Overview of Ocean Observing Systems
The first lecture explained why we observe the ocean. This one, again with Frederic Bonou, introduces the how – the global network of platforms that together watch the sea, and how their observations flow into forecasting.
The lecture tours the observing system in two families:
- In-situ observations – instruments in the water, measuring directly. You’ll meet the Argo programme (over 4,000 profiling floats measuring temperature and salinity through the upper ocean), moorings and buoys (fixed platforms giving long time series, like the tropical TAO, PIRATA, and RAMA arrays), the Ship-of-Opportunity Programme (commercial and research ships carrying instruments along shipping routes), gliders (steerable autonomous vehicles for targeted surveys), HF radar (shore-based mapping of coastal currents), and even animal-borne sensors (tagged seals sampling the remote Southern Ocean)
- Satellite observations – instruments in orbit, watching the surface from space. Satellites measure sea surface temperature, sea level, ocean colour, winds, waves, and sea ice across the whole globe. The lecture looks especially at satellite altimetry – the precise measurement of sea surface height that reveals currents, fronts, and eddies, sustained unbroken for over thirty years from TOPEX/Poseidon through Jason, Sentinel, and SWOT
Two big ideas tind the lecture together. First, no single system can observe the whole ocean – each platform measures different variables, in different places, at different scales, and their real power comes from being integrated into one observing system. Second, observations don’t stop at collection: they are quality-controlled, standardised, and fed into the forecasting workflow – collection, data assimilation, model forecast, verification, and delivery to users.
Keep that integration in mind: satellites for global surface coverage, in-situ instruments for depth and detail. The next lecture looks more closely at exactly how these two families complement each other – and where each reaches its limits.
