- Settore: Education
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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 ...
A unit of pressure equal to the pressure of 29. 530 in. or 750. 062 mm of mercury under the standard conditions of 0° C temperature and 9. 80665 m/s<sup>2</sup> gravitational acceleration. Also, a popular locale during lengthty conferences.
Industry:Earth science
One of five vertical ecological zones into which the deep sea is sometimes divided. This is the zone starting from 100 to 700 m deep (coinciding with the upper limit of the psychrosphere) at the 10 C isotherm. The number of species and populations decreases greatly as one proceeds into the bathypelagic zone where there is no light source other than bioluminescence, temperature is uniformly low, and pressures are great. This overlies the abyssopelagic zone and is overlain by the mesopelagic zone.
This is the lowest of the three vertical sections of the pelagic part of the ocean, the other two being the upper euphotic and the middle mesopelagic.
Industry:Earth science
A WHOI program in 1996 and 1997 who goal was to use two independent methods to quantify turbulent mixing in the eastern Brazil Basin. The methods employed were:
* injecting an SF6 tracer and tracking its dissipation over time; and
* making discrete, instantaneous estimates of the turbulence using the HRP instrument.
The experiment involved released approximately 110 kg of sulfur hexafluoride on an isopycnal near 4000 m depth near 21° 40' S, 18° 25' W. The location is over a system of ridge spurs and canyons that run zonally towards the crest of the Mid Atlantic Ridge. The spurs attain depths of nearly 4400 m in the vicinity of the tracer release and the canyon valleys about 5000 m, with both shoaling to the east towards the Ridge crest where individual bathymetric peaks extend to about 2000 m depth.
The tracer was surveyed in 1996 within two weeks of its release, with HRP measurements indicating weak turbulent dissipation at all depths (with a diapycnal diffusivity of about 0. 1 cm<sup>2</sup> s<sup>-1</sup>) in the western half of the Brazil Basin where the bottom is smooth. Mixing rates were much greater over the rough topography, with measured diapycnal diffusivity values of about 0. 5 cm<sup>2</sup> s<sup>-1</sup> for the depth and region of the tracer cloud (and values greater than twice this near the bottom). A survey cruise in 1997 sampled the distribution of sulfur hexafluoride about 14 months after its release. The average diffusivity over the 14 months on the injection isopycnal was estimated to be at least 1. 5 cm<sup>2</sup> s<sup>-1</sup>, with values of 10 cm<sup>2</sup> s<sup>-1</sup> estimated near the bottom of the canyons.
Industry:Earth science
An instrument for measuring optical and physical parameters in the water column.
Industry:Earth science
A BALTEX program to investigate vertical mixing and advection in the major basins of the Baltic Sea.
Industry:Earth science
The sloping section of a beach profile below the beach berm which is normally exposed to the action of the wave swash.
Industry:Earth science
A synoptic meteorology rule stating that if, in the northern hemisphere, an observer stands with his back to the wind, pressure is lower on his left hand than on his right, while in the southern hemisphere the converse is true. This was enunciated by Buys Ballot of Utrecht in 1857 and is basically a restatement of the fact that winds blow clockwise around a depression in the northern hemisphere and anticlockwise in the southern hemisphere.
Industry:Earth science
A experiment that took place in the North Pacific in 1986-87.
Industry:Earth science
In oceanography, depth-independent circulation due to changes in surface elevation.
Industry:Earth science
