{"id":366730,"date":"2026-07-04T17:28:36","date_gmt":"2026-07-04T11:58:36","guid":{"rendered":"https:\/\/forumias.com\/blog\/?p=366730"},"modified":"2026-07-04T17:28:36","modified_gmt":"2026-07-04T11:58:36","slug":"indian-ocean-dipole-iod","status":"publish","type":"post","link":"https:\/\/forumias.com\/blog\/indian-ocean-dipole-iod\/","title":{"rendered":"Indian Ocean Dipole (IOD)"},"content":{"rendered":"<div class=\"content-box-green\">\n<p><strong>News:<\/strong>\u00a0Delhi received the southwest monsoon on July 2 after a delayed onset, while June rainfall deficit renewed focus on the Indian Ocean Dipole (IOD).<\/p>\n<\/div>\n<h2 class=\"red-h2-box\"><strong>About Indian Ocean Dipole (IOD)<\/strong><\/h2>\n<figure id=\"attachment_366737\" aria-describedby=\"caption-attachment-366737\" style=\"width: 420px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\" wp-image-366737\" src=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-AFP-1.jpg?resize=420%2C339&#038;ssl=1\" alt=\"Indian Ocean Dipole (IOD)\" width=\"420\" height=\"339\" srcset=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-AFP-1.jpg?resize=300%2C242&amp;ssl=1 300w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-AFP-1.jpg?resize=1024%2C825&amp;ssl=1 1024w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-AFP-1.jpg?resize=768%2C619&amp;ssl=1 768w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-AFP-1.jpg?w=1083&amp;ssl=1 1083w\" sizes=\"auto, (max-width: 420px) 100vw, 420px\" \/><figcaption id=\"caption-attachment-366737\" class=\"wp-caption-text\">Source &#8211; AFP<\/figcaption><\/figure>\n<ul>\n<li><strong>Indian Ocean Dipole (IOD)<\/strong>\u00a0is an <strong>atmosphere-ocean coupled phenomenon<\/strong> characterized by <strong>differences in sea-surface temperatures across the Indian Ocean.<\/strong><\/li>\n<li><strong>Mechanism: <\/strong>The IOD develops when a <strong>difference in sea-surface temperatures emerges between the eastern and western Indian Ocean.<\/strong>\n<ul>\n<li>This <strong>temperature difference creates pressure differences<\/strong> that <strong>change wind movement<\/strong>, which <strong>influences moisture, clouds, and rainfall<\/strong> over surrounding regions.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Key Characteristics of IOD:<\/strong>\n<ul>\n<li><strong>Temperature Difference:<\/strong> The IOD is measured by the difference in sea-surface temperatures between the <strong>eastern Indian Ocean and the western Indian Ocean.<\/strong><\/li>\n<li><strong>Air-Sea Coupling:<\/strong> <strong>Temperature differences change wind patterns,<\/strong> and these <strong>winds further change ocean temperatures,<\/strong> creating a <strong>continuous interaction that drives the IOD.<\/strong><\/li>\n<li><strong>Development Pattern:<\/strong> The IOD <strong>develops in the equatorial Indian Ocean<\/strong> from <strong>April to May<\/strong> and generally <strong>peaks during September to November or October.<\/strong><\/li>\n<li><strong>Three Phases:<\/strong> The IOD occurs in <strong>positive, negative, and neutral phases<\/strong> depending on the temperature difference between the eastern and western Indian Ocean.\n<ul>\n<li data-start=\"406\" data-end=\"522\"><strong>Positive IOD: <\/strong>A positive IOD occurs <strong>when the western Indian Ocean is warmer than the eastern Indian Ocean.<\/strong><\/li>\n<li data-start=\"523\" data-end=\"639\"><strong>Negative IOD: <\/strong>A negative IOD occurs when the <strong>eastern Indian Ocean is warmer than the western Indian Ocean.<\/strong><\/li>\n<li data-start=\"640\" data-end=\"793\"><strong>Neutral IOD:<\/strong> A neutral IOD occurs when there is <strong>no significant sea-surface temperature difference<\/strong> between the eastern and western Indian Ocean.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li><strong>ENSO Link<\/strong>: <strong>El Ni\u00f1o, a climate phenomenon<\/strong> in which the <strong>central and eastern Pacific Ocean becomes warmer than usual,<\/strong> often precedes or strengthens a positive IOD.\n<ul>\n<li>However, the <strong>IOD can also develop independently because of local atmospheric variability.<\/strong><\/li>\n<\/ul>\n<\/li>\n<li><strong>Regional Impact<\/strong>: A <strong>positive IOD increases rainfall over East Africa<\/strong> <strong>and the Indian subcontinent<\/strong> while <strong>reducing rainfall over Indonesia and Australia<\/strong>, whereas a negative IOD produces the opposite pattern.<\/li>\n<\/ul>\n<h2 class=\"red-h2-box\"><strong>Madden-Julian Oscillation (MJO)<\/strong><\/h2>\n<figure id=\"attachment_366738\" aria-describedby=\"caption-attachment-366738\" style=\"width: 443px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" class=\" wp-image-366738\" src=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-ResearchGate-1.jpg?resize=443%2C356&#038;ssl=1\" alt=\"Madden-Julian Oscillation (MJO)\" width=\"443\" height=\"356\" srcset=\"https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-ResearchGate-1.jpg?resize=300%2C241&amp;ssl=1 300w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-ResearchGate-1.jpg?resize=768%2C617&amp;ssl=1 768w, https:\/\/i0.wp.com\/forumias.com\/blog\/wp-content\/uploads\/2026\/07\/Source-ResearchGate-1.jpg?w=791&amp;ssl=1 791w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><figcaption id=\"caption-attachment-366738\" class=\"wp-caption-text\">Source &#8211; ResearchGate<\/figcaption><\/figure>\n<ul>\n<li><strong>The Madden-Julian Oscillation (MJO)<\/strong> is an <strong>eastward-moving atmospheric disturbance of clouds, rainfall, winds, and pressure<\/strong> near the <strong>equator<\/strong> that <strong>circles the globe every 30\u201360 days.<\/strong><\/li>\n<li><strong>Nature<\/strong>: It is the <strong>primary driver of intra-seasonal variability in tropical weather<\/strong> and <strong>directly influences the active and break phases of the Indian monsoon.<\/strong><\/li>\n<li><strong>Rainfall Influence<\/strong>: The <strong>MJO acts as a travelling pulse of rain-bearing clouds and winds<\/strong>, strengthening or suppressing rainfall depending on its location.<\/li>\n<li><strong>Geographical Phases:<\/strong> Its movement is <strong>monitored in eight geographical phases,<\/strong> covering the <strong>Western Hemisphere and Africa, the Indian Ocean, Indonesia, the eastern Indian Ocean, and the Western and Central Pacific.<\/strong><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>News:\u00a0Delhi received the southwest monsoon on July 2 after a delayed onset, while June rainfall deficit renewed focus on the Indian Ocean Dipole (IOD). About Indian Ocean Dipole (IOD) Indian Ocean Dipole (IOD)\u00a0is an atmosphere-ocean coupled phenomenon characterized by differences in sea-surface temperatures across the Indian Ocean. Mechanism: The IOD develops when a difference in&hellip; <a class=\"more-link\" href=\"https:\/\/forumias.com\/blog\/indian-ocean-dipole-iod\/\">Continue reading <span class=\"screen-reader-text\">Indian Ocean Dipole (IOD)<\/span><\/a><\/p>\n","protected":false},"author":10401,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"categories":[1566,11209,12039],"tags":[11872],"class_list":["post-366730","post","type-post","status-publish","format-standard","hentry","category-daily-factly-articles","category-geography-in-news","category-knolls","tag-9pm-daily-factly","entry"],"jetpack_featured_media_url":"","views":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/366730","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/users\/10401"}],"replies":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/comments?post=366730"}],"version-history":[{"count":0,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/366730\/revisions"}],"wp:attachment":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/media?parent=366730"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/categories?post=366730"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/tags?post=366730"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}