Coastal upwelling

Ekman transport can also cause coastal upwelling and downwelling as shown in Figures 4.5c and d for the southern hemisphere. The patterns woifld be reversed for the northern hemisphere southerly winds induce downwelling and northerly winds lead to upwelling. 

Because phosphate is released during remineralization with no decrease in O2, the A02/AP0 produced via denitrification should be lower than that predicted by the aerobic respiration of Redfield-Richards planktonic detritus. To reach the suboxic conditions required for denitrification requires the aerobic respiration of a considerable amount of POM and, hence, release of phosphate. Thus, A02/AP0 ratios less than 138 are most likely to be found in waters with high phosphate concentrations. The prevalence of denitrification in deep waters is suggested by their low (14.7) average N-to-P ratio (Figure 8.3). Areas where the OMZ are pronoimced, such as coastal upwelling areas, have particularly low N-to-P ratios as shown in Figure 10.7. 

Phosphorite deposits are currently forming in areas of high organic productivity and low detrital input. These are typically coastal upwelling zones adjacent to arid continental lands. Phosphorites form at slow rates, so low detrital input is important to prevent dilution or burial. As shown in Figure 18.10, sites of formation include the continental margins of Peru, Chile, and southwest Africa. 

On the eastern margin, a small deposit of siliceous ooze is located slightly south of the equator. This deposit is associated with the coastal upwelling area near Walvis Bay (23°S). The geographic spread of this deposit is limited because the seafloor in this area lies above the CCD, so calcite dilutes the BSi. This effect increases with increasing distance from the upwelling area. 

Coastal all Controls by the mixed layer are modified by seasonality of winds causing coastal upwelling, tidal mixing, formation of fronts and river discharge. Includes marginal seas. 

Hypoxia has also been observed on the continental shelves considerably offshore. Most has been ascribed to natural coastal upwelling, such as off Peru and western Africa. But in some settings, such as coastal Oregon and New Jersey, controversy exists as to the role of anthropogenic forcing. For New Jersey, the most dramatic hypoxic episode... 

Coastal upwelling The upward advection of water from the base of the mixed layer toward the sea surface caused by Ekman Transport. This water motion brings nutrient-rich water to the sea surface. 

Suess E. and von Huene R. (1988) Ocean drilling program Leg 112, Peru continental margin Part II, Sedimentary history and diagenesis in a coastal upwelling environment. Geology 16, 939-943. 

Brassell, S.C., and Eglinton, G. (1983) The potential of organic geochemical compounds as sedimentary indicators of upwelling. In Coastal Upwelling Its Sediment Record (Suess, E., and Thiede, J., eds.), pp. 545-571, Plenum Press, New York. 

Nelson, D.M., Goering, J.J., and Boisseau, D.W. (1981) Consumption and regeneration of silicic acid in three coastal upwelling systems. In Coastal Upwelling (Richards, F.A., ed.), pp. 242-256, American Geophysical Union, Washington, DC. 

Keywords Black Sea Coastal anticyclonic eddies Coastal upwelling ... 

Local synoptic wind impacts also favor the intensification of the horizontal water exchange in the Black Sea. For example, they cause wind effected phenomena and formation of filaments of coastal upwellings and provide the separation of coastal anticyclones from the eastern coast (under northerly winds) or removal of the shelf waters to the deep-water basin by anticyclones over the northwestern continental slope (under westerly winds). 

In the summer months, coastal upwelling results in sharp temperature drops near the coasts (by 10-15 °C off the Crimea [7]). The transformed waters of upwelling driven from the shore by jets and eddies over distances more than 100 km toward the deep-water part of the sea feature a temperature contrast with respect to the adjacent waters of 1-2 °C (see [21,22], see also Ginzburg AI, Zatsepin AG, Kostianoy AG, Sheremet NA Mesoscale Water Dynamics , in this volume). 

Factors Affecting Nitrogen Assimilation in Coastal Upwelling Areas... 

---