Data

ESA CCI SM v08.1

The latest version v08.1 includes data to December 31^st, 2022. The algorithm has been updated as follows:

The uncertainty estimates obtained through Triple Collocation Analysis and the consequent merging weights are now generated on a seasonal basis. The product uncertainty is now more representative of seasonal errors in soil moisture retrieval.
The barren ground flagging strategy has been changed to a majority decision, where at least 50% + 1 of the observing sensors are needed to raise the flag. The flag is kept optional, i.e., the soil moisture data is not masked.
Temporal break correction, which was provided as a separate experimental product in previous versions, is now included in COMBINED.
The temporal extent of the products is brought up to the end of 2022.

Further information can be found in the documentation. Licensing conditions follow the principles of openness and transparency wherever applicable. All ECV data products resulting from the project are freely accessible.

Downloading the Data

The ftp site is only accessible via SFTP (secure file transfer protocol). You will need to use ftp software that can handle this protocol, e.g. Filezilla. You will need to set the communication port to 22. If you cannot access it please recheck the login credentials, and port settings, and re-try. If you cannot access to the ftp site after number of attempts over a couple of days, please contact us via the e-mail addresses provided in e-mail you received with the login credentials.

If you download the data in the zipped format, this can be extracted using software such as 7-zip or via the command line.

Using the Data

For information on how to use the product, please read the Product User Guide (PUG). This is also available in the docs folder of the FTP site (from which the data can be downloaded).

A package is available in python for reading the data as daily images and converting these images to time series and reading them.

The source code for our python package and installation instructions are available here: https://github.com/TUW-GEO/esa_cci_sm
The package can be installed via pip using "pip install esa_cci_sm"
The documentation for this package is available here: https://esa-cci-sm.readthedocs.io/en/latest/

Any software that can handle CF conform data should be able to import the raw .nc files (e.g. CDO, NCO, QGIS, ArCGIS, Matlab, R, ...). You can also use the GUI software Panoply to view each file.

Citing the data

The following citations are compulsory with the use of the dataset:

Gruber, A., Scanlon, T., van der Scalie, R., Wagner, W., Dorigo, W. (2019), Evolution of the ESA CCI Soil Moisture climate data records and their underlying merging methodology, Earth System Science Data, 11, 717-739, https://doi.org/10.5194/essd-11-717-2019.
Dorigo, W.A., Wagner, W., Albergel, C., Albrecht, F., Balsamo, G., Brocca, L., Chung, D., Ertl, M., Forkel, M., Gruber, A., Haas, E., Hamer, P. D., Hirschi, M., Ikonen, J., de Jeu, R., Kidd, R., Lahoz, W., Liu, Y. Y.,Miralles, D., Mistelbauer, T., Nicolai-Shaw, N., Parinussa, R., Pratola, C., Reimer, C., van der Schalie, R., Seneviratne, S. I. Smolander, T., Lecomte, P. (2017). ESA CCI Soil Moisture for improved Earth system understanding: State-of-the art and future directions, Remote Sensing of Environment. https://doi.org/10.1016/j.rse.2017.07.001.
(compulsory with the use of the COMBINED product) Preimesberger, W., Scanlon, T., Su, C. -H., Gruber, A. and Dorigo, W. (2021). Homogenization of Structural Breaks in the Global ESA CCI Soil Moisture Multisatellite Climate Data Record, in IEEE Transactions on Geoscience and Remote Sensing, vol. 59, no. 4, pp. 2845-2862, April 2021, doi: 10.1109/TGRS.2020.3012896.

Further information

If you are interested in previous product versions, please visit the CEDA Archive or send us a request at:

CCI_SM_CONTACT@EODC.EU