The base products, for this processing chains, are the SMOS L2 OS products - https://doi.org/10.57780/SM1-294cb1b - from ESA (European Space Agency).

The L3OS 3G Arctic product contains daily salinity fields over Arctic from a 9 days temporal gaussian average, corrected from land-sea contamination, similar to L2Q products, mixing ascending and descending orbits.

Products from reprocessing RE08 are available for the period 02/2010 - 05/2024. Products from operational (OPER) processing are available since 06/2024. Reprocessed products and operational products are derived using the same algorithm and configuration, hence ensuring the temporal continuity.

File naming :

SM_clas_MIR_CSNG09_startdate_enddate_vvv_ccc_7

- clas : File class (OPER : operational mode, REXX : reprocessing xx)

- startdate : sensing start date/time of the data (format yyyymmddThhmiss)

- enddate : sensing end date/time of the data (format yyyymmddThhmiss)

- vvv : version number of the processor generating the product

- ccc : file counter

File format :

In each archive file (.tgz extension), there are two files

- A Header file (.HDR), which is a text file, in XML Earth Explorer Header format

- A Data file (.DBL.nc), which is a netcdf file, format variant 2 (netcdf 3 with 64 bits offset option)

Reference :

A. Supply et al., “New insights into SMOS sea surface salinity retrievals in the Arctic Ocean”, Remote Sensing of Environment, vol. 249, p. 112027, Nov. 2020, doi: 10.1016/j.rse.2020.112027