Pulse of the Pacific

The 8 °C tilt that moves the world.

The tropical Pacific normally runs about 8 °C warmer off Asia than off South America3, held that way by the easterly and a tilted . When that tilt slips, the whole planet feels it.

Neutral−0.5 < ONI < +0.5 °C

Baseline Pacific: steady easterly trade winds, a warm pool in the west, a cold tongue in the east, and a thermocline tilted up toward South America.

Toggle the phase pill, top-right — every visualization on the site responds.

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Act I

Anatomy of a Phenomenon

ENSO is a ocean–atmosphere system: the ocean moves the air, and the air moves the ocean right back2. Three machines drive it — an atmospheric conveyor belt, a runaway feedback, and a pair of slow ocean waves. Here is each one, in order.

1 · The Walker Engine

Under normal conditions, easterly drag warm surface water west, piling the against Indonesia — about 8 °C warmer than the cold, upwelled water off South America3. The warm west fuels towering ; the air sinks again over the cool east — the closed loop Sir Gilbert first mapped. Pick a phase and watch it reorganize.

2 · The Bjerknes Feedback

Tip that balance and it runs away. Warmer eastern water weakens the trades, which weakens , which warms the water further — Jacob 1969 insight into why a small nudge becomes a full event4. Run the loop, then brake it.

3 · Kelvin & Rossby Waves

So what ends it? The ocean carries its own messengers. Fast run east in weeks; slow drift west and reflect back off the far coast39 — the delayed timing that first builds an El Niño and then dismantles it.

Act II

Measuring the Beast

A planet-spanning oscillation is hard to watch all at once. The trick is to shrink it — to a few boxes of ocean and a handful of numbers that, between them, tell you which phase you are in.

1 · Where we watch — the Niño regions

Four boxes straddle the equatorial Pacific. The middle one, Niño 3.4, matters most: the averaged there is the basis of the official index4. Click a box to fly to it.

2 · The record — 76 years of the ONI

Average Niño 3.4, smooth it over three months, and you get the . Cross +0.5 °C for five seasons and it is an El Niño; −0.5 a La Niña4. Here is every month since 1950 — drag the playhead and the whole site shifts to the phase you land on.

3 · The rulers, compared

The ONI is the official ruler, but not the only one. The reads the atmosphere's pressure seesaw between Tahiti and Darwin; the blends six variables at once. They mostly agree — and when they don't, that itself is a story4.

Act III

A History of Events

ENSO is not a hypothesis — it is a track record. Here are the events the modern world has actually lived through, and what they cost.

Every major event since 1972

Each bar is scaled by its peak intensity. Tap one for the toll it took.

Set two side by side

The 1997-98 giant against the 2015-16 record — same class, different fingerprints.

Act IV

The World Feels It

A shift in one patch of the Pacific does not stay there. ENSO is the planet's most powerful — it reroutes jet streams and rainfall belts, so a warm tongue off Peru can dry out Australia, flood East Africa, and quiet the Atlantic hurricane season at once8.

The world, region by region

Flip the phase and watch each region's story turn over.

Or take the whole planet at once

Pick a layer — rainfall, temperature, or storms — choose a phase, and click any country to fly there and read its story. Every claim is cited to the research.

Act V

India — A Deeper Look

For most of India, the year turns on four months of rain. The southwest monsoon delivers 70–80% of the country's annual rainfall61 — so when El Niño weakens it, the question is not abstract. It decides whether the harvest comes in. This is the part of the story closest to home.

1 · How the rains arrive — and how El Niño thins them

Drag the ENSO slider and watch the moisture flux off the two seas thin out as the Pacific's rising air slides east, leaving sinking, drying air over the subcontinent. The counter is the season's rainfall as a share of the .

2 · It has happened before — and 2026 looks uneasy

Every El Niño year since 1965, and what it did to the monsoon. 1997 is the year India slipped the noose — a strongly positive Indian Ocean Dipole held the rains. The ledger ends on 2026.

3 · What it means where you live

A weak monsoon does not fall evenly. Tap your home state to see how exposed its harvest is — its main crops, how much it leans on rain versus irrigation, and whether it is flagged for the August–September 2026 shortfall54.

Act VI

A Warming World

A warming world does not simply add heat to ENSO — it loads the dice. The signal is contested in places and robust in others; here is the honest version, not the scary one.

What is settled, and what isn't

Switch the emissions path and see which signals the models agree on — and which they still don't.

Where the damage lands

The same anomaly, magnified: fisheries, reefs, fire, and disease.

Act VII

Predicting the Unpredictable

So why can't anyone just tell you what 2026 will do? Because every spring the ocean briefly hides its hand — and that is exactly the season the forecast must cross now.

The spring predictability barrier

Pick the month a forecast is made and watch its skill collapse when the lead crosses March–May. A forecast made now is far harder than one made in October.

Where the Pacific stands today

The live status board, as of late May 2026 — neutral now, but on watch.