Climate Oscillations: ENSO and the IOD
First published: 2018
Brief summary
Australian Academy explanation of ENSO and the Indian Ocean Dipole.
Article
El Niño–Southern Oscillation and the Indian Ocean Dipole are coupled ocean-atmosphere patterns that alter rainfall, temperature and circulation across the Indo-Pacific region. Both have warm and cool phases, but they develop in different ocean basins and need not occur together.
ENSO is centred in the tropical Pacific. El Niño occurs when the central and eastern equatorial Pacific becomes warmer than average and trade winds weaken, while La Niña involves cooler water and stronger trade winds.
The Indian Ocean Dipole is defined by the contrast in sea-surface temperature between the western and eastern tropical Indian Ocean. A positive phase has warmer water in the west and cooler water near Indonesia, while a negative phase has the opposite pattern.
These modes influence the location of tropical convection and the movement of moisture. Their phases can alter rainfall in Australia, Indonesia, eastern Africa and surrounding regions, and interactions between them can strengthen or offset seasonal climate effects.
Source details and credits
- Source / publisher: Australian Academy of Science
- Source type: Educational article
- URL type: WWW
- Credits: Australian Academy of Science
- URL: https://www.science.org.au/curious/earth-environment/climate-oscillations-enso-and-iod