Interannual Climate Dynamics of the Indian Ocean and ENSO

The interannual climate dynamics of the Indian Ocean and the El Niño–Southern Oscillation (ENSO) are governed by a complex interplay of oceanic and atmospheric processes that span the tropical Indo-Pacific basin. Sea-surface temperature (SST) anomalies in the Indian Ocean, notably the Indian Ocean Dipole (IOD) and basin-wide (IOB) mode, can modulate wind patterns, convection and ocean currents, thereby influencing the onset, intensity and termination of El Niño and La Niña events. Conversely, ENSO‐driven anomalies in the tropical Pacific propagate into the Indian Ocean via an atmospheric bridge, altering regional heat fluxes, precipitation and monsoon strength. Subsurface pathways, including equatorial and coastal Kelvin and Rossby waves and the Indonesian Throughflow, form an oceanic tunnel that links basin-scale thermocline variations. Interannual interactions are also modulated on decadal timescales by changes in background state, leading to variability in predictability and regional climate impacts such as extreme rainfall, drought and fisheries yield. Understanding these cross-basin teleconnections is critical for improving seasonal to multi-annual forecasts and for assessing climate change impacts on socio-economic systems in the wider Indo-Pacific region.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Interannual Climate Dynamics of the Indian Ocean and ENSO publication trend

The graph below shows the total number of articles in interannual climate dynamics of the indian ocean and enso across all publications each year (not limited to Nature Index journals).

Technical terms

El Niño–Southern Oscillation (ENSO): A quasi-periodic fluctuation in tropical Pacific SSTs and atmospheric pressure driving global climate anomalies.

Indian Ocean Dipole (IOD): A zonal SST gradient in the tropical Indian Ocean characterised by warm western and cool eastern anomalies (positive phase) or vice versa.

Indian Ocean Basin (IOB) mode: A basin-wide, uniform SST anomaly pattern that influences convection and surface winds across the Indian Ocean.

Atmospheric bridge: A teleconnection mechanism by which SST anomalies in one basin modify atmospheric circulation patterns, affecting distant ocean–atmosphere systems.

Oceanic channel dynamics (oceanic tunnel): Subsurface pathways, including Kelvin and Rossby waves and throughflow currents, that propagate anomalies between the Indian and Pacific Oceans.

Indonesian Throughflow (ITF): The ocean current transporting water from the Pacific into the Indian Ocean through the archipelagic passages of Indonesia, crucial for heat and mass exchange.

References

1. Boosting effect of strong western pole of the Indian Ocean Dipole on the decay of El Niño events. npj Climate and Atmospheric Science (2024).
2. Assessment of the oceanic channel dynamics responsible for the IOD-ENSO precursory teleconnection in CMIP5 climate models. Frontiers in Climate (2022).
3. Indian Ocean impact on ENSO evolution 2014–2016 in a set of seasonal forecasting experiments. Climate Dynamics (2021).