Quality indicators

The MyOcean SST analyses are compared to the following sources :

• drifting buoys : in situ drifting buoys constitute a completely independant reference to which ODYSSEA products can be compared to, since they are not used in the data merging (unlike many other analyses), despite they don't correspond exactly to the same sensing depth as the satellite data. Only nighttime measurements are selected in the comparison, to approach the foundation SST estimated by ODYSSEA, processed and averaged onto the same grid as the ODYSSEA products.
• AATSR : AATSR is arguably one of the most accurate and stable sensors and so considered as a good reference for comparison, despite it is not an independent source (AATSR is used in ODYSSEA merging process) and it does not correspond exactly to the same sensing depth (skin sea surface temperature) as the ODYSSEA products (foundation sea surface temperature) and there is a significant shift between these two depths. Only nighttime measurements are selected in the comparison processed, and averaged onto the same grid as the ODYSSEA products.
• climatology : The climatology used for comparison is derived from the NODC/Casey climatology, resampled to ODYSSEA temporal and spatial resolution
• previous day analysis : high differences with the previous day analysis are a strong indicator for input data or processing issues

These comparisons are accessible through the following links :

Other resources

• Buoy blacklists : drifting buoys are a major source of reference data for the validation of satellite products. However they are not perfect and sensor's performance tends to decrease with time; therefore some drifting buoys should be excluded from validation datasets starting from a given date or over a given time frame. The drifting buoys are monitored over ten days periods by the SST TAC team and blacklists are issued periodically. These blacklists should of course be considered with caution. They can be found here.
• Validation areas : the SST TAC team has defined common validation areas over which to derive some quality indicators for the various SST products (input data or MyOcean products). The definition file of these predefines areas can be found here.
• Climatology : a global climatology is available on ftp (login and password to be requested to CERSAT help desk at This email address is being protected from spambots. You need JavaScript enabled to view it. ). It is used as first guess in ODYSSEA processing chain and it has been decided by the SST TAC team to use it as a reference for the sst validation and monitoring activities. This climatology was built from Casey/Pathfinder climatology, applying some spatial smoothering and temporal interpolation to obtain a daily climatology.
• an ensemble comparison of all available GHRSST global analyses