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Mercator Guide

How to download Mercator Ocean current data directly from Copernicus Marine, without using the built-in Downloader.

This is currently the only way to get Mercator data into STFM. Unlike HYCOM, GFS, and ERA5, the Downloader doesn't fetch Mercator currents, and the Converter doesn't yet have a dedicated card for them that support is being worked on. If HYCOM currents are enough for your project, the Downloader Guide is a faster path.

Overview

Mercator Ocean's global current model is distributed through the Copernicus Marine Service, product GLOBAL_ANALYSISFORECAST_PHY_001_024 a 1/12° resolution ocean physics analysis and forecast, including eastward and northward current velocity.

Creating an account

  1. Go to data.marine.copernicus.eu and click Register. Fill in name, email, country, and organisation type.
  2. Confirm your email and log in.

This account is separate from the one used for ERA5. Copernicus Marine and the Climate Data Store (CDS) both carry the "Copernicus" name but run independent account systems an account on one doesn't work on the other. If you're setting up both, expect to register twice.

Step by step

1. Find the product

Search for Global Ocean Physics Analysis and Forecast (product ID GLOBAL_ANALYSISFORECAST_PHY_001_024). Confirmed specs from the product page: 1/12° resolution (0.083° × 0.083°), 50 depth levels from 0 to 5500 m, and Hourly / Daily / Monthly time frequency options.

Copernicus Marine product page for Global Ocean Physics Analysis and Forecast, showing the Description tab and left sidebar with Data access link
The product page. Data access, in the left sidebar, is where the actual download form lives.

2. Select your variables

The product's full variable list (visible under the Classification section) confirms the exact names to look for:

  • Eastward sea water velocity
  • Northward sea water velocity

Also select the depth levels (surface only for 2D simulations, the full range for 3D) and a time frequency matching your simulation's timestep.

Copernicus Marine product Classification table showing spatial extent, resolution, temporal resolution, depth levels, and the full variable list
The Classification table confirms variable names, resolution, and depth levels directly from the source.

3. Open Data access and pick the right dataset row

Direct link: data.marine.copernicus.eu/.../services opens the Data access page directly (log in first). Instead of one generic form, this opens a table listing every variant of the product different variables and time frequencies, each as its own row with its own Form / Browse / WMTS links.

Copernicus Marine Data access and mapping services page, explaining Subset, Files, Maps, and Toolbox access methods, with the start of the dataset table
Data access and mapping services four methods explained, with the dataset table starting below.

For a single STFM project, use the Subset column's Form link described on the page as "the most intuitive graphical approach for subsetting data in time, space and/or variables."

Two valid dataset choices, pick based on your setup:

  • Currents, 6-hourly / daily / monthly (cmems_mod_glo_phy-cur_anfc_0.083deg_*) the standard multi-depth ocean current output. Use this if you're also loading wave data into STFM's Waves panel separately, so wave-driven drift isn't calculated twice.
  • Surface currents, hourly (cmems_mod_glo_phy_anfc_merged-uv_PT1H-i) the "SMOC" (Surface merged Ocean Current) product, which already blends in wave and tidal drift. Use this if you're not loading a separate wave source, so drift is still accounted for.

The form below is identical either way only the Dataset dropdown and file size change.

Dataset table listing Currents 6-hourly, daily, monthly, Salinity, Sea level, Surface currents hourly (merged-uv), Temperature, and Vertical currents, each with Form, Browse, and WMTS links
The dataset table "Surface currents, hourly" (merged-uv) is the SMOC product; the plain "Currents" rows are the standard model output.

4. Fill in the subset form

Clicking Form opens the request page, showing the file size estimate (~70.56 MB for the default selection) and a Dataset dropdown confirming which row you picked you can switch it here without going back.

  • Variables: Eastward sea water velocity (uo, m/s) and Northward sea water velocity (vo, m/s) are checked by default leave both checked.
  • Area of interest: use Draw on map, or type exact bounds into the N / W / E / S fields, matching your STFM grid area.
Mercator subset form showing the Dataset dropdown set to Currents 6-hourly, the Variables checkboxes for eastward and northward sea water velocity, and the Area of interest world map
Dataset, Variables, and the start of Area of interest both current components are checked by default.
  • Date range: defaults to just today's date for both From and To change these to cover your actual simulation period (the page shows the full available range above the fields as a reference, e.g. 01/06/2022 to the present).
  • Depth range: defaults to the shallowest available layer (around 0.49 m) for both From and To for 2D simulations this default is already correct (surface only); for 3D, widen it toward the deeper end of the available range shown above the fields.
Mercator subset form showing the Date range fields defaulting to today's date, and the Depth range fields defaulting to 0.49 meters
Date range and Depth range both default to a single point, not the full available span. Widen them to match your simulation.

Once everything is set, click Download (or Automate for a scriptable request, useful for repeating the same area across several days).

5. Download and save

Once your request is submitted, save the resulting file into your project's RAW_DATA/ folder.

Next steps

Mercator currents don't have a dedicated Converter card yet see the note in the Converter Guide for the current status.

More Guides

Continue with ERA5 winds

Currents alone aren't enough STFM always requires wind data too.

ERA5 Guide Back to Tutorials