How does El Niño affect global weather and records?

Numbers match the citations in the article. A working link isn't proof that a page supports a claim; check the quoted passage and date.

1. 1

   Stronger ENSO-induced global SST variability in a warming climate.

   Nature communications (Hong et al.)Published Mar 19, 2026Checked Oct 13, 2026

   “The El Niño-Southern Oscillation (ENSO) is a leading mode of interannual climate variability with far-reaching global impacts. Understanding how ENSO-driven changes evolve in a warming climate is essential to project future climate variability. Here, we show that climate models robustly project an amplification of ENSO's influence on global sea surface temperature (SST) under greenhouse warming. This amplification is primarily driven by two factors: changes in El Niño-induced surface wind speed and alterations in the climatological air-sea humidity difference. The former is linked to enhanced atmospheric teleconnections associated with ENSO, while the latter stems from an overall increase in global SST. Our findings suggest that future El Niño events may exert stronger regional climate impacts, not only through intensified atmospheric teleconnections but also by reinforcing local air-sea interactions.”

2. 2

   The Teleconnection of El Niño Southern Oscillation to the Stratosphere

   Reviews of Geophysics (Domeisen et al.)Published Nov 30, 2018Checked Oct 13, 2026

   “El Niño events are associated with a warming and weakening of the polar vortex in the polar stratosphere of both hemispheres, while a cooling can be observed in the tropical lower stratosphere. These impacts are linked by a strengthened Brewer‐Dobson circulation. Anomalous upward wave propagation is observed in the extratropics of both hemispheres. For La Niña, these anomalies are often opposite. The stratosphere in turn affects surface weather and climate over large areas of the globe. Since these surface impacts are long‐lived, the changes in the stratosphere can lead to improved surface predictions on time scales of weeks to months. Over the past decade, our understanding of the mechanisms through which ENSO can drive impacts remote from the tropical Pacific has improved. This study reviews the possible mechanisms connecting ENSO to the stratosphere in the tropics and the extratropics of both hemispheres while also considering open questions, including nonlinearities in the teleconnections, the role of ENSO diversity, and the impacts of climate change and variability.”

3. 3

   Indices of El Niño Evolution

   Journal of Climate (Trenberth & Stepaniak)Published Apr 1, 2001Checked Oct 13, 2026

   “To characterize the nature of El Niño–Southern Oscillation (ENSO), sea surface temperature (SST) anomalies in different regions of the Pacific have been used. An optimal characterization of both the distinct character and the evolution of each El Niño or La Niña event is suggested that requires at least two indices: (i) SST anomalies in the Niño-3.4 region (referred to as N3.4), and (ii) a new index termed here the Trans-Niño Index (TNI), which is given by the difference in normalized anomalies of SST between Niño-1+2 and Niño-4 regions. The first index can be thought of as the mean SST throughout the equatorial Pacific east of the date line and the second index is the gradient in SST across the same region. Consequently, they are approximately orthogonal. TNI leads N3.4 by 3 to 12 months prior to the climate shift in 1976/77 and also follows N3.4 but with opposite sign 3 to 12 months later. However, after 1976/77, the sign of the TNI leads and lags are reversed.”

4. 4

   Greenhouse warming exacerbates El Niño-induced Indian monsoon droughts.

   Nature communications (Zhao et al.)Published Jul 30, 2026Checked Oct 13, 2026

   “However, confidence in the projection of this enhancement remains relatively low. We attribute the model spread in ENSO-monsoon links to variations in ENSO-induced Walker circulation anomalies, primarily through zonal wind feedback processes. Through the use of multiple observations to constrain such atmospheric dynamic processes, we find that the observation-constrained sensitivity of monsoons to the ENSO by the end of this century will become almost 40% greater than that from 1963-2023. Such intensification occurs because, even if the degree of El Niño-induced sea surface warming remains unchanged, the response of tropical precipitation to sea surface warming will increase, causing further eastward displacement of Walker circulation anomalies and an increased subsidence over the Indian subcontinent, which will reduce monsoon precipitation further. Our findings suggest intensified hydrological extremes and increased risks for food security in India in a warmer future.”

5. 5

   Future Changes to El Niño–Southern Oscillation Temperature and Precipitation Teleconnections

   Geophysical Research Letters (Perry et al.)Published Oct 9, 2017Checked Oct 13, 2026

   “Potential changes to the El Niño–Southern Oscillation (ENSO) resulting from climate change may have far reaching impacts through atmospheric teleconnections. Here ENSO temperature and precipitation teleconnections between the historical and high‐emission future simulations are compared in 40 models from phase 5 of the Coupled Model Intercomparison Project. Focusing on the global land area only, we show that there are robust increases in the spatial extent of ENSO teleconnections during austral summer in 2040–2089 of ~19% for temperature and ~12% for precipitation in the multimodel mean (MMM), relative to the 1950–1999 period. The MMM further shows that the expansion of ENSO teleconnection extent is at least partly related to a strengthening of ENSO teleconnections over continental regions; however, a consistent strengthening is not found across the individual models. This suggests that while more land may be affected by ENSO, the existing teleconnections may not be simply strengthened.”

6. 6

   Relationships between precipitation and surface temperature

   Geophysical Research Letters (Trenberth & Shea)Published Jul 18, 2005Checked Oct 13, 2026

   “Results are combined for the 5 months for northern winter (November to March) and summer (May to September). Over land, negative correlations dominate, as dry conditions favor more sunshine and less evaporative cooling, while wet summers are cool. At high latitudes in winter, positive correlations dominate as warm moist advection in extratropical cyclones favors precipitation and the water holding capacity of the atmosphere limits precipitation amounts in cold conditions. Where ocean conditions drive the atmosphere, higher surface air temperatures are associated with precipitation, as in El Niño, but some areas, such as the western Pacific in northern summer, feature negative correlations indicating that the atmosphere determines the surface temperatures. In the CAM driven with observed sea surface temperatures and the CCSM in fully coupled mode the latter mechanism is largely absent, and correlations are generally much stronger than observed, indicating more local control. Neither temperature nor precipitation records should be interpreted without considering the strong covariability that exists.”

7. 7

   Super El Niño sets another record as it strengthens to 'unprecedented levels'

   BBC NewsPublished Oct 13, 2026Checked Oct 13, 2026

   “El Niño has continued to strengthen, with several key measures now in record territory. Simon King explores how it compares to previous events.”