335 articles
Deep Argo
Deep Argo is an expansion of the international Argo program in which profiling floats measure temperature and salinity from the ocean surface to the sea floor every 10 days.
Deep sea
Deep sea: ocean below about 200 m where light fades; also called the aphotic, twilight, midnight, abyssal, and hadal zones. Cold (~4°C), high pressure, food-poor; explored by bathysphere, Trieste, and DEEPSEA CHALLENGER; targeted for seabed mining.
Deep Sea Drilling Project
The Deep Sea Drilling Project was a US-led scientific ocean drilling program run from Scripps Institution of Oceanography that used the drillship Glomar Challenger to core the deep seafloor from 1968 to 1983.
Deep Sea Warrior (AUV)
The Deep Sea Warrior (Shenhai Yongshi) is China's second deep-sea manned submersible, a 4,500-meter-class crewed vehicle delivered in 2017 that reached 4,534 meters on its first dive test.
Deep-ocean Assessment and Reporting of Tsunamis
Deep-ocean Assessment and Reporting of Tsunamis (DART) is a NOAA tsunami monitoring system pairing seafloor pressure recorders with moored surface buoys, expanded to 39 US stations in 2008.
Deep-submergence vehicle
A deep-submergence vehicle (DSV), also called a human-occupied vehicle when crewed, is a submersible launched from a support ship to work at great ocean depths.
Deepsea Challenger
Deepsea Challenger, also known as DCV 1, is a one-person full-ocean-depth submersible built in Sydney, Australia, and piloted by James Cameron to Challenger Deep on March 26, 2012.
Diapycnal mixing
Diapycnal mixing is the turbulent transport of heat, salt, and tracers across density surfaces in stratified fluids, driven mainly by breaking internal waves and supplying the energy the ocean's overturning circulation needs.
Diel vertical migration
Diel vertical migration is the daily movement of aquatic animals toward the surface at night and into deeper water by day, the largest synchronized movement of biomass on Earth.
Dissolved inorganic carbon
Dissolved inorganic carbon (DIC) is the total inorganic carbon dissolved in seawater, mainly bicarbonate, carbonate, and carbon dioxide, and is the route by which human-made CO₂ enters the ocean.
Drifter (oceanography)
A drifter, also known as a Lagrangian drifter, is a satellite-tracked ocean buoy with a subsurface drogue at 15 m depth that follows currents while measuring temperature and position.
DSV Alvin
DSV Alvin, also known as RV Alvin, is a U.S. Navy-owned research submersible operated by Woods Hole Oceanographic Institution since 1964, reaching depths of 6,500 meters.
DSV Limiting Factor
The DSV Limiting Factor is a two-person submersible rated to 11,000 m, built for Victor Vescovo's Five Deeps Expedition and sold in 2022 to Gabe Newell's Inkfish.
Dynamic topography
Dynamic topography is the height of the sea surface relative to the geoid, produced by ocean currents, or the solid-Earth deformation caused by flow in the convecting mantle.
East Australian Current
The East Australian Current is a major ocean current flowing south along Australia's east coast from the Coral Sea, known for large eddies and warming the Tasman Sea.
Echo sounding
Echo sounding, also called depth sounding, measures water depth by timing a sound pulse's return from the seabed; it replaced the lead line in the early twentieth century.
Edge wave
An edge wave is a surface ocean wave trapped against a sloping coast by refraction, propagating along the shoreline with an amplitude that decays rapidly offshore.
Ekman layer
The Ekman layer is the wind-driven surface layer of the ocean, about 100 m deep, where the current spirals with depth due to Earth's rotation.
Ekman pumping
Ekman pumping is the vertical motion induced in a rotating fluid where a frictional boundary layer meets the interior, caused by friction turning the flow across isobars.
Ekman transport
Ekman transport is the net horizontal movement of wind-driven surface water in the ocean, deflected 90 degrees to the right of the wind in the Northern Hemisphere.
Equatorial undercurrent
The equatorial undercurrent is a narrow subsurface ocean current flowing eastward along the Equator in the Pacific, Atlantic, and Indian Oceans, against the trade winds, about 100 meters deep in the Pacific.
Equatorial upwelling
Equatorial upwelling is the rising of cold, nutrient-rich subsurface water to the ocean surface along the equator, driven by trade winds through Ekman transport and supporting major fisheries.
Eric A. D’Asaro
Eric A. D'Asaro is an American physical oceanographer at the University of Washington's Applied Physics Laboratory who developed the Lagrangian float and was elected to the National Academy of Sciences in 2014.
Euphotic zone
The euphotic zone is the sunlit upper ocean layer where 1 percent of surface light still penetrates, allowing photosynthesis and nearly all marine primary production, typically 40 to 200 meters deep.
Euro-Argo
Euro-Argo is the European Research Infrastructure Consortium, created in 2014, that coordinates Europe's contribution to Argo, the global array of profiling floats measuring ocean temperature and salinity.
Exopolymeric substances
Exopolymeric substances (EPS) are organic polymers, mostly polysaccharides and proteins, excreted by microbes such as bacteria and phytoplankton, binding marine snow aggregates and driving biofilm fouling.
Export production
Export production (EP) is the organic carbon produced in the ocean's sunlit surface layer that sinks toward the deep ocean, linking photosynthesis to the biological carbon pump.
f-ratio (oceanography)
The f-ratio is a dimensionless index in biological oceanography, the fraction of phytoplankton production fueled by nitrate rather than recycled ammonium, introduced by Dugdale and Goering in 1967.
Fast ice
Fast ice, also called landfast ice, is sea ice fixed along the coast to shore, shoals, or grounded icebergs, covering about 1.8 million km² of the Arctic in winter.
Fecal pellet
In oceanography, a fecal pellet is a compacted package of organic waste egested by zooplankton or fish, and a major vehicle of the biological carbon pump.