What it is
Sea Levels is a single page that answers four questions about the ocean, each with the measurement system built to answer it: where is the water now (tide gauges and satellite altimetry), what is arriving over the next few weeks (the residual at a chain of Pacific gauges, where El Niño’s coastally trapped waves show up), how fast is it rising and why (the altimetry record plus the GRACE-FO / Argo budget), and what comes next (IPCC AR6 and NOAA 2022 projections).
Open the tracker → /sealevels/
How it works
- Live tide gauges: the page queries the NOAA CO-OPS Data API directly from your browser — no backend, no key. Pick a station and get its latest six-minute reading plus ten years of monthly mean sea level.
- Weeks to months: eight open-coast stations from San Diego to Sitka, observed minus predicted water level per day with the long-term trend removed, drawn as a distance-along-coast versus time grid with a 6 mph reference slope. It is the tide-gauge version of the filtered altimetry diagram Dillon Amaya posted on 2026-09-01 showing a major coastally trapped wave from the Super El Niño heading for US waters. Live Niño 3.4 comes from the Miami companion’s ice monitor, and a range chart shows how trend, El Niño, wave pulses, the 2026 king tides, and storm surge stack on one California gauge.
- The satellite era: the global mean sea level record since 1993 (TOPEX/Poseidon → Jason → Sentinel-6) as an interactive chart, with the AR6 sea level budget term by term — roughly one-third thermal expansion, two-thirds meltwater.
- Projections: AR6 likely ranges for 2100 by emissions scenario (0.28–1.01 m) and the NOAA 2022 ~25–30 cm-by-2050 US-coast figure.
- Hand-built charts: no chart library — small React islands render SVG with crosshair tooltips and table fallbacks, validated for colorblind-safe palettes.
Why it matters
Relative sea level is local. The same ocean is rising ~9 mm/yr against Grand Isle, Louisiana (the delta is subsiding) while falling ~13 mm/yr at Juneau, Alaska (the land is rebounding faster than the sea can follow). Vertical land motion often dominates what any specific shoreline experiences — which is why the page pairs the global satellite record with per-station gauge data instead of quoting one number.
To see what these global curves mean when they arrive at one real coastline, this tracker has a local companion: Downtown Miami Flood Risk — LiDAR terrain, the aquifer, the drainage system, and a 3D visualiser for the place where US sea level exposure is most concentrated.