Salinity distribution

Figure 5.21. Salinity distribution on the northern Great Bahama Bank. (After Morse etal., 1984.)...

Fig. 16.21 Mars Hill, 1973 location and isochloride contours (mg/1). Groundwater has almost recovered, but the salinity distribution still reflected the southward direction of groundwater flow. (From Dennis, 1973.)...

Computed from global temperature and salinity distribution (WOAOl) assuming 100% saturation. Estimated uncertainty about 10%. 

Figure 1 Salinity distribution with depth of the reservoir rocks from several basins in North America. Note the different trends and the reversal of salinity in California and south Louisiana (source Kharaka and Thordsen, 1992).

The distribution of salinity in surface waters of the ocean is presented in Fig. 1.1. Because the concentrations for many major seawater constituents are unaffected by chemical reaction on the time scale of ocean circulation, local salinity distributions are controlled by a balance between two physical processes, evaporation and precipitation. This balance is reflected by low salinities in equatorial regions that result from extensive rain due to rising atmospheric circulation (atmospheric lows) and high salinities in hot diy subtropical g5Tes that flank the equator to the north and south (20-35 degrees of latitude) where the atmospheric circulation cells descend (atmospheric highs). 

The fast changes in the transition area are illustrated in Fig. 19.5, which shows model snapshots of current patterns and of salinity distribution at intervals of 14-28 h. The simulations are carried out with a horizontal grid resolution of 1 nautical mile and reproduce the observations of a ship campaign very well (see Schmidt et al., 1998). This combined approach of field measurements and modeling revealed that the typical processes in the Belt Sea are too fast for a synoptic representation of data measured by ships. During a ship survey of two to three days, currents may change direction several times and a combination of the data into a quasi-synoptic picture may suggest spurious spatial correlations. 

FIGURE 19.5 Model snapshots of salinity distribution (gray scale and isolines) and currents (arrows) in 5 m depth. 

FIGURE 1. Diagrammatic view of an estuary, showing typical, nontidal water circulation and resultant salinity distribution (parts per thousand). 

Manheim and Horn (1968) summarized subsurface hydrochemical data from a shoreline transect extending from Long Island to the Florida Keys and provided a map of inferred salinity distributions from surface to igneous—metamorphic basement. The southeastern Atlantic region from... 

In interpreting the diagrams, we note that the isosalines may be subject to error, particularly where salinity distributions are complex, as between Echols and Mitchell counties, Georgia, (between MI-J and EC-2, Figs. 1 and 3), or in the deeper parts of the offshore basin. There may be inliers of different salinity and complex microstructure that cannot be depicted at the scale used here. Moreover, the salinities derived from the SP log in the deeper Southeast Georgia Embayment may be in error because of clay colloids and may understate true formation-fluid salinity. 

The vertical salinity distribution in the open sea in summer was characterized by slight growth from the surface downwards to the sea bottom. This increase was more significant in the southwestern and western parts of the sea where in July-August a halocline was formed in the surface layer that coincided with the thermo-cline, which made the vertical mixing much more difficult. 

In August the desalting effect of river flow was rather prominent and could be traced in salinity distribution over the sea. The lowest water salinity of 9.3-9.5 ppt was recorded in the southwestern part of the sea (see Fig. 5). In the central part it increased on the surface to 10.4 ppL High salinity of surface waters was observed in August (10.5-10.6 ppt) in the eastern shallow part where the evaporation was most intensive. In sununer, due to the growing effect of the river flow, the vertical salinity gradients also increased. Near the bottom it was 10.2-10.6 ppt practically over the whole sea (Fig. 6). The maximum salinity near the sea bottom - 10.7 ppt was recorded in the central and western parts which could be attributed to saline water creeping from the eastern shallow areas. 

In October, the salinity distribution was more even than in August (see Fig. 5). Decrease of the river flow was accompanied by growing water salinity in the southwestern part of the sea where its values varied from 9.6 to 10.2 ppt. In other sea areas the water salinity was 10.3-10.6 ppt. With the water cooling and development of convection the vertical salinity distribution in October became rather uniform in all regions of the sea except for the western trough (Fig. 6). 

Explain how the salt tolerance data of Table 11.2 might be related to real-world salinity distributions, such as shown in Figs. 11.2,11.3, and 11.5. 

The potential values presented in Table 9.2 are based on the consideration of all river systems worldwide. In practice, only a part of the rivers offers suitable conditions for the operation of osmotic power plants, taking practical and economic considerations into account. Salinity distribution depends on the characteristics of the river estuary that can determine the four configurations shown in Figure 9.16. 

Figure 9.16 Basic circulation and salinity distribution in salt wedge, partially mixed, well-mixed and fjord-type estuaries. Numbers and shading show salinity values [34]...

The Amazon and Fly River (Papua New Guinea) estuaries serve as good examples of the five features outlined above. The salinity distribution of dissolved Nd (<0.22 pm) in fig. 12 is representative of the other bivalent lanthanides. This figure contains data for both surface and deep waters the bottom part B is an expanded scale for S >3 samples. The Fly and Amazon data sets have Nd-salinity distributions for surface waters which are remarkably similar and exhibit the same two major features (1) removal of dissolved lanthanides in the low (0-5) salinity region and (2) desorption in the seaward region. Hence, it appears that the removal process and the release process (desorption) are decoupled. 

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