Dissolved inorganic between

Salinity, S(%e), is defined as the weight ia grams of the dissolved inorganic matter ia 1 kg of seawater after all Br and 1 have been replaced by the equivalent quantity of Cl and HCO3 and ate converted to oxide. In over 97% of the seawater ia the world, the salinity S is between 33%c and... 

The saltiness of the ocean is defined in terms of salinity. In theory, this term is meant to represent the total number of grams of dissolved inorganic ions present in a kilogram of seawater. In practice, salinity is determined by measuring the conductivity of a sample and by calibration through empirical relationships to the International Association of Physical Sciences of the Ocean (IAPSO) Standard Sea Water. With this approach, salinity can be measured with a precision of at least 0.001 parts per thousand. This is fortunate, considering that 75% of all of the water in the ocean falls neatly between a salinity of 34 and 35. Obviously, these high-precision measurements are required to observe the small salinity variations in the ocean. 

Equations 11.171.1 to 11.171.3 are, however, of limited practical application because they demand precise knowledge of the state of speciation of carbonates in aqueous solution during solid phase condensation (or late exchanges). The fact that different carbonate solute species distinctly fractionate is masterfully outlined by the experiments of Romanek et al. (1992), which indicate a marked control by solution pH of the fractionation between total dissolved inorganic carbon (DIC) and gaseous CO2 (figure 11.38). 

Fig. 2.15 Oxygen isotope fractionations between dissolved inorganic carbon (DIC) and water as a function of pH and temperatures (after Beck et al. 2005)...

When reactants of large molecular size, such as oleic acid, were reacted over an ion exchanger catalyst, a direct proportionality between the reaction rate and the surface area of the catalyst was found [433]. The authors explain the result by assuming that, for the bulky reactant molecules, only acid groups at or near the surface of the catalyst particle can be effective catalysts. The efficiency of the catalyst (the rate coefficient with the resin compared to the rate coefficient with the same stoichiometric amount of dissolved inorganic acid) was found to be considerably... 

Seawater contains dissolved inorganic salts. An aqueous solution of about 35 gL-1 NaCl is often taken as a model solution for seawater. The salt effect on the solubility of nonelectrolyte organic compounds has been investigated systematically by Sechenov [68] and by Long and McDevit [69]. Correlations between pure water solubility, Sw, and the solubility at different salt concentrations are compound dependent. For example, the seawater solubility, 5SW, of PAHs are from 30 to 60% below their freshwater solubilities [1], depending on the particular structure of the PAH. We concentrate our interest on the question if, for certain compound classes, Ssw can be estimated from known Sw without any input of further compound-specific parameters. 

Figure 9.1 Freshwater-marine mixing ratios of dissolved inorganic carbon (DIC) and isotopic composition (DI13C) across three different salinity gradients. Bottom isotopic change between — 10%e at the freshwater end-member, and +2%c at the marine end-member, both end-member values are based on concentration-weighted averages (data sources Spiker and Schemel, 1979 Spiker, 1980). (Modified from Fry, 2002.)...

Figure 11.10 Negative correlations between dissolved inorganic phosphorus (pM) and oxygen (mL L-1) concentrations in bottom waters of the Baltic Sea. (Modified from Conley et al., 2002.)...

The major disadvantage of solid phase extraction is that it provides a chemically biased view of the DOM reservoir, and seems to preferentially extract compounds with relatively low amounts of N. Other problems include sample contamination by various resins and incomplete elution of adsorbed DOM. SoHd phase extraction remains, however, the only technique capable of reproducibly isolating DOM compounds within the entire range of MWs. Furthermore, the radiocarbon content (A " C) of DOC isolated by XAD resins is depleted relative to the total dissolved inorganic carbon (DIG) reservoir values for XAD isolates are between —300... 

Figure 11.8 Upper frame Direct relationships between dissolved inorganic N input and primary production in a various estuarine and coastal ecosystems. Figure adapted from Nixon eta/., 1996. Lower frame Direct relationship between dissolved inorganic N input and phytoplankton biomass, as mean annual chlorophyll a content of several Western Australian estuarine systems. Figure adapted fromlwomey andThompson, 2001.

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