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 was recently migrated to Zarr v3. As part of this migration, the chunking scheme was changed to improve data access performance. See Chunking Specifications for further details.

To access this dataset, you will need a Zarr v3-compatible library (e.g., zarr-python >= 3.x). Python users can upgrade their environment using: pip install "zarr>3".

The previous version of the dataset is still available here.

How to download the data

The default (and preferred) way to access the data requires accessing the api.earthdatahub.destine.eu domain and a valid API key.

Method 1: quick access

It is possible to include the token directly in the URL.

1import xarray as xr
2
3xr.open_dataset(
4    "https://edh:<your personal access token>@api.earthdatahub.destine.eu/era5/era5-single-levels-ocean-waves-v0.zarr",
5    chunks={},
6    engine="zarr",
7)

Method 2: advanced access

The Python snippet gather the token from a netrc file.

It's required to before running the code snippet below.
1import xarray as xr
2
3xr.open_dataset(
4    "https://api.earthdatahub.destine.eu/era5/era5-single-levels-ocean-waves-v0.zarr",
5    storage_options={"client_kwargs":{"trust_env":True}},
6    chunks={},
7    engine="zarr",
8)

Variables

Short NameUnitsDescription
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

DestinE platform