Editing Indian Ocean (section)

==Climate==
[[File:Indian Ocean Monsoon.jpg|thumb|During summer, warm continental masses draw moist air from the Indian Ocean hence producing heavy rainfall. The process is reversed during winter, resulting in dry conditions.]]
Several features make the Indian Ocean unique. It constitutes the core of the large-scale [[Tropical Warm Pool]] which, when interacting with the atmosphere, affects the climate both regionally and globally. Asia blocks heat export and prevents the ventilation of the Indian Ocean [[thermocline]]. That continent also drives the Indian Ocean [[monsoon]], the strongest on Earth, which causes large-scale seasonal variations in ocean currents, including the reversal of the [[Somali Current]] and [[Indian Monsoon Current]]. Because of the Indian Ocean [[Walker circulation]] there are no continuous equatorial easterlies. [[Upwelling]] occurs near the [[Horn of Africa]] and the [[Arabian Peninsula]] in the [[Northern Hemisphere]] and north of the trade winds in the Southern Hemisphere. The [[Indonesian Throughflow]] is a unique Equatorial connection to the Pacific.<ref>{{Harvnb|Schott|Xie|McCreary|2009|loc=Introduction, pp. 1–2}}</ref>

The climate north of the [[equator]] is affected by a [[monsoon]] climate. Strong north-east winds blow from October until April; from May until October south and west winds prevail. In the Arabian Sea, the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are generally milder, but summer storms near Mauritius can be severe. When the monsoon winds change, cyclones sometimes strike the shores of the [[Arabian Sea]] and the [[Bay of Bengal]].<ref name="oceanographer-2001">{{Cite web|title=U.S. Navy Oceanographer|url=http://oceanographer.navy.mil/indian.html|access-date=4 August 2001|archive-url=https://web.archive.org/web/20010802084832/http://oceanographer.navy.mil/indian.html|archive-date=2 August 2001|url-status=dead}}</ref> Some 80% of the total annual rainfall in India occurs during summer and the region is so dependent on this rainfall that many civilisations perished when the Monsoon failed in the past. The huge variability in the Indian Summer Monsoon has also occurred pre-historically, with a strong, wet phase 33,500–32,500&nbsp;BP; a weak, dry phase 26,000–23,500&nbsp;BC; and a very weak phase 17,000–15,000&nbsp;BP,
corresponding to a series of dramatic global events: [[Bølling–Allerød warming]], [[Heinrich event|Heinrich]], and [[Younger Dryas]].<ref>{{Harvnb|Dutt|Gupta|Clemens|Cheng|2015|loc=Abstract; Introduction, pp. 5526–5527}}</ref>

[[File:Aerosol pollution over Northern India, Bangladesh, and Bay of Bengal.jpg|thumb|upright=.9|Air pollution in South Asia spread over the Bay of Bengal and beyond.]]
The Indian Ocean is the warmest ocean in the world.<ref>{{Cite web|title=Which Ocean is the Warmest?|publisher=Worldatlas|date=17 September 2018|url=https://www.worldatlas.com/articles/which-ocean-is-the-warmest.html|access-date=28 April 2019|archive-date=28 April 2019|archive-url=https://web.archive.org/web/20190428092339/https://www.worldatlas.com/articles/which-ocean-is-the-warmest.html|url-status=live}}</ref> Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, at about {{Convert|1.2|°C|abbr=on}} (compared to {{Convert|0.7|°C|abbr=on}} for the warm pool region) during 1901–2012.<ref name=":0">{{Harvnb|Roxy|Ritika|Terray|Masson|2014|loc=Abstract}}</ref> Research indicates that human induced [[greenhouse warming]], and changes in the frequency and magnitude of [[El Niño]] (or the [[Indian Ocean Dipole]]), events are a trigger to this strong warming in the Indian Ocean.<ref name=":0" /> While the Indian Ocean warmed at a rate of 1.2&nbsp;°C per century during 1950–2020, climate models predict accelerated warming, at a rate of 1.7&nbsp;°C–3.8&nbsp;°C per century during 2020–2100.<ref name=":1">{{cite book|doi=10.1016/b978-0-12-822698-8.00004-4|chapter=Future projections for the tropical Indian Ocean|title=The Indian Ocean and its Role in the Global Climate System|date=2024|last1=Roxy|first1=M.K.|last2=Saranya|first2=J.S.|last3=Modi|first3=Aditi|last4=Anusree|first4=A.|last5=Cai|first5=Wenju|last6=Resplandy|first6=Laure|last7=Vialard|first7=Jérôme|last8=Frölicher|first8=Thomas L.|pages=469–482|isbn=978-0-12-822698-8}}</ref><ref name=":2">{{Cite web|title=Future Indian Ocean|url=https://www.climate.rocksea.org/research/future-indian-ocean/|access-date=1 July 2024|website=Climate Research Lab @ IITM|language=en-US}}</ref> Though the warming is basin-wide, maximum warming is in the northwestern Indian Ocean including the Arabian Sea, and reduced warming off the Sumatra and Java coasts in the southeast Indian Ocean. Global warming is projected to push the tropical Indian Ocean into a basin-wide near-permanent heatwave state by the end of the 21st century, where marine heatwaves are projected to increase from 20 days per year (during 1970–2000) to 220–250 days per year.<ref name=":1" /><ref name=":2" />

South of the Equator (20–5°S), the Indian Ocean is gaining heat from June to October, during the austral winter, while it is losing heat from November to March, during the austral summer.<ref>{{Harvnb|Carton|Chepurin|Cao|2000|p=321}}</ref>

In 1999, the [[Indian Ocean Experiment]] showed that fossil fuel and biomass burning in South and Southeast Asia caused air pollution (also known as the [[Asian brown cloud]]) that reach as far as the [[Intertropical Convergence Zone]]. This pollution has implications on both a local and global scale.<ref>{{Harvnb|Lelieveld|Crutzen|Ramanathan|Andreae|2001|loc=Abstract}}</ref>