×

UPSC Courses

DNA banner

DAILY NEWS ANALYSIS

  • 13 August, 2022

  • 6 Min Read

Indian Ocean Dipole (IOD)

Indian Ocean Dipole (IOD)

The likelihood of above-average rainfall over much of Australia has increased due to a negative Indian Ocean dipole event that has been proclaimed.

What is the Indian Ocean Dipole (IOD)?

  • It is an atmosphere-ocean coupled phenomenon in the tropical Indian Ocean (like the El Nino is in the tropical Pacific), characterized by a difference in sea-surface temperatures.
  • A ‘positive IOD’ — or simply ‘IOD’ — is associated with cooler than normal sea-surface temperatures in the eastern equatorial Indian Ocean and warmer than normal sea-surface temperatures in the western tropical Indian Ocean.
  • The opposite phenomenon is called a ‘negative IOD’, and is characterised by warmer than normal SSTs in the eastern equatorial Indian Ocean and cooler than normal SSTs in the western tropical Indian Ocean

More About Indian Ocean Dipole (IOD)

  • The difference in sea surface temperature between two regions (or poles, hence a dipole) — a western pole in the Arabian Sea (western Indian Ocean) and an eastern pole in the eastern Indian Ocean south of Indonesia — defines it.
  • According to science, the IOD is an ENSO-like coupled ocean-atmosphere event that occurs in the equatorial Indian Ocean.
  • It is believed that the IOD and ENSO occurrences are connected by the Walker Circulation's westward expansion and its related Indonesian throughflow (the flow of warm tropical ocean water from the Pacific into the Indian Ocean).
  • The IOD significantly contributes to the variability of rainfall in this area and has an impact on the climate of Australia and other nations that border the Indian Ocean Basin.

The positive event linked to it

  • Less cloud cover to Australia's northwest, warmer sea surface temperatures in the western Indian Ocean compared to the east, easterly wind anomalies across the Indian Ocean, and less rainfall over southern Australia and the Top End

Negative event:

  • Winds turn more westward, increasing cloud cover in Australia's northwest and increasing rainfall in the Top End and southern Australia due to cooler sea surface temperatures in the western Indian Ocean compared to the east.

Source: The Indian Express


Oceanic Anoxic Event 1a and MASS EXTINCTION

Oceanic Anoxic Event 1a from the Paris Basin (Environment) Paper-3 PMP OAE 1a refers to a period during the Cretaceous Period (145 million years ago and ended 66 million years ago) when Earth's oceans became depleted of oxygen, causing a significant disruption in marine life.  Cause: The event is believed to have been

Viksit Panchayat Karmayogi (Good governance)

Viksit Panchayat Karmayogi (Good governance) Governance GS PAPER-2 PMP Dr. Jitendra Singh launched the ‘Viksit Panchayat Karmayogi’ initiative on Good Governance Day, celebrated to mark the 100th birth anniversary of former Prime Minister Atal Bihari Vajpayee. The initiative, which is part of the broader ‘Prashasan Gaon

Major programmes to control Air Pollution

Major programmes to control Air Pollution National Clean Air Programme? It was launched by the Ministry of Environment, Forests and Climate Change (MoEFCC) in January 2019. It is the first-ever effort in the country to frame a national framework for air quality management with a time-bound reduction target. The

Air pollution and Air quality Measures in India

Air pollution and Air quality Measures in India (Environment) GS Paper-3 P-M-P Air pollution may be defined as the presence of any solid, liquid or gaseous substance including noise and radioactive radiation in the atmosphere in such concentration that may be directly and/or indirectly injurious to humans or other l

Geopolitical Significance of Ports

Geopolitical Significance of Ports (IR)  Act as geopolitical assets: Ports enhance the projection of strategic reach, which helps strengthen the country’s control over important sea and energy supply routes.  E.g. Indian Navy’s staging base at Agalega Islands will enable marine patrols

Toppers

Search By Date

Newsletter Subscription
SMS Alerts

Important Links

UPSC GS Mains Crash Course - RAW Prelims Answer Key 2024