Atlantic Ocean ratios

G. P. Blanch, A. Glausch, V. Schurig, R. Serrano and M. J. Gonzalez, Quantification and determination of enantiomeric ratios of chkal PCB 95, PCB 132 and PCB 149 in shark liver samples (C. coelolepis) from the Atlantic ocean , 7. High Resolut. Chromatogr. 19 392-396 (1996). 

The inductive salinometer has become the measurement technique of choice because of its ease of use, speed, and precision. The reason for this high precision lies in the inductive salinometer s ability to detect very small differences in the ratio of the conductivity of a seawater sample as compared to that of a standard. By international agreement, this standard is prepared by diluting filtered Atlantic ocean water to produce seawater of chlorinity 19 374%o. The International Association for Physical Sciences of the Ocean (lAPSO) has designated Ocean Scientific International Ltd. (OSH) in Wormley, UK, as the sole preparer and distributor of this standard, which is called lAPSO Standard Seawater. ... 

As indicated in Table 10.1, this ratio is greater than 1 for all the biolimiting elements, demonstrating that their deepwater concentrations are greater in the Pacific than in the Atlantic Ocean since at most locations, is much less than Cj ep The... 

Group 4 elemental profiles in the ocean are shown in Fig. 12.6. Titanium (Ti), zirconium (Zr) and hafnium (Hf) exhibit substantial covariance in their distributions, and the correspondence between Zr and Hf is particularly close. In the Atlantic Ocean, Zr/Hf concentration ratios (Godfrey et at., 1996) generally range between 170 and 240. 

Figure 12.6 Vertical distributions of Group 4 elements in the North Pacific. Data sources Ti (Orians et at., 1990), Zr (McKelvey and Orians, 1993) and Hf (Godfrey et at., 1996). The Hf distribution (dotted line) was calculated based on the average Atlantic Ocean Zr/Hf ratio of Godfrey et at. (1996) and the Pacific Ocean Zr profile of McKelvey and Orians (1993).

The Caribbean transects data shown by Saltzman and Cooper ( ) was obtained in oceanic air with easterly winds which should be representative of the subtropical/tropical Atlantic Ocean. On this cruise two filters were used in series, and correction was made for the OCS artifact 130). The resultant data showed H2S concentrations averaging less than 10 ppt with a slight daytime minimum, as expected for a species such as HiS which should be removed predominantly by photochemically produced OH. The maximum/minimum concentration ratio is 1.7, which is similar to that observed for DMS on the same cruise. However, it should be noted that this diurnal variation is only a few ppt, which is close to the precision of the method. We wish to stress that considerably more data is needed to verify this observation, as the data used are compiled from measurements over a considerable geographic range and because the variations involved are small. 

Figure 2.6 Air-sea flux densities of N2 (bold lines) calculated as F = (0.39ujq ) (SRCair-Cair) (Scn2/660) (Wanninkhof, 1992). SR stands for the N2 saturation ratio and Um stands for the wind speed in a height of 10m. Water temperature and salinity were set to 25° C and 35, respectively. C ir is the equilibrium concentration of atmospheric N2 and was calculated with the equation given by Hamme and Emerson (2004). The dashed lines represent maximum (3110 pmol N m day ) and minimum (161 pmol N m day ) mean N2 fixation rates for the North Atlantic Ocean (Capone et a/., 2005).

Only occasionally has the N content of solid phase extracts been reported. At a site in the Atlantic Ocean the carbon to nitrogen ratio (C N) of XAD 8 and XAD 2 extracts fell in the range of 40-57 (57 0.9 and 41.1 3.3, respectively DrufFel et ai, 1992). In contrast, at the same site XAD 4, when used as the second resin in series with XAD 8 or XAD 2, extracted compounds with lower C N ratios - 19—24 (21.0 2.4). These values are only slighdy higher than ratios reported for total DOM (see below). McKnight and Aiken (1998) reported a C N value of 37 for DOM extracted by XAD 8 at one site in the Pacific Ocean at other sites in the N. Pacific Ocean XAD 2 was found to extract DOM with a C N ratio between 32 and 46.5 (Druffel et al, 1992 Meyers-Schulte and Hedges, 1986). Bronk (2002, Table III) compiled various literature values and arrived at an average C N ratio of 32.8 19.5 for total humic substances isolated from a variety of aqueous environments (see McCarthy and Bronk, this volume). 

Panning, K. (1987). Anomalous NO3/PO4 ratios in the west central North Atlantic Ocean (abstract). Eos Trans. AGU 68, 1754. 

The authors found strong stabtiizing feedbacks in the northern Indian Ocean and in the North Atlantic that act to minimize changes in the marine N inventory over relatively short timescales ( 30—200 years) and concluded that rates of N2 fixation are tightly linked to N P ratios in surface waters and thus denitrification, locally for the Indian Ocean and more remotely for the Atlantic Ocean. ITowever, the strength of these stabilizing feedbacks was weaker in other regions mainly due to Fe... 

Several decades ago it was realized that chemistry of the shells of benthic foraminifera (carbon isotope and Cd/Ca ratios) carried an imprint of the nutrient content of deep-water masses (Shackleton, 1977 Broecker, 1982 Boyle, 1981). This led rapidly to the recognition that the water masses in the Atlantic Ocean were arrayed differently during the last glacial maximum than they are today, and the hypothesis that the glacial arrangement reflected a diminished contribution of low-nutrient North Atlantic deep water (NADW) (Curry and Lohmann, 1982 Boyle and Keigwin, 1982). More detailed spatial reconstructions indicated a shallow nutrient-depleted water... 

Both protactinium and thorium are produced in the water column and scavenged by particles onto the seafloor. Because protactinium is scavenged less efficiently by marine particles (Anderson et al., 1983), much of the protactinium produced in the Atlantic Ocean is transported to the Southern Ocean by deep waters before it is scavenged onto the seafloor. This produces a low (below production) Pa/ °Th ratio in Atlantic Ocean and a high Pa/ °Th ratio in Atlantic Ocean in the Southern Ocean (Yu et al., 1996). Reconstruction of the Pa/ °Th ratio suggests... 

In order to expand the scope of comparison with the A S ratios, we also consider several sites in the equatorial Atlantic Ocean where denitrification consumes a significant fraction of the NOs released to pore waters by oxic decomposition. In these cases, we use models describing pore-water NO and O2 profiles to estimate the O2 NOs ratio during oxic decompostion. For example, we consider a site at 3,100 m water depth on the... 

Thomas H. (2002) RemineraUzation ratios of carbon, nutrients, and oxygen in the North Atlantic Ocean a field data based assessment. Global Biogeochem. Cycles 16(3), 1051 doi 10.1029/2001 GB001452. 

Figure 15.7. Stoichiometric correlations among nitrate, phosphate, oxygen, sulfide, and carbon. The correlations can be explained by the stoichiometry of reactions such as equation 3 concentrations are in micromolar, (a) Correlation between nitrate nitrogen and phosphate phosphoms corrected for salt error in waters of the western Atlantic, (b) Correlation between nitrate nitrogen and apparent oxygen utilization in same samples. The points falling off the line are for data from samples above 1000 m (Redfield, 1934, p. 177). (c) Correlation between nitrate nitrogen and carbonate carbon in waters of the western Atlantic, (d) Relation of sulfide sulfur and total carbonate carbon in waters of the Black Sea. Numbers indicate depth of samples. Slope of line corresponds to AS /AC = 0.36. (From data of Skopintsev et al., 1958, as quoted in Redfield et al., 1966.) (e) Correlation of the concentration of nitrogen to phosphate in the Atlantic Ocean (GEOSECS data). The slope through all the data yields an N/P ratio close to 16.

Salinity-normalized (S = 35) total alkalinity. Ay n> versus salinity-normalized dissolved inorganic carbon, DICn, for the world s ocean. Data are for the deep ocean at depths >2.5 km except for the section labeled North Atlantic Shallow," which is 100-1000 m in the North Atlantic Ocean. Lines indicate different DICn At.n ratios. (See Plate 2.)... 

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