Vertical profiles salinity

An interesting vertical profile of the metabolite concentrations was observed the compounds showed a tendency to accumulate at the two-phase boundaries of air-freshwater and freshwater-saline water (the halocline). Thus, concentration maxima were observed at depths of 0 and 2 m (see Fig. 6.4.1) [6]. The observed distribution may result from either the physicochemical properties of these compounds (surface activity and hydrophobicity), or their formation at the interface due to increased biological activity. For the parent surfactants a similar but less pronounced vertical distribution pattern was observed (with maxima at 0 and 2 m of 17 and 9 xg L 1, respectively) [5],... 

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. 

Fig. 3 Vertical profiles of the water potential temperature (T , degrees Celsius), water salinity (S, practical salinity unit), and water specific potential density (or , kgm-3) a in upper layer of the Black Sea central area in August 1995 and b in deep layer (mean values based on high vertical resolution CTD measurements). 1 Upper mixed layer, 2 seasonal pycnocline (thermocline), 3 cool intermediate layer, 4 main pycnocline (halocline), 5 deep pycnocline, 6 bottom mixed layer...

Consideration of the thermohaline structure of the Black Sea provides new results on the statistical and physical analysis of the historical data of ship-borne observations of the vertical profiles of the temperature and salinity of the waters. The general features of the vertical thermohaline structure of the Black Sea waters, the seasonal and interannual variabilities of the horizontal structure of the temperature and salinity in all the main water layers are described. The relations of the large-scale features of the hydrology of the Black Sea waters to external forcing (heat and moisture fluxes across the water surface, river mouths and straits, fluxes of the momentum and relative vorticity of wind) are shown. The generalization of the results of the studies of the T,S-structure of the Black Sea waters and of its seasonal and interannual variability allows the following conclusions to be made. 

Fig. 2 Vertical profiles of temperature, salinity, density, dissolved oxygen and nitrate in the northern Arabian Sea during the northeast monsoon (SS161)...

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 4 Vertical profiles of total dissolved inorganic carbon (TIC) in the ocean. Curve A corresponds to a theoretical profile that would have been obtained prior to the Industrial Revolution with an atmospheric CO2 concentration of 280 ixmol mol The curve is derived from the solubility coefficients for CO2 in seawater, using a typical thermal and salinity profile from the central Pacific Ocean, and assumes that when surface water cools and sinks to become deep water it has equilibrated with atmospheric CO2. Curve B corresponds to the same calculated solubility profile of TIC, but in the year 1995, with an atmospheric CO2 concentration of 360 xmol moPk The difference between these two curves is the integrated oceanic uptake of CO2 from anthropogenic emissions since the beginning of the Industrial Revolution, with the assumption that biological processes have been in steady state (and hence have not materially affected the net influx of CO2). Curve C is a representative profile of measured TIC from the central Pacific Ocean. The difference between curve C and B is the contribution of biological processes to the uptake of CO2 in the steady state (i.e. the contribution of the biological pump to the TIC pool.) (courtesy of Doug Wallace and the World Ocean Circulation Experiment).

Characteristic vertical profiles of temperature and salinity for the period 2002 through 2008 are shown in Fig. 4 and summarized in Table 3. The archetypal vertical structure in 2002-2003 characterized by enhanced stratification was generally two-layered, with minimum salinity in the upper mixed layer of 7-23 m followed by a more or less steep halocline where the salinity increased sharply downwards, attaining maximum values at the bottom (Fig. 5). In the fall season when most of the measurements were made, the halocline was typically accompanied by temperarnre inversions. During those years, we believed that the stratification of the western basin was permanent and the conditions were meromictic. 

Fig. 4 Vertical profiles of salinity (Itfi) and temperature (right) observed in 2002-2008. The deepest site of the western basin (Station A2,45°05.89 N, 58°23.41 E)...

Fig. 6.5 Vertical profiles of (a) temperature (- -) and salinity (-) (b) oxygen (- + -) and nitrate (- -) and (c) chlorophyll a (- -) and PP (- + -) at a station located over the Indian continental shelf off Mangalore (12°54 N, 74°11 E) sampled on 20 September 2001 (Wajih Naqvi, Shailaja Prabhu Matondkar, unpublished).

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.)...

One of the first applications of ocean radiocarbon data was as a constraint on the vertical diffusivity, upwelling, and oxygen consumption rates in the deep waters below the main thermocline. As illustrated in Figure 2, the oxygen and radiocarbon concentrations in the North Pacific show a minimum at mid-depth and then increase toward the ocean seabed. This reflects particle remineralization in the water column and the inflow and gradual upwelling of more recently ventilated bottom waters from the Southern Ocean. Mathematically, the vertical profiles for radiocarbon, oxygen (O2), and a conservative tracer salinity (5) can be posed as steady-state, 1-D balances ... 

Vertical profiles of temperature, nutrient, dissolved oxygen (DO), and salinity... 

For recording vertical profiles of basic hydrochemical pararmeters in the sea (such as salinity, pH, oxygen and nutrient concentrations), water samples from different depths should be taken quasi-synchronously. On a number of ships, the famous Nansen bottle (Fig. 1-4) introduced more than 70 years ago (Knudsen, 1923,1929) is still part of standard oceanographic equipment. Even on modem research vessels it is often carried for comparison purposes and as a back-up. 

Other applications require internal data storage for at least some time as they are not vessel based CTDs that are moored at a fixed depth to obtain a time series at a fixed position CTDs that glide along a mooring line up and down at prescribed times to obtain time series of vertical profiles at fixed positions and CTDs that are incoqxtrated into freely drifting subsurface floats to obtain vertical profiles when the float surfaces to transmit its data via satellite. In all these cases, it is impossible to have bottle samples for calibration, and consequently accuracy in salinity critically depends on the laboratory calibration of the conductivity sensor and its stability. 

Longitudinal profiles in the Atlantic Ocean at about 25°W. (a) Potential temperature (°C), (b) salinity, (o) potential density (0 dbar), (d) potential density (4000 dbar), and (e) dissolved oxygen ( j,mol/kg). Source-. After Talley, L. (1996). Atlantic Ocean Vertical Sections and datasets for selected lines. http /sam.ucsd.edu/vertical.sections/Atlantic.html. Scripps Institute of Oceanography, University of California - San Diego. Data are from WOCE hydrographic program. (See companion website for color version.)... 

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. 

However, salinity values are easily obtained with a salinometer (which measures electrical conductivity and is appropriately calibrated with standard solutions and adjusted to account for T effects). The salinity of seawater increases if the loss of H2O (evaporation, formation of ice) exceeds the atmospheric input (rain plus rivers), and diminishes near deltas and lagoons. Salinity and temperature concur antithetically to define the density of seawater. The surface temperature of the sea reflects primarily the latitude and season of sampling. The vertical thermal profile defines three zones surface (10-100 m), where T is practically constant thermoclinal (100-1000 m), where T diminishes regularly with depth and abyssal... 

The deep-water observations with conductivity, temperature, depth (CTD) profilers performed in the Black Sea during the past two decades allowed one to distinguish the near-bottom mixed layer (NBML). In Fig. 3b, we present profiles of the potential temperature (T ), salinity (S), and potential density (ct ) of the Black Sea waters in the layer from 1500 to 2100 m obtained by averaging of 46 CTD profiles observed in 1985-1992 in different regions of the deep-sea area. In all three profiles shown in Fig. 3b, a distinct upper boundary of the NBML is traced at depths from 1750 to 1800 m. Above it, up to a depth of 1700 m, one finds a layer with increased vertical gradients of T , S, and a with a thickness about 100 m it separates NBML from the deep stratified layer. 

---