ERA5 hourly data on single levels - ocean waves
This dataset is a curated subset of ocean-waves quantities derived from ECMWF’s ERA5 hourly data on single levels.
Built upon the Climate Data Store (CDS) version of ERA5, this dataset is distributed as a Zarr archive. It is designed to offer a fast, highly accessible alternative for querying ERA5-Land global reanalysis data.
📊 Chunking Specifications
To optimize data access performance for regional and time-series analyses, the dataset employs a spatio-temporal chunking scheme of 60 days × 30° latitude × 30° longitude. This corresponds to an array chunk shape of 1440 (valid_time) × 60 (latitude) × 60 (longitude).
⚠️ Changelog
This dataset moved to Zarr v3 in July 2026 and needs zarr-python 3 or newer. The previous Zarr v2 version is no longer updated: please switch using the migration guide.
How to download the data
This Python snippet includes the token directly in the URL.
1import xarray as xr 2 3xr.open_dataset( 4 # Replace <your API key> with your actual key 5 "https://edh:<your API key>@data.earthdatahub.destine.eu/era5/era5-single-levels-ocean-waves-v0.zarr", 6 chunks={}, 7 engine="zarr", 8)
Variables
| Short Name | Units | Description |
|---|---|---|
cdww | dimensionless | Coefficient of drag with waves |
dwi | degrees | 10 metre wind direction |
dwps | radians | Wave spectral directional width for swell |
dwww | radians | Wave spectral directional width for wind waves |
hmax | m | Envelop-maximum individual wave height |
mdts | degrees | Mean direction of total swell |
mdww | degrees | Mean direction of wind waves |
mp1 | s | Mean wave period based on first moment |
mp2 | s | Mean zero-crossing wave period |
mpts | s | Mean period of total swell |
mpww | s | Mean period of wind waves |
msqs | dimensionless | Mean square slope of waves |
mwd | Degree true | Mean wave direction |
mwd1 | degrees | Mean wave direction of first swell partition |
mwd2 | degrees | Mean wave direction of second swell partition |
mwd3 | degrees | Mean wave direction of third swell partition |
mwp | s | Mean wave period |
mwp1 | s | Mean wave period of first swell partition |
mwp2 | s | Mean wave period of second swell partition |
mwp3 | s | Mean wave period of third swell partition |
p1ps | s | Mean wave period based on first moment for swell |
p1ww | s | Mean wave period based on first moment for wind waves |
p2ps | s | Mean wave period based on second moment for swell |
p2ww | s | Mean wave period based on second moment for wind waves |
phiaw | Numeric | Normalized energy flux into waves |
phioc | Numeric | Normalized energy flux into ocean |
pp1d | s | Peak wave period |
rhoao | kg m-3 | Air density over the oceans |
shts | m | Significant height of total swell |
shww | m | Significant height of wind waves |
swh | m | Significant height of combined wind waves and swell |
swh1 | m | Significant wave height of first swell partition |
swh2 | m | Significant wave height of second swell partition |
swh3 | m | Significant wave height of third swell partition |
tauoc | Numeric | Normalized stress into ocean |
tmax | s | Period corresponding to maximum individual wave height |
wdw | radians | Wave spectral directional width |
wind | m s-1 | 10 metre wind speed |
wmb | m | Model bathymetry |
wsk | dimensionless | Wave spectral kurtosis |
wsp | dimensionless | Wave spectral peakedness |
wss | Numeric | Wave Spectral Skewness |
wstar | m s-1 | Free convective velocity over the oceans |