Density Currents

Density Currents

 

currents in the seas and oceans caused by the horizontal pressure gradients resulting from the nonuniform distribution of density in seawater. Permanent density currents, along with wind currents, play an important part in the overall circulation system of the surface waters of the world ocean. In the deep layers, where wind-driven currents are attenuated, density currents predominate. They are characteristic in straits between bodies of water with different densities. Owing to the Coriolis force, density currents move perpendicular to the horizontal density gradients.

The theory of density currents is based on the circulation theory of the Norwegian geophysicist V. F. K. Bjerknes. The theory was elaborated by the Norwegian B. Helland-Hansen, the Swede J. W. Sandström, and the Soviet scientist N. N. Zubov, who propounded the dynamic method of calculating sea currents from the distribution of water density.

References in periodicals archive ?
Convectively generated cold pools (such as from an MCS) and other density currents (such as sea breezes or cold fronts) may develop bores when they intrude into a SBL of sufficient depth.
The agency reiterated its warning to the public that sudden explosions, lava collapses, pyroclastic density currents and ashfalls could still occur and threaten villages along the slopes of the volcano.
The public is reminded that sudden explosions, lava collapses, pyroclastic density currents (PDCs) and ashfall can still occur and threaten areas in the upper to middle slopes of Mayon.
The public is also reminded of sudden explosions, lava collapses, pyroclastic density currents or PDCs and ashfall that may threaten areas in the upper to middle slopes of Mayon.
Fine dust from pyroclastic density currents, due to its small size, can be suspended in the air, and may eventually reach residential areas outside the danger zone, she warned.
"Lahar flow from Mayon, composed of 9 million cubic metre pyroclastic density currents and 1.5 million cubic metres of ash fall found their way to the Mi-isi, Lidung/Basud, and Buyuan channels, and could bury villages of Camalig and Daraga towns of Albay province since the volcano first spewed ash since Monday," Philippine Institute of Volcanology and Seismology (Phivolcs) head Renato Solidum told Gulf News on Sunday.
"A total of two (2) explosion-type earthquakes corresponding to the vertical column eruptions, fifteen (15) tremor events, some corresponding to lava fountaining episodes, thirty five (35) rockfall events and (2) pyroclastic density currents or PDCs from lava collapse were recorded by Mayon's seismic monitoring network," it said.
on Monday, lasting five and seven minutes respectively and producing rock falls and small-volume pyroclastic density currents. "These events appear to have originated from the lava front and produced an ash cloud that drifted to the southwest sector," the institute explained, adding that ash fall had been reported in at least 27 villages in the municipalities of Guinobatan and Camalig in Albay province.
The theory of density currents was developed by Benjamin [11], based on previous studies [12-15].
The 2016 edition of the esteemed series features lengthy articles on the fluid mechanics of heart valve replacements and pyroclastic density currents, and the dynamics of vortex pairs, microtubules, and motor protein assemblies.
which has the shape of a diffusion equation; local diffusion of probability density currents or virtual outflows of matter at the actual particle position.
Generation of density currents in reservoirs significantly influence transferring and discharging of silt particles from the reservoir and generally increases the progress of large size particles towards dam wall.