4 types of new level 4 "research" products were developed by the CATDS/IFREMER expertise center for salinity (CATDS/CEC-OS SMOS Level 4) and are now accessible for download.
These new Level 4 research products are weekly (7 days) composite at 50 km resolution. The products coverage is May 2010-December 2014.
Level 4a include weekly SMOS SSS biased-corrected at large scale (10°x10°) using monthly in situ OI (ISAS) fields.In addition, these L4a products also include an ensemble of geophysical parameters derived from well-acknowledged products in the scientific communities that are useful for synergistic science applications using SMOS data. These include Sea Surface Temperature (ECMWF), surface currents (OSCAR), rain (TRMM & CMORPH), evaporation (OAFLUX), surface wind stresses (ASCAT), mixed-layer depth from In situ OI(APDRC), Surface salinity from in situ OI (ISAS) and salinity at the base of the mixed-layer depth estimated also from In Situ OI.
Level 4 a synergistic products:
These products include key geophysical variables to analyse the salinity budget in the upper ocean mixed layer. These include:
- SSS from SMOS & in situ OI (ISAS),
- SST from ECMWF,
- wind speed modulus (ECMWF)
- wind stress components (ASCAT),
- ocean surface current components (OSCAR),
- Evaporation (OAFLUX),
- Precipitation (TRMM3B42 & CMORPH),
- Mixed Layer Depth (In situ OI),
- Salinity at the base of the mixed-layer
These fields are averaged or cummulated in time -or interpolated- over the week of the SMOS L4a SSS and gridded at the same 1/2° spatial resolution.
In addition we include the following thematic datasets:
L4aSSS In situ Match-up products
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 L4a 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, etc..
A match-up database file per in situ sensor type is provided for each week of the L4a products.
L4b density products
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 ECMWF SST data. In addition, the products include:
- mean sea level anomalies from AVISO
- OSCAR currents components
- Wind stress components from ASCAT
L4c anomaly products
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 an annual-averaged 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