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IABO

Abbreviation for International Association for Biological Oceanography. See the IABO Web site.

IABP

Abbreviation for the International Arctic Buoy Program, a network of automatic data buoys for monitoring synoptic-scale fields of pressure, temperature and ice motion throughout the Arctic Basin. See the IABP Web site.

IACOMS

Acronym for International Advisory Committee on Marine Sciences. This was replaced by SCOR.

IAMSLIC

Abbreviation for International Association of Aquatic and Marine Science Libraries and Information Centers.

Iapetus Ocean

A paleogeographic term for the ocean that lay between Baltica and Laurentia during the late Precambrian and early Paleozoic. It was subducted during the early Paleozoic and is thought to have disappeared completely by the Late Silurian-early Devonian (around 400 Ma).

IAPO

Abbreviation for International Association for Physical Oceanographers, the name of what is now known as the IAPSO from 1948 to 1967.

IAPP

Abbreviation for International Arctic Polynya Program, an AOSB project to address the physical and biological role of polynyas in the Arctic.

[http://www.aosb.org/IAPP.html]

IAPSO

Abbreviation for International Association for the Physical Sciences of the Ocean, one of seven assocations of the IUGG, itself one of the unions of the ICSU. The IAPSO had its genesis in the formation of a Section of Physical Oceanography (with Prince Albert of Monaco as its first president) at the meeting establishing the IUGG in Brussels, Belgium in 1919. This Section was renamed the Association of Physical Oceanography (APO) at a meeting in Seville, Spain in 1929 held separately from the IUGG General Assembly. In 1948 it was further renamed to the International Association of Physical Oceanography (IAPO) at an IUGG General Assembly in Oslo, Norway. It obtained its present acronym at an IUGG General Assembly held in Bern, Switzerland in 1967 where it was renamed to International Association of Physical Sciences of the Ocean, and its present slightly modified name at an IAPSO General Assembly in Vienna, Austria in 1991. The IAPSO General Assemblies were split off from those of the IUGG starting at a meeting in Tokyo, Japan in 1970.

The primary goal of IAPSO is ``promoting the study of scientific problems relating to the oceans and the interactions taking places at the sea floor, coastal, and atmospheric boundaries insofar as such research is conducted by the use of mathematics, physics, and chemistry.'' This goal is addressed through four objectives:

• organizing, sponsoring, and co-sponsoring format and informal international forums permitting ready means of communication amongst ocean scientists throughout the world;
• establishing commissions, sub-committees, and organizing commensurate workshops to encourage, stimulate, and coordinate new and advanced international research activities;
• providing basic services significant to the conduct of physical oceanography; and
• publishing proceedings of symposia, meetings, and workshops, and fundamental references on the current state of the art and knowledge of physical oceanography.

These objectives are carried out through the efforts of the IAPSO Bureau (consisting of the President and Secretary-General) and the IAPSO Executive Committee, with most of the organization and work carried out via various commissions periodically constituted to address particular areas of interest. It maintains formal liasons with both SCOR and IOC.

The presently (1998) constituted IAPSO commissions are the Commissions on Mean Sea Level and Tides, on Sea Ice, on Natural Marine Hazards, and for Cooperation with Developing Countries. There is also a Tsunami Commission jointly constituted with the IASPEI. Other services are a Permanent Service for Mean Sea Level (PSMSL and a Standard Seawater Service. IAPSO publications include a Publications Scientifiques series (of which 35 have been printed between 1931 and 1995), a Process Verbaux series of General Assembly reports, a Reports and Abstract of Communications series of abstracts presented at General Assemblies, and a general series of yearly reports from commissions and other activities.

[http://www.olympus.net/IAPSO/]

IBC

Abbreviation for International Bathymetric Chart.

IBCCA

Abbreviation for International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico, an ocean mapping activity of the IOC.

IBCAO

Abbreviation for International Bathymetric Chart of the Arctic Ocean, an initiative to develop a digital database containing all available bathymetric data north of 64 degrees north.

[http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/arctic.html]

IBCEA

Abbreviation for International Bathymetric Chart of the Central Eastern Atlantic, an ocean mapping activity of the IOC.

IBCM

Abbreviation for International Bathymetric Chart of the Mediterranean and Its Geological and Geophysical Series, a series of 1:250,000 maps of the bathymetric, geological and geophysical characteristics of the Mediterrean Sea area. This is an activity of the IOC.

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

IBCRSGA

Abbreviation for International Bathymetric Chart of the Red Sea and Gulf of Aden.

IBCWIO

Abbreviation for International Bathymetric Chart of the Western Indian Ocean, an ocean mapping activity sponsored by the IOC, UNESCO, and the German government. The initial mission of the project is to create a new bathymetric mapping of the Western Indian Ocean, with future missions involving the mapping of other measurements such as sediment thickness, potential fields, and geological structure. The German Hydrographic Office (GHO) is taking the responsibility for providing project coordination, editing, conversion to digital media, printing, and distribution of the new bathymetry. The IBCWIO is coordinate with four other international regional ocean mapping projects sponsored by the IOC: IBCCA, IBCWP, IBCEA, and IBCM, with the project also coordinate with GEBCO.

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

IBCWP

Abbreviation for International Bathymetric Chart for the Western Pacific, an ocean mapping activity of the IOC.

IBEX

Acronym for Ice Backscattering Experiment, a project of the APL at the University of Washington School of Oceanography. It was part of ONR's Sea Ice Mechanics Initiative (SIMI) and was conducted during April 1994. The goal of IBEX was to use the CABEX array to image sea ice at 400 Hz and to hopefully observe crack formation and display the resulting images in near real-time. See the IBEX Web site.

Iberia Basin

An ocean basin located to the west of Spain in the eastern North Atlantic Ocean. This is connected to the West Europe Basin to the north via the Theta Gap and includes the Tagus Abyssal Plain and the Horseshoe Abyssal Plain. This has also been called the Spanish Basin. See Fairbridge (1966).

ice shelf

An ice sheet that extends over the sea and floats on the water. These range in thickness from a few hundred to over 1000 meters and are connected to land at coastal grounding lines and where they flow around islands. They calve icebergs at their seaward fronts and gain mass by flow from grounded ice sheets and glaciers and from new snow accumulation. Iceberg calving is the primary ablation process with melting providing a secondary mechanism. Ice shelves are key indicators of climate change since they respond much more rapidly than grounded ice sheets or glaciers to changes in climate. The continent of Antarctica is surrounded by ice shelves, with the largest being the Ross Ice Shelf, covering over 500,000 km$^2$.

iceberg

Large floating chunks of ice formed by the breaking off, i.e. calving of ice sheets at their seaward edges.

Icelandic low

A center of action between Greenland and Iceland and extending to the Canadian Arctic over Baffin Island. It persists year round with some variation in intensity, extent, and central location. The center has a mean surface pressure of around 994 mb in January. See Angell and Korshover (1974).

Iceland Basin

See van Aken (1995).

Iceland-Faroe Front

An oceanic front topographically locked to the Iceland-Faroe Ridge. The front separates the waters of the Atlantic Ocean to the south from the cold, low salinity waters of the Arctic Mediterranean to the north. More specifically, it separates the Atlantic water from colder and fresher water which is in most areas a mixture of water from the north and recirculated Atlantic Water either from the North Iceland Irminger Current or from the Faroe Current. The near surface expression of the Iceland-Faroe Front is usually well represented by the path of the 35.00 isohaline.

The Front extends from the southeast coast of Iceland where the Iceland-Faroe Ridge impinges upon the Icelandic shelf. The Front is generally sharp with abrupt cross-frontal temperature and salinity changes as it begins close to Iceland. As it progresses eastwards, it becomes more diffuse so that north of the Faroes, cross-frontal gradients become considerably smaller. There is an associated progressive change in the vertical slope of the front, from 0.015 at 400 m depth close to Iceland to a factor of 5 less northeast of the Faroes. The Front maintains contact with the bottom until it reaches the sharp eastern corner of the Faroe Plateau, where its near-surface expression has also become much more diffuse.

The Front is not a smoothly varying boundary, but is typically distorted by meanders and eddies of 30-50 km scale. The frontal meanders are probably due to baroclinic instability, and move eastwards along the front. The meanders have been measured to propagate with an average speed of 3.3. km/day and were discernible for 2-3 months. Eddies derived from unstable meanders are found on both sides of the Front, with observed scales ranging from 15 to 70 km. Eddy production is estimated to be about one per day. The eddies are most pronounced in the 70 km wide uppermost 100 m layer of the Front, although the effects can usually be seen down to the typical 400 m depth of the crest of the ridge or deeper. See Hansen and Osterhus (2000).

Iceland-Scotland Overflow Water

A deep water mass found over the slopes of the Iceland-Scotland Ridge in the Iceland Basin. The typical characteristcs at around 20$^\circ$W are $\Theta$ = 2.5$^\circ$C and S = 34.98. The main source for ISOW is assumed to be the NSDW found below the permanent pycnocline in the Norwegian Sea. The O$_2$ and Si concentrations in ISOW are also slightly lower than in NSDW. See van Aken (1996).

Iceland Sea

A marginal sea located in the North Atlantic Ocean. It is roughly defined as the waters lying to the west of Jan Mayen Ridge at about 7$^\circ$ W. It adjoins the waters of the Norwegian Sea to the east, the Greenland Sea to the north, the Denmark Strait to the west, and the North Atlantic Ocean to the south. The average depth of this region is about 1128 m.

In the summer, the volume of the Iceland Sea is composed of about 60% Greenland Sea Deep Water (GSDW), 30% upper and lower Arctic Intermediate Water (AIW), with the remaining 10% distributed among the Polar Intermediate Water (PIW), - surface water masses (i.e. Polar Water (PW), Atlantic Water (AW), and Arctic Surface Water (ASW)). See Swift (1986), Hopkins (1991) and Buch et al. (1996).

ICES

Acronym for International Council for the Exploration of the Sea, a scientific forum for the exchange of information and ideas on the sea and its living resources and for the promotion and coordination of marine research by scientists within its member countries. ICES, the oldest intergovernmental organization in the world concerned with marine and fisheries science, was established in Copenhagen in 1902. While it was established in 1902, it had its genesis in an international conference convened by King Oscar II of Sweden in Stockholm in the spring of 1899. Both good and bad fishing years had started to so greatly affect seafaring nations in the 19th century that several governments had appointed committees and commissions to study fishing in their territorial waters. The 1899 conference was proposed to create a larger and more comprehensive program of research not confined to the territorial waters of any single nation. The delegates were a who's who of reknowned ocean scientists at the time including John Murray, Victor Hensen, Friedrich Heincke, Otto Krummel, Otto Pettersson, Gustav Ekman, Theodor Cleve, Fridtjof Nansen, and Johan Hjort. After three years of resolving various political and scientific differences, the ICES was finally established in 1902 with charter members Britain, Denmark, Finland, Germany, Holland, Norway, Russia and Sweden. See Thomasson (1981). See the ICES Web site.

ICITA

Acronym for International Cooperative Investigation for the Tropical Atlantic, an IOC project.

ICOIN

Acronym for the Canadian Inland Waters, Coastal and Ocean Information Network. See the ICOIN Web site.

ICSEM

Acronym for International Commission for the Scientific Exploration of the Mediterranean Sea.

ICSPRO

Abbreviation for Inter-Secretariat Committee on Scientific Programs Relating to Oceanography, composed of UN/FAO/UNESCO/WMO/IMO.

ICW

Abbreviation for Indian Central Water.

ideal gas law

A simplifed equation of state that can be used to relate the pressure, density and temperature of gases in a dry atmosphere. The law can be stated as

$$P\,=\,\rho\,{R_d}\,T$$

where $P$ is the pressure, $\rho$ the density and $T$ the temperature. ${R_d}$ is the gas constant for dry air and equal to 287.053 JK$^{-1}$kg$^{-1}$ or 0.287053 kPaK$^{-1}$m$^3$kg$^{-1}$. This can also be used for calculations with moist air via the virtual temperature concept.

IDEAS

Acronym for International Decade of Exploration and Assessment of the Seas. Now defunct.

IDMS

Abbreviation for International Directory of Marine Scientists.

IDOE

Abbreviation for International Decade of Ocean Exploration, an IOC initiative lasting from 1971-1980. IDOE was a long-term, multipurpose oceanographic research program carried out on an international cooperative basis during the 1970s. The idea was first proposed by the U.S. President in March 1968, and endorsed by the U.N. in December 1968. The NSF was charged with planning, managing and funding the U.S. part of IDOE in late 1969. The goals of IDOE were to:

• provide the scientific basis needed to improve environmental forecasting;
• determine the potential resources of the ocean floor;
• determine the quality of the ocean world environment, evaluate the impact of human activities on that environment, and establish a scientific understanding of the basis for corrective actions needed to preserve it;
• improve worldwide data exchange through updating and standardizing national and international marine data colllection, processing and distribution; and
• provide basis knowledge of biological processes needed for the intelligent use of living ocean resources.

The cooperative projects accomplished in pursuit of these objectives included GEOSECS, MODE, NORPAX, CLIMAP, ISOS, POLYMODE, CUEA, the Seabed Assessment Program, Project FAMOUS and the Living Resources Program.

[http://www.nap.edu/books/0309063981/html/index.html]

IEO

Abbreviation for Instituto Españal de Oceanografía, the national oceanographic institute of Spain. See the IEO Web site.

IES

Abbreviation for inverted echo sounder.

IFREMER

Acronym for Institut Français de Recherche pour l'Exploitation de la Mer. See the IFREMER Web site.

IFYGL

Abbreviation for International Field Year on the Great Lakes. See Csanady (1974).

IGBP

Abbreviation for International Geosphere-Biosphere Program, a scientific research program built around a family of core projects whose mission is to deliver scientific knowledge to help human societies develop in harmony with Earth's environment. The core projects are:

• BAHC (Biospheric Aspects of the Hydrological Cycle);
• GAIM (Global Analysis, Integration and Modeling);
• GCTE (Global Change and Terrestrial Ecosystems);
• GLOBEC (Global Ocean Ecosystem Dynamics);
• IGAC (International Global Atmospheric Chemistry);
• IGBP-DIS (Data and Information Services);
• JGOFS (Joint Global Ocean Flux Study);
• LOICZ (Land-Ocean Interactions in the Coastal Zone);
• LUCC (Land-Use and Land-Cover Change);
• PAGES (Past Global Changes);
• START (System for Analysis, Research and Training);

[http://www.igbp.kva.se/]

IGOM

Acronym for integrated global ocean monitoring.

IGOS

Acronym for Integrated Global Observating Strategy, a program to unite the major satellite and surface-based systems for global environmental observations of the atmosphere, oceans and land. The major objectives of IGOS include:

• strengthening space-based/in situ linkages to improve the balance between satellite remote sensing and ground- or ocean-based observing programs;
• encouraging the transition from research to operational environmental observations within appropriate institutional structures;
• improving data policies and facilitating data access and exchange;
• stimulating better data archiving to build the long-term time series needed to monitor environmental change; and
• increasing attention to harmonization, quality assurance, and calibration/validation so data can be used more effectively.

[http://ioc.unesco.org/igospartners/igoshome.htm]

IGOSS

Acronym for the Integrated Global Ocean Services System. See the IGOSS Web site.

IGSP

Abbreviation for International Greenland Sea Project.

IGY

Abbreviation for International Geophysical Year, and ICSU project during 1957-1958.

IHB

Abbreviation for International Hydrographic Bureau, later replaced by IHO.

IHO

Abbreviation for International Hydrographic Organization, located in Monte Carlo, Monaco. The IHO is an intergovernmental consultative and technical organization working to support the safety of navigation and the protection of the marine environment. The genesis of the IHO was at a Hydrographic Conference in London in 1919 where 24 nations met and decided to create a permanent body. This led to the creation of the International Hydrographic Burea (IHB) in 1921 with 19 Member States. The IHB was provided with headquarters in the Principality of Monaco at the invitation of Prince Albert I. The name of the organization was changed to IHO (with the headquarters in Monaco remaining the IHB) in 1970. As of 1998, the IHO has 62 maritime States with ten more in the process of becoming members. The official representative of each Member State is usually the national Hydrographer or Director of Hydrography, with these persons (along with their technical staffs) meeting every 5 years in Monaco for an International Hydrographic Conference. There progress is reviewed on current projects, new projects are adopted, and a Directing Committee of three senior hydrographers is elected to guide the Bureau until the next conference.

The chief activities of the IHO are:

• working towards standardization in the specifications, symbols, style and formats used for nautical charts and related publications;
• producing a common, worldwide chart series (INT charts) to a single set of agreed specifications, with the program for INT small scale (i.e. 1/10,000,000 and 1/3,500,000) charts started in 1971 completed and those for large and medium scales proceeding rapidly;
• managing radio navigational warnings via the Global Maritime Distress and Safety System (GMDSS);
• coordinating the development of Electronic Chart Display and Information Systems (ECDIS) to ensure the standardization of specifications, including the establishment of the IHO Data Center for Digital Bathymetry (DCDB) located at the NGDC;
• creating and publishing (along with the Fédération Internationale des Géomètres, or FIG) a comprehensive set of standards of competence for hydrographic surveyors;
• providing technical assistance for establishing and strengthening the hydrographic capabilities of developing nations;
• examining and archiving copies of every unclassified new chart and publication of each Member State (with the archives holding more than 21,000 charts);
• overseeing a computerized Tidal Constituent Data Bank (TCDB) which archives and supplies data for over 4,000 tidal stations;
• encouraging the establishment of Regional Hydrographic Commissions and advising those thus established;
• overseeing such services as the World Series of Bathymetric Plotting Sheets and the General Bathymetric Chart of the Oceans GEBCO; and
• publishing associated material.

Among the more than 40 publications of the IHO are the semi-annual International Hydrographic Review (containing original papers on technical aspects in the fields of hydrography, descriptive oceanography, and cartography), the monthly International Hydrographic Bulletin (containing topical news of worldwide hydrographic activities including lists of charts and nautical publications of member states), a Yearbook, an Annual Report, and numerous other limited, specialty publications.

[http://www.iho.shom.fr/]

IIOE

Abbreviation for International Indian Ocean Expedition, an IOC project carried out in 1964. It included the first intensive measurements of simultaneous momentum, heat and moisture fluxes using profile methods. See

IMAGES

Acronym for International Marine Global Change Study, a joint project of SCOR and PAGES whose primary goals are to quantify climate and chemical variability of the ocean on time scales of oceanic and cryospheric processes, determine the sensitivity of the ocean to identified internal and external forcing functions, and determine the ocean's role in controlling atmospheric CO$_2$. A global program including at least 30 dedicated oceanographic expeditions from 1994-2004 is planned to answer questions concerning how changes in ocean properties controlled the evolution of global heat transfer through to deep and surface ocean and so modified the climate, how changes in ocean circulation, chemistry, and biological activity have interacted to generate the observed record of pCO$_2$ over the past 300 Ka, and how close continental climate has been linked to ocean surface and deep water properties.

IMDC

Abbreviation for Irish Marine Data Center. See the IMDC Web site.

implicit scheme

In numerical modeling, an integration algorithm that temporally advances an approximate solution via discrete steps using information from present as well as from previous time steps. These are computationally more complex than explicit schemes but allow longer time stepping intervals and usually have better numerical stability properties. See Kowalik and Murty (1993).

IMR

Abbreviation for Institute of Marine Research, a research institute located in Bergen, Norway. See the IMR Web site.