SMOS Level-2C Datacube Service

The service provides ESA SMOS Level-2 data in form of analysis-ready Level-2C datacubes with the dimensions time, lat, and lon. The datacubes are computed on-the-fly from the SMOS data archive s3://EODATA/SMOS hosted on CREODIAS.

Spatial coverage and resolution

The SMOS data is provided globally or for a custom area of interest using a geographic projection (EPSG:4326 aka WGS84, World Geodetic System 1984). Users can choose from five spatial resolutions by specifying a resolution level ranging from zero to four. Zero refers to a resolution of 360/8192 ~ 0.044 degrees ~ 4.88 km. Higher levels subsequently increase the resolution by a factor of two.Note that the native spatial resolution of SMOS data is roughly 25 km. This service performs an oversampling of the data to ensure no information is lost during spatial projection. It therefore uses a nearest-neighbor resampling at higher resolution involving pixel duplication.

Temporal coverage and resolution

The SMOS satellite completes one orbit approximately every 100.1 minutes. Therefore, 29 (number of orbits times two) level-2 data products are stored per day. If no aggregation interval is specified, the service will append a time step for each level-2 data product to the datacube. Otherwise, data variables are aggregated by their mean, with a minimum aggregation interval of one day.Currently, the provided time range must not exceed 400 days.

Service parameters

Name Type Value range
product_type string "SMOS-L2C-SM" or "SMOS-L2C-OS"
time_range string "YYYY-MM-DD/YYYY-MM-DD"
agg_interval string "none", "1D", "2D", "4D", defaults to "1D"
bbox string Spatial AOI as Geometry WKT, defaults global coverage
res_level integer 0 to 4, defaults to 0

Service output

The output of the service is a SMOS Level-2C raster datacube comprising a number of geophysical data variables with the dimensions time, lat, and lon. The variables depend on the selected SMOS product type, either Soil Moisture or Ocean Salinity. The datacube is provided as a Zarr v2 dataset (.zarr).Soil Moisture datacubes of type SMOS-L2C-SM contain the following variables:
Variable Type Units
Soil_Moisture float32 m3 m-3
Soil_Moisture_DQX float32 m3 m-3
Chi_2 uint8 -
Chi_2_P uint8 -
N_RFI_Y uint16 -
N_RFI_X uint16 -
RFI_Prob uint8 -
Ocean Salinity datacubes of type SMOS-L2C-OC contain the following variables:
Variable Type Units
SSS_anom float32 psu
SSS_corr float32 psu
Sigma_SSS_anom float32 psu
Sigma_SSS_corr float32 psu
Dg_quality_SSS_anom uint16 -
Dg_quality_SSS_corr uint16 -
Dg_chi2_corr uint16 -
Dg_RFI_X uint16 -
Dg_RFI_Y uint16 -
Coast_distance uint8 -
Mean_acq_time float32 dd
X_swath float32 m

Supported delivery methods


The price depends on the selected time range and area of interest. The minimum price per request is 10€; a non-linearly increasing discount is provided for larger coverages:
Time range Spatial AOI Price
1 day 10° x 10° 10€
1 day 90° x 90° 10€
1 month 90° x 90° 25€
1 month global 140€
1 year 90° x 90° 150€
1 year global 1150€