Quick Links
Quick Links
UPSC Exams
Latest Update
UPSSSC Junior Assistant Admit Card 2025 Fastag Annual Pass 2025 UGC NET Exam Analysis 2025 UGC NET Question Paper 2025 AP LAWCET Result 2025 UGC NET City Slip 2025 UPSC DAF 1 2025 Rajasthan PTET Answer Key 2025 UPSC Prelims Result 2025 UPSC IFS Result 2025 8th Pay Commission Salary Hike News UPSC 2024 Prelims Answer Key UPSC 2026 Calendar UPSC Admit Card 2025 UPSC Prelims Result Date 2025 UPSC Prelims Answer Key 2025 UPSC Prelims 2025 Expected Cut Off UPSC Prelims Exam Analysis 2025 UPSC Final Result 2025 UPSC Topper Shakti Dubey UPSC Application Rejected List 2025 UPSC Application Date Re-Extended UPSC Interview Date 2024 UPSC Notification 2025 UPSC Admit Card 2025 for Prelims UPSC CSE Prelims 2025 Question Paper UPSC IFS Notification 2025 Indian Navy MR Result 2025 Indian Navy SSR Result 2025
Coaching
UPSC Current Affairs
Syllabus
UPSC Notes
Previous Year Papers
UPSC Mains Previous Year Question Papers Last 25 Years UPSC Prelims Question Papers Last 10 Years UPSC Question Papers UPSC CSE Prelims 2025 Question Paper UPSC Mains 2024 Model Answers UPSC 2024 Question Papers UPSC 2023 Question Papers UPSC 2022 Question Papers UPSC 2021 Question Papers UPSC 2020 Question Papers UPSC 2019 Question Papers UPSC 2018 Question Papers UPSC 2017 Question Papers UPSC 2016 Question Papers UPSC 2015 Question Papers UPSC 2014 Question Papers UPSC CSAT Question Papers UPSC IFS Previous Year Paper UPSC Assistant Labour Commissioner Previous Question Year Papers UPSC Combined Geo Scientist Previous Year Paper UPSC APFC Previous Year Question Papers UPSC CMS Previous Year Question Paper UPSC EPFO Previous Year Paper UPSC Air Safety Officer Previous Year Papers UPSC SO Steno Previous Year Paper UPSC IES ISS Previous Year Question Papers
Mock Tests
UPSC Editorial
Bilateral Ties
Albania India Relations India Algeria Relations Andorra India Relations India Angola Relations India Antigua Barbuda Relations India Argentina Relations Austria India Relations India Azerbaijan Relations Bahamas India Relations India Bahrain Relations Barbados India Relations India Belarus Relations Belgium India Relations Belize India Relations Benin India Relations Bolivia India Relations India Bosnia Herzegovina Relations India Botswana Relations Brazil India Relations Brunei India Relations Bulgaria India Relations Burundi India Relations Cabo Verde India Relations India Cambodia Relations India Cameroon Relations Canada India Relations India Cayman Islands Relations India Central African Republic Relations India Chad Relations Chile India Relations India Colombia Relations India Comoros Relations India Democratic Republic Of The Congo Relations India Republic Of The Congo Relations India Cook Islands Relations India Costa Rica Relations India Ivory Coast Relations India Croatia Relations India Cyprus Relations India Czech Republic Relations India Djibouti Relations India Dominica Relations India Dominican Republic Relations India Ecuador Relations India El Salvador Relations India Equatorial Guinea Relations India Eritrea Relations Estonia India Relations India Ethiopia Relations India Fiji Relations India Finland Relations India Gabon Relations India Gambia Relations India Georgia Relations Germany India Relations India Ghana Relations India Greece Relations India Grenada Relations India Guatemala Relations India Guinea Relations India Guinea Bissau Relations India Guyana Relations India Haiti Relations India Holy See Relations India Honduras Relations India Hong Kong Relations India Hungary Relations India Iceland Relations India Indonesia Relations India Iran Relations India Iraq Relations India Ireland Relations India Jamaica Relations India Kazakhstan Relations India Kenya Relations India Kingdom Of Eswatini Relations India Kiribati Relations India Kuwait Relations India Kyrgyzstan Relations India Laos Relations Latvia India Relations India Lebanon Relations India Lesotho Relations India Liberia Relations Libya India Relations Liechtenstein India Relations India Lithuania Relations India Luxembourg Relations India Macao Relations Madagascar India Relations India Malawi Relations India Mali Relations India Malta Relations India Marshall Islands Relations India Mauritania Relations India Micronesia Relations India Moldova Relations Monaco India Relations India Montenegro Relations India Montserrat Relations India Morocco Relations Mozambique India Relations India Namibia Relations India Nauru Relations Netherlands India Relations India Nicaragua Relations India Niger Relations India Nigeria Relations India Niue Relations India North Macedonia Relations Norway India Relations India Palau Relations India Panama Relations India Papua New Guinea Relations India Paraguay Relations Peru India Relations India Philippines Relations Qatar India Relations India Romania Relations Rwanda India Relations India Saint Kitts And Nevis Relations India Saint Lucia Relations India Saint Vincent And Grenadines Relations India Samoa Relations India Sao Tome And Principe Relations Saudi Arabia India Relations India Senegal Relations Serbia India Relations India Sierra Leone Relations India Singapore Relations India Slovak Republic Relations India Slovenia Relations India Solomon Islands Relations Somalia India Relations India South Sudan Relations India Spain Relations India Sudan Relations Suriname India Relations India Sweden Relations India Syria Relations India Tajikistan Relations Tanzania India Relations India Togo Relations India Tonga Islands Relations India Trinidad And Tobago Relations India Tunisia Relations India Turkmenistan Relations India Turks And Caicos Islands Relations India Tuvalu Relations India Uganda Relations India Ukraine Relations India Uae Relations India Uruguay Relations India Uzbekistan Relations India Vanuatu Relations India Venezuela Relations India British Virgin Islands Relations Yemen India Relations India Zambia Relations India Zimbabwe Relations
Books
Government Schemes
Production Linked Incentive Scheme Integrated Processing Development Scheme Rodtep Scheme Amended Technology Upgradation Fund Scheme Saathi Scheme Uday Scheme Hriday Scheme Samagra Shiksha Scheme India Nishta Scheme Stand Up India Scheme Sahakar Mitra Scheme Mdms Mid Day Meal Scheme Integrated Child Protection Scheme Vatsalya Scheme Operation Green Scheme Nai Roshni Scheme Nutrient Based Subsidy Scheme Kalia Scheme Ayushman Sahakar Scheme Nirvik Scheme Fame India Scheme Kusum Scheme Pm Svanidhi Scheme Pmvvy Scheme Pm Aasha Scheme Pradhan Mantri Mahila Shakti Kendra Scheme Pradhan Mantri Lpg Panjayat Scheme Mplads Scheme Svamitva Scheme Pat Scheme Udan Scheme Ek Bharat Shresth Bharat Scheme National Pension Scheme Ujala Scheme Operation Greens Scheme Gold Monetisation Scheme Family Planning Insurance Scheme Target Olympic Podium Scheme
Topics
NASA Space Missions
NASA Mercury-Redstone 3 (Freedom 7) Mission NASA Mercury-Redstone 4 (Liberty Bell 7) Mission NASA Mercury-Atlas 6 (Friendship 7) Mission NASA Mercury-Atlas 7 (Aurora 7) Mission NASA Mercury-Atlas 8 (Sigma 7) Mission NASA Mercury-Atlas 9 (Faith 7) Mission NASA Gemini 3 Mission NASA Gemini 4 Mission NASA Gemini 5 Mission NASA Gemini 7 Mission NASA Gemini 8 Mission NASA Gemini 9 Mission NASA Gemini 10 Mission NASA Gemini 11 Mission NASA Gemini 12 Mission NASA Apollo 1 (AS‑204) Mission NASA Apollo 7 Mission NASA Apollo 8 Mission NASA Apollo 9 Mission NASA Apollo 10 Mission NASA Apollo 11 Mission NASA Apollo 12 Mission NASA Apollo 13 Mission NASA Apollo 14 Mission NASA Apollo 15 Mission NASA Apollo 16 Mission NASA Apollo 17 Mission NASA Skylab Orbital Workshop Mission NASA Skylab 2 Mission NASA Skylab 3 Mission NASA Skylab 4 Mission NASA Apollo–Soyuz Test Project Mission NASA STS‑1 Columbia Mission NASA STS‑3 Columbia Mission NASA STS‑7 Challenger Mission NASA STS‑8 Challenger Mission NASA STS‑41B Challenger Mission NASA STS‑41G Discovery (1st female EVA) Mission NASA STS‑51L Challenger (accident) Mission NASA STS‑26 Discovery (Return‑to‑Flight) Mission NASA STS‑31 Discovery (Hubble Launch) Mission NASA STS‑49 Endeavour (first capture EVA) Mission NASA STS‑61 Endeavour (Hubble Servicing 1) Mission NASA STS‑73 Columbia (microgravity) Mission NASA STS‑95 Discovery (John Glenn returns) Mission NASA STS‑107 Columbia (accident) Mission NASA STS‑114 Discovery (RTF‑2) Mission NASA STS‑120 Discovery (Node 2) Mission NASA STS‑125 Atlantis (Final Hubble Service) Mission NASA STS‑132 Atlantis Mission NASA STS‑135 Atlantis (Final Shuttle flight) Mission NASA Artemis I (Orion/ SLS‑1) Mission NASA Artemis II (Planned) Mission NASA Artemis III (Planned lunar landing) Mission NASA Mariner 4 Mission NASA Mariner 6 Mission NASA Mariner 7 Mission NASA Mariner 9 Mission NASA Viking 1 Orbiter/Lander Mission NASA Viking 2 Orbiter/Lander Mission NASA Mars Pathfinder & Sojourner Mission NASA Mars Global Surveyor Mission NASA 2001 Mars Odyssey Mission NASA Mars Exploration Rover – Spirit Mission NASA Mars Exploration Rover – Opportunity Mission NASA Mars Reconnaissance Orbiter Mission NASA Phoenix Mars Lander Mission NASA InSight Mars Lander Mission NASA Mars 2020 (Perseverance & Ingenuity) Mission NASA Mars Sample Return – SRL (planned) Mission NASA Pioneer 10 Mission NASA Pioneer 11 Mission NASA Voyager 1 Mission NASA Voyager 2 Mission NASA Galileo Jupiter Orbiter/Probe Mission NASA Cassini–Huygens Mission NASA New Horizons (Pluto & KBO) Mission NASA Juno Mission NASA Europa Clipper (planned) Mission NASA Parker Solar Probe Mission NASA Solar Orbiter (ESA/NASA) Mission NASA Surveyor 1 Mission NASA Lunar Orbiter 1 Mission NASA Lunar Prospector Mission NASA LCROSS Mission NASA LADEE Mission NASA Lunar Reconnaissance Orbiter (LRO) Mission NASA CAPSTONE Mission NASA VIPER Rover (planned) Mission NASA NEAR Shoemaker Mission NASA Deep Space 1 Mission NASA Stardust Mission NASA Genesis Mission NASA Deep Impact Mission NASA Dawn (Vesta/Ceres) Mission NASA OSIRIS‑REx Mission NASA Lucy Mission NASA DART Mission NASA Landsat‑1 (ERTS‑1) Mission NASA Landsat‑5 Mission NASA Landsat‑9 Mission NASA Terra Mission NASA Aqua Mission NASA Aura Mission NASA Suomi NPP Mission NASA Sentinel‑6 Michael Freilich Mission NASA ICESat‑2 Mission NASA GRACE‑FO Mission NASA SMAP Mission NASA GPM Core Observatory Mission NASA CALIPSO Mission NASA CloudSat Mission NASA NISAR (NASA‑ISRO) Mission NASA Explorer 1 Mission NASA COBE Mission NASA Compton Gamma Ray Observatory Mission NASA Hubble Space Telescope Mission NASA Chandra X‑ray Observatory Mission NASA Spitzer Space Telescope Mission NASA WISE Mission NASA Kepler Mission NASA TESS Mission NASA Fermi Gamma‑ray Space Telescope Mission NASA NICER Mission NASA IXPE Mission NASA Roman Space Telescope (planned) Mission NASA NuSTAR Mission NASA GALEX Mission NASA Swift Mission NASA SOHO (ESA/NASA) Mission NASA Cluster II (ESA/NASA) Mission NASA TIMED Mission NASA STEREO‑A/B Mission NASA MMS Mission NASA IRIS Mission NASA Solar Dynamics Observatory Mission NASA X‑37B OTV‑1 (USAF/NASA liaison) Mission NASA X‑59 QueSST Mission NASA Mars Helicopter Ingenuity Mission NASA Valkyrie R5 Robot Mission NASA Low‑Boom Flight Demo Mission NASA CRS‑1 Dragon Mission NASA CRS‑1 Cygnus Mission NASA Crew Dragon Demo‑2 Mission NASA Starliner OFT‑2 Mission NASA STS-2 (Shuttle flight) Mission NASA STS-4 (Shuttle flight) Mission NASA STS-5 (Shuttle flight) Mission NASA STS-6 (Shuttle flight) Mission NASA STS-41C (Shuttle flight) Mission NASA STS-41D (Shuttle flight) Mission NASA STS-51A (Shuttle flight) Mission NASA STS-61C (Shuttle flight) Mission NASA STS-26 (Shuttle flight) Mission NASA STS-27 (Shuttle flight) Mission NASA STS-29 (Shuttle flight) Mission NASA STS-30 (Shuttle flight) Mission NASA STS-32 (Shuttle flight) Mission NASA STS-34 (Shuttle flight) Mission NASA STS-38 (Shuttle flight) Mission NASA STS-45 (Shuttle flight) Mission NASA STS-60 (Shuttle flight) Mission NASA STS-70 (Shuttle flight) Mission NASA STS-71 (Shuttle flight) Mission NASA STS-73 (Shuttle flight) Mission NASA STS-88 (Shuttle flight) Mission NASA STS-92 (Shuttle flight) Mission NASA STS-97 (Shuttle flight) Mission NASA STS-99 (Shuttle flight) Mission NASA STS-100 (Shuttle flight) Mission NASA STS-104 (Shuttle flight) Mission NASA STS-106 (Shuttle flight) Mission NASA STS-110 (Shuttle flight) Mission NASA STS-112 (Shuttle flight) Mission NASA STS-115 (Shuttle flight) Mission NASA STS-116 (Shuttle flight) Mission NASA STS-117 (Shuttle flight) Mission NASA STS-118 (Shuttle flight) Mission NASA STS-120 (Shuttle flight) Mission NASA STS-122 (Shuttle flight) Mission NASA STS-123 (Shuttle flight) Mission NASA STS-126 (Shuttle flight) Mission NASA STS-130 (Shuttle flight) Mission NASA Vanguard 1 Mission NASA Transit 1B Mission NASA Echo 1 Mission NASA Telstar 1 Mission NASA Syncom 3 Mission NASA ATS‑6 Mission NASA Skynet Mission NASA Nimbus‑1 Mission NASA Nimbus‑7 Mission NASA ERS-1 Mission NASA SeaSat Mission NASA QuikSCAT Mission NASA Jason‑1 Mission NASA Jason‑3 Mission NASA ICESat Mission NASA Earth Observing‑1 Mission NASA Orbiting Carbon Observatory‑2 Mission NASA CYGNSS Mission NASA PACE Mission NASA TRMM Mission NASA Terrestrial Planet Finder (cxl) Mission NASA Laser Interferometer Space Antenna (LISA) Mission NASA Explorer 33 Mission NASA Voyager Interstellar Mission Mission NASA Helios‑A Mission NASA Helios‑B Mission NASA ISEE‑3 (ICE) Mission NASA ACE Mission NASA DSCOVR Mission NASA IBEX Mission NASA Solar Orbiter Heliospheric Imager Mission NASA SAGE‑III ISS Mission NASA SPACE Telescope Imaging Spectrograph Mission NASA ARIEL (ESA/NASA) Mission NASA OSAM‑1 (Restore‑L) Mission NASA Dragonfly (Titan rotorcraft) Mission NASA VERITAS (Venus orbiter) Mission NASA DAVINCI (Venus probe) Mission NASA SPHEREx Mission NASA MAGGIE (Mars Geophysical) Mission NASA CLPS – Peregrine Mission NASA CLPS – VIPER Delivery Mission NASA CAPSTONE Mission NASA Gateway (HALO / PPE) Mission NASA Mars Telecommunication Orbiter (cxl) Mission NASA Mars Polar Lander (MPL) Mission NASA Mars Climate Orbiter Mission NASA Pathfinder Mission Mission NASA SLS Block 1B (Exploration Upper Stage) Mission NASA Orion Crew Module Mission NASA Commercial LEO Destinations – Axiom Station Mission NASA ISS Expedition 1 Mission NASA ISS Expedition 70 Mission NASA CRS‑11 (Dragon) Mission NASA CRS‑21 (Dragon 2) Mission NASA Snoopy CubeSat Mission
Home / IAS Preparation / Indian Ocean Dipole

Indian Ocean Dipole (IOD): Characteristics, Effects & More

Last Updated on May 03, 2025
Also Read Indian Ocean Dipole in Hindi
Download As PDF
IMPORTANT LINKS
Agriculture Notes For UPSC Public Administration UPSC Notes Modern History Books For UPSC Overseas Citizen Of India Caste System & Panchayati Raj Godavari River Federalism Indira Point New Development Bank Battle Of Sinhagad Sankalp And Strive Schemes Digital India High Yielding Varieties Economic Growth Development League Of Nations Ease Of Doing Business Mid Day Meal Scheme Wildlife Protection Act 1972 UPSC Notes International Union Conservation Nature

The Indian Ocean Dipole (IOD) is an ocean-atmosphere climate phenomenon characterized by differences in sea surface temperatures between the eastern and western Indian Ocean. It significantly influences weather patterns, including monsoon rainfall across India, Southeast Asia, East Africa, and Australia. The Indian Ocean Dipole involves distinct phases—positive, negative, and neutral—which determine regional climatic conditions. Changes in these phases directly impact agriculture, water resources, and economic stability of countries surrounding the Indian Ocean region. This article explains the Indian Ocean Dipole, detailing its formation, phases, impacts, and relevance with updated facts and data.

Indian Ocean Dipole UPSC

Know more about Indian Ocean Commission!

Syllabus

General Studies - I

Topics for Prelims

Monsoon, Wind Systems, Easterlies, Westerlies, Jet Streams

Topics for Mains

Indian Geography, Physical Geography, Climatology

What is the Indian Ocean Dipole?

The Indian Ocean Dipole is defined by the difference in sea surface temperatures between two regions: the western Indian Ocean (near the Arabian Sea) and the eastern Indian Ocean (near the Indonesian coast). This temperature difference influences atmospheric convection and wind patterns, leading to variations in precipitation across the Indian Ocean basin. The IOD operates in three phases: positive, negative, and neutral.

Phases of the IOD

  • Positive IOD: Characterized by warmer sea surface temperatures in the western Indian Ocean and cooler temperatures in the eastern part. This phase enhances rainfall over East Africa and the Indian subcontinent while suppressing it over Indonesia and Australia.
  • Negative IOD: Features cooler sea surface temperatures in the western Indian Ocean and warmer temperatures in the eastern part. This leads to increased rainfall over Indonesia and Australia and reduced precipitation over East Africa and parts of India.
  • Neutral IOD: Occurs when there is little to no difference in sea surface temperatures between the western and eastern Indian Ocean, resulting in typical weather patterns without significant anomalies.

Know more about Cyclones!

- pehlivanlokantalari.com
📚 Exclusive Free UPSC Notes Created by Our Experts
Subjects PDF Link
Download Free Ancient History Notes PDF Created by UPSC Experts Download Link
Grab the Free Economy Notes PDF used by UPSC Aspirants Download Link
Get your hands on the most trusted Free UPSC Environmental Notes PDF Download Link
Exclusive Free Indian Geography PDF crafted by top mentors Download Link
UPSC Toppers’ trusted notes, Now FREE for you. Download the Polity Notes PDF today! Download Link
Thousands of UPSC aspirants are already using our FREE UPSC notes. Get World Geography Notes PDF Here Download Link
FREEMentorship Program by
Ravi Kapoor, Ex-IRS
UPSC Exam-Hacker, Author, Super Mentor, MA
100+ Success Stories
Key Highlights
Achieve your Goal with our mentorship program, offering regular guidance and effective exam strategies.
Cultivate a focused mindset for exam success through our mentorship program.
2 Lakh+ Students Mentored Get
Get Free Mentorship Now
UPSC Beginners Program

Get UPSC Beginners Program SuperCoaching @ just

₹50000

Claim for free
Want to know more about this pass ?
Explore SuperCoaching

Causes of Indian Ocean Dipole

The primary cause of the Indian Ocean Dipole involves interactions between oceanic and atmospheric systems. These changes in sea surface temperatures (SSTs) in the Indian Ocean are caused by several factors, some of which include:

  • Ocean Currents: Change in ocean currents involves differential heating of the ocean surface. A positive Indian Ocean Dipole (IOD) is created when the western Indian Ocean warms up, while cooling of western Indian ocean leads to formation of negative Indian Ocean Dipole.
  • Trade Winds: The trade winds are very significant in terms of strength and direction. When the IOD is in its positive phase, stronger trade winds blow. This ensures that warm water gets pushed westward, thus causing high SSTs in the western Indian Ocean.
  • Walker Circulation: Large-scale atmospheric circulation is quite relevant for shifting weather in the Indian Ocean. The modifications in Walker circulation have been related to many instances involving changes in temperature differences across the ocean. However, at times, these modifications also reinforced the phases of IOD.
  • Interaction with ENSO: The Indian Ocean Dipole can also interact with ENSO. IOD is in a phase of positive tendency, during years of El Niño, enhancing the climate variability effect.

Characteristics of Indian Ocean Dipole

The Indian Ocean Dipole (IOD) has several distinct characteristics, which are crucial for understanding its influence on climate:

  • Ocean Temperature Differences: The Indian Ocean Dipole occurs due to differences in sea surface temperatures in the Indian Ocean. Warm water in the west and cool water in the east characterize the positive IOD phase. Conversely, a negative IOD shows warm water in the eastern Indian Ocean and cooler conditions in the west.
  • Wind Patterns: The IOD significantly alters wind circulation patterns over the Indian Ocean region. In a positive IOD phase, strong easterly winds blow from east to west. These winds push warm water towards Africa and cooler water rises near Indonesia.
  • Impact on Rainfall: A positive Indian Ocean Dipole typically brings increased rainfall to India, especially central and western regions, and East Africa. It simultaneously causes drought conditions in Australia and Indonesia. A negative IOD reverses this pattern, causing dryness in India and East Africa, and heavy rainfall in Australia and Indonesia.
  • Interaction with Monsoon: The IOD strongly influences the Indian monsoon. Positive phases generally lead to better monsoon rains, beneficial for Indian agriculture. Negative phases often weaken the monsoon, resulting in drought and negatively impacting agriculture.

  • Duration and Frequency: Typically, IOD events begin around May or June, peak between August and October, and weaken by November. An average IOD event lasts around six months, though extreme events can vary. Positive IOD events historically occurred approximately every 3-7 years, but recent studies indicate an increasing frequency due to climate change.
  • Relation to ENSO: The Indian Ocean Dipole interacts significantly with the El Niño-Southern Oscillation (ENSO). A positive IOD event can counteract the negative impacts of El Niño on the Indian monsoon, potentially restoring normal rainfall conditions. Conversely, a negative IOD combined with El Niño can exacerbate drought conditions.
  • Global Climate Impacts: Though primarily regional, the Indian Ocean Dipole indirectly influences global weather patterns. Changes in rainfall distribution due to the IOD can affect agriculture, water availability, and economic stability beyond the immediate Indian Ocean region.
  • Measurement and Monitoring: The IOD is monitored using the Dipole Mode Index (DMI), calculated from sea surface temperature differences between the western and eastern Indian Ocean. Regular monitoring helps predict monsoon rainfall, agricultural planning, and disaster preparedness.

Know more about Indian Agriculture!

Effects of Indian Ocean Dipole

The Indian Ocean Dipole (IOD) significantly influences weather patterns across the Indian Ocean region. Its phases—positive, negative, and neutral—affect rainfall distribution, temperature anomalies, and climatic events in various countries. Below are detailed and factual impacts:

Impact on Indian Monsoon

  • Positive IOD: Enhances the southwest monsoon, increasing rainfall over central and western India, benefiting agriculture but sometimes causing floods.
  • Negative IOD: Weakens monsoon rains, leading to reduced rainfall, drought conditions, and negative impacts on agriculture and water availability.

Effects on East Africa

  • Positive IOD: Causes higher-than-average rainfall in East African nations like Kenya, Ethiopia, and Somalia, reducing drought conditions but increasing flood risks.
  • Negative IOD: Results in drier conditions, leading to severe drought, impacting food security, agriculture, and water resources in East Africa.

Influence on Australia

  • Positive IOD: Reduces rainfall across southern and central Australia, leading to drought conditions and increased risk of bushfires.
  • Negative IOD: Increases rainfall, beneficial for agriculture but sometimes leading to floods in parts of southern Australia.

Global Climatic Impacts

  • Positive IOD: Associated with extreme weather events globally, intensifying rainfall or causing droughts, and interacts with phenomena like El Niño to amplify climate impacts.
  • Negative IOD: May help moderate global weather extremes but can still lead to unusual weather events regionally.

Impact of Indian Ocean Dipole on Indian Monsoon

The Indian Ocean Dipole significantly influences the Indian monsoon. A positive IOD can enhance the southwest monsoon, leading to increased rainfall over central and western India. Conversely, a negative IOD may weaken the monsoon, causing drought-like conditions in various regions. The IOD's impact on the monsoon is particularly crucial for agriculture, as a substantial portion of India's farming relies on monsoon rains.

Influence of IOD Phases on Monsoon Rainfall

The Indian Ocean Dipole (IOD) significantly influences the Indian Summer Monsoon Rainfall (ISMR). During a positive IOD phase, warmer sea surface temperatures in the western Indian Ocean enhance rainfall over India. Cooler temperatures in the eastern Indian Ocean cause drier conditions in regions like Indonesia and Australia. Conversely, a negative IOD phase leads to cooler temperatures in the western ocean and warmer conditions in the east. This usually results in lower monsoon rainfall across India and increased rains in Southeast Asia and Australia.

Historical Correlation Between IOD and Monsoon Variability

Historical data from 1960 to 2020 shows a clear relationship between IOD phases and India's monsoon rainfall. Positive IOD events often bring above-average rainfall to central and western India. Negative IOD events typically result in below-average monsoon rainfall, sometimes causing drought conditions in various regions of the country.

Interaction with El Niño–Southern Oscillation (ENSO)

The IOD interacts closely with El Niño–Southern Oscillation (ENSO), another key climate phenomenon. During El Niño, monsoon rainfall usually decreases in India. However, a positive IOD can partially offset the negative impact of El Niño, resulting in near-normal or increased rainfall. Conversely, if El Niño coincides with a negative IOD, the chances of drought-like conditions significantly increase across India.

Recent Observations and Trends

In 2023, a strong positive IOD event occurred, boosting rainfall in several Indian states, including Chhattisgarh. This event coincided with an El Niño phase, demonstrating how a positive IOD can reduce the expected negative impacts of El Niño on monsoon rains. These observations highlight the importance of monitoring IOD trends to predict monsoon patterns accurately.

Implications for Agriculture and Water Resources

The impact of IOD on the monsoon directly affects India's agriculture and water resources. Positive IOD phases generally benefit crop production due to increased rainfall. Conversely, negative phases often pose risks to agriculture by reducing water availability. Effective management strategies depend on accurately forecasting IOD phases to mitigate potential adverse impacts on food security and water management.

Interaction with El Niño and La Niña

The IOD interacts with the El Niño–Southern Oscillation (ENSO), a climate pattern characterized by periodic warming (El Niño) or cooling (La Niña) of the central and eastern Pacific Ocean. A positive IOD can counteract the adverse effects of El Niño on the Indian monsoon, potentially leading to normal or above-normal rainfall. However, the combined occurrence of El Niño and a negative IOD can exacerbate drought conditions in India.

Key Takeaways for UPSC Aspirants

  • Definition: IOD refers to a disturbed oscillation of sea surface temperatures between the eastern (around Indonesia) and western (around East Africa) Indian Ocean.
  • Impact on Monsoon: The IOD modulates the intensity as well as variability of the Indian monsoon. Indian monsoons are sensitive to agriculture as well as water resources.
  • Impact on Cyclones: A positive phase of IOD can increase the occurrence and strength of tropical cyclones in the Arabian Sea while the negative IOD Phase may reduce the activity of cyclones.
  • Socio-Economic Impact: The IOD affects livelihoods, food security, and public health, making it essential to rural economies.
  • Global Climate: The IOD is an interacting climate phenomenon with El Niño and La Niña, thus influencing greater climate trends and patterns.

Conclusion

The Indian Ocean Dipole is a vital climate phenomenon influencing weather patterns across the Indian Ocean region. Its phases significantly affect the Indian monsoon, with implications for agriculture, water resources, and disaster preparedness. The IOD's interaction with ENSO adds complexity to climate variability, underscoring the importance of continuous monitoring and research. For UPSC aspirants, a thorough understanding of the IOD is indispensable for tackling questions related to physical geography and current affairs.

Testbook is one of the best e-learning platforms for those students who are preparing for different competitive exams, especially government exams. Testbook is always on the top of the list because of its best quality assured products like live tests, mocks, content pages, GK and current affairs videos and much more. So, to make your dream successful, download the Testbook App now!

More Articles for IAS Preparation

Indian Ocean Dipole UPSC FAQs

A positive IOD often enhances monsoon rains, while a negative IOD can enhance drought conditions.

During a positive IOD, the cyclones in the Arabian Sea intensify while a negative IOD can also delay the onset of cyclones.

Positive IOD phases often indicate enhanced crop production due to increased rainfall. Negative phases may cause droughts or crop failures, thus posing a threat to food security.

The IOD is a climatic event characterized by regular fluctuations in sea surface temperatures between the west and east Indian Ocean, which typically influences the weather across that area.

Positive IOD: Sea surface temperature in the west Indian Ocean is warmer, while it's cooler in the east Indian Ocean. During this period, there is increased rainfall in India. Negative IOD: Colder temperatures in the western Indian Ocean and warmer temperatures in the eastern Indian Ocean, often leading to weaker monsoon conditions.
Report An Error
Exams Tests Super Practice