Changes

[[File:lighterstill.jpg]][[File:Changing_weather.jpg|right|frame]]

[[File:lighterstill.jpg]][[File:Changing_weather.jpg|right|frame]]

'''Weather''' is a set of all the [[phenomena]] occurring in a given [[atmosphere]] at a given [[time]]. Most weather phenomena occur in the [http://en.wikipedia.org/wiki/Troposphere troposphere], just below the [http://en.wikipedia.org/wiki/Stratosphere stratosphere]. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas [[climate]] is the term for the average atmospheric conditions over longer periods of time. When used without qualification, "weather" is understood to be the weather of [[Earth]].

'''Weather''' is a set of all the [[phenomena]] occurring in a given [[atmosphere]] at a given [[time]]. Most weather phenomena occur in the [https://en.wikipedia.org/wiki/Troposphere troposphere], just below the [https://en.wikipedia.org/wiki/Stratosphere stratosphere]. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas [[climate]] is the term for the average atmospheric conditions over longer periods of time. When used without qualification, "weather" is understood to be the weather of [[Earth]].

Weather occurs due to [[density]] (temperature and moisture) [[differences]] between one place and another. These differences can occur due to the [[sun]] [[angle]] at any particular spot, which varies by [[latitude]] from the tropics. The strong temperature [[contrast]] between polar and tropical air gives rise to the [http://en.wikipedia.org/wiki/Jet_stream jet stream]. Weather [[systems]] in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream [[flow]]. Because the Earth's [[axis]] is tilted [[relative]] to its orbital plane, sunlight is incident at different angles at different times of the year. On Earth's [[surface]], temperatures usually range ±40 °C (100 °F to −40 °F) annually. Over thousands of years, changes in Earth's orbit affect the amount and [[distribution]] of [[Sun|solar]] [[energy]] received by the Earth and influence long-term climate.

Weather occurs due to [[density]] (temperature and moisture) [[differences]] between one place and another. These differences can occur due to the [[sun]] [[angle]] at any particular spot, which varies by [[latitude]] from the tropics. The strong temperature [[contrast]] between polar and tropical air gives rise to the [https://en.wikipedia.org/wiki/Jet_stream jet stream]. Weather [[systems]] in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream [[flow]]. Because the Earth's [[axis]] is tilted [[relative]] to its orbital plane, sunlight is incident at different angles at different times of the year. On Earth's [[surface]], temperatures usually range ±40 °C (100 °F to −40 °F) annually. Over thousands of years, changes in Earth's orbit affect the amount and [[distribution]] of [[Sun|solar]] [[energy]] received by the Earth and influence long-term climate.

[[Surface]] temperature [[differences]] in turn cause [[pressure]] differences. Higher altitudes are cooler than lower altitudes due to differences in compressional [[heat]]ing. Weather [[forecasting]] is the [[application]] of [[science]] and [[technology]] to [[predict]] the [[state]] of the [[atmosphere]] for a [[future]] time and a given location. The atmosphere is a [[chaotic]] system, so small changes to one part of the system can [[grow]] to have large effects on the system as a [[whole]]. Human attempts to [[control]] the weather have occurred throughout human [[history]], and there is [[evidence]] that human activity such as [[agriculture]] and industry has inadvertently modified weather [[patterns]].

[[Surface]] temperature [[differences]] in turn cause [[pressure]] differences. Higher altitudes are cooler than lower altitudes due to differences in compressional [[heat]]ing. Weather [[forecasting]] is the [[application]] of [[science]] and [[technology]] to [[predict]] the [[state]] of the [[atmosphere]] for a [[future]] time and a given location. The atmosphere is a [[chaotic]] system, so small changes to one part of the system can [[grow]] to have large effects on the system as a [[whole]]. Human attempts to [[control]] the weather have occurred throughout human [[history]], and there is [[evidence]] that human activity such as [[agriculture]] and industry has inadvertently modified weather [[patterns]].

[[Studying]] how the weather works on other planets has been helpful in [[understanding]] how weather works on Earth. A famous landmark in the [[Solar System]], [http://en.wikipedia.org/wiki/Great_Red_Spot, Jupiter's Great Red Spot], is an anticyclonic storm known to have existed for at least 300 years. However, weather is not limited to planetary bodies. A [[star]]'s [http://en.wikipedia.org/wiki/Corona corona] is constantly being lost to [[space]], creating what is essentially a very thin [[atmosphere]] throughout the [[Solar System]]. The [[movement]] of [[mass]] ejected from the [[Sun]] is known as the [http://en.wikipedia.org/wiki/Solar_wind solar wind].[http://en.wikipedia.org/wiki/Weather]

[[Studying]] how the weather works on other planets has been helpful in [[understanding]] how weather works on Earth. A famous landmark in the [[Solar System]], [https://en.wikipedia.org/wiki/Great_Red_Spot, Jupiter's Great Red Spot], is an anticyclonic storm known to have existed for at least 300 years. However, weather is not limited to planetary bodies. A [[star]]'s [https://en.wikipedia.org/wiki/Corona corona] is constantly being lost to [[space]], creating what is essentially a very thin [[atmosphere]] throughout the [[Solar System]]. The [[movement]] of [[mass]] ejected from the [[Sun]] is known as the [https://en.wikipedia.org/wiki/Solar_wind solar wind].[https://en.wikipedia.org/wiki/Weather]

[[Category: Ecology]]

[[Category: Ecology]]

[[Category: Earth Science]]

[[Category: Earth Science]]