jet stream

The first indications of this phenomenon came from American professor Elias Loomis (1811–1889), when he proposed the hypothesis of a powerful air current in the upper air blowing west to east across the United States as an explanation for the behaviour of major storms.Sunny Intervals and Showers: our changing weather, p.142; Weidenfeld & Nicolson, London, 1992. After the 1883 eruption of the Krakatoa volcano, weather watchers tracked and mapped the effects on the sky over several years. They labelled the phenomenon the "equatorial smoke stream".{{Cite news | last =Winchester | first =Simon | author-link =Simon Winchester | title =A Tale of Two Volcanos | newspaper =The New York Times | date =15 April 2010 | url =https://www.nytimes.com/2010/04/16/opinion/16winchester.html | access-date =25 February 2017 | archive-date =20 October 2023 | archive-url =https://web.archive.org/web/20231020194435/https://www.nytimes.com/2010/04/16/opinion/16winchester.html | url-status =live }}See:

1. Bishop, Sereno E. (17 January 1884) "Letters to the Editor: The remarkable sunsets," Nature, 29: 259–260; on [https://books.google.com/books?id=IscKAAAAYAAJ&pg=PA260 page 260], Bishop speculates that a rapid current in the upper atmosphere was carrying the dust from the eruption of Krakatau westward around the equator.
2. Bishop, S.E. (May 1884) [https://books.google.com/books?id=vLYx_8gCXq0C&pg=PA106 "The equatorial smoke-stream from Krakatoa,"] The Hawaiian Monthly, vol. 1, no. 5, pages 106–110.
3. Bishop, S.E. (29 January 1885) [https://books.google.com/books?id=9OLp4UZFtqYC&pg=PA288 "Letters to the Editor: Krakatoa,"] Nature, vol. 31, pages 288–289.
4. Rev. Sereno E. Bishop (1886) "The origin of the red glows," American Meteorological Journal, vol. 3, pages [https://books.google.com/books?id=UcowAQAAMAAJ&pg=PA127 127–136], [https://books.google.com/books?id=UcowAQAAMAAJ&pg=PA193 193–196]; on pages 133–136, Bishop discusses the "equatorial smoke stream" that was produced by the eruption of Krakatau.
5. Hamilton, Kevin (2012) [http://iprc.soest.hawaii.edu/users/kph/K.pdf "Sereno Bishop, Rollo Russell, Bishop's Ring and the discovery of the "Krakatoa easterlies","] {{webarchive|url=https://web.archive.org/web/20121022072917/http://iprc.soest.hawaii.edu/users/kph/K.pdf |date=22 October 2012 }} Atmosphere-Ocean, vol. 50, no. 2, pages 169–175.
6. Krakatoa Committee of the Royal Society [of London], The Eruption of Krakatoa and Subsequent Phenomena (London, England: Harrison and Sons, 1888). Evidence of an equatorial high-speed, high-altitude current (the quasi-biennial oscillation) is presented in the following sections:

::* Part IV., Section II. General list of dates of first appearance of all the optical phenomena. By the Hon. Rollo Russell., [https://books.google.com/books?id=Vk8PAAAAYAAJ&pg=PA263 pages 263–312].

::* Part IV., Section III. (A). General geographic distribution of all the optical phenomena in space and time; including also velocity of translation of smoke stream. By the Hon. Rollo Russell., [https://books.google.com/books?id=Vk8PAAAAYAAJ&pg=PA312 pages 312–326].

::* Part IV., Section III. (B). The connection between the propagation of the sky haze with its accompanying optical phenomena, and the general circulation of the atmosphere. By Mr. E. Douglas Archibald., [https://books.google.com/books?id=Vk8PAAAAYAAJ&pg=PA326 pages 326–334]; that Rev. S.E. Bishop of Honolulu first noticed a westward circulation of dust from Krakatau is acknowledged on page 333.

::* Part IV., Section III. (C). Spread of the phenomena round the world, with maps illustrative thereof. By the Hon. Rollo Russell., [https://books.google.com/books?id=Vk8PAAAAYAAJ&pg=PA334 pages 334–339]; after page 334 there are map inserts, showing the progressive spread, along the equator, of the dust from Krakatau. In the 1920s Japanese meteorologist Wasaburo Oishi detected the jet stream from a site near Mount Fuji.{{cite journal | last1 = Lewis | first1 = John M. | year = 2003 | title = Oishi's Observation: Viewed in the Context of Jet Stream Discovery | journal = Bulletin of the American Meteorological Society | volume = 84 | issue = 3| pages = 357–369 | doi=10.1175/BAMS-84-3-357| bibcode = 2003BAMS...84..357L | doi-access = free }}Ooishi, W. (1926) Raporto de la Aerologia Observatorio de Tateno (in Esperanto). Aerological Observatory Report 1, Central Meteorological Observatory, Japan, 213 pages. He tracked pilot balloons ("pibals"), used to measure wind speed and direction,{{cite web| title= Pilot Weather Balloon (Pibal) Optical Theodolites| date= 25 November 2009| website= Martin Brenner's, Pilot Balloon Resources| publisher= California State University Long Beach| url= https://home.csulb.edu/~mbrenner/balloon.htm| access-date= 24 July 2023| archive-date= 2 December 2023| archive-url= https://web.archive.org/web/20231202073736/https://home.csulb.edu/~mbrenner/balloon.htm| url-status= live}} as they rose in the air. Oishi's work largely went unnoticed outside Japan because it was published in Esperanto, though chronologically he has to be credited for the scientific discovery of jet streams. American pilot Wiley Post (1898–1935), the first man to fly around the world solo in 1933, is often given some credit for discovery of jet streams. Post invented a pressurized suit that let him fly above {{convert|6200|m|ft}}. In the year before his death, Post made several attempts at a high-altitude transcontinental flight, and noticed that at times his ground speed greatly exceeded his air speed.{{cite web | title=Wiley Post: First to Fly Solo Around the World, in the Winnie Mae|first= Stephen|last=Sherman|date=January 2001|orig-date=Updated 27 June 2011|publisher=AcePilots| url=http://acepilots.com/post.html | archive-url= https://web.archive.org/web/20130809033421/http://acepilots.com/post.html | archive-date=9 August 2013 | url-status=live}}

German meteorologist Heinrich Seilkopf is credited with coining a special term, Strahlströmung (literally "jet current"), for the phenomenon in 1939.Seilkopf, H., Maritime meteorologie, which is volume II of: R. Habermehl, ed., Handbuch der Fliegenwetterkunde [Handbook of Aeronautical Meteorology] (Berlin, Germany: Gebrüder Radetzke [Radetzke Brothers], 1939); Seilkopf coins the word "Strahlströmung" on page 142 and discusses the jet stream on pages 142–150.Arbeiten zur allgemeinen Klimatologie by Hermann Flohn [https://books.google.com/books?id=OlwLAQAAIAAJ&q=seilkopf+Strahlstr%C3%B6mung p. 47] Many sources credit real understanding of the nature of jet streams to regular and repeated flight-path traversals during World War II. Flyers consistently noticed westerly tailwinds in excess of {{convert|100|mph|abbr=on|order=flip}} in flights, for example, from the US to the UK.{{cite web|url= http://www.bbc.co.uk/weather/features/basics_jetstreams.shtml|title=Weather Basics – Jet Streams |access-date=8 May 2009 |url-status=dead |archive-url=https://web.archive.org/web/20060829012128/http://www.bbc.co.uk/weather/features/basics_jetstreams.shtml |archive-date=29 August 2006}} Similarly in 1944 a team of American meteorologists in Guam, including Reid Bryson, had enough observations to forecast very high west winds that would slow bombers raiding Japan.{{Cite web |url= http://www.statesman.com/news/news/opinion/when-the-jet-stream-was-the-wind-of-war/nRxPD/ |title=When the jet stream was the wind of war |access-date=9 December 2018 |archive-url= https://web.archive.org/web/20160129055603/http://www.statesman.com/news/news/opinion/when-the-jet-stream-was-the-wind-of-war/nRxPD/ |archive-date=29 January 2016 |url-status=dead}}

File:Jetstreamconfig.jpg

File:Jetcrosssection.svg

The polar and subtropical jet streams are the product of two factors: the atmospheric heating by solar radiation that produces the large-scale polar, Ferrel, and Hadley circulation cells, and the action of the Coriolis force acting on those moving masses. The Coriolis force is caused by the planet's rotation on its axis. The polar jet stream forms near the interface of the polar and Ferrel circulation cells; the subtropical jet forms near the boundary of the Ferrel and Hadley circulation cells.{{cite web | author=University of Illinois | url=http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cyc/upa/jet.rxml | title=Jet Stream | access-date=4 May 2008 | author-link=University of Illinois | archive-date=6 November 2018 | archive-url=https://web.archive.org/web/20181106095747/http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cyc/upa/jet.rxml | url-status=live }}

Polar jet streams are typically located near the 250 hPa (about 1/4 atmosphere) pressure level, or {{cvt|30000|ft|mi km}} ( according to engineeringtoolbox's equation, 250 hPa is 33,700ft, not 30,000 ft ) above sea level while the weaker subtropical jet streams are somewhat higher.{{cite web |title=Jet Stream |url=https://skybrary.aero/articles/jet-stream |publisher=SKYbrary Aviation Safety |access-date=2 December 2024}}

The polar jets, at lower altitude, and often intruding into mid-latitudes, strongly affect weather and aviation.David R. Cook [http://www.newton.dep.anl.gov/askasci/wea00/wea00067.htm Jet Stream Behavior.] {{Webarchive|url=https://web.archive.org/web/20130602041056/http://www.newton.dep.anl.gov/askasci/wea00/wea00067.htm |date=2 June 2013 }} Retrieved on 8 May 2008.B. Geerts and E. Linacre. [http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/tropo.html The Height of the Tropopause.] {{Webarchive|url=https://web.archive.org/web/20200427090700/http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/tropo.html |date=27 April 2020 }} Retrieved on 8 May 2008. The polar jet stream is most commonly found between latitudes 30° and 60° (closer to 60°), while the subtropical jet streams are located close to latitude 30°. These two jets merge at some locations and times, while at other times they are well separated. The northern polar jet stream is said to "follow the sun" as it slowly migrates northward as that hemisphere warms, and southward again as it cools.National Weather Service JetStream. [http://www.srh.noaa.gov/jetstream//global/jet.htm The Jet Stream.] {{Webarchive|url=https://web.archive.org/web/20131022193119/http://www.srh.noaa.gov/jetstream//global/jet.htm |date=22 October 2013 }} Retrieved on 8 May 2008.McDougal Littell. [http://www.classzone.com/books/earth_science/terc/content/investigations/es1908/es1908page04.cfm Paths of Polar and Subtropical Jet Streams.] {{Webarchive|url=https://web.archive.org/web/20131113191900/http://www.classzone.com/books/earth_science/terc/content/investigations/es1908/es1908page04.cfm |date=13 November 2013 }} Retrieved on 13 May 2008.

The width of a jet stream is typically a few hundred kilometres or miles and its vertical thickness often less than {{convert|5|km|ft|abbr=off|spell=in}}.{{Cite web| url=https://www.pbs.org/wgbh/nova/balloon/science/jetstream.html| title=Frequently Asked Questions About The Jet Stream| website=PBS.org| publisher=NOVA| access-date=24 October 2008| archive-date=22 September 2008| archive-url=https://web.archive.org/web/20080922004117/http://www.pbs.org/wgbh/nova/balloon/science/jetstream.html| url-status=live}}

Jet streams are typically continuous over long distances, but discontinuities are also common.Glossary of Meteorology. [http://amsglossary.allenpress.com/glossary/search?id=jet-stream1 Jet Stream.] {{webarchive|url=https://web.archive.org/web/20070301135911/http://amsglossary.allenpress.com/glossary/search?id=jet-stream1 |date=1 March 2007 }} Retrieved on 8 May 2008. The path of the jet typically has a meandering shape, and these meanders themselves propagate eastward, at lower speeds than that of the actual wind within the flow. Further, the meanders can split or form eddies.{{cite web |title=The Jet Stream |url=https://www.noaa.gov/jetstream/global/jet-stream |publisher=NOAA |date=20 September 2023 | access-date=2 December 2024}}

Each large meander, or wave, within the jet stream is known as a Rossby wave (planetary wave). Rossby waves are caused by changes in the Coriolis effect with latitude.{{cite book |last1=Rhines |first1=Peter |url=https://www.gfdl.noaa.gov/wp-content/uploads/files/user_files/io/rhines.pdf |title=Rossby Waves, in Encyclopedia of Atmospheric Sciences, Holton, Pyle and Curry Eds. |year=2002 |publisher=Academic Press, London |page=2780 pages |access-date=8 June 2022 |archive-date=7 October 2022 |archive-url=https://web.archive.org/web/20221007052127/https://www.gfdl.noaa.gov/wp-content/uploads/files/user_files/io/rhines.pdf |url-status=live }} Shortwave troughs, are smaller scale waves superimposed on the Rossby waves, with a scale of {{convert|1000|to(-)|4000|km|mi|-2}} long,Glossary of Meteorology. [http://amsglossary.allenpress.com/glossary/search?id=cyclone-wave1 Cyclone wave.] {{webarchive|url=https://web.archive.org/web/20061026100253/http://amsglossary.allenpress.com/glossary/search?id=cyclone-wave1 |date=26 October 2006 }} Retrieved on 13 May 2008. that move along through the flow pattern around large scale, or longwave, "ridges" and "troughs" within Rossby waves.Glossary of Meteorology. [http://amsglossary.allenpress.com/glossary/search?p=1&query=short+wave&submit=Search Short wave.] {{webarchive|url=https://web.archive.org/web/20090609104745/http://amsglossary.allenpress.com/glossary/search?p=1&query=short+wave&submit=Search |date=9 June 2009 }} Retrieved on 13 May 2008.

The wind speeds are greatest where temperature differences between air masses are greatest, and often exceed {{convert|92|km/h|kn mph|abbr=on}}. Speeds of {{convert|400|km/h|kn mph|abbr=on}} have been measured.

The jet stream moves from west to east bringing changes of weather.[http://www.space.com/scienceastronomy/solarsystem/jupiter_sidebar_000209.html Jet Streams On Earth and Jupiter.] {{webarchive|url=https://web.archive.org/web/20080724112429/http://www.space.com/scienceastronomy/solarsystem/jupiter_sidebar_000209.html |date=24 July 2008 }} Retrieved on 4 May 2008. The path of jet streams affects cyclonic storm systems at lower levels in the atmosphere, and so knowledge of their course has become an important part of weather forecasting. For example, in 2007 and 2012, Britain experienced severe flooding as a result of the polar jet staying south for the summer.{{Cite news |title = Why has it been so wet? |publisher = BBC |date = 23 July 2007 |url = http://news.bbc.co.uk/1/hi/magazine/6911918.stm |access-date = 31 July 2007 |archive-date = 26 September 2008 |archive-url = https://web.archive.org/web/20080926165122/http://news.bbc.co.uk/1/hi/magazine/6911918.stm |url-status = live }}Blackburn, Mike; Hoskins, Brian; Slingo, Julia: {{Cite web |url = http://www.walker-institute.ac.uk/news/summer_2007.pdf |title = Notes on the Meteorological Context of the UK Flooding in June and July 2007 |publisher = Walker Institute for Climate System Research |date = 25 July 2007 |access-date = 29 August 2007 |url-status = dead |archive-url = https://web.archive.org/web/20070926220024/http://www.walker-institute.ac.uk/news/summer_2007.pdf |archive-date = 26 September 2007}}{{Cite news |title = Why, oh why, does it keep raining? |publisher = BBC |date = 10 July 2012 |url = https://www.bbc.co.uk/news/science-environment-18783422 |access-date = 18 July 2012 |work = BBC News |last1 = Shukman |first1 = David |archive-date = 11 December 2012 |archive-url = https://web.archive.org/web/20121211152503/http://www.bbc.co.uk/news/science-environment-18783422 |url-status = live }}

File:Earth Global Circulation - en.svg

{{See also|Extratropical cyclone|Thermal wind}}

In general, winds are strongest immediately under the tropopause (except locally, during tornadoes, tropical cyclones or other anomalous situations). If two air masses of different temperatures or densities meet, the resulting pressure difference caused by the density difference (which ultimately causes wind) is highest within the transition zone. The wind does not flow directly from the hot to the cold area, but is deflected by the Coriolis effect and flows along the boundary of the two air masses.John P. Stimac. [http://www.ux1.eiu.edu/~cfjps/1400/pressure_wind.html Air pressure and wind.] {{Webarchive|url=https://web.archive.org/web/20070927210111/http://www.ux1.eiu.edu/~cfjps/1400/pressure_wind.html |date=27 September 2007 }} Retrieved on 8 May 2008.

All these facts are consequences of the thermal wind relation. The balance of forces acting on an atmospheric air parcel in the vertical direction is primarily between the gravitational force acting on the mass of the parcel and the buoyancy force, or the difference in pressure between the top and bottom surfaces of the parcel. Any imbalance between these forces results in the acceleration of the parcel in the imbalance direction: upward if the buoyant force exceeds the weight, and downward if the weight exceeds the buoyancy force. The balance in the vertical direction is referred to as hydrostatic. Beyond the tropics, the dominant forces act in the horizontal direction, and the primary struggle is between the Coriolis force and the pressure gradient force. Balance between these two forces is referred to as geostrophic. Given both hydrostatic and geostrophic balance, one can derive the thermal wind relation: the vertical gradient of the horizontal wind is proportional to the horizontal temperature gradient. If two air masses in the northern hemisphere, one cold and dense to the north and the other hot and less dense to the south, are separated by a vertical boundary and that boundary should be removed, the difference in densities will result in the cold air mass slipping under the hotter and less dense air mass. The Coriolis effect will then cause poleward-moving mass to deviate to the East, while equatorward-moving mass will deviate toward the west. The general trend in the atmosphere is for temperatures to decrease in the poleward direction. As a result, winds develop an eastward component and that component grows with altitude. Therefore, the strong eastward moving jet streams are in part a simple consequence of the fact that the Equator is warmer than the north and south poles.

The thermal wind relation does not explain why the winds are organized into tight jets, rather than distributed more broadly over the hemisphere. One factor that contributes to the creation of a concentrated polar jet is the undercutting of sub-tropical air masses by the more dense polar air masses at the polar front. This causes a sharp north–south pressure (south–north potential vorticity) gradient in the horizontal plane, an effect which is most significant during double Rossby wave breaking events.{{cite journal |last1=Messori |first1=Gabriele |last2=Caballero |first2=Rodrigo |title=On double Rossby wave breaking in the North Atlantic |journal=Journal of Geophysical Research: Atmospheres |date=2015 |volume=120 |issue=21 |pages=11,129–11,150 |doi=10.1002/2015JD023854|bibcode=2015JGRD..12011129M |doi-access=free }} At high altitudes, lack of friction allows air to respond freely to the steep pressure gradient with low pressure at high altitude over the pole. This results in the formation of planetary wind circulations that experience a strong Coriolis deflection and thus can be considered 'quasi-geostrophic'. The polar front jet stream is closely linked to the frontogenesis process in midlatitudes, as the acceleration/deceleration of the air flow induces areas of low/high pressure respectively, which link to the formation of cyclones and anticyclones along the polar front in a relatively narrow region.

A second factor which contributes to a concentrated jet is more applicable to the subtropical jet which forms at the poleward limit of the tropical Hadley cell, and to first order this circulation is symmetric with respect to longitude. Tropical air rises to the tropopause, and moves poleward before sinking; this is the Hadley cell circulation. As it does so it tends to conserve angular momentum, since friction with the ground is slight. Air masses that begin moving poleward are deflected eastward by the Coriolis force (true for either hemisphere), which for poleward moving air implies an increased westerly component of the windsLyndon State College Meteorology. [http://apollo.lsc.vsc.edu/classes/met130/notes/chapter10/subt_jet_form.html Jet Stream Formation – Subtropical Jet.] {{Webarchive|url=https://web.archive.org/web/20110927115127/http://apollo.lsc.vsc.edu/classes/met130/notes/chapter10/subt_jet_form.html |date=27 September 2011 }} Retrieved on 8 May 2008.

File:Jet Stream Rigs Apart Flossie 2.jpg over Hawaii in 2007. Note the large band of moisture that developed East of Hawaii Island that came from the hurricane.]]

The subtropical jet stream rounding the base of the mid-oceanic upper trough is thought{{Cite web |url=http://www.prh.noaa.gov/cphc/summaries/2007.php |title=NOAA Overview of Hurricane Flossie |access-date=14 June 2011 |archive-date=7 September 2015 |archive-url=https://web.archive.org/web/20150907125835/http://www.prh.noaa.gov/cphc/summaries/2007.php |url-status=live }} to be one of the causes most of the Hawaiian Islands have been resistant to the long list of Hawaii hurricanes that have approached. For example, when Hurricane Flossie (2007) approached and dissipated just before reaching landfall, the U.S. National Oceanic and Atmospheric Administration (NOAA) cited vertical wind shear as evidenced in the photo.

{{clear}}

The northern polar jet stream is the most important one for aviation and weather forecasting, as it is much stronger and at a much lower altitude than the subtropical jet streams and also covers many countries in the northern hemisphere, while the southern polar jet stream mostly circles Antarctica and sometimes the southern tip of South America.{{cite web |title=The Polar Jet Stream and Polar Vortex |url=https://climate.mit.edu/explainers/polar-jet-stream-and-polar-vortex |website=MIT Climate Portal |date=21 May 2024 |access-date=2 December 2024}}

File:Greatcircle Jetstream routes.svg and Los Angeles using the jet stream eastbound and a great circle route westbound.]]

The location of the jet stream is important for aviation. Aircraft flight time can be dramatically affected by either flying with the flow or against it. Often, airlines work to fly with the jet stream to obtain significant fuel cost and time savings.{{cite news |last=Osborne |first=Tony |title=Strong Jet Streams Prompt Record Breaking Transatlantic Crossings |publisher=Aviation Week|date= 10 February 2020 |url=https://aviationweek.com/air-transport/strong-jet-streams-prompt-record-breaking-transatlantic-crossings |archive-url=https://web.archive.org/web/20200211165218/https://aviationweek.com/air-transport/strong-jet-streams-prompt-record-breaking-transatlantic-crossings |archive-date= 11 February 2020 |access-date=11 February 2020 |url-status=live}}Ned Rozell. [http://www.gi.alaska.edu/ScienceForum/ASF17/1727.html Amazing flying machines allow time travel.] {{Webarchive |url=https://web.archive.org/web/20080605031147/http://www.gi.alaska.edu/ScienceForum/ASF17/1727.html |date=5 June 2008 }} Retrieved on 8 May 2008.

Commercial use of the jet stream began on 18 November 1952, when Pan Am flew from Tokyo to Honolulu at an altitude of {{convert|7600|m|ft}}. It cut the trip time by over one-third, from 18 to 11.5 hours.{{cite journal |last=Taylor |first=Frank J. |title=The Jet Stream Is The Villain |journal=Popular Mechanics |year=1958 |pages=97 |url=https://books.google.com/books?id=5d0DAAAAMBAJ&q=1952+tokyo+honolulu&pg=PA96 |access-date=13 December 2010}}

Within North America, the time needed to fly east across the continent can be decreased by about 30 minutes if an airplane can fly with the jet stream.{{cite news |title=Flying east from Dallas-Fort Worth? Strong jet-stream winds could get you there early |url=https://www.dallasnews.com/news/weather/2019/02/21/flying-east-from-dallas-fort-worth-strong-jet-stream-winds-could-get-you-there-early/ |last=Jimenez |first=Jesus |date=21 February 2019 |publisher=The Dallas Morning News |access-date=2 December 2024}} Across the Atlantic Ocean the North Atlantic Tracks service allows airlines and air traffic control to accommodate the jet stream for the benefit for airlines and other users.{{cite web |title=North Atlantic Operations - Organised Track System |url=https://skybrary.aero/articles/north-atlantic-operations-organised-track-system |publisher=SKYbrary Aviation Safety |access-date=2 December 2024}}

Associated with jet streams is a phenomenon known as clear-air turbulence (CAT), caused by vertical and horizontal wind shear caused by jet streams.BBC. [http://www.bbc.co.uk/weather/features/understanding/jetstreams_uk.shtml Jet Streams in the UK.] {{webarchive |url=https://web.archive.org/web/20080118235955/http://www.bbc.co.uk/weather/features/understanding/jetstreams_uk.shtml |date=18 January 2008 }} Retrieved on 8 May 2008. The CAT is strongest on the cold air side of the jet,M. P. de Villiers and J. van Heerden. [http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=73339 Clear air turbulence over South Africa.] {{Webarchive|url=https://web.archive.org/web/20131115004322/http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=73339 |date=15 November 2013 }} Retrieved on 8 May 2008. next to and just under the axis of the jet.Clark T. L., Hall W. D., Kerr R. M., Middleton D., Radke L., Ralph F. M., Neiman P. J., Levinson D. [http://cat.inist.fr/?aModele=afficheN&cpsidt=1345004 Origins of aircraft-damaging clear-air turbulence during the 9 December 1992 Colorado downslope windstorm : Numerical simulations and comparison with observations.] {{Webarchive|url=https://web.archive.org/web/20120127002040/http://cat.inist.fr/?aModele=afficheN&cpsidt=1345004 |date=27 January 2012 }} Retrieved on 8 May 2008. Clear-air turbulence can cause aircraft to plunge and so present a passenger safety hazard that has caused fatal accidents, such as the death of one passenger on United Airlines Flight 826 in 1997.National Transportation Safety Board. [https://www.ntsb.gov/Pressrel/1997/971230.htm Aircraft Accident Investigation United Airlines flight 826, Pacific Ocean 28 December 1997.] {{Webarchive|url=https://web.archive.org/web/20090902231609/http://ntsb.gov/Pressrel/1997/971230.htm |date=2 September 2009 }} Retrieved on 13 May 2008.{{Cite news| url = http://www.cnn.com/US/9712/29/united.turbulence/ | title = NTSB investigates United Airlines plunge | author = Staff writer | publisher = CNN | date = 29 December 1997 | access-date =13 May 2008 |archive-url = https://web.archive.org/web/20080412021327/http://www.cnn.com/US/9712/29/united.turbulence/ |archive-date = 12 April 2008}} Unusual wind speed in the jet stream in late February 2024 pushed commercial jets to excess of {{cvt|800|mph|km/h kn}} relative to the ground.{{Cite news |last= Cerullo |first=Megan |date=23 February 2024 |editor-last= Picchi |editor-first=Aimee |title=Some international flights are exceeding 800 mph due to high winds. One flight arrived almost an hour early |url=https://www.cbsnews.com/news/flights-over-800-mph-high-winds-early-arrival/ |url-status=live |archive-url=https://web.archive.org/web/20240301225339/https://www.cbsnews.com/news/flights-over-800-mph-high-winds-early-arrival/ |archive-date=1 March 2024 |access-date=14 June 2024 |work=CBS News}}{{Cite news |last= Longo |first=Adam |date=20 February 2024 |title=Flight from Dulles to London hits 800 mph due to near-record winds |url=https://www.wusa9.com/article/weather/flight-dulles-london-800-mph-due-near-record-winds/65-d249e946-4e66-4abb-9de5-4df9bfaa8cb4 |url-status=live |archive-url=https://web.archive.org/web/20240221004928/https://www.wusa9.com/article/weather/flight-dulles-london-800-mph-due-near-record-winds/65-d249e946-4e66-4abb-9de5-4df9bfaa8cb4 |archive-date=21 February 2024 |access-date=14 June 2024 |work=WUSA9}}

{{See also|High-altitude wind power}}

Scientists are investigating ways to harness the wind energy within the jet stream. According to one estimate of the potential wind energy in the jet stream, only one percent would be needed to meet the world's current energy needs. In the late 2000s it was estimated that the required technology would reportedly take 10–20 years to develop.Keay Davidson. [http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2007/05/07/MNGNEPMD801.DTL Scientists look high in the sky for power.] {{Webarchive|url=https://web.archive.org/web/20080607212714/http://www.sfgate.com/cgi-bin/article.cgi?file=%2Fc%2Fa%2F2007%2F05%2F07%2FMNGNEPMD801.DTL |date=7 June 2008 }} Retrieved on 8 May 2008.

There are two major but divergent scientific articles about jet stream power. Archer & CaldeiraArcher, C. L. and Caldeira, K. {{usurped|1=[https://web.archive.org/web/20110915075738/http://www.awec2010.com/public/img/media/archer_caldeira.pdf Global assessment of high-altitude wind power, IEEE T. Energy Conver., 2, 307–319, 2009.]}} Retrieved on 24 October 2012. claim that the Earth's jet streams could generate a total power of 1700 terawatts (TW) and that the climatic impact of harnessing this amount would be negligible. However, Miller, Gans, & KleidonL.M. Miller, F. Gans, & A. Kleidon [http://www.earth-syst-dynam.net/2/201/2011/esd-2-201-2011.pdf Jet stream wind power as a renewable energy resource: little power, big impacts. Earth Syst. Dynam. Discuss. 2. 201–212. 2011.] {{Webarchive|url=https://web.archive.org/web/20120118233208/http://www.earth-syst-dynam.net/2/201/2011/esd-2-201-2011.pdf |date=18 January 2012 }} Retrieved on 16 January 201208. claim that the jet streams could generate a total power of only 7.5 TW and lacks the potential to make a significant contribution to renewable energy.

Near the end of World War II, from late 1944 until early 1945, the Japanese Fu-Go balloon bomb, a type of fire balloon, was designed as a cheap weapon intended to make use of the jet stream over the Pacific Ocean to reach the west coast of Canada and the United States. Relatively ineffective as weapons, they were used in one of the few attacks on North America during World War II, causing six deaths and a small amount of damage.{{Cite web |url=http://www.faqs.org/docs/air/avfusen.html |title=The Fire Balloons |access-date=3 October 2009 |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303175214/http://www.faqs.org/docs/air/avfusen.html |url-status=live }} American scientists studying the balloons thought the Japanese might be preparing a biological attack.{{cite magazine |last=McPhee |first=John |date=29 January 1996|title=Balloons of War |magazine=The New Yorker|url=https://archives.newyorker.com/newyorker/1996-01-29|access-date=27 January 2024}}

File:El nino north american weather.png and La Niña on North America]]

{{Main|Effects of the El Niño–Southern Oscillation in the United States}}

El Niño–Southern Oscillation (ENSO) influences the average location of upper-level jet streams, and leads to cyclical variations in precipitation and temperature across North America, as well as affecting tropical cyclone development across the eastern Pacific and Atlantic basins. Combined with the Pacific Decadal Oscillation, ENSO can also impact cold season rainfall in Europe.Davide Zanchettin, Stewart W. Franks, Pietro Traverso, and Mario Tomasino. [http://www3.interscience.wiley.com/journal/114802316/abstract On ENSO impacts on European wintertime rainfalls and their modulation by the NAO and the Pacific multi-decadal variability described through the PDO index.]{{dead link|date=February 2019|bot=medic}}{{cbignore|bot=medic}} Retrieved on 13 May 2008. Changes in ENSO also change the location of the jet stream over South America, which partially affects precipitation distribution over the continent.Caio Augusto dos Santos Coelho and Térico Ambrizzi. [http://www.cptec.inpe.br/~caio/chile2000.pdf 5A.4. Climatological Studies of the Influences of El Niño Southern Oscillation Events in the Precipitation Pattern Over South America During Austral Summer.] {{Webarchive|url=https://web.archive.org/web/20080530032314/http://www.cptec.inpe.br/~caio/chile2000.pdf |date=30 May 2008 }} Retrieved on 13 May 2008.

During El Niño events, increased precipitation is expected in California due to a more southerly, zonal, storm track.John Monteverdi and Jan Null. [http://tornado.sfsu.edu/geosciences/elnino/elnino.html "WESTERN REGION TECHNICAL ATTACHMENT NO. 97-37 November 21, 1997: El Niño and California Precipitation."] {{Webarchive|url=https://web.archive.org/web/20091227155828/http://tornado.sfsu.edu/geosciences/elnino/elnino.html |date=27 December 2009 }} Retrieved on 28 February 2008. During the Niño portion of ENSO, increased precipitation falls along the Gulf coast and Southeast due to a stronger than normal, and more southerly, polar jet stream.Climate Prediction Center. [http://www.cpc.noaa.gov/products/analysis_monitoring/ensocycle/ensorain.shtml El Niño (ENSO) Related Rainfall Patterns Over the Tropical Pacific.] {{Webarchive|url=https://web.archive.org/web/20100528035733/http://www.cpc.noaa.gov/products/analysis_monitoring/ensocycle/ensorain.shtml |date=28 May 2010 }} Retrieved on 28 February 2008. Snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well below normal across the Upper Midwest and Great Lakes states.Climate Prediction Center. [http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/us_impacts/ustp_impacts.shtml ENSO Impacts on United States Winter Precipitation and Temperature.] {{Webarchive|url=https://web.archive.org/web/20080412000000/https://web.archive.org/web/20080412152736/http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/us_impacts/ustp_impacts.shtml |date=12 April 2008 }} Retrieved on 16 April 2008. The northern tier of the lower 48 exhibits above normal temperatures during the fall and winter, while the Gulf coast experiences below normal temperatures during the winter season.Climate Prediction Center. [http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/ond.gif Average October–December (3-month) Temperature Rankings During ENSO Events.] {{Webarchive|url=https://web.archive.org/web/20080530032315/http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/ond.gif |date=30 May 2008 }} Retrieved on 16 April 2008.Climate Prediction Center. [http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/djf.gif Average December–February (3-month) Temperature Rankings During ENSO Events.] {{Webarchive|url=https://web.archive.org/web/20080530032314/http://www.cpc.ncep.noaa.gov/products/predictions/threats2/enso/elnino/UStrank/djf.gif |date=30 May 2008 }} Retrieved on 16 April 2008. The subtropical jet stream across the deep tropics of the northern hemisphere is enhanced due to increased convection in the equatorial Pacific, which decreases tropical cyclogenesis within the Atlantic tropics below what is normal, and increases tropical cyclone activity across the eastern Pacific.{{Cite web|url=http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensofaq.shtml#HURRICANES|publisher=Climate Prediction Center|format=FAQ|access-date=21 March 2008|title=How do El Niño and La Nina influence the Atlantic and Pacific hurricane seasons?|archive-url=https://web.archive.org/web/20090827143632/http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensofaq.shtml#HURRICANES|archive-date=27 August 2009|url-status=dead}} In the southern hemisphere, the subtropical jet stream is displaced equatorward, or north, of its normal position, which diverts frontal systems and thunderstorm complexes from reaching central portions of the continent.

Across North America during La Niña, increased precipitation is diverted into the Pacific Northwest due to a more northerly storm track and jet stream.Nathan Mantua. [http://www.ccb.ucar.edu/lanina/report/mantua.html La Niña Impacts in the Pacific Northwest.] {{webarchive|url=https://web.archive.org/web/20071022030057/http://www.ccb.ucar.edu/lanina/report/mantua.html |date=22 October 2007 }} Retrieved on 29 February 2008. The storm track shifts far enough northward to bring wetter than normal conditions (in the form of increased snowfall) to the Midwestern states, as well as hot and dry summers.Southeast Climate Consortium. [http://www.agclimate.org/Development/apps/agClimate/controller/perl/agClimate.pl/agClimate.pl?function=climforecast/outlook.html&location=local&type SECC Winter Climate Outlook.] {{webarchive|url=https://web.archive.org/web/20080304212445/http://www.agclimate.org/Development/apps/agClimate/controller/perl/agClimate.pl/agClimate.pl?function=climforecast%2Foutlook.html&location=local&type |date= 4 March 2008 }} Retrieved on 29 February 2008.Reuters. [https://www.reuters.com/article/domesticNews/idUSN1619766420070216 La Nina could mean dry summer in Midwest and Plains.] {{Webarchive|url=https://web.archive.org/web/20080421224855/http://www.reuters.com/article/domesticNews/idUSN1619766420070216 |date=21 April 2008 }} Retrieved on 29 February 2008. Snowfall is above normal across the Pacific Northwest and western Great Lakes. Across the North Atlantic, the jet stream is stronger than normal, which directs stronger systems with increased precipitation towards Europe.Paul Simons and Simon de Bruxelles. [http://www.timesonline.co.uk/tol/news/environment/article3200801.ece More rain and more floods as La Niña sweeps across the globe.]{{dead link|date=September 2024|bot=medic}}{{cbignore|bot=medic}} Retrieved on 13 May 2008.

Evidence suggests the jet stream was at least partly responsible for the widespread drought conditions during the 1930s Dust Bowl in the Midwest United States. Normally, the jet stream flows east over the Gulf of Mexico and turns northward pulling up moisture and dumping rain onto the Great Plains. During the Dust Bowl, the jet stream weakened and changed course traveling farther south than normal. This starved the Great Plains and other areas of the Midwest of rainfall, causing extraordinary drought conditions.{{Cite web|url=https://www.thoughtco.com/1930s-dust-bowl-drought-3444382|title=What Caused the U.S. Dust Bowl Drought of the 1930s?|last=Oblack|first=Rachelle|website=ThoughtCo|language=en|access-date=2019-07-02|archive-date=2 July 2019|archive-url=https://web.archive.org/web/20190702152954/https://www.thoughtco.com/1930s-dust-bowl-drought-3444382|url-status=live}}

File:Jetstream - Rossby Waves - N hemisphere.svgs) of the northern hemisphere's polar jet stream developing (a), (b); then finally detaching a "drop" of cold air (c). Orange: warmer masses of air; pink: jet stream.]]

Since the early 2000s, climate models have consistently identified that global warming will gradually push jet streams poleward. In 2008, this was confirmed by observational evidence, which proved that from 1979 to 2001, the northern jet stream moved northward at an average rate of {{convert|2.01|km|mi}} per year, with a similar trend in the southern hemisphere jet stream.{{Cite journal |last1=Archer |first1=Cristina L. |last2=Caldeira |first2=Ken |date=18 April 2008 |title=Historical trends in the jet streams |journal=Geophysical Research Letters |language=en |volume=35 |issue=8 |doi=10.1029/2008GL033614 |bibcode=2008GeoRL..35.8803A |s2cid=59377392 |doi-access=free }}{{cite web |date=2008-04-18 |title=Jet stream found to be permanently drifting north |url=http://komonews.com/news/local/jet-stream-found-to-be-permanently-drifting-north |publisher=Associated Press |language=en |access-date=7 October 2022 |archive-date=17 August 2016 |archive-url=https://web.archive.org/web/20160817133858/http://komonews.com/news/local/jet-stream-found-to-be-permanently-drifting-north |url-status=dead }} Climate scientists have hypothesized that the jet stream will also gradually weaken as a result of global warming. Trends such as Arctic sea ice decline, reduced snow cover, evapotranspiration patterns, and other weather anomalies have caused the Arctic to heat up faster than other parts of the globe, in what is known as the Arctic amplification. In 2021–2022, it was found that since 1979, the warming within the Arctic Circle has been nearly four times faster than the global average,{{Cite journal |last1=Rantanen |first1=Mika |last2=Karpechko |first2=Alexey Yu |last3=Lipponen |first3=Antti |last4=Nordling |first4=Kalle |last5=Hyvärinen |first5=Otto |last6=Ruosteenoja |first6=Kimmo |last7=Vihma |first7=Timo |last8=Laaksonen |first8=Ari |date=11 August 2022 |title=The Arctic has warmed nearly four times faster than the globe since 1979 |journal=Communications Earth & Environment |language=en |volume=3 |issue=1 |page=168 |doi=10.1038/s43247-022-00498-3 |bibcode=2022ComEE...3..168R |s2cid=251498876 |issn=2662-4435|doi-access=free |hdl=11250/3115996 |hdl-access=free }}{{cite web |date=2021-12-14 |title=The Arctic is warming four times faster than the rest of the world |url=https://www.science.org/content/article/arctic-warming-four-times-faster-rest-world |website=Science Magazine |language=en |access-date=6 October 2022 |archive-date=8 November 2023 |archive-url=https://web.archive.org/web/20231108114005/https://www.science.org/content/article/arctic-warming-four-times-faster-rest-world |url-status=live }} and some hotspots in the Barents Sea area warmed up to seven times faster than the global average.{{Cite journal |last1=Isaksen |first1=Ketil |last2=Nordli |first2=Øyvind |display-authors=etal |date=15 June 2022 |title=Exceptional warming over the Barents area |journal=Scientific Reports |language=en |volume=12 |issue=1 |page=9371 |doi=10.1038/s41598-022-13568-5 |pmid=35705593 |pmc=9200822 |bibcode=2022NatSR..12.9371I }}{{cite web |date=2022-06-15 |title=New data reveals extraordinary global heating in the Arctic |author=Damian Carrington |url=https://www.theguardian.com/environment/2022/jun/15/new-data-reveals-extraordinary-global-heating-in-the-arctic |website=The Guardian |language=en |access-date=7 October 2022 |archive-date=1 October 2023 |archive-url=https://web.archive.org/web/20231001165931/https://www.theguardian.com/environment/2022/jun/15/new-data-reveals-extraordinary-global-heating-in-the-arctic |url-status=live }} While the Arctic remains one of the coldest places on Earth today, the temperature gradient between it and the warmer parts of the globe will continue to diminish with every decade of global warming as the result of this amplification. If this gradient has a strong influence on the jet stream, then it will eventually become weaker and more variable in its course, which would allow more cold air from the polar vortex to leak mid-latitudes and slow the progression of Rossby waves, leading to more persistent and more extreme weather.{{cite journal |doi=10.1029/2012GL051000 |title=Evidence linking Arctic amplification to extreme weather in mid-latitudes |year=2012 |last1=Francis |first1=Jennifer A. |author-link=Jennifer Francis|last2=Vavrus |first2=Stephen J. |journal=Geophysical Research Letters |volume=39 |issue=6 |bibcode=2012GeoRL..39.6801F |pages=L06801|citeseerx=10.1.1.419.8599 |s2cid=15383119 }}

The hypothesis above is closely associated with Jennifer Francis, who had first proposed it in a 2012 paper co-authored by Stephen J. Vavrus. While some paleoclimate reconstructions have suggested that the polar vortex becomes more variable and causes more unstable weather during periods of warming back in 1997,{{cite journal |doi= 10.1130/0016-7606(1997)109<0547:piotim>2.3.co;2|year=1997 |volume=109 |pages=547–559 |title=Paleoenvironmental implications of the insoluble microparticle record in the GISP2 (Greenland) ice core during the rapidly changing climate of the Pleistocene-Holocene transition |last1=Zielinski |first1=G. |last2=Mershon |first2=G. |journal=Bulletin of the Geological Society of America |issue=5 |bibcode=1997GSAB..109..547Z}} this was contradicted by climate modelling, with PMIP2 simulations finding in 2010 that the Arctic Oscillation (AO) was much weaker and more negative during the Last Glacial Maximum, and suggesting that warmer periods have stronger positive phase AO, and thus less frequent leaks of the polar vortex air.{{cite journal |doi=10.1175/2010JCLI3331.1 |year=2010 |volume=23 |pages=3792–3813 |title=Arctic Oscillation during the Mid-Holocene and Last Glacial Maximum from PMIP2 Coupled Model Simulations |last1=Lue |first1=J.-M. |last2=Kim |first2=S.-J. |last3=Abe-Ouchi |first3=A. |last4=Yu |first4=Y. |last5=Ohgaito |first5=R. |journal=Journal of Climate |issue=14|bibcode=2010JCli...23.3792L |s2cid=129156297 |doi-access=free }} However, a 2012 review in the Journal of the Atmospheric Sciences noted that "there [has been] a significant change in the vortex mean state over the twenty-first century, resulting in a weaker, more disturbed vortex.",{{Cite journal|last1=Mitchell|first1=Daniel M.|last2=Osprey|first2=Scott M.|last3=Gray|first3=Lesley J.|last4=Butchart|first4=Neal|last5=Hardiman|first5=Steven C.|last6=Charlton-Perez|first6=Andrew J.|last7=Watson|first7=Peter|date=August 2012|title=The Effect of Climate Change on the Variability of the Northern Hemisphere Stratospheric Polar Vortex|journal=Journal of the Atmospheric Sciences|language=en|volume=69|issue=8|pages=2608–2618|doi=10.1175/jas-d-12-021.1|issn=0022-4928|bibcode=2012JAtS...69.2608M|s2cid=122783377 |doi-access=free}} which contradicted the modelling results but fit the Francis-Vavrus hypothesis. Additionally, a 2013 study noted that the then-current CMIP5 tended to strongly underestimate winter blocking trends,{{cite journal |doi=10.1175/JCLI-D-12-00466.1 |title=Winter and Summer Northern Hemisphere Blocking in CMIP5 Models |year=2013 |last1=Masato |first1=Giacomo |last2=Hoskins |first2=Brian J. |last3=Woollings |first3=Tim |journal=Journal of Climate |volume=26 |issue=18 |pages=7044–7059|bibcode=2013JCli...26.7044M |doi-access=free }} and other 2012 research had suggested a connection between declining Arctic sea ice and heavy snowfall during midlatitude winters.{{Cite journal |last1=Liu |first1=Jiping |last2=Curry |first2=Judith A. |author-link=Judith Curry |last3=Wang |first3=Huijun |last4=Song |first4=Mirong |last5=Horton |first5=Radley M. |date=27 February 2012 |title=Impact of declining Arctic sea ice on winter snowfall |journal=PNAS |language=en |volume=109 |issue=11 |pages=4074–4079 |doi=10.1073/pnas.1114910109|pmid=22371563 |pmc=3306672 |bibcode=2012PNAS..109.4074L |doi-access=free }}

In 2013, further research from Francis connected reductions in the Arctic sea ice to extreme summer weather in the northern mid-latitudes,{{cite journal|author=Qiuhong Tang|author2=Xuejun Zhang|author3-link=Jennifer A. Francis|last3=Francis|first3=J. A.|date=December 2013|title=Extreme summer weather in northern mid-latitudes linked to a vanishing cryosphere|journal=Nature Climate Change|volume=4|issue=1|pages=45–50|doi=10.1038/nclimate2065|bibcode=2014NatCC...4...45T }} while other research from that year identified potential linkages between Arctic sea ice trends and more extreme rainfall in the European summer.{{cite journal|first=J A|last=Screen|date=November 2013|title=Influence of Arctic sea ice on European summer precipitation|journal=Environmental Research Letters|volume=8|issue=4|doi=10.1088/1748-9326/8/4/044015|pages=044015|bibcode=2013ERL.....8d4015S |doi-access=free|hdl=10871/14835|hdl-access=free}} At the time, it was also suggested that this connection between Arctic amplification and jet stream patterns was involved in the formation of Hurricane Sandy{{cite news|last=Friedlander|first=Blaine|title=Arctic ice loss amplified Superstorm Sandy violence|url=http://www.news.cornell.edu/stories/2013/03/arctic-ice-loss-amplified-superstorm-sandy-violence|access-date=7 January 2014|newspaper=Cornell Chronicle|date=4 March 2013|archive-date=11 June 2015|archive-url=https://web.archive.org/web/20150611114925/http://www.news.cornell.edu/stories/2013/03/arctic-ice-loss-amplified-superstorm-sandy-violence|url-status=live}} and played a role in the early 2014 North American cold wave.{{cite magazine|first=Bryan|last=Walsh|title=Polar Vortex: Climate Change Might Just Be Driving the Historic Cold Snap|magazine=Time|url=https://science.time.com/2014/01/06/climate-change-driving-cold-weather/|date=6 January 2014|access-date=7 January 2014|archive-date=11 January 2018|archive-url=https://web.archive.org/web/20180111215416/http://science.time.com/2014/01/06/climate-change-driving-cold-weather/|url-status=live}}{{cite news|last=Spotts|first=Pete|title=How frigid 'polar vortex' could be result of global warming (+video)|url=http://www.csmonitor.com/Science/2014/0106/How-frigid-polar-vortex-could-be-result-of-global-warming-video|access-date=8 January 2014|newspaper=The Christian Science Monitor|date=6 January 2014|archive-date=9 July 2017|archive-url=https://web.archive.org/web/20170709030842/https://www.csmonitor.com/Science/2014/0106/How-frigid-polar-vortex-could-be-result-of-global-warming-video|url-status=live}} In 2015, Francis' next study concluded that highly amplified jet-stream patterns are occurring more frequently in the past two decades. Hence, continued heat-trapping emissions favour increased formation of extreme events caused by prolonged weather conditions.{{cite journal|journal=Philosophical Transactions|title=Evidence linking rapid Arctic warming to mid-latitude weather patterns|doi=10.1098/rsta.2014.0170|pmid=26032322 |author1=Jennifer Francis |author2=Natasa Skific |date=1 June 2015|bibcode = 2015RSPTA.37340170F|volume=373|issue=2045|page=20140170|pmc=4455715}}

Studies published in 2017 and 2018 identified stalling patterns of Rossby waves in the northern hemisphere jet stream as the culprit behind other almost stationary extreme weather events, such as the 2018 European heatwave, the 2003 European heat wave, 2010 Russian heat wave or the 2010 Pakistan floods, and suggested that these patterns were all connected to Arctic amplification.{{cite journal|last1=Mann|first1=Michael E.|last2=Rahmstorf|first2=Stefan|date=27 March 2017|title=Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events|journal=Scientific Reports|volume=7|pages=45242|doi=10.1038/srep45242|pmid=28345645|pmc=5366916|bibcode=2017NatSR...745242M}}{{cite web|url=https://www.theguardian.com/environment/2018/jul/27/extreme-global-weather-climate-change-michael-mann|title=Extreme global weather is 'the face of climate change' says leading scientist|year=2018|work=The Guardian|access-date=8 October 2022|archive-date=13 April 2019|archive-url=https://web.archive.org/web/20190413154627/https://www.theguardian.com/environment/2018/jul/27/extreme-global-weather-climate-change-michael-mann|url-status=live}} Further work from Francis and Vavrus that year suggested that amplified Arctic warming is observed as stronger in lower atmospheric areas because the expanding process of warmer air increases pressure levels which decreases poleward geopotential height gradients. As these gradients are the reason that cause west to east winds through the thermal wind relationship, declining speeds are usually found south of the areas with geopotential increases.{{Cite journal|title = Amplified Arctic warming and mid latitude weather: new perspectives on emerging connections|volume = 8|issue = 5|pages = e474|publisher = 2017 Wiley Periodicals,Inc|url = http://web.mit.edu/jlcohen/www/papers/Francis_WIREsCC_2017_pub.pdf|journal = Wiley Interdisciplinary Reviews: Climate Change|author1 = Francis J|author2 = Vavrus S|author3 = Cohen J.|year = 2017|doi = 10.1002/wcc.474|doi-access = free|bibcode = 2017WIRCC...8E.474F|access-date = 8 October 2022|archive-date = 21 March 2023|archive-url = https://web.archive.org/web/20230321223150/http://web.mit.edu/jlcohen/www/papers/Francis_WIREsCC_2017_pub.pdf|url-status = live}} In 2017, Francis explained her findings to the Scientific American: "A lot more water vapor is being transported northward by big swings in the jet stream. That's important because water vapor is a greenhouse gas just like carbon dioxide and methane. It traps heat in the atmosphere. That vapor also condenses as droplets we know as clouds, which themselves trap more heat. The vapor is a big part of the amplification story—a big reason the Arctic is warming faster than anywhere else."{{cite web|url=https://www.scientificamerican.com/article/the-arctic-is-getting-crazy/|title=The Arctic Is Getting Crazy|year=2017|work=Scientific American|first=Mark|last=Fischetti|access-date=8 October 2022|archive-date=22 April 2022|archive-url=https://web.archive.org/web/20220422105448/https://www.scientificamerican.com/article/the-arctic-is-getting-crazy/|url-status=live}}

In a 2017 study conducted by climatologist Judah Cohen and several of his research associates, Cohen wrote that "[the] shift in polar vortex states can account for most of the recent winter cooling trends over Eurasian midlatitudes".{{Cite journal|last1=Kretschmer|first1=Marlene|author1-link=Marlene Kretschmer|last2=Coumou|first2=Dim|last3=Agel|first3=Laurie|last4=Barlow|first4=Mathew|last5=Tziperman|first5=Eli|last6=Cohen|first6=Judah|s2cid=51847061|date=January 2018|title=More-Persistent Weak Stratospheric Polar Vortex States Linked to Cold Extremes|journal=Bulletin of the American Meteorological Society|language=en|volume=99|issue=1|pages=49–60|doi=10.1175/bams-d-16-0259.1|issn=0003-0007|bibcode=2018BAMS...99...49K|url=http://centaur.reading.ac.uk/92432/3/01Sep2020manuscript_BAMS_revised_round3.pdf|access-date=8 October 2022|archive-date=9 October 2022|archive-url=https://web.archive.org/web/20221009050237/https://centaur.reading.ac.uk/92432/3/01Sep2020manuscript_BAMS_revised_round3.pdf|url-status=live}} A 2018 paper from Vavrus and others linked Arctic amplification to more persistent hot-dry extremes during the midlatitude summers, as well as the midlatitude winter continental cooling.{{Cite journal|last1=Coumou|first1=D.|last2=Di Capua|first2=G.|last3=Vavrus|first3=S.|last4=Wang|first4=L.|last5=Wang|first5=S.|date=2018-08-20|title=The influence of Arctic amplification on mid-latitude summer circulation|journal=Nature Communications|volume=9|issue=1|page=2959|doi=10.1038/s41467-018-05256-8|pmid=30127423|pmc=6102303|bibcode=2018NatCo...9.2959C|issn=2041-1723}} Another 2017 paper estimated that when the Arctic experiences anomalous warming, primary production in North America goes down by between 1% and 4% on average, with some states suffering up to 20% losses.{{Cite journal |last1=Kim |first1=Jin-Soo |last2=Kug |first2=Jong-Seong |last3=Jeong |first3=Su-Jong |last4=Huntzinger |first4=Deborah N. |last5=Michalak |first5=Anna M. |last6=Schwalm |first6=Christopher R. |last7=Wei |first7=Yaxing |last8=Schaefer |first8=Kevin |date=26 October 2021 |title=Reduced North American terrestrial primary productivity linked to anomalous Arctic warming |url=https://www.nature.com/articles/ngeo2986 |journal=Nature Geoscience |volume=10 |issue=8 |pages=572–576 |doi=10.1038/ngeo2986 |osti=1394479 |access-date=15 October 2022 |archive-date=28 November 2022 |archive-url=https://web.archive.org/web/20221128184826/https://www.nature.com/articles/ngeo2986 |url-status=live }} A 2021 study found that a stratospheric polar vortex disruption is linked with extreme cold winter weather across parts of Asia and North America, including the February 2021 North American cold wave.{{cite news |title=Climate change: Arctic warming linked to colder winters |url=https://www.bbc.com/news/science-environment-58425526 |access-date=20 October 2021 |work=BBC News |date=2 September 2021 |archive-date=20 October 2021 |archive-url=https://web.archive.org/web/20211020112818/https://www.bbc.com/news/science-environment-58425526 |url-status=live }}{{cite journal |last1=Cohen |first1=Judah |last2=Agel |first2=Laurie |last3=Barlow |first3=Mathew |last4=Garfinkel |first4=Chaim I. |last5=White |first5=Ian |title=Linking Arctic variability and change with extreme winter weather in the United States |journal=Science |date=3 September 2021 |volume=373 |issue=6559 |pages=1116–1121 |doi=10.1126/science.abi9167 |pmid=34516838 |bibcode=2021Sci...373.1116C |s2cid=237402139 |url=https://doi.org/10.1126/science.abi9167 |url-access=subscription |access-date=8 October 2022 |archive-date=16 April 2023 |archive-url=https://web.archive.org/web/20230416155730/https://www.science.org/doi/10.1126/science.abi9167 |url-status=live }} Another 2021 study identified a connection between the Arctic sea ice loss and the increased size of wildfires in the Western United States.{{Cite journal |last1=Zou |first1=Yofei |last2=Rasch |first2=Philip J. |last3=Wang |first3=Hailong |last4=Xie |first4=Zuowei |last5=Zhang |first5=Rudong |date=26 October 2021 |title=Increasing large wildfires over the western United States linked to diminishing sea ice in the Arctic |journal=Nature Communications |volume=12 |issue=1 |page=6048 |doi=10.1038/s41467-021-26232-9 |pmid=34702824 |pmc=8548308 |bibcode=2021NatCo..12.6048Z |s2cid=233618492 }}

However, because the specific observations are considered short-term observations, there is considerable uncertainty in the conclusions. Climatology observations require several decades to definitively distinguish various forms of natural variability from climate trends.{{cite journal |doi=10.1007/s00376-012-1238-1 |year=2012 |volume=29 |pages=867–886 |title=Impacts of multi-scale solar activity on climate. Part I: Atmospheric circulation patterns and climate extremes |last1=Weng |first1=H. |journal=Advances in Atmospheric Sciences |issue=4|bibcode = 2012AdAtS..29..867W |s2cid=123066849 }} This point was stressed by reviews in 2013{{cite journal|title=Atmospheric science: Long-range linkage|date=December 8, 2013|author=James E. Overland|journal=Nature Climate Change|volume=4|pages=11–12|doi=10.1038/nclimate2079|issue=1|bibcode=2014NatCC...4...11O}} and in 2017.{{Cite journal|last=Seviour|first=William J.M.|date=14 April 2017|title=Weakening and shift of the Arctic stratospheric polar vortex: Internal variability or forced response?|journal=Geophysical Research Letters|volume=44|issue=7|pages=3365–3373|bibcode=2017GeoRL..44.3365S|doi=10.1002/2017GL073071|url=https://research-information.bris.ac.uk/en/publications/weakening-and-shift-of-the-arctic-stratospheric-polar-vortex(caf74781-222b-4735-b171-8842cead4086).html|hdl=1983/caf74781-222b-4735-b171-8842cead4086|s2cid=131938684 |hdl-access=free}} A study in 2014 concluded that Arctic amplification significantly decreased cold-season temperature variability over the northern hemisphere in recent decades. Cold Arctic air intrudes into the warmer lower latitudes more rapidly today during autumn and winter, a trend projected to continue in the future except during summer, thus calling into question whether winters will bring more cold extremes.{{cite journal|first=James A.|last=Screen|date=15 June 2014|title=Arctic amplification decreases temperature variance in northern mid- to high-latitudes|doi=10.1038/nclimate2268|journal=Nature Climate Change|url=https://www.sciencedaily.com/releases/2014/06/140615143834.htm|volume=4|issue=7|pages=577–582|bibcode=2014NatCC...4..577S|hdl=10871/15095|hdl-access=free|access-date=8 October 2022|archive-date=23 February 2022|archive-url=https://web.archive.org/web/20220223230945/https://www.sciencedaily.com/releases/2014/06/140615143834.htm|url-status=live}} A 2019 analysis of a data set collected from 35 182 weather stations worldwide, including 9116 whose records go beyond 50 years, found a sharp decrease in northern midlatitude cold waves since the 1980s.{{Cite journal |last1=van Oldenborgh |first1=Geert Jan |last2=Mitchell-Larson |first2=Eli |last3=Vecchi |first3=Gabriel A. |last4=de Vries|first4=Hylke |last5=Vautar |first5=Robert |last6=Otto |first6=Friederike |date=22 November 2019 |title=Cold waves are getting milder in the northern midlatitudes |journal=Environmental Research Letters |language=en |volume=14 |issue=11 |page=114004 |doi=10.1088/1748-9326/ab4867|bibcode=2019ERL....14k4004V |s2cid=204420462 |doi-access=free }}

Moreover, a range of long-term observational data collected during the 2010s and published in 2020 suggests that the intensification of Arctic amplification since the early 2010s was not linked to significant changes on mid-latitude atmospheric patterns.{{cite journal |last1=Blackport |first1=Russell |last2=Screen |first2=James A. |last3=van der Wiel |first3=Karin |last4=Bintanja |first4=Richard |title=Minimal influence of reduced Arctic sea ice on coincident cold winters in mid-latitudes |journal=Nature Climate Change |date=September 2019 |volume=9 |issue=9 |pages=697–704 |doi=10.1038/s41558-019-0551-4|bibcode=2019NatCC...9..697B |hdl=10871/39784 |s2cid=199542188 |url=https://pure.rug.nl/ws/files/96090906/s41558_019_0551_4.pdf |hdl-access=free }}{{cite journal |last1=Blackport |first1=Russell |last2=Screen |first2=James A. |title=Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves |journal=Science Advances |date=February 2020 |volume=6 |issue=8 |pages=eaay2880 |doi=10.1126/sciadv.aay2880|pmid=32128402 |pmc=7030927 |bibcode=2020SciA....6.2880B |doi-access=free }} State-of-the-art modelling research of PAMIP (Polar Amplification Model Intercomparison Project) improved upon the 2010 findings of PMIP2; it found that sea ice decline would weaken the jet stream and increase the probability of atmospheric blocking, but the connection was very minor, and typically insignificant next to interannual variability.{{Cite journal |last1=Streffing |first1=Jan |last2=Semmler |first2=Tido |last3=Zampieri |first3=Lorenzo |last4=Jung |first4=Thomas |date=24 September 2021 |title=Response of Northern Hemisphere Weather and Climate to Arctic Sea Ice Decline: Resolution Independence in Polar Amplification Model Intercomparison Project (PAMIP) Simulations |journal=Journal of Climate |language=en |volume=34 |issue=20 |pages=8445–8457 |doi=10.1175/JCLI-D-19-1005.1|bibcode=2021JCli...34.8445S |s2cid=239631549 |doi-access=free }}{{cite web |date=2021-05-12 |author=Paul Voosen |title=Landmark study casts doubt on controversial theory linking melting Arctic to severe winter weather |url=https://www.science.org/content/article/landmark-study-casts-doubt-controversial-theory-linking-melting-arctic-severe-winter |website=Science Magazine |language=en |access-date=7 October 2022 |archive-date=9 March 2023 |archive-url=https://web.archive.org/web/20230309190222/https://www.science.org/content/article/landmark-study-casts-doubt-controversial-theory-linking-melting-arctic-severe-winter |url-status=live }} In 2022, a follow-up study found that while the PAMIP average had likely underestimated the weakening caused by sea ice decline by 1.2 to 3 times, even the corrected connection still amounts to only 10% of the jet stream's natural variability.{{Cite journal |last1=Smith |first1=D.M. |last2=Eade |first2=R. |last3=Andrews |first3=M.B. |display-authors=etal |date=7 February 2022 |title=Robust but weak winter atmospheric circulation response to future Arctic sea ice loss |journal=Nature Communications |language=en |volume=13 |issue=1 |page=727 |doi=10.1038/s41467-022-28283-y|pmid=35132058 |pmc=8821642 |bibcode=2022NatCo..13..727S |s2cid=246637132 }}

Additionally, a 2021 study found that while jet streams had indeed slowly moved polewards since 1960 as was predicted by models, they did not weaken, in spite of a small increase in waviness.{{Cite journal |last1=Martin |first1=Jonathan E. |date=14 April 2021 |title=Recent Trends in the Waviness of the Northern Hemisphere Wintertime Polar and Subtropical Jets |url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033668 |journal=Journal of Geophysical Research: Atmospheres |language=en |volume=126 |issue=9 |doi=10.1029/2020JD033668 |bibcode=2021JGRD..12633668M |s2cid=222246122 |access-date=8 October 2022 |archive-date=15 October 2022 |archive-url=https://web.archive.org/web/20221015073038/https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033668 |url-status=live }} A 2022 re-analysis of the aircraft observational data collected over 2002–2020 suggested that the North Atlantic jet stream had actually strengthened.{{Cite journal |last1=Tenenbaum |first1=Joel |last2=Williams |first2=Paul D. |last3=Turp |first3=Debi |last4=Buchanan |first4=Piers |last5=Coulson |first5=Robert |last6=Gill |first6=Philip G. |last7=Lunnon |first7=Robert W. |last8=Oztunali |first8=Marguerite G. |last9=Rankin |first9=John |last10=Rukhovets |first10=Leonid |date=July 2022 |title=Aircraft observations and reanalysis depictions of trends in the North Atlantic winter jet stream wind speeds and turbulence |url=https://onlinelibrary.wiley.com/doi/10.1002/qj.4342 |journal=Quarterly Journal of the Royal Meteorological Society |language=en |volume=148 |issue=747 |pages=2927–2941 |doi=10.1002/qj.4342 |bibcode=2022QJRMS.148.2927T |s2cid=250029057 |issn=0035-9009|doi-access=free }} Finally, a 2021 study was able to reconstruct jet stream patterns over the past 1,250 years based on Greenland ice cores, and found that all of the recently observed changes remain within range of natural variability: the earliest likely time of divergence is in 2060, under the Representative Concentration Pathway 8.5 which implies continually accelerating greenhouse gas emissions.{{Cite journal |last1=Osman |first1=Matthew B. |last2=Coats |first2=Sloan |last3=Das |first3=Sarah B. |last4=McConnell |first4=Joseph R. |last5=Chellman |first5=Nathan |date=13 September 2021 |title=North Atlantic jet stream projections in the context of the past 1,250 years |journal=PNAS |language=en |volume=118 |issue=38 |doi=10.1073/pnas.2104105118|pmid=34518222 |pmc=8463874 |bibcode=2021PNAS..11804105O |doi-access=free }}

The polar-night jet stream forms mainly during the winter months when the nights are much longer – hence the name referencing polar nights – in their respective hemispheres at around 60° latitude. The polar night jet moves at a greater height (about {{convert|80000|ft|m|order=flip}}) than it does during the summer.{{Cite web| title=Jet Streams around the World| url=http://www.bbc.co.uk/weather/features/understanding/jetstreams_world.shtml| publisher=BBC| access-date=26 September 2009| archive-date=13 February 2009| archive-url=https://web.archive.org/web/20090213061211/http://www.bbc.co.uk/weather/features/understanding/jetstreams_world.shtml| url-status=dead}} During these dark months the air high over the poles becomes much colder than the air over the Equator. This difference in temperature gives rise to extreme air pressure differences in the stratosphere which, when combined with the Coriolis effect, create the polar night jets, that race eastward at an altitude of about {{convert|30|mi|km|order=flip}}.{{Cite web | title=The Jet Stream | url=http://www.gi.alaska.edu/ScienceForum/ASF6/640.html | last=Gedney | first=Larry | publisher=University of Alaska Fairbanks | year=1983 | access-date=13 December 2018 | archive-url=https://web.archive.org/web/20100115013949/http://www.gi.alaska.edu/ScienceForum/ASF6/640.html | archive-date=15 January 2010 | url-status=dead}} The polar vortex is circled by the polar night jet. The warmer air can only move along the edge of the polar vortex, but not enter it. Within the vortex, the cold polar air becomes increasingly cold, due to a lack of warmer air from lower latitudes as well as a lack of energy from the Sun entering during the polar night.{{Cite web|url=http://www.stat.osu.edu/~sses/collab_ozone_split_background.php |title=2002 Ozone-Hole Splitting – Background |publisher=Ohio State University |url-status=dead |archive-url=https://web.archive.org/web/20100621115326/http://www.stat.osu.edu/~sses/collab_ozone_split_background.php |archive-date=21 June 2010 }}

There are wind maxima at lower levels of the atmosphere that are also referred to as jets.

A barrier jet in the low levels forms just upstream of mountain chains, with the mountains forcing the jet to be oriented parallel to the mountains. The mountain barrier increases the strength of the low level wind by 45 percent.J. D. Doyle. [http://cat.inist.fr/?aModele=afficheN&cpsidt=2721180 The influence of mesoscale orography on a coastal jet and rainband.] {{Webarchive|url=https://web.archive.org/web/20120106231443/http://cat.inist.fr/?aModele=afficheN&cpsidt=2721180 |date=6 January 2012 }} Retrieved on 25 December 2008. In the North American Great Plains a southerly low-level jet helps fuel overnight thunderstorm activity during the warm season, normally in the form of mesoscale convective systems which form during the overnight hours.Matt Kumijan, Jeffry Evans, and Jared Guyer. [http://www.spc.noaa.gov/publications/evans/kumjian.pdf The Relationship of the Great Plains Low-Level Jet to Nocturnal MCS Development.] {{Webarchive|url=https://web.archive.org/web/20080530032314/http://www.spc.noaa.gov/publications/evans/kumjian.pdf |date=30 May 2008 }} Retrieved on 8 May 2008. A similar phenomenon develops across Australia, which pulls moisture poleward from the Coral Sea towards cut-off lows which form mainly across southwestern portions of the continent.L. Qi, L.M. Leslie, and S.X. Zhao. [https://archive.today/20130105053537/http://www3.interscience.wiley.com/journal/68500464/abstract?CRETRY=1&SRETRY=0 Cut-off low pressure systems over southern Australia: climatology and case study.] Retrieved on 8 May 2008.

Coastal low-level jets are related to a sharp contrast between high temperatures over land and lower temperatures over the sea and play an important role in coastal weather, giving rise to strong coast parallel winds.{{cite journal |last1=Cardoso |first1=Rita M. |last2=Soares |first2=Pedro M. M. |last3=Lima |first3=Daniela C. A. |last4=Semedo |first4=Alvaro |title=The impact of climate change on the Iberian low-level wind jet: EURO-CORDEX regional climate simulation |journal=Tellus A: Dynamic Meteorology and Oceanography |date=1 December 2016 |volume=68 |issue=1 |pages=29005 |doi=10.3402/tellusa.v68.29005 |bibcode=2016TellA..6829005C |doi-access=free }} Most coastal jets are associated with the oceanic high-pressure systems and thermal low over land and are mainly located along cold eastern boundary marine currents, in upwelling regions offshore California, Peru–Chile, Benguela, Portugal, Canary and West Australia, and offshore Yemen–Oman.

A valley exit jet is a strong, down-valley, elevated air current that emerges above the intersection of the valley and its adjacent plain. These winds frequently reach speeds of up to {{cvt|20|m/s|km/h mph|||}} at heights of {{cvt|40|-|200|m||}} above the ground. Surface winds below the jet tend to be substantially weaker, even when they are strong enough to sway vegetation.

Valley exit jets are likely to be found in valley regions that exhibit diurnal mountain wind systems, such as those of the dry mountain ranges of the US. Deep valleys that terminate abruptly at a plain are more impacted by these factors than are those that gradually become shallower as downvalley distance increases.Whiteman, C. David (2000). Mountain Meteorology, p. 193. Oxford University Press, New York. {{ISBN|978-0-19-803044-7}}, pp. 191–193.

{{See also|African easterly jet|Climate of Africa}}

There are several important low-level jets in Africa. Numerous low-level jets form in the Sahara, and are important for the raising of dust off the desert surface. This includes a low-level jet in Chad, which is responsible for dust emission from the Bodélé Depression,Washington, R., and Todd, M. C. (2005), Atmospheric controls on mineral dust emission from the Bodélé Depression, Chad: The role of the low level jet, Geophys. Res. Lett., 32, L17701, doi:10.1029/2005GL023597. the world's most important single source of dust emission. The Somali Jet, which forms off the East African coast is an important component of the global Hadley circulation,Heaviside, C. and Czaja, A. (2013), Deconstructing the Hadley cell heat transport. Q.J.R. Meteorol. Soc., 139: 2181-2189. https://doi.org/10.1002/qj.2085 and supplies water vapour to the Asian Monsoon.Boos, W.R. and Emanuel, K.A. (2009), Annual intensification of the Somali jet in a quasi-equilibrium framework: Observational composites. Q.J.R. Meteorol. Soc., 135: 319-335. https://doi.org/10.1002/qj.388 Easterly low-level jets forming in valleys within the East African Rift System help account for the low rainfall in East Africa and support high rainfall in the Congo Basin rainforest.Munday, C., Savage, N., Jones, R.G. et al. Valley formation aridifies East Africa and elevates Congo Basin rainfall. Nature 615, 276–279 (2023). https://doi.org/10.1038/s41586-022-05662-5 The formation of the thermal low over northern Africa leads to a low-level westerly jet stream from June into October, which provides the moist inflow to the West African monsoon.B. Pu and K. H. Cook (2008). [http://adsabs.harvard.edu/abs/2008AGUFM.A13A0229P Dynamics of the Low-Level Westerly Jet Over West Africa.] {{Webarchive|url=https://web.archive.org/web/20171119014622/http://adsabs.harvard.edu/abs/2008AGUFM.A13A0229P |date=19 November 2017 }} American Geophysical Union, Fall Meeting 2008, abstract #A13A-0229. Retrieved on 8 March 2009.

While not technically a low-level jet, the mid-level African easterly jet (at 3000–4000 m above the surface) is also an important climate feature in Africa. It occurs during the northern hemisphere summer between 10°N and 20°N above in the Sahel region of West Africa.Dr. Alex DeCaria. [http://snowball.millersville.edu/~adecaria/ESCI344/esci344_lesson04_seasonal_mean_wind_fields.pdf Lesson 4 – Seasonal-mean Wind Fields.] {{Webarchive|url=https://web.archive.org/web/20130909054657/http://snowball.millersville.edu/~adecaria/ESCI344/esci344_lesson04_seasonal_mean_wind_fields.pdf |date=9 September 2013 }} Retrieved on 3 May 2008. It is considered to play a crucial role in the West African monsoon,Kerry H. Cook. [http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0442(1999)012%3C1165%3AGOTAEJ%3E2.0.CO%3B2 Generation of the African Easterly Jet and Its Role in Determining West African Precipitation.] {{Webarchive|url=https://web.archive.org/web/20200226084709/https://journals.ametsoc.org/doi/full/10.1175/1520-0442%281999%29012%3C1165%3AGOTAEJ%3E2.0.CO%3B2 |date=26 February 2020 }} Retrieved on 8 May 2008. and helps form the tropical waves which move across the tropical Atlantic and eastern Pacific oceans during the warm season.Chris Landsea. AOML Frequently Asked Questions. [http://www.aoml.noaa.gov/hrd/tcfaq/A4.html Subject: A4) What is an easterly wave ?] {{webarchive|url=https://web.archive.org/web/20060718105909/http://www.aoml.noaa.gov/hrd/tcfaq/A4.html|date=18 July 2006}} Retrieved on 8 May 2008.

File:Hubble Takes Close-up Portrait of Jupiter.png

For other planets, internal heat rather than solar heating is believed to drive their jet streams.

Jupiter's atmosphere has multiple jet streams caused by the convection cells driven by internal heating. These form the familiar banded color structure.Robert Roy Britt. [http://www.space.com/scienceastronomy/solarsystem/jupiter_sidebar_000209.html Jet Streams On Earth and Jupiter.] {{webarchive|url=https://web.archive.org/web/20080724112429/http://www.space.com/scienceastronomy/solarsystem/jupiter_sidebar_000209.html |date=24 July 2008 }} Retrieved on 4 May 2008.

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• Atmospheric river
• Block (meteorology)
• Polar vortex
• Surface weather analysis
• Sting jet
• Tornado
• Tropical Easterly Jet
• Wind shear
• Weather

{{Reflist}}

{{Commons category|Jet streams}}

• [https://earth.nullschool.net/#current/wind/isobaric/250hPa/winkel3 Current map of winds at the 250 hPa level] {{Webarchive|url=https://web.archive.org/web/20170208003512/https://earth.nullschool.net/#current/wind/isobaric/250hPa/winkel3 |date=8 February 2017 }}
• Tim Woolings, [https://books.google.com/books?id=Xx6yDwAAQBAJ&q=Tim+Woollins+Jet+Stream+%22ooishi%22&pg=PA64 Jet Stream - A Journey Through our Changing Climate] {{Webarchive|url=https://web.archive.org/web/20230512164022/https://books.google.com/books?id=Xx6yDwAAQBAJ&q=Tim+Woollins+Jet+Stream+%22ooishi%22&pg=PA64 |date=12 May 2023 }}, 2020, Oxford University Press, ISBN 978-0-19-882851-8

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