[[File:OceanTemps AMSRE 18sep05.jpg|thumb|Thermal satellite image of worldwide ocean temperatures, with the Indo-Pacific Warm Pool centered.]]
The '''Tropical Warm Pool''' (TWP) or '''Indo-Pacific Warm Pool''' (IPWP) is a mass of ocean water located in the western [[Pacific Ocean]] and eastern [[Indian Ocean]] which consistently exhibits the highest water temperatures over the largest expanse of the Earth's surface.<ref>[http://www.usgs.gov/newsroom/article_pf.asp?ID=2690 USGS News Release Jan. 28, 2011]</ref> Climate change and the [[Intertropical Convergence Zone]] have been increasingly affecting the warming of the IPWP.<ref name=":2" /><ref name=":02" />
== History == The Tropical Western Pacific waters hold the ocean's warmest waters.<ref name=":02">{{Cite journal |last=Moffa‐Sanchez|first=Paola|last2=Rosenthal|first2=Yair|last3=Babila|first3=Tali L.|last4=Mohtadi|first4=Mahyar|last5=Zhang|first5=Xu|date=2019|title=Temperature Evolution of the Indo‐Pacific Warm Pool Over the Holocene and the Last Deglaciation|url=https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018PA003455|journal=Paleoceanography and Paleoclimatology|language=en|volume=34|issue=7|pages=1107–1123|doi=10.1029/2018PA003455|issn=2572-4517}}</ref> This area is also referred to as the Western Pacific Warm Pool, which is a part of the larger Indo-Pacific Warm Pool.<ref name=":02" /> Annual sea surface temperatures in this area reach above 28 degrees celsius.<ref name=":02" /> As a result of higher sea surface temperatures, the IPWP is a source of warm moisture. Ultimately leading to heavy local rainfall.<ref name=":02" /> High water temperatures are due to seasonal changes in precipitation along the path of the [[Ocean conveyor belt|Great Ocean Conveyor Belt]], from the western Pacific Ocean across the [[Indonesian Archipelago]] into the eastern Indian Ocean.<ref name=":1">{{Cite journal |last=De Deckker |first=Patrick |date=2016-06-29 |title=The Indo-Pacific Warm Pool: critical to world oceanography and world climate |url=https://doi.org/10.1186/s40562-016-0054-3 |journal=Geoscience Letters |language=en |volume=3 |issue=1 |pages=20 |doi=10.1186/s40562-016-0054-3 |doi-access=free|issn=2196-4092}}</ref> Its intensity and extent appear to oscillate over a time period measured in decades.<ref>[https://earthobservatory.nasa.gov/Features/WarmPool/ NASA: "Reverberations of the Pacific Warm Pool"]</ref>
== Climate change effects == [[File:Madden–Julian oscillation diagram.png|thumb|[[Madden-Julian Oscillation]] Diagram]]
The Indo-Pacific warm pool has been warming rapidly and expanding during the recent decades, largely from [[climate change]] in response to increased [[carbon emissions]] from [[fossil fuel]] burning.<ref name=":2">{{Cite journal|last1=Weller|first1=Evan|last2=Min|first2=Seung-Ki|last3=Cai|first3=Wenju|last4=Zwiers|first4=Francis W.|last5=Kim|first5=Yeon-Hee|last6=Lee|first6=Donghyun|date=2016-07-01|title=Human-caused Indo-Pacific warm pool expansion|journal=Science Advances|volume=2|issue=7|article-number=e1501719|doi=10.1126/sciadv.1501719|pmid=27419228 |pmc=4942332 |bibcode=2016SciA....2E1719W |issn=2375-2548|doi-access=free}}</ref> The warm pool nearly doubled in size, from an area of 22 million km<sup>2</sup> during 1900–1980, to an area of 40 million km<sup>2</sup> during 1981–2018;<ref name=":0">{{Cite journal|last1=Roxy|first1=M. K.|last2=Dasgupta|first2=Panini|last3=McPhaden|first3=Michael J.|last4=Suematsu|first4=Tamaki|last5=Zhang|first5=Chidong|last6=Kim|first6=Daehyun|date=November 2019|title=Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle|url=https://www.nature.com/articles/s41586-019-1764-4|journal=Nature|volume=575|issue=7784|pages=647–651|doi=10.1038/s41586-019-1764-4|pmid=31776488 |bibcode=2019Natur.575..647R |osti=1659516 |s2cid=208329374 |issn=1476-4687}}</ref> however, latest research suggests that this expansion rate may be overestimated.<ref>{{Cite journal |last=Leung |first=Jeremy Cheuk-Hin |last2=Zhang |first2=Banglin |last3=Gan |first3=Qiuying |last4=Wang |first4=Lei |last5=Qian |first5=Weihong |last6=Hu |first6=Zeng-Zhen |date=2022-11-24 |title=Differential expansion speeds of Indo-Pacific warm pool and deep convection favoring pool under greenhouse warming |url=https://www.nature.com/articles/s41612-022-00315-w |journal=npj Climate and Atmospheric Science |language=en |volume=5 |issue=1 |pages=1–15 |doi=10.1038/s41612-022-00315-w |issn=2397-3722|doi-access=free }}</ref> This expansion of the warm pool has allowed more [[cyclone]]s as well as altered global rainfall patterns and variations by changing the life cycle of the [[Madden Julian Oscillation]] (MJO), which is the most dominant mode of weather fluctuation originating in the tropics.<ref name=":0" /><ref>{{Cite web|url=https://www.climate.rocksea.org/research/warm-pool-expansion-warps-mjo/|title=Warm pool expansion warps MJO – Climate Research Lab, CCCR, IITM|access-date=2019-11-29}}</ref> This oscillation is showcased by eastward movement of suppressed tropical rainfall, specifically over the Pacific and Indian Oceans.<ref>{{Citation |title=Madden–Julian oscillation |date=2026-03-09 |work=Wikipedia |url=https://en.wikipedia.org/w/index.php?title=Madden%E2%80%93Julian_oscillation&oldid=1342486601 |access-date=2026-03-21 |language=en}}</ref>
== Intertropical Convergent Zone == [[File:ITCZ january-july.png|thumb|Intertropical Convergence Zone across the globe, with emphasis on January-July <ref>{{Cite web |date=2006-12-13 |title=File:ITCZ january-july.png - Wikipedia |url=https://commons.wikimedia.org/wiki/File:ITCZ_january-july.png |access-date=2026-04-13 |website=commons.wikimedia.org |language=en}}</ref>]] The Hadley circulation's ascending branch includes the [[Intertropical Convergence Zone|Intertropical Convergent Zone]] (ITCZ), a narrow tropical area of wind convergence and maximal surface moist static energy.<ref name=":02" /> The Asian-Australian [[Monsoon|monsoons]] are caused by the rainbelt's latitudinal migration and the winds that accompany it.<ref name=":02" /><ref name=":12">{{Cite journal |last=Qu|first=Tangdong|last2=Meyers|first2=Gary|date=2005-02-01|title=Seasonal Characteristics of Circulation in the Southeastern Tropical Indian Ocean*|url=http://journals.ametsoc.org/doi/10.1175/JPO-2682.1|journal=Journal of Physical Oceanography|language=en|volume=35|issue=2|pages=255–267|doi=10.1175/JPO-2682.1|issn=1520-0485|url-access=subscription}}</ref> Significant seasonal variations in the local SST are caused by variations in the monsoonal activity, which impact the wind direction and intensity over the IPWP.<ref name=":02" /> In particular, the seasonal reversal of the monsoonal winds affects the Indian Ocean sector of the IPWP, which includes the [[Timor Sea|Timor]], [[Arafura Sea|Arafura]], and [[Banda Sea|Banda Seas]].<ref name=":02" /><ref name=":12" /> This results in the upwelling of colder waters by [[Ekman transport]].<ref name=":02" /><ref name=":12" />
==See also== * [[Maritime Continent]]
==References== {{reflist}}
[[Category:Regional climate effects]] [[Category:Tropical meteorology]]
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