North Pacific vertical profiles

Depth profiles of Ne, N2, Ar, Kr, and Xe supersaturations (in %) measured at station ALOHA (22°45 N 158°W) in August 2004. Station ALOHA is located in the central region of fhe North Pacific Subtropical Gyre, about 100 km north of Oahu. Equilibrium with the atmosphere is indicated by the vertical line at 0%. Points indicate individual samples while the lines are the average of duplicates. Source After Hamme, R. C., and J. P. Severinghaus (2007). Deep Sea Research Part I Oceanographic Research Papers 54, 939-950. 

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... 

Upper panels show vertical profiles of manganese in the North Pacific Ocean at (a) an open-ocean station, (b) a coastal station, and (c) the Mn content of surface water with increasing distance from the California coast. Note the tenfold scale difference in concentration between these diagrams. Source From Landing, W. M., and K. W. Bruland (1980). Earth and Planetary Sciences Letters, 49, 45-56. 

Vertical profiles of (a) excess He and (b) dissolved manganese at two sites in the North Pacific Ocean. The data represented by the solid circles were obtained from water located directly over the crest of the East Pacific Rise at 21 °N. Source From Broecker, W. S., and T.-H. Peng (1982). Tracers In the Sea, Lamont-Doherty Geological Observatory, p. 229. See Broecker and Peng (1982) for data sources. 

Vertical concentration profiles of (a) temperature, (b) potential density, (c) salinity, (d) O2, (e) % saturation of O2, (f) bicarbonate and TDIC, (g) carbonate alkalinity and total alkalinity, (h) pH, (i) carbonate, ( ) carbon dioxide and carbonic acid concentrations, and (k) carbonate-to-bicarbonate ion concentration ratio. Curves labeled f,p have been corrected for the effects of in-situ temperature and pressure on equilibrium speciation. Curves labeled t, 1 atm have been corrected for the in-situ temperature effect, but not for that caused by pressure. Data from 50°27.5 N, 176°13.8 W in the North Pacific Ocean on June 1966. Source From Culberson, C., and R. M. Pytkowicz (1968). Limnology and Oceanography, 13, 403-417. 

Saturation state of seawater, Cl, with respeot to (a) calcite and (b) aragonite as a function of depth. The dashed vertical line marks the saturation horizon. North Pacific profile is from 27.5°N 179.0°E (July 1993) and North Atlantio profile is from 24.5°N 66.0°W (August 1982) from CDIAC/WOCE database http //cdiac.esd.oml.gov/oceans/CDIACmap.html) Section P14N, Stn 70 and Section A05, Stn 84. Source From Zeebe, R.E. and D. Wolf-Gladrow (2001) Elsevier Oceanography Series, 65, Elsevier, p. 26. 

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 6. Some vertical profiles of nC in the North Pacific Ocean...

Figure 12.4 Vertical profiles of the Group 3 elements in the North Pacific Ocean, including selected actinides. Data sources Sc (Spencer et al., 1970), Y, La, Pr-Lu (Zhang and Nozaki, 1996), Ce (Piepgras and Jacobsen, 1992), Ac (Nozaki, 19 84), 232Th (Roy-Barman et al., 1996), U (Chen et al., 1986) and 241Am (Livingston et al., 1983). Relative species abundance is shown to the right of each figure in descending order.

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).

Typical vertical saturation profiles for the North Atlantic, North Pacific, and Central Indian oceans are presented in Figure 4.10. The profiles in the Atlantic and Indian oceans are similar in shape, but Indian Ocean waters at these GEOSECS sites are definitely more undersaturated than the Atlantic Ocean. The saturation profile in the Pacific Ocean is complex. The water column between 1 and 4 km depth is close to equilibrium with calcite. This finding is primarily the result of a broad oxygen minimum-C02 maximum in mid-water and makes choosing the saturation depth (SD) where Oc = 1 difficult (the saturation depth is also often referred to as the saturation level SL). 

Figure 1.7 Average vertical profiles of (A) NO3, (B) NO2, (C) NH, and (d) PON from the fourJGOFS process studies sites, i.e., Southern Ocean in 1996-1998 (80°S-51°S 160°E-161°W), Arabian Sea in 1995 (8°N-26°N 54°E-71°E), Equatorial Pacific in 1992 (146°W-135°W 13°S-12 N), and North Atlantic in 1989 (41°N-59°N 25°W-17°W). Data were obtained from usjgofs.whoi.edu and were averaged for each study without consideration of exact location or season.

Figure 3.IB shows a vertical profile of the concentration of DON and HMWDON in the eastern North Pacific and Central Pacific, respectively. As is clear from this figure ultrafiltration only isolates a fraction (<30%) of total DON. In the case of HMWDOM isolated from estuarine, coastal and open ocean areas the C N ratio ranges from 11 to 25. These ratios are lower than those of DOM extracted onto chromatographic supports as discussed above. HMWDOM from marine sites are on the low end of this range with average ratios ( lct) of 16.0 ( 1.8 n = 41) for surface waters, 16.6 ( 3 n = 9) for mesopelagic waters (750—1200 m) and...

Figure 1 Vertical profiles of (a) silicic acid and (b) dissolved zinc observed at high latitudes of the North Atlantic (O) (59° 3(y N, 20° 45 W data from Martin et al., 1993) and the North Pacific ( ) (50° N, 145° W data from Martin et al., 1989).

Figure 3 Vertical profiles of dissolved silver in the North Atlantic (O) (composite of two stations 54.5° N, 48.5° W, and 52.7° N, 35° W data from Rivera-Duarte et al., 1999) and the western North Pacific ( ) (40° N, 145° W data from Zhang et al, 2001).

Aluminum is the best illustration of a trace metal with a scavenged-type distribution in the oceans. The major external input of aluminum is from the partial dissolution of atmospheric dust delivered to the surface ocean. Vertical profiles in the Mediterranean, the North Atlantic, and the North Pacific are presented in Figure 4. Extremely elevated concentrations of dissolved aluminum are observed in the Mediterranean Sea (Hydes et al., 1988), a region that receives a high atmospheric input of dust. Concentrations in... 

Figure 4 Vertical profiles of dissolved aluminum in the Mediterranean Sea (O) (34° 18 N, 20° 02 W data from Hydes et al., 1988), the North Atlantic (O) (40°51 N, 64° 10 W data from Hydes, 1979), and the North Pacific ( ) (28° 15 N, 155° 07 W data from Orians and Bruland, 1986).

Figure 6 Vertical profiles of dissolved germanium species from the North Pacific inorganic germanium ( ) (25° N, 170° 05 E data from Froelich and Andreae, 1981) methyl-germanium (O, O) (data from Lewis et al., 1985).

Figure 8 Vertical profiles of dissolved lead in the central North Atlantic (34° 15 N, 66° 17 W data from Schaule and Patterson, 1983), the central North Pacific (32°41 N, 145°W data from Schaule and Patterson, 1981), and the central South Pacific (20°S, 160°W source Regal and Patterson, 1983). Estimates of the atmospheric input at the time of sampling and in ancient times prior to the large anthropogenic lead input are also shown (Flegal and...

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).

FIGURES. Vertical profile of dissolved bismuth at North Pacific Ocean (17° 30 N, 109° OO W water depth, 3550m) (modified from Reference 108)... 

Dissolved and particulate concentrations of Fe have been shown to be quite low in the euphotic zone of the North Pacific oligotrophic and eastern equatorial Pacific waters. The dissolved concentration is normally lower than 0.1 nM and the particulate is about 0.2 nM. The concentration along the water column shows a nutrient-type vertical profile characterized by surface depletion and increase with depth. Iron concentration reaches typically values >0.5 nMat depths below 1000 m (158). 

In the centre of the north Pacific subtropical gyre, Bruland et al., on the basis of a vertical profile, emphasized a significant aeolian contribution to the dissolved Fe concentration in the surface mixed layer (surface concentration of 0.35 nM compared with the minimum of 0.02 nM at 70-100 m) (159). Taking into account the study of Hutchins et al. demonstrating that Fe assimilated by plankton in sueh oceanic waters is recycled on a timescale of days, they concluded that a substantial part of Fe entering through the atmospheric input is recycled and is retained in the oligotrophic mixed layer (160). 

Figure 1 Vertical profiles of elemenfs in fhe North Pacific Ocean.

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