Earth

=== Weather and climate ===
{{Main|Weather|Climate}}
{{Multiple image
| align             = right
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| width             = 300
| image1            = IntertropicalConvergenceZone-EO.jpg
| caption1          = The [[ITCZ]]'s band of clouds over the Eastern Pacific and the Americas as seen from space
| image5            = Köppen-Geiger Climate Classification Map (1980–2016) no borders.png
| caption5          = Worldwide [[Köppen climate classification]]s
}}
Earth's atmosphere has no definite boundary, gradually becoming thinner and fading into outer space.<ref>{{cite web|url=https://www.nationalgeographic.com/science/article/where-is-the-edge-of-space-and-what-is-the-karman-line|archive-url=https://web.archive.org/web/20210304132146/https://www.nationalgeographic.com/science/article/where-is-the-edge-of-space-and-what-is-the-karman-line|url-status=dead|archive-date=4 March 2021|title=Where, exactly, is the edge of space? It depends on who you ask|website=[[National Geographic]] |last1=Drake |first1=Nadia |author-link1=Nadia Drake|date=20 December 2018|access-date=4 December 2021}}</ref> Three-quarters of the atmosphere's mass is contained within the first {{convert|11|km|mi|abbr=on}} of the surface; this lowest layer is called the troposphere.<ref>{{cite web|url=https://spaceplace.nasa.gov/troposphere/en/ |title=Troposphere |website=SpacePlace|publisher=[[NASA]]|last1=Erickson|first1=Kristen|last2=Doyle|first2=Heather|date=28 June 2019|access-date=4 December 2021}}</ref> Energy from the Sun heats this layer, and the surface below, causing expansion of the air. This lower-density air then rises and is replaced by cooler, higher-density air. The result is [[atmospheric circulation]] that drives the weather and climate through redistribution of thermal energy.<ref name="moran2005" />

The primary atmospheric circulation bands consist of the [[trade winds]] in the equatorial region below 30° latitude and the [[westerlies]] in the mid-latitudes between 30° and 60°.<ref name="berger2002" /> [[Ocean heat content]] and [[Ocean current|currents]] are also important factors in determining climate, particularly the [[thermohaline circulation]] that distributes thermal energy from the equatorial oceans to the polar regions.<ref name=rahmstorf2003 />

Earth receives 1361&nbsp;W/m<sup>2</sup> of&nbsp;[[solar irradiance]].<ref>{{cite web |title=Earth Fact Sheet |website=NASA Space Science Data Coordinated Archive |date=5 June 2023 |url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html |access-date=17 September 2023}}</ref><ref>{{cite journal | first1=Odele | last1=Coddington | first2=Judith L. | last2=Lean | author2-link=Judith Lean | first3=Peter | last3=Pilewskie | first4=Martin | last4=Snow | first5=Doug | last5=Lindholm |date=2016 |title=A Solar Irradiance Climate Data Record |journal=Bulletin of the American Meteorological Society |volume=97 |issue=7 |pages=1265–1282 |bibcode=2016BAMS...97.1265C |doi=10.1175/bams-d-14-00265.1 |doi-access=free}}</ref> The amount of solar energy that reaches Earth's surface decreases with increasing latitude. At higher latitudes, the sunlight reaches the surface at lower angles, and it must pass through thicker columns of the atmosphere. As a result, the mean annual air temperature at sea level decreases by about {{convert|0.4|C-change|F-change|1}} per degree of latitude from the equator.<ref name="sadava_heller2006" /> Earth's surface can be subdivided into specific latitudinal belts of approximately homogeneous climate. Ranging from the equator to the polar regions, these are the tropical (or equatorial), [[Subtropics|subtropical]], [[temperate]] and [[Polar region|polar]] climates.<ref name="climate_zones" />

Further factors that affect a location's climates are its [[Continentality|proximity to oceans]], the oceanic and atmospheric circulation, and topology.<ref>{{cite book |last1=Rohli |first1=Robert. V.|title=Climatology|last2=Vega|first2=Anthony J.|publisher=Jones & Bartlett Learning|year=2018|isbn=978-1-284-12656-3|edition=fourth|page=49}}</ref> Places close to oceans typically have colder summers and warmer winters, due to the fact that oceans can store large amounts of heat. The wind transports the cold or the heat of the ocean to the land.<ref>{{cite book|last1=Rohli|first1=Robert. V.|title=Climatology|last2=Vega|first2=Anthony J.|publisher=Jones & Bartlett Learning |year=2018 |isbn=978-1-284-12656-3|edition=fourth|page=32}}</ref> Atmospheric circulation also plays an important role: San Francisco and Washington DC are both coastal cities at about the same latitude. San Francisco's climate is significantly more moderate as the prevailing wind direction is from sea to land.<ref>{{cite book |last1=Rohli |first1=Robert. V.|title=Climatology|last2=Vega|first2=Anthony J.|publisher=Jones & Bartlett Learning|year=2018|isbn=978-1-284-12656-3|edition=fourth|page=34}}</ref> Finally, temperatures [[Lapse rate|decrease with height]] causing mountainous areas to be colder than low-lying areas.<ref>{{cite book|last1=Rohli|first1=Robert. V. |title=Climatology |last2=Vega |first2=Anthony J. |publisher=Jones & Bartlett Learning |year=2018 |isbn=978-1-284-12656-3 |edition=fourth |page=46}}</ref>

Water vapor generated through surface evaporation is transported by circulatory patterns in the atmosphere. When atmospheric conditions permit an uplift of warm, humid air, this water condenses and falls to the surface as [[precipitation]].<ref name="moran2005" /> Most of the water is then transported to lower elevations by river systems and usually returned to the oceans or deposited into lakes. This [[water cycle]] is a vital mechanism for supporting life on land and is a primary factor in the erosion of surface features over geological periods. Precipitation patterns vary widely, ranging from several meters of water per year to less than a millimeter. Atmospheric circulation, topographic features, and temperature differences determine the average precipitation that falls in each region.<ref name="hydrologic_cycle" />

The commonly used [[Köppen climate classification]] system has five broad groups ([[tropical climate|humid tropics]], [[arid]], [[humid subtropical climate|humid middle latitudes]], [[Continental climate|continental]] and cold [[polar climate|polar]]), which are further divided into more specific subtypes.<ref name="berger2002" /> The Köppen system rates regions based on observed temperature and precipitation.<ref>{{cite book|last1=Rohli|first1=Robert. V.|title=Climatology|last2=Vega|first2=Anthony J.|publisher=Jones & Bartlett Learning|year=2018|isbn=978-1-284-12656-3|edition=fourth|page=159}}</ref> Surface [[Highest temperature recorded on Earth|air temperature can rise to]] around {{convert|55|C|F}} in [[hot desert]]s, such as [[Death Valley National Park|Death Valley]], and [[Lowest temperature recorded on Earth|can fall as low as]] {{convert|-89|C|F}} in [[Antarctica]].<ref>{{Cite journal | first1=Khalid I. | last1=El Fadli | first2=Randall S. | last2=Cerveny | first3=Christopher C. | last3=Burt | first4=Philip | last4=Eden | first5=David | last5=Parker | first6=Manola | last6=Brunet | first7=Thomas C. | last7=Peterson | first8=Gianpaolo | last8=Mordacchini | first9=Vinicio | last9=Pelino | first10=Pierre | last10=Bessemoulin | first11=José Luis | last11=Stella | first12=Fatima | last12=Driouech | first13=M. M Abdel | last13=Wahab | first14=Matthew B. | last14=Pace |display-authors=1|date=2013|title=World Meteorological Organization Assessment of the Purported World Record 58°C Temperature Extreme at El Azizia, Libya (13 September 1922)|journal=Bulletin of the American Meteorological Society |language=en |volume=94 |issue=2 |pages=199–204 |doi=10.1175/BAMS-D-12-00093.1|bibcode=2013BAMS...94..199E|issn=0003-0007|doi-access=free}}</ref><ref>{{Cite journal|last1=Turner|first1=John|display-authors=et al |date=2009 |title=Record low surface air temperature at Vostok station, Antarctica|journal=Journal of Geophysical Research: Atmospheres |language=en |volume=114 |issue=D24 |page=D24102 |doi=10.1029/2009JD012104|bibcode=2009JGRD..11424102T|issn=2156-2202|doi-access=free}}</ref>