In situ | EN.4.2.2 (Argo, WOD, GTSPP, and ASBO) | profile & gridded | https://www.metoffice.gov.uk/hadobs/en4/download-en4-2-2.html | 1°x 1° | monthly | 1900/1/1-present |
Satellite | SMAP RSS V5.0 | L2 | https://podaac.jpl.nasa.gov/dataset/SMAP_RSS_L2_SSS_V5 | ~70km | 98-minute orbit | 2015/4/1-present |
| SMAP RSS V5.0 | L3 | https://podaac.jpl.nasa.gov/dataset/SMAP_RSS_L3_SSS_SMI_MONTHLY_V5 | 0.25°x0.25° | Monthly | 2015/4/1-present |
| SMOS v700 | L2 | https://earth.esa.int/eogateway/catalog/smos-science-products | 30-80 km | 50-minute half orbit | 2010/6/1-present |
| SMOS CATDS-CPDC (RE07 & OPER) | L3 | https://www.catds.fr/Products/Available-products-from-CPDC | 50km x 50km | monthly | 2010/1/1-present |
Model | HYCOM | Included in SMAP L2 product | https://podaac.jpl.nasa.gov/dataset/SMAP_RSS_L2_SSS_V5 | Same as SMAP L2 | Same as SMAP L2 | 2015/4/1-present |