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Founded in 1876, Texas A&M University is a U.S. public and comprehensive university offering a wide variety of academic programs far beyond its original label of agricultural and mechanical trainings. It is one of the few institutions holding triple federal designations as a land-, sea- and ...
In physical oceanography, a type of water mass in the Southern Ocean thought to originate mainly through convective overturning of surface waters during winter west of South America, after which it is injected into the subtropical gyre and fills the southern subtropics and tropics from the east.
In the Atlantic, the densest SAMW found in the Subantarctic Zone between the Subantarctic Front and the Subtropical Front is thought to be the primary precursor to AAIW, although some postulate substantial input across the Subantarctic Front. The AAIW in the South Atlantic originates from a surface region of the circumpolar layer, especially in the northern Drake Passage and the Falkland Current loop. AAIW from the Indian Ocean is added to the Atlantic AAIW via Agulhas Current leakage. The AAIW is recognized by a subsurface oxygen maximum and a salinity minimum north of about 50°S, although the oxygen maximum becomes weak north of 15°S. The oxygen maximum is found at a slightly lower density than the salinity minimum.
The salinity minimum is found at about 300 m near the Subantarctic Front at around 45°S, descends northward to 900 m at 30°S near the subtropical gyre center, and rises again to 700 m at the equator. The AAIW spreads to the North Atlantic, identified by a salinity minimum near the equator at a ''σθ''value of about 27. 3. This minimum has been found to 24°N, although traces of AAIW can be followed as far north as 60°N. AAIW is characterized by a temperature near 2. 2° C and a salinity around 33. 8 near its formation region, but erodes by the time it reaches the Subtropical Front to values closer to 3° C and 34. 3.
Industry:Earth science
A condition observed annually in the coast water off Peru in which the water is discolored red or yellow and there is a significant loss of marine life. It typically occurs from April through June and is probably caused by an increase in water temperatures via the importation of warmer waters by ocean currents. This causes the death of temperature sensitive marine organisms such as dinoflagellates, which may in turn kill other organisms via the release of toxins. The annual nature of this phenomenon makes it distinct from the El Nino phenomenon occurring in the same region. This is also known as salgaso or aqua enferma.
Industry:Earth science
An ocean basin located off the southern tip of Africa at about 43 ° S in the South Atlantic Ocean. It includes the Agulhas Abyssal Plain.
Industry:Earth science
A workshop for physical oceanographers held at Monterey, California from December 15-17, 1997. The goal was to evaluate the current status of research in physical oceanography and to identify future opportunities and infrastructure needs. Similar workshops were held at the time for biological oceanography (sf OEUVRE), ocean chemistry (FOCUS) and marine geology and geophysics (FUMAGES).
Future directions and problems mentioned in the final report included:
* the difficulties inherent in global climate prediction wherein the decadal timescale only allows scientists to observe a few realizations in their lifetimes, and the need to circumvent this by expanding the current database and framing hypotheses about past climate change and ocean circulation using paleoceanographic studies;
* better understanding the ocean's role in the hydrologic cycle;
* advancements on fundamental issues such as the causes of the temperature-salinity relationship, thermocline maintenance, and interhemispheric water mass exchanges;
* the increasing use of observational tools such as satellites and tomography to obtain large-scale, detailed and long-term measurements of the oceans;
* emerging issues concerning connections between large- and small-scale motions, e.g. between small-scale turbulent mixing and large-scale meridional overturning circulation;
* better understanding of the processes involved in cross-shelf transports;
* increased understanding of inland waters such as estuaries, wetlands, tide flats and lakes will probably lead to progress on the general circulation problem;
* unraveling the connections between the spatial and temporal distribution of turbulent mixing, the large-scale meridional overturning circulation, and climate variability;
* radical advances in knowledge of the structure of the ocean on scales between the mesoscale (50 km) and the microscale (less than 10 m) via the use of towed and autonomous vehicles; and
* general circulation model components greatly in need of improvement include deep convection, boundary currents and benthic boundary layers, the representation of the dynamics and thermohaline variability of the upper mixed layer, fluxes across the air-sea interface, diapycnal mixing and topographic effects.
Industry:Earth science
An experiment over the Baltic Sea that is a component of BALTEX. ASCAP is a comprehensive campaign for an air-sea interaction field campaign in the Baltic Sea, with the central aim being to improve model parameterization schemes via a better understanding of the physical mechanisms and validation of remote sensing algorithms. The objectives are:
* measurements of parameters determining air-sea interaction processes, the sea state, and wave spectra;
* in-situ measurements and observations of clouds, water vapor and precipitation;
* parameterization of air-sea interaction processs in region models;
* validation of algorithms to estimate cloud parameters, water vapor and precipitation from radar and satellite data; and
* validation of numerical models against long-term measurements.
The measurement phase took place from 1995 until 1997.
Industry:Earth science
A project funded by MAST III to create a European fleet of lander vehicles that can operate together in joint research projects. Lander vehicles will be built to carry out a variety of experiments ranging from sediment probes to fish tracking. Three facets of lander technology are to be addressed: (1) the development of techniques to launch a fleet of landers from a single ship; (2) the development of new sensors for examining processes in the water of the deep benthic boundary layer at depths ranging from 200 to 5000 meters; and (3) the design and construction of two new types of landers, i.e. one that can carry several sensing devices and another compact one that can be operated from a small vessel.
Industry:Earth science
A collaborative program between the U. S. , Canada and Japan that took place in two phases in 1975-1976. In summer 1975 four manned camps were maintained on ice floes in the Arctic Ocean to measure surface and geostrophic winds, ocean current velocities, and ice floe position. In April of 1976 the submarine USS Gurnard traversed 777 nautical miles along three tracklines in the Beaufort Sea, collecting ice thickness data from upward-looking acoustical soundings.
Industry:Earth science
A term applied to the relationship between isotopic composition and monthly rainfall where months with heavy rainfall show different isotopic concentrations than do months with low rainfall. In high rainfall months, rain frequency is higher which entails a higher relative humidity in sub-cloud air, hence less evaporation from raindrops. Since the rate of evaporation determines the isotopic concentrations (the greater the rate the higher the heavy stable isotope composition), low rainfall months should show a higher heavy stable isotopic composition than high rainfall months.
Industry:Earth science
The ASGAMAGE project started on March 1, 1996 and lasted until March 1, 1999. The scientific objectives were:
* to find relationships between the transport coefficients for the gas fluxes and any relevant geophysical parameters;
* to test new methods and new equipment for the measurement of air-sea fluxes of CO<sup>2</sup>, DMS and other gases;
* to intercompare different methods and systems to measure the transfer velocity of trace gases over the sea; and
* to find out whether and, if at all, under what conditions there can be a significant vertical gradient in the CO<sup>2</sup> concentration in the upper meters of the water column.
ASGAMAGE consisted of two experimental periods, with the first taking place from May 6 to June 7, 1996. It involved taking measurements at and around the Meetpost Noordwijk (MPN), a research platform 9 km off the Dutch coast. The second period, taking place from Oct. 7 to Nov. 8, 1996, involved more measurements at MPN and a cruise of the RRS Challenger. The measurement activities were primarily aimed at a determination of air-sea gas transfer coefficients with the differential tracer method being made simultaneously with micrometeorological experiments.
Industry:Earth science
One of three major basins in the Southern Ocean. It extends from its western border with the Pacific-Antarctic Basin at the Scotia Ridge and Drake Passage (at about 70° W) to its eastern border with the Australian-Atlantic Basin at the Kerguelan Plateau (about 75° E). It consists of the Enderby and Weddell Abyssal Plains and is bounded to the north below 4000 m by the Mid-Atlantic and South-West Indian Ridges except for deeper connections into the Argentine Basin in the western Atlantic and into the deep basins of the western Indian Ocean.
Industry:Earth science
