This SFTP site contains the ESA CCI Surface Soil Moisture Product.
There are various files available in four main directories:

1) doc

**Note**: the documentation for ESA CCI SM v08.1 will be added soon. In the meanwhile, please find the most recent documentation on the website page: www.esa-soilmoisture-cci.org

Contains:

* Changelog.txt document with the versions history of ESA CCI SM

and the following published papers, citation of which is compulsory with the use of the ESA CCI Soil Moisture product:

* Gruber, A. et al.: (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. et al.: (2017). ESA CCI Soil Moisture for improved Earth system understanding: State-of-the art and future directions. Remote Sensing of Environment, 2017, ISSN 0034-4257.  https://doi.org/10.1016/j.rse.2017.07.001

and if using the COMBINED product:

* W. Preimesberger, T. Scanlon, C. -H. Su, A. Gruber and W. Dorigo, "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.

2) daily_files
Contains the ACTIVE, PASSIVE and COMBINED products. Within each product folder there are yearly directories with daily global merged surface soil moisture data files.
The daily global images are available as NetCDF-4-classic file format covering the period (yyyy-mm-dd) 1978-11-01 to 2022-12-31 for the PASSIVE and the COMBINED product. The temporal coverage for the ACTIVE product is 1991-08-05 to 2022-12-31.
Product version = v08.1; file version = fv08.1

Product volume size for ESA CCI SM v08.1:

* ACTIVE Product:   1991-08-05 to 2022-12-31 = 11472 days = 11472 files = 8.4 GB
* PASSIVE Product:  1978-11-01 to 2022-12-31 = 16132 days = 16132 files = 19.6 GB
* COMBINED Product: 1978-11-01 to 2022-12-31 = 16132 days = 16132 files = 21.5 GB

3) alldata_zip_compressed
Contains 3 zip compressed archives providing the complete NetCDF daily files for all 3 products:

* ESACCI-SOILMOISTURE-L3S-SSMS-ACTIVE_1991-2022-v08.1.zip   = 7.2 GB
* ESACCI-SOILMOISTURE-L3S-SSMV-PASSIVE_1978-2022-v08.1.zip  = 16.7 GB
* ESACCI-SOILMOISTURE-L3S-SSMV-COMBINED_1978-2022-v08.1.zip = 18.9 GB

Please consider the archive size and your local reception rate if you are downloading these files.

4) ancillary
Contains ancillary files provided along with the ESA CCI ECV SM v08.1 product: 

* Global land and rainforest mask used in the ESA CCI v08.1 products
* Global porosity map derived by applying soil water characteristic equations of 
  Saxton and Rawls (2006) to texture data of the Harmonized World Soil Database v1
* Global AMSR-E LPRM v6 Vegetation Optical Depth averaged over the period 2002-2011
* Global topographic complexity
* Global Wetland fraction

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For more information on these products please contact cci_sm_contact@eodc.eu
These data were produced as part of the ESA CCI+ Soil Moisture project,
contract No. ESRIN 4000126684/19/I-NB.

-- 
Vienna, 24 May 2023.

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Vienna University of Technology
Department of Geodesy and Geoinformation
Research Group Climate and Environmental Remote Sensing
Wiedner-Hauptstraße 8-10/E120
1040 Vienna
Austria
Phone: +43 1 58801-12001
E-Mail: cci_sm_contact@eodc.eu
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