SHIP'S PAPERS
Where the ocean comes from, how it is drawn, and what it is not.
The data
Everything on the charts is the Copernicus Marine Service's — the European Union's operational ocean service — read the morning it is published and redrawn here. Nothing is reanalysed or blended; a current on this site is the current in the model.
| Layer | Model | Grid · step | Product |
|---|---|---|---|
| Currents, temperature, sea level, mixed layer, ocean heat content | Mercator Ocean, NEMO global, with data assimilation | 1/12° (≈ 9 km) · hourly to 10 days | GLOBAL_ANALYSISFORECAST_PHY_001_02410.48670/moi-00016 |
| Waves and swell | Météo-France MFWAM, forced by ECMWF winds | 1/12° · 3-hourly to 10 days | GLOBAL_ANALYSISFORECAST_WAV_001_02710.48670/moi-00017 |
Both models run once a day. Each run begins from an analysis of the previous day, which has taken in satellite altimetry, sea-surface temperature, Argo floats and moorings, and then forecasts ten days ahead. The timeline opens two days before the run starts and ends where the forecast does; older runs are not kept.
How it is drawn
- On one world chart. Web Mercator in the chart room, with the dateline stitched so the Pacific has no seam; Equal Earth on the front page, so the oceans are at their true size.
- On fixed scales. Every colour is pinned to a physical value — a knot is always the same teal — so a loop shows the water changing, never the palette re-fitting itself. The ramps are Kristen Thyng's cmocean, oceanography's standard set.
- Hurricane fuel, worked out here. Ocean heat content — tropical cyclone heat potential — is the one chart that is not a model field redrawn. It is integrated from Mercator's daily temperature profile: the heat in the water warmer than 26 °C, summed from the surface down to the depth where the water cools to 26 °C, in kilojoules per square centimetre (Leipper and Volgenau 1972, with the constants NOAA uses: 1025 kg/m³ and 4.0 kJ/kg·K). That depth is charted too. About 50 kJ/cm² sustains a hurricane; above 90, rapid intensification becomes much more likely.
- In knots. Currents default to knots, the unit on every chart and in every pilot book; metres per second are one click away.
- Currents as streaks. The front-page plate is a line-integral convolution: noise smeared along the flow, so the direction of the water through every pixel is visible and the eddies draw themselves.
Credit and licence
Generated using E.U. Copernicus Marine Service Information; https://doi.org/10.48670/moi-00016, https://doi.org/10.48670/moi-00017. Copernicus Marine data are free and open under the Copernicus Marine licence. Coastlines and borders from Natural Earth; the basemap is the Forecast Network's own, from OpenStreetMap data via Protomaps.
Not for navigation
This is a picture of a model. It is not a nautical chart, a notice to mariners, a search and rescue tool or a substitute for official forecasts and warnings. Where lives or vessels depend on it, use your national meteorological and hydrographic services.