North Atlantic vertical profile

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 profile of dissolved aluminum in the North Atlantic (40°5TN, 64°10 W). Source From Hydes, D. J. (1979). Science, 205, 1260-1262. 

Fig. 3.21 Vertical profiles of dissolved CO2, 6 C, dissolved O2 and 6 0 in the North Atlantic (Kroopnick et al, 1972)...

Similar vertical profiles have been reported in subsequent aircraft studies. Luria et al. (2Q) measured DMS concentrations over the Gulf of Mexico averaging 27 ppt in the marine boundary layer, 7 ppt in boundary layer of continental origin, and <3 ppt in the free troposphere. Van Valin et al. (16) reported highly variable DMS levels over the north Atlantic Ocean in the pollutant plume from the Northeastern U.S., measured in the vicinity of Boston. Those workers also reported a vertical profile from Bermuda which was virtually identical to the stable case of Ferek et al. (15) off Barbados. 

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 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 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...

The vertical profiles of BOD in the North Atlantic waters studied by Aisatullin and Leonov (1972) show, however, a relationship between the profiles of the OM input to the water and its oxidation. The ability to decompose either particulate or dissolved OM in the ocean water seems to be potentially similar. According to Menzel and Goering (1966), the decrease of particulate organic C is for surface water from 16 to 57% of the initial for a period of 90 days at 20° C. At 200 m and 1000 m depth the changes are... 

In 1982, the first oceanographically consistent vertical profiles were reported for nine out of ten lanthanides that could be measured by the ID-TIMS method in the North Atlantic. Since then, a significant amount of data on the distribution of REEs have accumulated from various oceanic regions. For example, Figure 2 shows the station locations where the REEs were measured in seawater, together with the... 

The vertical profiles of dissolved (< 0.04 pm) REEs for different oceanic basins are shown in Figure 3. Except for Ce, all REEs show nutrient-like gradual increase with depth. There are small but systematic differences in the profiles across the series, although the North Atlantic profiles show somewhat complex features dominated by horizontal advection of different water masses (from the above, the Sargasso Sea Surface Water, the North Atlantic Deep Water, and the Antarctic Bottom Water). For instance, in the Southern Ocean and the North Pacific, the light and middle REEs (e.g. Pr-Gd) almost linearly increase... 

Figure 3 The vertical profiles of dissolved (< 0.04 pm) REEs in the western North Pacific (CM-22 ), and the Southern Ocean (PA-41 O) from Alibo and Nozaki, unpublished. The North Atlantic profile data based on dissolved (<0.4pm) REEs (SS- 8 ) from Sholkovitz and Schneider (1991) and acid-soluble total concentrations for monoisotopic REEs (DBB- 86/1 ) from De Baar et al. (1983) and yttrium (TPG-7/8 A) from Alibo et al. (1999).

Indium (In) is a trivalent metal that exists as In(OH)3 in sea water, with a minor contribution from In(OH)4 (6%). Dissolved indium ranges from 0.05 to 4.7 pmol kg, with the lowest values in the North Pacific and the highest values in the Mediterranean. Vertical profiles of dissolved indium in the Pacific show low concentrations (0.06-0.10 pmolkg ) that are relatively invariant with depth, with a slight suggestion of a surface maximum. In the Atlantic the concentrations increase gradually with depth from 0.6 to 1.7 pmol kg, and in the Mediterranean the concentration is about 4pmolkg and relatively... 

Combining a series of vertical profiles, as in Figure 2, will give a slice or section through the ocean. Sections through the eastern Pacific and Atlantic are shown in Figure 3. The absence of CFCs in the deep waters of the Pacific Ocean shows the relative isolation of the deep Pacific from contact with the atmosphere on timescales of decades. In contrast, the North Atlantic north of 35°N has CFCs in deep and bottom waters, because these waters form in the high latitudes of the North Atlantic and easily spread equatorward on timescales of 10-20 years. As part of the density-driven, thermohaline circulation some of these waters will eventually be transported into the Pacific, but it will take hundreds of years. The upper waters of both oceans are in contact with the atmosphere on much shorter timescales. These upper waters are part of the wind-driven circulation. 

Figure 2 Vertical profiles of oceanographic data. (A) North Pacific salinity and potential temperature, (B) North Pacific CFC-11 and CFC-12, (C) North Pacific oxygen, (D) North Atlantic salinity and potential temperature, (E) North Atlantic CFC-11 and CFC-12, (F) North Atlantic oxygen. North Pacific World Ocean Circulation Experiment cruise P17C station 20, 33°N, 135°W, June 1991 North Atlantic Subtropical Atlantic Climate Studies cruise station 7, 26.5°N, 76°W, June 1990. (North Atlantic data from Johns etal. (1997) Journal of Physical Oceanography 27 2187-2208 Pacific data from Fine etal. (2001) Journal of Geophysical Research.)...

Figure 4 Vertical profiles of dissolved lead in the north Atlantic near Bermuda. The low point at 200 m in 1984 could not be accounted for by the authors, even though the analysis had been replicated and checked, and was thought to be a residual from the deep mixed layer from the previous winter. (Reprinted from Wu and Boyle (1997), copyright 1997, with permission from Elsevier Science.)...

Fig. 14. Two vertical profiles of dissolved La, Nd, Er, and Ce concentrations and the Ce anomaly, parts a-e respectively a comparison of the South Atlantic station of German et al. (1995) and the western North Pacific station ( 271-1) of Piepgras and Jacobsen (1992).

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).

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