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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 ...
(1535-1582) A British innkeeper who wrote what some consider to be the first popularization of the extent ideas constituting that which we now consider to be the field of oceanography. In this book, entitled A booke called the Treasure for Traveilers, deuided into fiue Bookes and published in 1578, he invoked the primum mobilus concept as the driving force beyond the movement of the moon, but also ascribed to the moon itself some unknown power responsible for the observed tides and steady currents (whose complexity beyond the steady westward flow of the primum mobilus he also deemed partially due to the distrupting presence of land masses).
Bourne's picture of the flow in the Atlantic started with the general westward flow around the southern tip of Africa merging with that in the Atlantic, with the combined volume being too great to squeeze through the Straits of Magellan. Thus part of the flow was diverted northwards along the South American coast, into the Gulf of Mexico, and then out between Florida and Cuba and eastwards towards Europe. He also proposed a second type of steady, non-tidal current that flows against the wind during periods of strong winds, with the driving force being a hypothesized upward tilt of the sea surface downwind caused by waves piling up water there.
Industry:Earth science
An experiment conducted between March 1 and 10, 1994 aboard the RV A. V. Humboldt as a collaborative project between the IRSA in Italy and the Institute for Baltic Sea Research-IOW in Germany. Water was collected along several transects and at anchor stations over the diel cycle from four or five depths using a rosette. A pulse amplitude modulated (PAM) fluorometer was used on sample concentrated by gentle filtration to measure phytoplankton photosynthesis.
Industry:Earth science
A set of filtering approximations originally developed by Boussinesq.
In his attempts to explain the motion of the light in the aether Boussinesq (in 1903) opened a wide perspective of mechanics and thermodynamics. With a theory of heat convection in fluids and of propagation of heat in deforming or vibrating solids he showed that density fluctuations are of minor importance in the conservation of mass. The motion of a fluid initiated by heat results mostly in an excess of buoyancy and is not due to internal waves excited by density variations. In other words, the continuity equation may be reduced to the vanishing of the divergence of the velocity field, and variations of the density can be neglected in the inertial accelerations but not in the buoyancy term. Although used before him, Boussinesq's theoretical approach established a cardinal simplification for a special class of fluids which fundamentally differ from gases and may eliminate acoustic effects.
They result in an equation set applied to almost all oceanic motions except sound waves. The four approximation steps are:
* subtracting a motionless hydrostatically balanced reference state from the equations of motion;
* making the anelastic approximation;
* assuming that the vertical scale of motion is small compared to the scale depth (or height); and
* ignoring the inertial but not the buoyancy effects of variations in the mean density.
The term ``Boussinesq approximation'' is not always used identically with the above series of approximation steps, e.g. it may or may not include the assumption of incompressibility.
Mahrt (1986) addresses the issue of which assumptions properly constitute the Boussinesq approximations:
The derivation of conditions for the validity of the Boussinesq approximations is not as straightforward as many would assume. In the literature, a variety of sets of conditions have been assumed which, if satisfied, allow application of the Boussinesq approximations. The Boussinesq approximation can be divided into two parts. The first group of assumptions allows use of incompressible mass continuity and linearization of the ideal gas law, which are referred to as the shallow motion approximations. Additional restrictions allow neglect of the pressure influence on buoyancy. This more restrictive subclass of shallow motions is equivalent to the full Boussinesq approximations, also referred to as the shallow convection approximations.
The different derivations of the shallow motion approximations share the following conditions:
* the perturbations of variables of state must be small compared to basic state averaged values;
* the motion must be shallow compared to the scale depth of the basic flow; and
* restrictions on the time scale are required.
Industry:Earth science
A U. K. contribution to JGOFS funded by the NERC. The goal of GOFS was to study differences in glacial-interglacial paleoenvironments of the eastern Atlantic Ocean, especially between the last glacial and the Holocene. The results are presented in a special issue of Paleoceanography (Vol. 10, No. 3, 1995).
Industry:Earth science
A cooperative endeavor among national government agencies in the countries surrounding the Baltic Sea responsible for the collection of observations, model operations and production of forecasts, services and information for the marine industry, and public and other end users. BOOS is a regional Task Team under EuroGOOS.
BOOS will be implemented from 1999-2003 by the accomplishment of nine projects:
* optimizing the existing operational observing network;
* use of remote sensted radar and satellite data;
* an operational mesoscale analysis system called PRODAS;
* optimization of existing models and coupled models;
* ecological modeling;
* study of harmful algae blooms via HABWARN;
* development of an anthropogenic load model;
* development of Info-BOOS.
Industry:Earth science
The hypothesis that ENSO varies as a self-sustained cycle in which anomalies of SST in the Pacific cause the trade winds to strengthen or slacken, and that this in turn drives the changes in ocean circulation that produce anomalous SST. First advanced by Bjerknes (1969).
Industry:Earth science
One of three major components of deep sea sediments, the other two being authigenic and detrital. Biogenic sediment consists mainly of calcite and opal produced as the hard parts of organisms and eventually precipitated. Calcite is formed by coccoliths (plants) and foraminifera (animals) and opal by diatoms (plants) and radiolarians (animals).
Industry:Earth science
A project of the MAST and INCO program of the EU. The objectives of BASYS are to further the understanding of the susceptibility of the Baltic Sea to external forcing and to improve the quantification of past and present fluxes.
Industry:Earth science
A research expedition carried out in the Antarctic regions from 1897 to 1899 aboard the ship `Belgica. This was the first vessel to winter in the Antarctic regions.
Industry:Earth science
The ratio of the acoustic power scattered at an angle of 180° from the incident acoustic wave to the acoustic intensity incident on a unit volume or area. This measure, typically referenced to a unit distance, e.g. 1 m, is the ratio of the reflected acoustic power to incident acoustic power per unit area. The units of this ratio are area, e.g. m<sup>2</sup>.
Industry:Earth science
