experience like no other… – FlightGear Flight Simulator|url=https://www.flightgear.org/tours/an-experience-like-no-other/|url-status=live|archive-url=https://web.archive.org/web/20210315092603/https://www.flightgear.org/tours/an-experience-like-no-other/|archive-date=15 March 2021|access-date=2019-08-31|website=FlightGear.org|language=en-US}}</ref> A model of the observed [[Magnetic declination#Air navigation|variation]] in the Earth's [[Dynamo theory|complex]] magnetic field, and the option to simulate, to an extent, the propagation of radio wave signals due to interaction with different types of terrain, also exists in ''FlightGear''.<ref>{{Cite web|title=Avionics and instruments - FlightGear wiki|url=http://wiki.flightgear.org/Avionics_and_instruments#Compass|access-date=2019-09-05|website=wiki.flightgear.org}}</ref><ref>{{Cite web|title=Radio propagation - FlightGear wiki|url=http://wiki.flightgear.org/Radio_propagation#Rationale|access-date=2019-09-05|website=wiki.flightgear.org}}</ref>

''FlightGear'' uses an exact, [[Figure of the Earth|non-spherical]], model of Earth, and is also able to simulate flight in [[Polar regions of Earth|polar regions]] and airports ([[:Category:Airports in the Arctic|arctic]] or [[List of airports in Antarctica|antarctic]]) without simulator errors due to issues with coordinate systems.