Four Level 4a products were generated by the Centre d'Expertise Ifremer du CATDS-Ocean Salinity (CECI-OS)
L4aSSS products correspond to re-sampled and temporally accumulated Sea surface Salinity data from SMOS merged with in situ and other EO data. At the CECI-OS, the first L4 products, so-called "L4a" are computed likewise the L3 products except that the large-scale biais corrections are not applied using as a reference the World Ocean Atlas 2001 SSS monthly climatology but using Optimally Interpolated monthly in situ data produced by the french Coriolis DAC center (the so-called ISAS products). These so-called "CECI-OS Ifremer SMOS Level 4a SSS research products" are weekly composite products at a spatial resolution of 0.50° x 0.50° covering the period 1st of May 2010 to 31 december 2014; The auxilliary data provided together with SMOS salinity L4 products include estimates of: -ECMWF wind speed module -ECMWF sst -Cummulated Evaporation from OAFlux -Cummulated Precipitaions from TRMM3B42 -Cummulated Precipitation from CMORPH -Mixed layer depth from APDRC -Wind stress components from ASCAT -Salinity at the base of the Mixed Layer -OSCAR currents components -ISAS temporally interpolated monthly SSS fields These fields are averaged or cummulated in time or interpolated over the week of the SMOS L4 and gridded at the same 1/2° spatial resolution.
Quality controlled surface salinity and temperature measurements from Argo floats, ship TSG, surface drifters, Tropical Moorings and sea seals data provided by the Coriolis, GOSUD, SAMOS and LOCEAN data centers are collected weekly over each of the L4 composite product period and co-locatized with SMOS L4 SSS products. Supplementary data are provided with the in situ match-up database such as vertical profiles of S and T if available, co-localized ASCAT and TRMM3B42 data. A match-up database file per in situ sensor type is provided.
L4b density products are satellite surface density fields. These surface density fields are so-called "CATDS/CECOS Ifremer SMOS Level 4c research products" and are weekly composite products of surface density at a spatial resolution of 0.50° x 0.50° deduced from the L4aSSS data and GHRSST SST data. In addition, the products include: -mean sea level anomalies from AVISO -OSCAR currents components -Wind stress components from ASCAT
L4c products are Anomaly fields. These surface salinity anomaly fields are so-called "CECI-OS Ifremer SMOS Level 4c SSSA research products" and are weekly composite products at a spatial resolution of 0.50° x 0.50° deduced from the L4aSSS data. The anomalies are evaluated by removing a static reference weekly composite field evaluated by averaging the SMOS L4aSSS data over 5 years (2010 to 2014). weekly anomalies for various thematic fields are also included such as: -ECMWF sst anomalies -Cummulated Evaporation anomalies from OAFlux -Cummulated Precipitaions anomalies from TRMM3B42 -Cummulated Precipitation anomalies from CMORPH -Mixed layer depth anomalies from APDRC -Wind stress components anomalies from ASCAT -Anomalies of the Salinity at the base of the Mixed Layer -OSCAR currents components anoamlies -ISAS temporally interpolated monthly SSS & SST fields anomalies -surface density anaomalies -MSLA |