38 research outputs found
Assimilation of dynamic topography in a global model
Absolute dynamic topography, i.e. the difference between time dependent multi-mission altimetric sea surface
height and one of the most recent GOCE and GRACE based geoids, is assimilated in a global ocean general
circulation model. To this end we apply an ensemble based Kalman technique, the "Error Subspace Transform
Kalman Filter" (ESTKF).
Here we present an update of our work. First of all the geoid is improved over previous versions. The
ocean model now includes better dynamics and full sea-ice ocean interactions and more realistic surface forcing.
Finally the assimilation method is augmented by a fixed lag smoother technique. This smoother allows to
significantly improve the model performance, most strikingly in the first adjustment phase
Isolation and Genetic Analysis of Bovine Viral Diarrhea Virus from Infected Cattle in Indiana
Species and biotype distribution was determined in 44 bovine viral diarrhea virus- (BVDV-) positive samples submitted to the Animal Disease Diagnostic Laboratory (ADDL) in Indiana during 2006â2008. BVDV RNA was detected in the 5âČ-untranslated region and Npro region using reverse transcriptase PCR followed by sequencing analysis of the PCR product. Additionally, cases were classified into one of six categories according to history and/or lesions: acute symptomatic, hemorrhagic, respiratory distress, reproductive, persistent infection (PI), and mucosal disease (MD). Of 44 BVDV-positive samples, 33 were noncytopathic (ncp), 10 were cytopathic (cp), and one presented both ncp and cp biotypes. Sequencing analysis demonstrated that all samples belonged to BVDV-1a, BVDV-1b, or BVDV-2. The most common isolate was ncp BVDV-1b, (44%) followed by ncp BVDV-2a (24%). Among the six categories, respiratory clinical signs were the most common (36%) followed by PI (25%) and MD (16%)
On the assimilation of absolute geodetic dynamic topography in a global ocean model: impact on the deep ocean state
General ocean circulation models are not perfect. Forced with observed atmospheric fluxes they gradually drift away from measured distributions of temperature and salinity. We suggest data assimilation of absolute dynamical ocean topography (DOT) observed from space geodetic missions as an option to reduce these differences. Sea surface information of DOT is transferred into the deep ocean by defining the analysed ocean state as a weighted average of an ensemble of fully consistent model solutions using an error-subspace ensemble Kalman filter technique. Success of the technique is demonstrated by assimilation into a global configuration of the ocean circulation model FESOM over 1 year. The dynamic ocean topography data are obtained from a combination of multi-satellite altimetry and geoid measurements. The assimilation result is assessed using independent temperature and salinity analysis derived from profiling buoys of the AGRO float data set. The largest impact of the assimilation occurs at the first few analysis steps where both the model ocean topography and the steric height (i.e. temperature and salinity) are improved. The continued data assimilation over 1 year further improves the model state gradually. Deep ocean fields quickly adjust in a sustained manner: A model forecast initialized from the model state estimated by the data assimilation after only 1 month shows that improvements induced by the data assimilation remain in the model state for a long time. Even after 11 months, the modelled ocean topography and temperature fields show smaller errors than the model forecast without any data assimilation
Initial stages of water solvation of stepped platinum surfaces
Catalysis and Surface Chemistr
Risk governance in organizations
Dieses Buch dokumentiert 10 Jahre Risk-Governance-Forschung an der UniversitĂ€t Siegen. In 50 BeitrĂ€gen reflektieren Forscher und Praktiker Risk Governance vor dem Hintergrund ihrer eigenen Forschungen und/oder Erfahrungen und geben jeweils einen Entwicklungsimpuls fĂŒr die Zukunft der Risk Governance. Das Buch zeigt die groĂe Bandbreite und Tiefe des Forschungsgebietes auf und diskutiert Grundannahmen, Implementierungsfragen, die Rolle der Risk Governance als Transformationsmotor, ihre Wirkung in den verschiedenen betrieblichen Funktionen, Entwicklungsperspektiven und den Beitrag der Risk Governance zu einer nachhaltigen Ausrichtung von Unternehmen.This book documents 10 years of risk governance research at the University of Siegen. In 50 contributions, researchers and practitioners reflect on risk governance against the background of their own research and/or experience and provide a development impetus for the future of risk governance. The book shows the wide range and depth of the research field and discusses basic assumptions, implementation issues, the role of risk governance as transformation engine, its impact in the various operational functions, development perspectives, and the contribution of risk governance to a sustainable orientation of companies
Geschichte in Geschichten verstrickt | Von Astrachan nach Kairouan (ĂŒber Jeruzalem)
Der Verfasser dieses Buches lehrt Ăffentliches Recht an der UniversitĂ€t TĂŒbingen. Aus AnlaĂ der Vollendung seines 65. Lebensjahres erscheinen in Buchform drei Studien, die sich in ungewöhnlicher Weise mit der Zeitgeschichte befassen. Der Obertitel knĂŒpft an den Titel des Buches von Wilhelm Schapp »In Geschichten verstrickt: Zum Sein von Mensch und Ding« an, also an das Werk eines Philosophen. Angeregt durch die BemĂŒhungen Schapps, der Sackgasse subjektivistischen Denkens auszuweichen, möchte der Verfasser bestimmte VorgĂ€nge in der neuesten Geschichte nicht in der ĂŒblichen Weise beschreiben, sondern verschĂŒttetes BewuĂtsein der Ălteren offenlegen und den JĂŒngeren verstĂ€ndlich machen. Europa war seit dem Jahre 1945 auch durch BewuĂtlosigkeit gespalten. Im Westen wirkte die Spaltung - vielleicht noch mehr als im Osten - mit zusĂ€tzlicher Spaltung zwischen den Generationen. Nach Meinung z bedeutet die Ăffnung von MĂ€rkten, bzw. die Herstellung gemeinsamer MĂ€rkte, viel, doch vermag das alleine nicht, europĂ€ische Gemeinschaft wiederherzustellen: Der neue »Ăberbau« in Europa muĂ labil bleiben, wenn BewuĂtsein und Kenntnis der »Basis« fehlen