observing systems

To achieve its goals Mersea needs high quality and reliable  information from fully validated global data sets, both remote sensed and in situ.

Remotely sensed data from satellites deliver near real-time, long-term, synoptic, high resolution, global estimates of key parameters (e.g. sea surface topography, sea surface temperature, ocean colour, sea ice, winds).

However, since they can sense only surface parameters, they must be complemented by in situ data, which are much more sparsely and irregularly distributed in time and space. The in situ data are indispensable for calibration of the satellite data, validation of the models, assimilation into the models and improving the assimilation of the satellite data.

Models also need surface forcing fields that are provided by ECMWF  and may be improved by combination with satellite data.