Diapycnal diffusivity and transport of matter in the open ocean estimated from underway acoustic profiling and microstructure profiling [Elektronische Ressource] / vorgelegt von Tim Fischer

Diapycnal diffusivity and transport of matterintheopenoceanestimated from underway acoustic profilingand microstructure profiling.Dissertationzur Erlangung des Doktorgradesder Mathematisch-Naturwissenschaftlichen Fakultätder Christian-Albrechts-Universitätzu Kielvorgelegt vonTim FischerKiel 2011Leibniz-Institut für Meereswissenschaftenan der Universität KielReferent: Prof. Dr. Peter BrandtKorreferent: Prof. Dr. Andreas OschliesTag der mündlichen Prüfung: 04.05.2011Zum Druck genehmigt: 25.05.2011Gez.: Prof. Dr. Lutz Kipp, DekanAbstractAccompanying to a large scale tracer release experiment (GUTRE) at the oxygenminimum zone (OMZ) off West Africa, microstructure measurements have been per-formed during two cruises to independently estimate diapycnal diffusion and fluxesof matter across the OMZ’s upper limit. The vessel mounted Acoustic Doppler Cur-rent Profilers have been used in this context to get underway estimates of finescaleshear and allow to infer diapycnal diffusivity K indirectly. In this way the regionalintegral K for the depth range of OMZ upper half and tracer location (150m to2−5 −5 m400m) has been determined to K =1 .2 · 10 ± 0.2 · 10 . This is a slightlyshigher value than expected for these latitudes and probably is caused by bottomtopographic influence. The influx of oxygen brought by zonal jets and then diapy-mmolcnally transferred to the OMZ has been estimated as |∇Φ | =1.7 ± 0.