751 articles
New production
New production is ocean primary production fueled by nitrogen from outside the sunlit surface layer, chiefly nitrate, and is the fraction exported to the deep ocean.
Nile
The Nile, also known as the River Nile, is the longest river in the world, flowing 6,695 km northward through eleven countries in eastern Africa to drain into the Mediterranean Sea.
Nitrogen limitation
Nitrogen limitation is the restriction of phytoplankton growth in a lake by available nitrogen rather than phosphorus; the Lake 227 experiment showed nitrogen-fixing cyanobacteria compensate when nitrogen inputs cease.
NLDAS
NLDAS, the North American Land Data Assimilation System, is a multi-model land modeling system producing quality-controlled datasets of soil moisture, snow, and surface fluxes across the continental United States.
NOAA Commissioned Officer Corps
The NOAA Commissioned Officer Corps (NOAA Corps) is one of the eight US uniformed services, whose roughly 360 officers operate NOAA's research ships and hurricane hunter aircraft.
NOAAS Ronald H. Brown
NOAAS Ronald H. Brown, commissioned in 1997, is a global-class oceanographic and atmospheric research ship, the largest in the NOAA fleet, homeported in Charleston, South Carolina.
Noah-MP
Noah-MP is an open-source land surface model that simulates energy, water, and carbon exchange between land and atmosphere, serving as the land component of NOAA's National Water Model.
North Atlantic Current
The North Atlantic Current, also called the North Atlantic Drift, is a warm ocean current that continues the Gulf Stream northeastward from the Grand Banks toward the British Isles.
North Atlantic Deep Water
North Atlantic Deep Water is a cold, salty water mass formed in the subpolar North Atlantic and Nordic Seas that flows southward and ventilates the deep ocean.
North Atlantic garbage patch
The North Atlantic garbage patch, or Atlantic Garbage Patch, is a zone of floating plastic debris, mostly microplastics, in the North Atlantic Subtropical Gyre near Bermuda.
North Pacific Intermediate Water
North Pacific Intermediate Water (NPIW) is the low-salinity water mass of the North Pacific, a salinity minimum at depths of roughly 300–800 m, sourced mainly from the Sea of Okhotsk.
North Sea flood of 1953
The North Sea flood of 1953, known in the Netherlands as the Watersnoodramp, killed 1,836 Dutch people and more than 300 in England on 1 February 1953.
Notice to Mariners
A Notice to Mariners is a periodic publication issued by national hydrographic offices announcing corrections to nautical charts, such as new dangers to navigation and changes to aids to navigation.
Nutrient criteria
Nutrient criteria are numerical water quality values for total phosphorus, total nitrogen, and response variables like chlorophyll a, set to prevent and assess eutrophic conditions.
Nutrient spiraling
Nutrient spiraling is the cycling of nutrients in streams and rivers, where uptake and mineralization combine with downstream transport to trace a spiral path, formalized in 1981.
Ocean circulation
Ocean circulation: the wind-driven surface and density-driven deep movement of seawater, including the AMOC, which transports heat, carbon, and nutrients globally and regulates climate; the ocean absorbs over a quarter of carbon emissions and about 93% of excess heat.
Ocean color
Ocean color is the spectral distribution of visible light leaving the sea surface, measured from satellites to track chlorophyll a, phytoplankton biomass, and the ocean's role in the carbon cycle.
Ocean current
An ocean current, also called a sea or marine current, is a continuous stream of seawater driven by wind, density differences, and tides, carrying heat poleward and shaping climate.
Ocean data management and dissemination
Ocean data management and dissemination covers the practices, institutions, and standards for quality-controlling, archiving, and distributing oceanographic data, coordinated through the IODE program of UNESCO's Intergovernmental Oceanographic Commission.
Ocean deoxygenation
Ocean deoxygenation is the loss of dissolved oxygen from the world ocean, driven by warming, altered circulation, and coastal eutrophication; the open ocean has lost about 2% of its oxygen since the 1960s.
Ocean Drilling Program
The Ocean Drilling Program (ODP) was an international scientific partnership, run from 1985 to 2003 aboard the drillship JOIDES Resolution, that cored sediments and crust beneath the ocean basins.
Ocean front
An ocean front is a narrow zone of sharp horizontal change in temperature, salinity, or density, separating two distinct water masses and concentrating pollutants and marine life.
Ocean gyre
An ocean gyre, or oceanic gyre, is a large rotating system of surface ocean currents circling an ocean basin; five subtropical gyres occupy the major oceans.
Ocean mixed layer
The ocean mixed layer is the turbulent uppermost ocean layer, nearly uniform in temperature, salinity, and density, through which the ocean exchanges heat, gas, and momentum with the atmosphere.
Ocean Networks Canada
Ocean Networks Canada (ONC) is a University of Victoria ocean observing facility operating cabled observatories NEPTUNE and VENUS plus Arctic monitoring, delivering free real-time ocean data online.
Ocean Observatories Initiative
The Ocean Observatories Initiative (OOI) is a National Science Foundation-funded network of over 900 ocean sensors in the Atlantic and Pacific, fully operational since 2016 with freely available data.
Ocean tracer
An ocean tracer is a dissolved substance whose measured concentration in seawater reveals the rates, pathways, and time scales of ocean circulation, mixing, and biogeochemical processes, most notably transient tracers such as CFCs.
Ocean ventilation
Ocean ventilation is the process by which young surface waters are injected into the ocean interior, carrying heat, carbon, and oxygen into the deep ocean.
Oceanic carbon cycle
The oceanic carbon cycle is the movement of carbon through the ocean, which holds about 40 times more carbon than the atmosphere and absorbs about a quarter of annual human CO2 emissions.
Oceanographer
An oceanographer is a scientist who studies the ocean, including its processes, seawater, seafloor, and marine life. The field divides into biological, chemical, geological, and physical branches.