Horizontal Segregation

Nutrients are carried back to the sea surface by the return flow of deep-water circulation. The degree of horizontal segregation exhibited by a biolimiting element is thus determined by the rates of water motion to and from the deep sea, the flux of biogenic particles, and the element s recycling efficiency (/and from the Broecker Box model). If a steady state exists, the deep-water concentration gradient must be the result of a balance between the rates of nutrient supply and removal via the physical return of water to the sea surface. 

Table 10.1 Horizontal Segregation of Biologically Utilized Elements between the Deep Atlantic and the Deep Pacific. ...

As with the calcareous tests, BSi dissolution rates depend on (1) the susceptibility of a particular shell type to dissolution and (2) the degree to which a water mass is undersaturated with respect to opaline silica. Susceptibility to dissolution is related to chemical and physical factors. For example, various trace metals lower the solubility of BSi. (See Table 11.6 for the trace metal composition of siliceous shells.) From the physical perspective, denser shells sink fester. They also tend to have thicker walls and lower surface-area-to-volume ratios, all of which contribute to slower dissolution rates. As with calcivun carbonate, the degree of saturation of seawater with respect to BSi decreases with depth. The greater the thermodynamic driving force for dissolution, the fester the dissolution rate. As shown in Table 16.1, vertical and horizontal segregation of DSi does not significantly coimter the effect of pressure in increasing the saturation concentration DSi. Thus, unlike calcite, there is no deep water that is more thermodynamically favorable for BSi preservation they are all corrosive to BSi. 

Export of DOM into Deep Ocean and Horizontal Segregation... 

Horizontal segregation The horizontal gradient in biogenic materials, such as nutrients and O2, that is established by the interacUon between the biogeochetnical cycling of pardculate organic matter and meridional overturning circulation. 

The situation can be quite complex since material is often fed into containers or on to belt conveyors from the side, hence the feeding itself can generate both vertical and horizontal segregation. Generally little is known in advance concerning the homogeneity of a system and uniformity is rarely constant and often non-random. Conditions often... 

There is also a horizontal segregation of biologically utilized elements in the deep Atlantic and the deep Pacific. The water circulation pattern in the ocean is responsible for the enrichment of biologically active elements in the deep Pacific relative to the deep Atlantic. Such effects are lucidly explained by Broecker and Peng (1982). 

Total of TIs for packages in the group Horizontal segregation distance (from forward face of group of packages to inside wall of occupied compartment (m))... 

K.E. Wirth and O. Molerus, Prediction of pressure drop in horizontal segregated pneumatic conveying with strands sliding along bottom of the pipe, German Chem. Eng. 4(5) (1981) 278-284. 

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