{"id":31950,"date":"2025-04-12T03:02:18","date_gmt":"2025-04-11T21:32:18","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=31950"},"modified":"2025-04-16T18:02:55","modified_gmt":"2025-04-16T12:32:55","slug":"el-nino-southern-oscillation-enso","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/el-nino-southern-oscillation-enso\/","title":{"rendered":"El Ni\u00f1o Southern Oscillation (ENSO)"},"content":{"rendered":"<h2>El Ni\u00f1o Southern Oscillation (ENSO) Latest News<\/h2>\n<p>The recent La Ni\u00f1a event in the tropical Pacific Ocean has officially ended, with the climate system now transitioning to ENSO-neutral conditions as confirmed by the National Oceanic and Atmospheric Administration (NOAA).<\/p>\n<h2>Key Points about ENSO and its Phases<\/h2>\n<ul>\n<li><strong>El Ni\u00f1o Southern Oscillation (ENSO): <\/strong>ENSO is a significant climate phenomenon that involves changes in sea-surface temperatures (<strong>SST<\/strong>) in the central and eastern tropical <strong>Pacific Ocean<\/strong>.\u00a0<\/li>\n<li>It affects various global weather patterns, including wind behavior, atmospheric pressure, and rainfall distribution.\n<ul>\n<li><strong>El Ni\u00f1o<\/strong>: Warmer-than-usual sea surface temperatures associated with unusual global warming patterns.<\/li>\n<li><strong>La Ni\u00f1a<\/strong>: Cooler-than-usual sea surface temperatures often linked with colder atmospheric patterns and stronger trade winds.<\/li>\n<li><strong>ENSO-Neutral<\/strong>: Neither <strong>El Ni\u00f1o<\/strong> nor <strong>La Ni\u00f1a<\/strong> dominates the climate system, making forecasts less certain but often acting as a <strong>transitional phase<\/strong> between the two extreme conditions.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>\u00a0ENSO-Neutral Phase<\/h3>\n<ul>\n<li>The <strong>ENSO-neutral phase<\/strong> is typically seen as a <strong>transition period<\/strong> between <strong>El Ni\u00f1o<\/strong> and <strong>La Ni\u00f1a<\/strong>.<\/li>\n<li>In March 2025, NOAA scientists observed that <strong>SST anomalies in the Ni\u00f1o-3.4 region<\/strong> had reached <strong>-0.01\u00b0C<\/strong>, much warmer than the <strong>La Ni\u00f1a threshold of -0.5\u00b0C<\/strong>.<\/li>\n<li>The <strong>cool waters<\/strong> that had characterized <strong>La Ni\u00f1a<\/strong> in previous months have now <strong>faded<\/strong>.<\/li>\n<li>Despite the presence of some <strong>La Ni\u00f1a-like atmospheric conditions<\/strong> (like <strong>strong trade winds<\/strong>), the <strong>lack of cool SSTs<\/strong> has led to the <strong>declaration of ENSO-neutral conditions<\/strong>.<\/li>\n<li><strong>Temperature and Atmospheric Changes: <\/strong>The shift to neutral conditions occurred as <strong>warm waters<\/strong> spread westward across the <strong>eastern Pacific<\/strong>. Simultaneously, the pool of <strong>cool water<\/strong> beneath the surface began to shrink.\n<ul>\n<li>Although <strong>signs of La Ni\u00f1a<\/strong> (like strong trade winds) persisted for a short time, the absence of cold surface waters meant the system no longer met the criteria to be classified as <strong>La Ni\u00f1a<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>El Ni\u00f1o Southern Oscillation (ENSO) FAQs<\/h2>\n<p><strong>Q1. <\/strong>What is ENSO\u2019s impact on India\u2019s monsoon?<br \/>\n<strong>Ans.<\/strong> El Ni\u00f1o weakens monsoon rains (e.g., 2023 saw 94% of average rainfall), while La Ni\u00f1a enhances it (2022: 106%).<\/p>\n<p><strong>Q2. <\/strong>How does ENSO affect global agriculture?<br \/>\n<strong>Ans.<\/strong> El Ni\u00f1o triggers droughts in Australia\/SE Asia but floods in South America. The 2023-24 El Ni\u00f1o reduced India\u2019s wheat output by 5%.<\/p>\n<p><strong>Q3. <\/strong>What is the \u201cWalker Circulation\u201d?<br \/>\n<strong>Ans.<\/strong> A Pacific air-current system disrupted during ENSO events, altering trade winds and ocean upwelling.<\/p>\n<p><strong>Q4. <\/strong>How is climate change affecting ENSO?<br \/>\n<strong>Ans.<\/strong> Studies suggest increased frequency of extreme El Ni\u00f1o events (from once every 20 to 10 years) due to warmer Pacific waters.<\/p>\n<p><strong>Q5. <\/strong>What is the Indian Ocean Dipole\u2019s (IOD) role?<br \/>\n<strong>Ans.<\/strong> A positive IOD (warm western Indian Ocean) can offset El Ni\u00f1o\u2019s monsoon impact, as seen in 2019.<\/p>\n<p><strong>Source: <\/strong><a href=\"https:\/\/www.downtoearth.org.in\/science-technology\/la-ni%C3%B1a-fades-as-enso-neutral-conditions-take-hold-across-the-pacific\" target=\"_blank\" rel=\"nofollow noopener\">DTE<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>ENSO is a significant climate phenomenon that involves changes in sea-surface temperatures (SST) in the central and eastern tropical Pacific Ocean.<\/p>\n","protected":false},"author":5,"featured_media":31951,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":{"0":"post-31950","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-prelims-current-affairs","8":"no-featured-image-padding"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/31950","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/comments?post=31950"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/31950\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/31951"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=31950"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=31950"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=31950"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}