Upper ocean layer

Biological Profiling in the Upper Oceanic Layers with a Batfish Vehicle A Review of Applications... 

The surface motion is of many scales, spanning from mm-waves to meso-scale eddies. In our discussion perhaps the range 10 1 to 103 meters is of interest. Surface slicks are only observed for relatively low and moderate winds. The surface motion during slick conditions may, however, be the result of earlier wind induced turbulence and Langmuir cells in the upper ocean layer. Small scale motion (of the order of 10 cm or less) is probably due to a convective motion in a shallow surface layer (Gemmerich and Hasse 1992). 

The feomdity of polar and sub-polar waters is, in part, explained by the variable sea ice cover. The freezing process enriches the surface water with brine, which renders the stratification of upper ocean layers unstable. This leads to convection and the up-welling of nutrient-rich water to the surface where, in the presence of sunlight, the food chain of plankton-fish-marine mammals is initiated. 

Other limitations on phytoplankton growth are chemical in nature. Nitrogen, in the form of nitrate, nitrite and ammonium ions, forms a basic building material of a plankton s cells. In some species silicon, as silicate, takes on this role. Phosphorus, in the form of phosphate, is in both cell walls and DNA. Iron, in the form of Fe(III) hydroxyl species, is an important trace element. Extensive areas of the mixed layer of the upper ocean have low nitrate and phosphate levels during... 

To determine whether his Pacific samples were in fact representative of other oceans, Patterson and a Japanese colleague, Mitsunobu Tat-sumoto, began developing profiles of the lead in ocean layers in Atlantic and Mediterranean waters. Patterson hated ocean-going field trips he often became violently seasick, once so seriously that he had to be given oxygen. Because the ships were coated with leaded paints and compounds, sampling was tricky, too. Despite the problems, Patterson could see that, as in the Pacific, lead was concentrated in the upper portions of the Atlantic and Mediterranean. 

As mentioned, the type of concentration-depth profiles observed in oceans should also be observed in lakes. However, the vertical concentration differences in lakes are often not as pronounced as in the ocean. The reason for this is, that the water column in lakes is much shorter mixing and stagnation in lakes is much more dynamic than in the oceans. Due to the presence of high concentrations of different particles in lakes, the release of trace elements from biogenic particles may not be clearly observed, due to readsorption to other particles. This would mean that low concentrations are observed throughout the water column, but that concentration differences are small. Atmospheric inputs to the upper water layers may also make it more difficult to observe a depletion of certain elements in the epilimnion. 

Oxygen in the upper photic layer of the World Ocean Ou 0.8 x 108... 

Mobile mud high-porosity BBL-upper seabed layer where diagenetic transformation processes are enhanced and commonly occur in river-dominated ocean margins. 

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). 

Sieburth J. M., Johnson P. W., EberhardtM. A., Sieracki M. E., Lidstrom M., and Laux D. (1987) The 1st methane-oxidizing bacterium from the upper ttrixing layer of the deep ocean— methylomonas-pelagica Sp-Nov. Current Microbiol. 14, 285-293. 

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