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dc.contributor.advisorJones, Burton
dc.contributor.authorAsfahani, Khaled
dc.date.accessioned2017-12-13T09:15:41Z
dc.date.available2017-12-13T09:15:41Z
dc.date.issued2017-12
dc.identifier.doi10.25781/KAUST-77ZVX
dc.identifier.urihttp://hdl.handle.net/10754/626360
dc.description.abstractA sequence of autonomous underwater glider deployments were used to characterize the spatial-temporal variability of the region over an eight month period from late September to May. Strongly stratified system was found in early fall with significant gradients in both temperature (T) and salinity (S), during winter T < 23°C and minimum S of 40.3 psu was observed and resulting in weakened stratification that enables deep convective mixing and upwelling of deep water by cyclonic circulations in the region leading to significant biomass increase. Throughout the entire observational period the slope of the 28 and 28.5 kg/m3 isopycnals remained sloping downward from offshore toward the coast reflected a persistent northward geostrophic flow. The depth of the 180 μmol/kg isopleth of oxygen, indicative of the top of the nutricline, paralleled the depth of the 28 kg/m3, but remained slightly deeper than the isopycnal. The deep winter mixing did not penetrate the nutricline where the mixed layer was deeper near the coast. However, because of the cyclonic signature the 28 kg/m3 rose to the surface offshore, injecting nutrients into the surface layer and promoting increased biomass in the central Red Sea. With the presence of cyclonic eddies, there was evidence of subduction associated with the cross-eddy circulation. This subducted flow was toward the coast within the domain of the glider observations. During this period, increases in the particulate backscatter were associated with increased chlorophyll indicating that the suspended particles were primarily phytoplankton particles. Within the mean northward flow there is a cross-basin flow wherein water is upwelled near the center of the Red Sea, there is a eastward component to the northward flow, and subsequent downwelling near the coasts. Within the surface flow subductive processes lead not only to a horizontal flow, but also a downward component toward the coast. Overall transport is very 3-dimensional in the northern Red Sea, such that northward transport and its associated embedded circulations are northward, while southward transport occurs on the western side of the Red Sea, in contrast to some of the descriptions of flow provided in earlier papers.
dc.language.isoen
dc.subjectNorthern Red Sea
dc.subjectWater formation
dc.subjectWinter circulation
dc.subjectdeep conviction
dc.subjectphytoplankton biomass
dc.subjectcyclonic eddies
dc.titleSeasonal evolution of physical processes and biological responses in the northern Red Sea
dc.typeDissertation
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberHoteit, Ibrahim
dc.contributor.committeememberBerumen, Michael L.
dc.contributor.committeememberLee, Craig
thesis.degree.disciplineMarine Science
thesis.degree.nameDoctor of Philosophy


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