Ocean stratification

For example, nearly aU cUmate projections for the 21st century suggest that oceanic stratification wiU increase (Sarmiento et al., 1998), primarily as a result of the input of heat into the surface ocean, but in part also by a freshening of the upper ocean. This will likely cause a decrease in export production in the low latitudes, as it will restrict the upward transport of nutrients (Bopp et al., 2001 Matear and Hirst, 1999 Sarmiento et al., 1998 ). On the other hand, export production in the mid-to high-latitudes may actually increase due to lower fight stress in a shallower mixed layer (Bopp et al., 2001). 

Similar to large, deep lakes, much of the ocean is thermally stratified, particularly in warmer equatorial areas. Thermocline depths are of the order of a thousand meters. As in the case of hypolimnetic waters in a lake, deep waters in such stratified ocean areas are cut off from atmospheric exchange of gases such as O2 and CO2. Unlike the seasonal formation and dissipation of stratification in temperate-zone lakes, however, this oceanic stratification is persistent, and deep waters can be isolated from atmospheric exchange for decades. 

The environmental sampling of waters and wastewaters provides a good illustration of many of the methods used to sample solutions. The chemical composition of surface waters, such as streams, rivers, lakes, estuaries, and oceans, is influenced by flow rate and depth. Rapidly flowing shallow streams and rivers, and shallow (<5 m) lakes are usually well mixed and show little stratification with... 

In this section we briefly review what controls the density of seawater and the vertical density stratification of the ocean. Surface currents, abyssal circulation, and thermocline circulation are considered individually. 

Sholkovitz ER, Elderfield H, Szymczak R, Casey K (1999) Island weathering riverine sources of rare earth elements to the western Pacific Ocean. Marine Chem 68 39-57 Skulan JL, Beard BL, Johnson CM (2002) Kinetic and equilibrium Fe isotope fractionation between aqueous Fe(III) and hematite. Geochim Cosmochim Acta 66 2995-3015 Sumner DY (1997) Carbonate precipitation and oxygen stratification in Late Archean seawater as deduced from facies and stratigraphy of the Gamohaan and Frisco Formations, Transvaal Supergroup, South Africa. Am J Sci 297 455-487... 

Yamaguchi KE, Beard BL, Johnson CM, Ohkouchi N, Ohmoto H (2003) Iron isotope evidence for redox stratification of the Archean oceans. Geochim Cosmochim Acta 67 550... 

Seasonal shifts at mid-latitudes in the standing stocks of nutrients, phytoplankton, and the heterotrophic consumer community of bacteria, protozoa, and zooplankton. Also shown are seasonal changes in density stratification of the mixed layer. Source From Black, J. A. (1986). Oceans and Coasts, Wm. C. Brown Publishers, p. 143. 

Do decreases in ice extent and upper stratification of the ocean signal a different sea ice regime ... 

In [48], it was shown that, in order to simulate the cold intermediate layer of the Black Sea (see [3]), one should take into account the dependence of the vertical turbulent mixing coefficient on the density stratification of the waters. In this case, the optimal coefficients in the well-known formula by Munk-Anderson for the Black Sea occurred to be an order of magnitude lower than those for the World Ocean. 

Seasonal cycle of CHL in deep regions (SW, E, and C) is characterized by a minimum in summer (July-August) (Fig. 3a) coinciding with SST maximum (Fig. 3b). This type of seasonality is typical to subtropical ocean regions [3,4], Summer minimum is a result of stratification hindering penetra-... 

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