Terms

An acid Lugol’s solution is an aqueous solution of iodine and potassium iodide with acid added. It is used in biological oceanography for the preservation and staining of phytoplankton.

An acoustic Doppler current profiler (ADCP) is a hydroactustic current meter similar to a sonar, used to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water column.

The Automatic Identification System (AIS) is an automatic tracking system that uses transceivers on ships and is used by vessel traffic services.

The biological pump is the mechanism by which carbon-containing compounds are exported by biological processes from the surface to the deep ocean (Sarmiento and Gruber, 2006). In the surface ocean, primary producers use sunlight as an energy source and dissolved inorganic nutrients to convert dissolved CO2 into organic carbon. As this organic carbon passes through consumers (zooplankton, bacteria, etc.) into the upper ocean, it is largely converted back to CO2 through food web processes. However, a small fraction of the organic matter formed in the upper ocean is transported to depth, where it is sequestered over time scales ranging from months to millennia.

The biological pump is the mechanism by which carbon-containing compounds are exported via biological processes from the surface to the deep ocean (Sarmiento and Gruber, 2006).

A CTD or sonde is an oceanography instrument used to measure the electrical conductivity, temperature, and pressure of seawater (the D stands for “depth”, which is closely related to pressure). Conductivity is used to determine salinity.

DCM stands for Deep Chlorophyll Maximum or Chlorophyll Maximum Depth which is determined using a submerged fluorometer.

Diatoms are single-celled algae living in “glass houses”. They are the only organism on the planet whose cell walls are composed of transparent, opaline silica that decorates them with complex patterns.

An eddy is a circular current of water.

The euphotic zone is the layer closer to the surface that receives enough light for photosynthesis to occur. Beneath lies the disphotic zone, which is illuminated but so poorly that rates of respiration exceed those of photosynthesis.

During the calibration and validation (CalVal) phase, SWOT was in a 1- day-repeat fast sampling orbit with enhanced temporal resolution.

Ship-ADCP (38kHz) velocities and shear during stations B3. Superimposed on the shear is the dissipation rate of turbulent kinetic energy measured by the Vertical Microstructure Profiler. Fig. 5a in Rolland et al. 2026

Near-inertial wave kinetic energy vertical flux (F_NIW) from Ship-ADCP 38 kHz and 150 kHz velocities measured during station B3. The dotted blue line is a linear fit on the flux from Ship-ADCP 38 kHz. Fig. 6f in Rolland et al. 2026.

In ocean and freshwater environments, the term “hypoxia” refers to low or depleted oxygen in a water body. Hypoxia is often associated with the overgrowth of certain species of algae, which can lead to oxygen depletion when they die, sink to the bottom, and decompose.

Station-averaged profiles of the dissipation rate and min-max range (shaded area). The dissipation is increased by one to two orders of magnitude down to ~250 m at B2 compared to F2 and A2. Fig. 4c in Rolland et al. 2026

Internal waves are waves that oscillate in the interior of the ocean, rather than at its surface. They exist when there are layers of sea water of different density.

Lagrangian Coherent Structures (LCSs) identify oceanic features that act as barriers to transport or as retentive and coherent regions (for instance, eddies or filaments). In particular, LCSs can allow the identification of frontal features, which are “lines at sea” separating water masses with different properties (such as temperature), usually associated with intense biological activity.

A marine protected area (MPA) is a section of the ocean where a government has placed limits on human activity. Many MPAs allow people to use the area in ways that do not damage the environment.

Marine spatial planning is a process that brings together multiple users of the ocean – including energy, industry, government, conservation and recreation – to make informed and coordinated decisions about how to use marine resources sustainably.

A numerical model for the Mediterranean Sea.

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In general, three size classes have been described for phytoplankton: picoplankton (diameter <2 μm), nanoplankton (diameter 2-20 μm), and microphytoplankton (diameter >20 μm) (Sieburth et al., 1978).

A Moving Vessel Profiler (MVP) is an automated data collection tool that can be used from vessels while underway. It has been effectively used to collect mid-water oceanographic information to support science and hydrographic survey operations.

A Niskin bottle is a plastic cylinder with a cap on each end to completely seal the bottle. This device allows water samples to be taken from a given depth without the risk of mixing with water from other depths. The water collected by the Niskin bottles can be used to study plankton or measure the physical characteristics of the sea. Niskin bottles are often installed either in a series of individual bottles or in a carousel of six bottles with a CTD instrument.

The physical pump is the mechanism by which carbon dioxide from the atmosphere moves to the surface of the ocean by diffusion. Carbon dioxide dissolved in the surface of the ocean can then be transferred to the deep ocean in areas where cold, dense surface waters sink.

This paradigma was first developed Levy et al., (2012) which said that “submesoscale dynamics therefore can change not only primary and export production, but also the structure and the functioning of the planktonic ecosystem.” Lévy, M., Ferrari, R., Franks, P. J., Martin, A. P., & Rivière, P. (2012). Bringing physics to life at the submesoscale. Geophysical Research Letters, 39(14).

Phytoplankton (From the Greek “phyton”, or plant) are autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to allow photosynthesis. Among the most important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores.

The PlanktoScope is a modular, open source hardware and software platform that enables high-throughput quantitative imaging of plankton samples in the fields of aquatic biology and ecology. Its small size, ease of use, and low cost allow it to be deployed in a range of applications, including monitoring laboratory cultures or natural microplankton communities. It can be controlled from any Wi-Fi enabled device, and its versatility allows for rapid reconfiguration to meet the user’s evolving needs. For more information, see here: https://www.planktoscope.org/.

A rotor current meter (RCM) is a mechanical current meter, an oceanographic device deployed within an oceanographic mooring measuring the flow within the world ocean to learn more about ocean currents. Many RCMs have been replaced by instruments measuring the flow by hydroacoustic, the so-called Acoustic Doppler Current Profilers.

Marine mucilage, also referenced as sea snot or sea saliva, is thick, gelatinous organic matter found in the ocean or in the seas and it carries diverse microorganisms. Triggers that cause it to form include increased phosphorus, drought conditions, and climate change.

Sea Surface Height (SSH): Ocean Surface Topography is the height of the ocean surface relative to a level of no motion defined by the geoid, a surface of constant geopotential, and provides information on tides, circulation, and the distribution of heat and mass in the Earth’s global ocean. (REF: https://podaac.jpl.nasa.gov/OceanSurfaceTopography)

Towed oscillating vehicle that can be equipped with instruments to carry out optical packages (CDOM, O2, Nitrate, Turbidity, Transmission, Fluorescence). Seasoars have already proven their relevance to rapidly scan biogeochemistry indicators that may help to understand the way the dynamical structures may shape the biological fields.

The spring bloom is a large increase in phytoplankton abundance (i.e. stock) that usually occurs in early spring and lasts until late spring or early summer. This seasonal event is characteristic of temperate North Atlantic, sub-polar and coastal waters.

In Stommel’s (1989) vision for the year 2021, oceans would be monitored using instruments with wings. These robots would profile through the water column by changing their buoyancy in alternating vertical cycles of ascents and descents, with their wings providing the horizontal propulsion to “glide” through the oceans. It is now timely to look back and revisit this vision and assess its status.

Definition taken by Bruvik et al. 2020. https://doi.org/10.5194/os-16-291-2020

Sensors to measure nitrate concentration in aquatic mediums.

A software that simulates SWOT observations of the sea surface height (SSH) that can be applied to an ocean general circulation model (OGCM), allowing the exploration of ideas and methods to optimize information retrieval from the SWOT Mission in the future.

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Ship-ADCP 38 kHz velocities and shear during stations B2, F2 and A2. Superimposed on the shear is the dissipation rate of turbulent kinetic energy measured by the Vertical Microstructure Profiler. Vertical dashed line indicate transits from stations B2 to F2 and F2 to A2. A strong near-inertial wave signal is visible in the first 250-300 m at B2. The trapping is highlighted by the abrupt drop in shear between B2 and F2. Fig. 4a Rolland et al. 2026.