Vertical profiles phosphate

The O2 content of the surface waters is lower at mid-latitudes because of higher temperatures, which lead to lower gas solubility. As shown in Figure 10.1a, the ther-mocline is characterized by a concentration minimum that increases in intensity from the Atlantic to the North Pacific. Note that the O2 minimum is less pronounced in the vertical profile from 45°S as compared to 9°N in the Atlantic Ocean because of close proximity to the site of AABW formation. Mid-water phosphate and nitrate maxima... 

Vertical profiles of O2 and particulate and dissolved trace metal concentrations at 32.5°E and 44.5°N in the Black Sea. (a) Temperature, salinity, fluorescence, and O2 (b) ammonium, silica, nitrate+nitrite, and phosphate (c) Fe (d) Mn (e) Co (f) Pb (g) Cu (h) Zn (I) Cd and Ni. In the trace metal profiles, the dissolved concentrations are represented as solid circles, the total particulate concentrations by open circles, the acid-leachable particulate concentrations by open squares, and the suspended particulate matter concentrations by the solid triangles. Source-. After Tankere, S. P. C., et al. (2001). Continental Shelf Research, 21, 1501-1532. 

In the anoxic water methane reaches about 16. iM. The vertical distribution of methane differs from that of hydrogen sulfide, ammonia, and phosphate its profile curve bends at 500-600 m and keeps similar concentrations deeper toward the bottom [73]. 

Figure 14.4 Comparison of vertical profiles of (A) temperature, (B) salinity, (C) silicate, (D) nitrate and (E) phosphate in the upper 200 m at one site each in the Arabian Sea (19.17°N, 67.17°E US JGOFS Cruise TN043 sampling date 13/01/1995) and the Bay of Bengal (19.11 °N, 92.65° E WOCE Leg 109N sampling date 24/02/1995).

Figure 22 The sequential drawdown of zinc, cadmium, and cobalt in the north Pacific suggestive of biochemical substitution in the phytoplankton community. Metal versus phosphate concentrations are plotted from vertical profile T-5 (after Sunda and Huntsman, 1995b, 2000 Martin et al, 1989).

Figure 9.5 Vertical profile of iodate, phosphate, and nitrate at Stn. 61 (36°S, 45°W). Reproduced from Wong and Brewer (1974) wtih permission.

Some typical vertical profiles of phosphate, nitrate and silicate in three major oceem basins are shown in Fig. 10-1. 

Depth profiles from the eastern tropical North Pacific (Figure 24.8) show the effects of nitrogen metabolism under 02-deficient conditions. The thermocline is characterized by a sharp decline in O2 concentrations that coincides with increasing nitrate and phosphate concentrations. The oxycline is produced by the respiration of sinking POM under vertically stagnant conditions. Below the oxycline, in depths where O2 concentrations are suboxic, phosphate concentrations continue to increase, but at a slower rate. In contrast, nitrate concentrations decline and reach a mid-water minimum that coincides with a nitrite maximum. The latter is referred to as the secondary nitrite maximum. (At this site the primary nitrite maximum is located at 50 m.)... 

Vertical concentration profiles of (a) nitrate, (b) nitrite and phosphate, and (c) O2 and temperature in the eastern tropical North Pacific in August 1962 (15°N 100°W). The calculated nitrate concentrations were estimated by multiplying the observed phosphate concentrations by the average nitrate to phosphate ratio in the three deepest samples (11.9 1.6 xmolN/L). Source From Thomas, W. H. (1966). Deep-Sea Research 13, 1109-1114. 

Figure 2. Free energy profile for converting di hydroxy acetone phosphate, the substrate (abbreviated S) and glyceraldehyde 3-phosphate, the product (abbreviated P), with intermediate formation of the enedi-olate (abbreviated Z). Catalysis occurs either by a free carboxyl group (levels connected by dotted lines) or by triose-phosphate isomerase (levels connected by dashed lines). The vertical arrows show the limits of those states that are less well defined as a result of uncertainty in the experimental data. The transition state marked "e" refers to the exchange of protons between the solvent and the enzyme-bound enediol intermediate (EZ). Reproduced with permission of the authors and the American Chemical Society.

The vertical distribution of dissolved iron in the vast majority of the ocean is similar to that of other biologically-assimilated nutrients, notably nitrate and phosphate, and characterized by the following key features (a) depletion at the surface, driven by biological uptake (b) a mid-depth maximum, correlated to the rate of export production from the photic zone and the result of microbial regeneration of exported material (c) reasonably stable, invariant concentrations at depth [71]. Iron, however, dilfers from the macronutrients in notable, sometimes surprising ways, which raise basic questions about how its nutrientlike profile is maintained (Fig. 3). 

Fig. 8 Elution profiles corresponding to the separation of (a) 40 mg (0.16 mmol) of pindolol using cellulose 3,5-dimethylphenylcarbamate (7.5 mg/mL) as CS solvent system MlBK-sodium phosphate buffer 50 mM pH 7.0 and (b) 50 mg (0.16 mmol) of warfarin using amylose 3,5-dimethylphenylcarbamate (7.5 mg/mL) as CS solvent system MTBE-sodium phosphate buffer 50 mM pH 8.0. Vertical axis, arbitrary absorbance units. Horizontal axis, time (min). Adapted from [38]...

As discussed in Chapter 2, the vertical distribution of Cd is very similar to that of major nutrients such as phosphate and nitrate it is depleted in the surface water as a result of biological uptake by phytoplankton and regenerated in deep water (Figure 1). This nutrient-like profile has been observed across ocean basins and in... 

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