Marine Institute

Space Week... And what technology we use?

October 8, 2018

National Glider Programme

National Glider Programme

The Marine Institute operates a marine glider called "Laochra na Mara," a 1,000m rated Teledyne Webb, G1 Slocum for Oceanographic surveying. Laochra na Mara can be operated from the national Research Vessel (RV) Celtic Explorer or RV Celtic Voyager and may also be operated from other appropriate vessels. The glider is capable of operating for 12-15 days autonomously whilst collecting oceanographic data to depths of 1,000m. The glider measures parameters such as conductivity, temperature, depth, fluorescence, turbidity and dissolved Oxygen. Without propellers or an engine, gliders rely on a movable internal ballast and external moveable fins to move across the ocean. They contain large battery packs to power the movement of the fins and change the internal ballast, these batteries also power the glider sensor payload for ocean monitoring.

Gliders are programmed to surface at designated times throughout their mission allowing them to transmit the data they have collected to shore while at the same time downloading new mission instructions. This two-way communications ability allows gliders to continually gather information about the most important and diverse regions of our ocean basins 24/7.

Gliders use a combination of ARGOS and IRRIDIUM satellite data transmission systems. Both satellite transmission systems are used in combination to provide a back-up or redundancy option in case one system fails at sea. ARGOS is a one-way system providing data to the gliders onshore pilot while IRRIDUM communication provides faster bi-directional data transmission allowing on-board parameters to be changed/altered from shore by the pilot (i.e. if the glider sends back interesting oceanographic information the pilot can alter the gliders route to further investigate a particular area or feature).

National Argo ProgrammeNational Argo Programme

The Argo network is a global array of autonomous profilers, deployed across the world's oceans, reporting subsurface ocean water properties to a wide range of users via satellite transmission. Argo floats measure temperature and salinity from the upper 2,000m of the ocean and these two essential climate variables describe the oceans' physical and thermodynamic state. The Argo array is an indispensable component of the Global Ocean Observing System (GOOS) required to understand and monitor the role of the ocean in the Earth's climate system, in particular the heat and water balance.

Euro-Argo is an established European Research Infrastructure Consortium or 'ERIC' with the objective of developing a European "infrastructure" for Argo to a level where the European partners have the capacity to procure and deploy about 250 floats per year, to monitor these floats and ensure all data is processed and delivered to users (both in real-time and delayed-mode). With an average float lifetime of 4 to 5 years, such a European contribution would support approximately a quarter of the global array and provide an additional 50 floats per year to enhance coverage in the European and marginal seas. The current total number of Argo profiling floats globally is ~4,000.

Argo profiling floats use either ARGOS or IRRIDIUM satellite data transmission systems. ARGOS communication is a one way system, designed for the float to surface and send its data back to shore via satellite communications, this takes approximately 8-12hours while the float is at the surface. IRRIDUM communication is becoming more popular on Argo floats as it provides faster bi-directional data transmission allowing on-board parameters to be changed/altered from shore. Faster communication also ensures that the float spends less time at the surface ~20min to complete data transmission, which significantly reduces the risk of ship-strikes and bio-fouling. Argo is strongly complementary to satellite observations where data from Argo profiling floats can be used to ground-truth satellite data. The Argo data are readily assimilated with those from satellites into ocean circulation and climate models, in support of research and operational applications. The proposed contribution to the Argo array is integrated into the Copernicus programme and the Global Earth Observation System of Systems (GEOSS).

 

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