Na-Nm

NAAG

Acronym for North Atlantic Arctic Gateways Program, a JOIDES project.

NABE

Acronym for North Atlantic Bloom Experiment, a 1989-1991 experiment that was one of the first major activities of JGOFS. It was a multidisciplinary and multinational study of the spring phytoplankton bloom in the North Atlantic and its associated biogeochemical processes. It was decided to conduct the pilot study in the North Atlantic because of its proximity to the founding nations of the project, the size and predictability of the bloom, and its fundamental impact on ocean biogeochemistry. The U.S. component took place from April through July 1989 on two cruises of the RV Atlantis II and one cruise of the RV Endeavor, with the stations located from 18-72$\deg$ N and from 8-47$\deg$ W. Research vessels from Canada, Germany, The Netherlands, and the U.K. also participated, along with over 200 scientists and students from more than a dozen nations.

Key scientific findings and technical advances during NABE included:

• the development and refinement of analytical techniques for CO$_2$, and the collection of a large data set on seasonal and spatial trends in spatial pCO$_2$;
• phytoplankton blooms are driven by an excess of production over consumption and export, leading to accumulations of biogenic material in surface waters;
• high rates of new production during blooms are supported by high concentrations of nitrate supplied during winter mixing;
• supplies of regenerated nutrients are abundant during the bloom;
• the unexpected importance of microbial activities during the bloom; and
• grazer activity may have stimulated bacterial production, e.g. a bacterial bloom lagged the phytoplankton bloom by 10-20 days.

See Ducklow (1989) and Ducklow and Harris (1993).

[http://www1.whoi.edu/mzweb/nabe.htm]
[http://usjgofs.whoi.edu/research/nabe.html]

NAC

Abbreviation for North Atlantic Current.

NACOA

Acronym for National Advisory Council on Oceans and Atmosphere, a U.S. committee.

NACW

Abbreviation for North Atlantic Central Water.

NADW

See North Atlantic Deep Water or North Adriatic Deep Water.

NAME

Acronym for North American Monsoon Experiment, an effort to determine the sources and limits of predictability of warm season precipitation over North American, with emphasis on time scales ranging from seasonal to interannual.

[http://www.cpc.ncep.noaa.gov/products/precip/monsoon/NAME.html]

Jerome Namias (1910-1997)

A meteorologist who was one of the best long-range forecasters.

[http://scilib.ucsd.edu/sio/archives/siohstry/namias-biog.html] [http://www.nap.edu/readingroom/books/biomems/jnamias.html]

Namib Col Current

An eastward-flowing current near 22$^\circ$S east of the Mid-Atlantic Ridge in the Angola Basin. It forms a continuous circulation structure from the Namib Col (a saddle on the Walvis Ridge of depth 3000-3250 m) west past the Mid-Atlantic Ridge into the western trough, and is identified by salinity and oxygen maxima. The transport estimate from hydrographic sections is about 3.6 $\times\,\,{10^6}$ m$^3$ s$^{-1}$. Associated with the current is a basin-wide salinity and oxygen front of varying intensity (weaker in the east) marking the transition to deep water whose North Atlantic characteristics have been partly erased by mixing with Circumpolar Deep Water (CDW) in the southwest South Atlantic. This current is a pathway for North Atlantic Deep Water (NADW) to cross and eventually leave the South Atlantic Ocean south of Africa. See Speer et al. (1995).

NAML

Abbreviation for the National Association of Marine Laboratories, organized in the late 1980s and representing marine and Great Lakes laboratories. It is composed of three regional associations:

• Northeastern Association of Marine and Great Lakes Laboratories (NEAMGLL);
• Southern Association of Marine Laboratories (SAML); and
• Western Association of Marine Laboratories (WAML).

[http://www.mbl.edu/labs/NAML/]

nanoplankton

Phytoplankton whose lengths range from 10 to 50 $\mu$m. Compare to microplankton and ultraplankton.

NANSEN

Acronym for North Atlantic and Norwegian Sea Exchange, an experiment whose objectives were to study the hydrography and circulation of the Iceland Basin and to study the temporal and spatial variability of the flows across the Greenland-Scotland Ridge. The ship observations in support of NANSEN were collected from 1986 to 1989. It consisted of a series of loosely connected research cruises conducted by different nations and laboratories in the area of interest, with the planning and execution of the program also seen as a pre-WOCE phase in the eastern North Atlantic. The main topics addressed by NANSEN were:

• the origin and characteristics of the upper ocean water masses feeding the Norwegian Sea;
• the characteristics and fate of the outflowing cold water in the North Atlantic; and
• pathways and variations of the inflows and outflows.

See van Aken (1996).

[http://www.ices.dk/ocean/project/data/nansen.htm]

Nansen, Fridtjof

A Norwegian scientist, diplomat and humanist who did much to advance the field of oceanography from the last decade of the 19th century until his death in 1930. He is the only oceanographer to ever win the Nobel Prize (in 1922), although he won it for his humanitarian work to aid refugees throughout Europe and Asia. He investigated many aspects of the northern polar regions, crossing the Greenland inland ice on his first polar expedition at the age of 27 in 1888 (after defending his dissertation in zoology on the histology of the central nervous system of the hagfish).

In 1892 he started planning what became known as the FRAM expedition, named after the polar vessel he specially constructed for this North Pole expedition. The significant results gained from that expedition included the discovery of a deep Arctic Ocean, the confirmation of the existence of a Transpolar Current, and observations of pack ice drift relative to the prevailing wind direction which provided the impetus for the later identification of the Ekman spiral (one of the cornerstones on which the modern theory of wind-driven circulation is built). The FRAM expedition and those that followed were also marked by careful measurement and compilation of data, detailed planning, and forceful execution, qualities that provided a firm baseline for all future expeditions.

Nansen had a strong practical bent as a scientist and explorer, improving old equipment and even inventing new equipment when the need arose. The most famous of his inventions was the Nansen bottle for sampling ocean water at various depths. He also strongly supported international cooperation in oceanography and, as a direct result, was one of the founding fathers of the International Council for the Exploration of the Sea (ICES) in 1902.

He become heavily involved in politics in his native Norway and played an important role in 1905 when Norway declared full independence from Sweden, which resulted in his being appointed the first Norwegian ambassador in London. After two years as ambassador, he returned to oceanography for several years until the advent of World War I, publishing the book The Norwegian Sea with B. Helland-Hansen during this period. He spent the remainder of his life after World War I engaged in various humanitarian activities until his death at age 60 in 1930, receving his Nobel Prize in 1922.

Nansen bottle

A reversing water bottle comprising a water bottle and a pair of thermometers on a reversing frame. This was developed by Fridtjof Nansen around 1910. See Schlee (1973).

NAO

Abbreviation for North Atlantic Oscillation.

NAS

Abbreviation for National Academy of Sciences.

NASA

Acronym for National Aeronautics and Space Administration.

NASCO

Acronym for National Academy of Sciences (NAS) Committee on Oceanography, now replaced by OAB.

Natal Pulse

Large, solitary meanders in the path of the Agulhas Current between Cape St. Lucia and the Agulhas Bank south of Africa. The pulses seem to originate in the region of the Natal Bight, a distinct offset in the coastline north of Durban. They manifest themselves as a cyclonic eddy in the current, move downstream at 10-20 km per day, and have diameters ranging from 30 to 200 km (growing steadily in size as they move downstream). It has been suggested that the Pulse may play a central role in the upstream retroflection of the Agulhas Current, and in the shedding of eddies from the seaward side of the current. See Lutjeharms and Roberts (1988) and de Ruijter (1999).

NATFE

Abbreviation for North Atlantic Transect Fluorescence Experiment, conducted between May 28 and June 6, 1993 aboard the CSS Hudson as the second leg of a collaborative research cruise between the IRSA of Italy and the BIO of Canada. Water was collected along a cross-basin transect from up to 13 depths between 0 and 120 meters, concentrated by gentle filtration, and a pump-and-probe fluorometer was used to estimate the minimum and maximum fluorescence yields on phytoplankton.

[http://me-www.jrc.it/other/data/atlatext.html]

National Academy of Sciences (NAS)

An organization formed in 1863 to provide independent, objective scientific advice to the nation. The Environment and Earth Sciences Program Unit provides funding for oceanographic research.

[http://www4.nationalacademies.org/nas/nashome.nsf]

National Aeronautics and Space Administration (NASA)

[http://www.nasa.gov/]

National Estuarine Research Reserve System (NERRS)

A protected areas network of federal, state and local partnerships to enhance informed management and scientific understanding of the U.S. estuarine and coastal habitats. It was created with the 1972 Coastal Zone Management Act. As of 1996, 22 estuarine reserves encompassing over 425,000 acres of estuarine waters, wetlands, and uplands have been designated, with another 6 reserves in development.

[http://inlet.geol.sc.edu/cdmohome.html]

National Ice Center (NIC)

A multi-agency operational center which includes personnel from two NOAA departments, the NESDIS and the NWS. Its mission is to provide worldwide, operational sea ice analyses and forecasts for the armed forced of the U.S. and allied nations as well as for other U.S. government agencies and the civil sector. These products are provided for the Arctic, Antarctic, Great Lakes and Chesapeake Bay.

[http://www.natice.noaa.gov/]

National Marine Sanctuary Program (NMSP)

A NOAA program whose mission is to identify, designate and manage areas of the marine environment of special national significance due to their conservation, recreational, ecological, historical, research, educational, or aesthetic qualities. The program was established under Title III of the Marine Protection, Research and Sanctuaries Act of 1972 and is administered by the Sanctuaries and Reserves Division of NOAA.

The twelve sanctuaries (as of 1997) are the Channel Islands (California), Cordell Bank (California), Fagatele Bay (America Samoa), Florida Keys (Florida), Flower Garden (Florida), Gray's Reef (Georgia), Gulf of the Farallones (California), Hawaiian Islands Humpback Whale (Hawaii), Monitor (North Carolina), Monterey Bay (California), Olympic Coast (Washington), and Stellwagen Bank (Massachusetts) National Marine Sanctuaries.

[http://www.sanctuaries.nos.noaa.gov/welcome.html]

National Oceanic and Atmospheric Administration

A branch of the U.S. Dept. of Commerce whose mission is to promote global environmental stewardship to conserve and wisely manage the nation's marine and coastal resources, and to describe monitor, and predict changes in the Earth's environment to ensure and enhance sustainable economic opportunities. NOAA comprises the following program offices: NESDIS, NMFS, NOS, NWS, OAR, COP, OGP and HPCC.

[http://www.noaa.gov/]

National Sea Grant

A partnership program between NOAA and various universities that encourages the wise stewardship of marine resources through research education, outreach and technology transfer. It began in 1966 when the U.S. Congress passed the National Sea Grant College Program Act. There are at present 29 Sea Grant Colleges engaged in marine research.

NATRE

Abbreviation for North Atlantic Tracer Release Experiment, an experiment that took place in the east-central Atlantic Ocean in March 1992 between 20-35$^\circ$ N and 35-10$^\circ$ W. See Montgomery et al. (1992).

natural variability

The range of climate variations that would theoretically exist in the absence of anthropogenic forcing. Information on this hypothesized spectrum of climate variability can be derived from instrumental data, paleoclimatic reconstructions, and numerical model results.

Naval Oceanographic Office (NAVOCEANO)

The mission of the U.S. Naval Oceanographic Office is to acquire and analyze global ocean and littoral data to provide specialized operationally significant products and services for warfighters and civilain, national and international customers. It is located at Stennis Space Center, Mississippi, USA and consists of around 1000 combined military and civilian personnel.

NAVOCEANO has its origin in 1830 when the U.S. Navy established the Depot of Charts and Instruments (DCI) to maintain a supply of navigational instruments and nautical charts for issue to naval vessels. Given the paucity of the available data, the DCI was soon enough obtaining its own data to produce charts, with the first products being four engraved charts published in 1837. These were published from the results of a survey by Charles Wilkes (later to lead the U.S. Exploring Expedition) that ranged over the eastern Atlantic to Antarctica, the coasts of both Americas, and into the west and southwest Pacific. The next five years saw 87 more chart published from the results of that survey.

A greater range of data became available after 1842 when Matthew Maury assumed commmand of the DCI. He suggested that all shipmasters submit reports to a central agency where it could be compiled and published for the benefit of all. This led to the submission of over 26 million reports to the DCI over the next five years, almost swamping the agency given its different and smaller original mission. These growing pains led to the name being changed to the U.S. Naval Observatory and Hydrographical Office in 1854, and again in 1866 when the two functions were separated with the latter half becoming the Naval Hydrographic Office with an expanded mission including carrying out surveys, collecting information, and printing charts.

The office continued to expand into the 20th century, with a significant landmark being the Titanic disaster of 1912 which led to the establishment of an ice patrol to document sea hazards. Shortcomings in the available data made obvious by the navigational needs of WWI led to the development of the first practical sonic sounding machine in 1922, a device allowing a quantum leap to be made in both the quality and quantity of available data. After Pearl Harbor and a forty-old increase in the demand for charts, the Office was moved to Suitland, Maryland and placed under the Chief of Naval Operations. Additional ships were obtained and outfitted such that 43 million charts were printed and issued in one year at the peak of WWII.

The office was given its present name in 1962 and relocated to its present location at NASA's Stennis Space Center in Mississippi in 1976, where it shares the facilities with over 20 other Federal and State agencies. The post-Cold War focus of the office has also shifted from deep water to coastal regions.

[http://www.navo.navy.mil/]

Navier-Stokes equations

The fundamental equations of the dynamics of an incompressible and Newtonian. When $\nu\,=\,0$, i.e. for infinite Reynolds numbers, the Navier-Stokes equations reduce to the Euler equations.

naviface

The interface between the atmosphere and the ocean. This was proposed, along with the adjectival form navifacial, in Montgomery (1969).

NAVOCEANO

Acronym for U.S. Naval Oceanographic Office. This is sometimes shortenedd to NAVO.

Nautilus Expedition

More later.

NBC

Abbreviation for North Brazil Current.

NCAAS

Abbreviation for NOAA CoastWatch Archive and Access System, a part of the CoastWatch program that handles its data archival and distribution tasks.

[http://www.nodc.noaa.gov/cwatch/ncaas-home.html]

NCAR

Acronym for the National Center for Atmospheric Research located in Boulder, Colorado. NCAR comprises five divisions: (1) Atmospheric Chemistry Division (ACD), (2) Atmospheric Technology Division (ATD), (3) Climate and Global Dynamics Division (CGD), (4) Mesoscale and Microscale Meteorology Division (MMM), and (5) Scientific Computing Division (SCD).

[http://www.ncar.ucar.edu/ncar/]

NCC

Abbreviation for Norwegian Coastal Current.

NCCCS

Abbreviation for Northern California Coastal Study, an experiment taking place from 1987-1989. See Bray and Greengrove (1993).

NCDC

Acronym for National Climate Data Center, a branch of the NESDIS division of the Office of Environmental Information Services of NOAA that is the collection center and custodian for all U.S. weather records.

[http://www.ncdc.noaa.gov/]

NCEP

Abbreviation for National Centers for Environmental Prediction, a NOAA program to provide timely, accurate, and continuually improving worldwide forecast guidance products.

[http://www.ncep.noaa.gov/]

NDBC

Abbreviation for National Data Buoy Center, a NOAA site that is the source of buoy-measured environmental data.

[http://www.ndbc.noaa.gov/]

NEADS

Acronym for Northeastern Atlantic Dynamics Study, an array of instrumentation moorings anchored in the northeastern Atlantic basin in the early 1980s. This was a collaboration between West Germany, England and France and complementary to the contemporanous MODE program.

NEADW

Abbreviation for Northeast Atlantic Deep Water.

NEAFC

Abbreviation for Northeast Atlantic Fisheries Commission.

neap tide

The tides produced when the gravitational pull of the Sun is in quadrature, i.e. at right angles to, with that of the Moon. These occur twice a month at about the times of the first and last quarters. In these situations the gravitational pull of the Sun/Moon produces high/low water or vice-versa, and as such the differences between high and low tides are unusually small, with both the high tide lower and the low tide higher than usual. The tidal height is about .375 that of maximum during neap tides. See also spring tide.

NEAR-GOOS

The North-East Asian Region-GOOS is a regional pilot project of GOOS in the Northeast Asian region. It is implemented by China, Japan, the Republic of Korea, and the Russian Federation as a WESTPAC activity. The purpose of the project is to demonstrate the usefulness of a regional ocean observing system to encourage further such efforts. The primary aim of NEAR-GOOS is to share oceanographic data in real time via the Internet to support the daily mapping of sea conditions in the marginal seas bordered by NEAR-GOOS countries. Other goals include improving ocean services in the region, providing data and information useful in the mitigation of natural disasters, increasing the efficiency of fishing vessels, providing information for pollution monitoring, monitoring parameters useful to mariculture, and providing data sets required for data assimilation, modeling and forecasting.

The essential elements of NEAR-GOOS are two databases. The Real Time Data Base (RTDB) exists for the daily mapping of sea conditions and is maintained by the JMA for online access via the Internet. Data are kept in the RTDB for thirty days and then transferred to the Delayed Mode Data Base (DMDB), which exists for archiving data. The DMDB is maintained by the JODC. Associate data bases include the Chinese Delayed Mode Data Base (CDMDB) and the Korea Coastal and Ocean Information Service (KCOIS). Observations included in the NEAR-GOOS database include temperature, salinity, current and wind wave data from the GTS. They also contain observations carried out by users in participating countries using moored buoys, drifting buoys, platforms, coastal stations, research vessels, voluntary observing ships, and remote sensing data.

[http://ioc.unesco.org/goos/neargoos.htm]

nearshore zone

A zone extending from the upper limit of a beach to the offshore. In terms of the beach profile, it consists of (progressing seawards) the backshore, foreshore and inshore. In terms of the wave and current regimes, it consists of (again progressing seawards) the swash zone, surf zone and breaker zone. See Komar (1976).

NEAT GIN

Acronym for North East Atlantic, Greenland-Iceland-Norwegian Sea Experiment, an experiment which took place during Sept.-Oct. 1989 at the Norwegian shelf edge near 68$^\circ$ N and comprised seven moorings, five in a closely spaced cross-slope section.

[http://www.pol.ac.uk/oshi/neatgin.html]

NEC

Abbreviation for North Equatorial Current.

NECBRE

Acronym for North Equatorial Current Bifurcation Region Experiment, an experiment planned by JAMSTEC to start in around 2006. The plan is to make tomographic observations of the North Equatorial Current bifurcation region in the Philippine Sea after the conclusion of the KESS program.

NECC

Abbreviation for North Equatorial Countercurrent.

NECOP

Acronym for Nutrient Enhanced Coastal Ocean Productivity, a NOAA/OAR/AOML program to study the dynamics of physical, geological, chemical and biological processes as they are influenced by the runoff from the Mississippi River and Atchafalaya Bay. The main objectives of the study include describing a clear anthropogenic signal and any resultant nutrient-enhanced productivity of significant magnitude and demonstrating the impact of enhanced production on coastal environmental quality.

[http://www.aoml.noaa.gov/ocd/necop/]

negative feedback

A type of feedback in which a perturbation to a system causes a damping of the process, and thus opposes itself.

NEGOM

Acronym for Northeastern Gulf of Mexico Physical Oceanography Program.

[http://negom.tamu.edu/negom/]

nekton

One of three major ecological groups into which marine organisms are divided, the other two being the benthos and the plankton. Nekton are strongly swimming pelagic animals such as fish, some crustaceans, cephalopods, and whales which are capable of progressing against most water currents.

NEONS

Acronym for the Naval Environmental Operational Nowcasting System, a software package that provides the capability to mange oceanographic and meteorological data in near real-time. It provides a set of tools to access, create and manage environmental data which is stored in a NEONS schema within a relational database.

[http://www.ncdc.noaa.gov/neons.html]

NEP

Abbreviation for net ecosystem production, the rate at which carbon from the atmosphere (as CO$_2$) is accumulated in the biosphere. It is equal to the NPP minus heterotrophic respiration. See Woodwell (1995).

NEP

Abbreviation for National Estuary Program, an EPA program to identify problems in estuaries and recommend solutions.

[http://www.epa.gov/owow/estuaries/nep.html]

NEPTUNE

Acronym for North East Pacific Time-series Undersea Networked Experiments, a project to establish a network of underwater observatories within the depths of the northeastern Pacific Ocean. A 2000 mile network of fiber optic cable will provide power and communications to the scientific instruments. NEPTUNE will be located in the northeastern Pacific and will be spatially associated with the Juan de Fuca tectonic plate.

[http://www.neptune.washington.edu/]

neritic

Living in coastal waters as opposed to living upon the high seas, i.e. oceanic. A division of the pelagic portion of the ocean that overlies the continental shelf.

NERRS

Abbreviation for National Estuarine Research Reserve System.

NESDIS

Acronym for the National Environmental Satellite, Data and Information Service, a NOAA office that manages U.S. civil environmental satellite systems as well as global data bases for meteorology, oceanography, solid-earth geophysics, and solar-terrestrial physics. NESDIS consists of the Offices of Environmental Information Services, Satellite Operations, Satellite Data Processing and Distribution, Research and Applications, and Systems Development.

[http://www.nesdis.noaa.gov/]

NESS

Acronym for National Environmental Satellite Service, a NOAA program.

nested modeling

In climate modeling this is a method for obtaining improved regional climate change predictions by the use of a spatial hierarchy of simulation models. Output from GCM simulations is used to provide initial and driving lateral boundary conditions for high resolution regional climate model (RegCM) simulations. There is no feedback from the ReGCM to the GCM. Different nesting techniques have been used, ranging from the standard technique of directly interpolating output from the coarse grid to the fine grid to the more sophisticated technique of spectral nesting. In the latter method the GCM forces the low wavenumber component of fields in the regional domain while the RegCM calculates the high wavenumber components. See Houghton and Filho (1995).

net irradiance

The sum of the irradiance and the exitance.

net primary production

See primary production.

NEUC

See North Equatorial Undercurrent.

Neumann, Gerhard

More later.

neuston

More later.

neutral density

A density for which three properties should ideally hold:

• it should be constant on approximate neutral surfaces;
• its horizontal gradients should coincide with the horizontal gradients of the in situ density; and
• its vertical gradient should be proportional to the static stability of the water column.

The rub is that no variable can satisfy all these conditions in the ocean, i.e. the concept is mathematically ill-defined. It is, though, possible to define and use approximate neutral densities that constitute a compromise between these properties. ee Eden and Willebrand (1999).

neutral surface

A surface on which no work is required to move a water parcel, as opposed to isopycnal surfaces where work is required due to the nonlinearity of the equation of state for seawater. Neutral surfaces are defined such that:

$$\alpha {\nabla_n}\theta \,=\,\beta{\nabla_n} S$$

where $\theta$ is the potential temperature, $S$ the salinity, $\alpha$ the thermal expansion coefficient, $\beta$ the saline contraction coefficient and $\nabla_n$ refers to the two-dimensional gradient in the neutral surface.

If $\theta$ and $S$ are split into their mean (as averaged over many eddy scales) and fluctuating parts, neutral surfaces can be defined for the mean field rather than the instantaneous or local field. Fluid parcels will not move exactly in this mean field surface, though, due to nonlinearities in the equation of state. It is nonetheless assumed that the tensor describing eddy diffusion by mesoscale eddies and small-scale processes is diagonal if axes are chosen in and normal to this surface. See McDougall (1987a), You and McDougall (1990), Jackett and McDougall (1997) and Eden and Willebrand (1999).

neutral trajectory

A three-dimensional path in the ocean defined such that no buoyancy forces act on a water parcel when it is moved a small distance along the path. Neutral trajectories are mathematically well defined but do not generally coincide with particle trajectories. See Eden and Willebrand (1999).

New Guinea Coastal Current (NGCC)

New Guinea Coastal Undercurrent (NGCUC)

new production

Photosynthesis due to the uptake of nitrate. It is so-called because ocean circulation is the only source of nitrate to the euphotic zone and, as such, the nitrate can be thought of as newly available to phytoplankton. See Najjar (1991).

Newfoundland Basin

An ocean basin lying between Newfoundland and the Azores whose floor is transected by the Mid-Ocean Canyon joining the Labrador Basin with the Sohm Abyssal Plain. It is separated from basins to the south by the Southeast Newfoundland Ridge. See Fairbridge (1966).

NEWLAND

Acronym for Northeast Water Polynya Project.

Newtonian fluid

A fluid in which deformation is proportional to velocity gradients.

NGCC

Abbreviation for New Guinea Coastal Current.

NGCUC

Abbreviation for New Guinea Coastal Undercurrent.

NGDC

Acronym for National Geophysical Data Center, a branch of the NESDIS division of the Office of Environmental Information Services of NOAA that manages environmental data in the fields of solar-terrestrial physics, solid earth geophysics, marine geology and geophysics, paleoclimatology, and glaciology. It operates a World Data Center for each field.

[http://www.ngdc.noaa.gov/ngdc.html]

NGWLMS

Abbreviation for Next Generation Water Level Management System, an automated system for collecting sea level and other data. The NGWLMS platform measures sea level position, air and water temperature, water density, wind speed and direction, and atmospheric pressure. Data is collected at various rates, stored every three minutes, and relayed via the NOAA GOES satellite to a central collection facility in Rockville, MD every three hours. See Beaumariage and Scherer (1987).

[http://www.pol.ac.uk/psmsl/gb/gb1/noaa.html]

NHRC

Abbreviation for North Hawaiian Ridge Current.

Ninetyeast Ridge Current

See ().

NIO

Abbreviation for National Institute of Oceanography, an institute of India and Pakistan.

NIOF

Abbreviation for National Institute of Oceanography and Fisheries, an Egyptian institute.

NIOMR

Abbreviation for Nigerian Institute for Oceanography and Marine Research.

NIOZ

Acronym for Nederlands Institut voor Onderzoek der Zee or, in translation, the Netherlands Institute for Sea Research.

[http://www.nioz.nl/]

Niskin bottle

A plastic sampling bottle with water tight clsoures at top and bottom used to collect seawater samples for discrete chemical and biological measurements. It is equipped with a subsampling spigot and an air vent and can be triggered at pre-determined depths to collect samples. It is made of polyvinylchloride (PVC), an unreactive substance, to minimize possible contamination of highly sensitive measurements.

nitrate/nitrite

Nitrate is ...

According to Kamykowski and Zentara (1991):

Nitrite occupies an intermediate oxidation state in the marine inorganic nitrogen cycle between the most reduced form, ammonia, and the most oxidized form, nitrate. Nitrite accumulation therefore identifies either loci of importation across the ocean boundaries (allocthonous sources) or of water column nitrogen fluxes where nitrite produce exceeds nitrite utilization (autochthonous sources). The most significant biological processes contributing to nitrite production are denitrification including assimilatory and dissimilatory nitrate reduction and nitrification dominated by ammonia oxidation. Nitrite accumulation occurs when at least one of these processes exceeds the uptake capabilities of phytoplankton and/or bacteria.

See Carpenter and Capone (1983), Sharp (1983) and Kamykowski and Zentara (1991).

NITREX

Acronym for Nitrogen Saturation Experiment.

nitrification

The process by which ammonia formed by the bacterial decay of marine organisms or excreted by marine animals is oxidized to nitrite and then nitrate. It is inhibited by light and proceeds very slow if at all in the euphotic zone. See Najjar (1991).

NMAT

Abbreviation for Night-time Marine Air Temperature. This is a temperature defined and measured so as to avoid the effects of the daytime heating of the decks of ships, the platforms on which such things are usually measured.

NMC

Abbreviation for National Meteorological Center (USA).

NMDIS

Abbreviation for National Marine Data and Information Service, located in China.

NMFS

Acronym for the National Marine Fisheries Service, a program office of NOAA that administers programs that support the domestic and international conservation and management of living marine resources.

[http://www.nmfs.noaa.gov/]