Sampling--Dependent Transition Paths of Iceland-Scotland Overflow Water

In this note, we apply Transition Path Theory (TPT) from Markov chains to shed light on the problem of Iceland-Scotland Overflow Water (ISOW) equatorward export. A recent analysis of observed trajectories of submerged floats demanded revision of the traditional abyssal circulation theory, which postulates that ISOW should steadily flow along a deep boundary current (DBC) around the subpolar North Atlantic prior to exiting it. The TPT analyses carried out here allow to focus the attention on the portions of flow from the origin of ISOW to the region where ISOW exits the subpolar North Atlantic and suggest that insufficient sampling may be biasing the aforementioned demand. The analyses, appropriately adapted to represent a continuous input of ISOW, are carried out on three time-homogeneous Markov chains modeling the ISOW flow. One is constructed using a high number of simulated trajectories homogeneously covering the flow domain. The other two use much fewer trajectories which heterogeneously cover the domain. The trajectories in the latter two chains are observed trajectories or simulated trajectories subsampled at the observed frequency. While the densely sampled chain supports a well-defined DBC, the more heterogeneously sampled chains do not, irrespective of whether observed or simulated trajectories are used. Studying the sampling sensitivity of the Markov chains, we can give recommendations for enlarging the existing float dataset to improve the significance of conclusions about time-asymptotic aspects of the ISOW circulation.Comment: Submitted to JPO. Comments welcomed

Transition paths of marine debris and the stability of the garbage patches

We used transition path theory (TPT) to infer "reactive" pathways of floating marine debris trajectories. The TPT analysis was applied on a pollution-aware time-homogeneous Markov chain model constructed from trajectories produced by satellite-tracked undrogued buoys from the NOAA Global Drifter Program. The latter involved coping with the openness of the system in physical space, which further required an adaptation of the standard TPT setting. Directly connecting pollution sources along coastlines with garbage patches of varied strengths, the unveiled reactive pollution routes represent alternative targets for ocean cleanup efforts. Among our specific findings we highlight: constraining a highly probable pollution source for the Great Pacific Garbage Patch; characterizing the weakness of the Indian Ocean gyre as a trap for plastic waste; and unveiling a tendency of the subtropical gyres to export garbage toward the coastlines rather than to other gyres in the event of anomalously intense winds.Comment: Submitted to Chao

Grundlagenuntersuchungen zu lasergestuetzten Nanolichtquellen fuer Life Science. Teilprojekt: Experimentelle Untersuchung von Nanometer-Lichtquellen bei Laserstrahl- und Elektronenstrahlanregung Abschlussbericht

SIGLEAvailable from TIB Hannover: F03B893 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

WTZ Russland: Kooperation mit der AdW Moskau in der Lasermedizin auf den Gebieten Strahlfuehrung, neue Laserkonzepte sowie Diagnostik und Dosimetrie im Rahmen des WTZ mit der UdSSR

Available from TIB Hannover: F94B1380+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Signalgewinnung aus streuenden Medien - Darstellung von Blut- und Lymphgefaessen bei Tumorpatienten mit NIR-Flureszenzangiographie Abschlussbericht

Available from TIB Hannover: F97B1211+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Machbarkeitsstudie zur laserinduzierten Lithotripsie Schlussbericht

SIGLEAvailable from TIB Hannover: FR 5487 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Mathematical Modeling of the Spreading of Innovations in the Ancient World

In this article, we develop a mathematical model for the spreading of the wool-bearing sheep in a population of herders in the Near East and Southeast Europe between 6200 and 4200 BC. Herders are considered as agents moving diffusively in a suitability landscape, such that motion into regions attractive for sheep herding are more probable than to unattractive regions. Simultaneously agents interact socially with another and pass on the innovation with some probability. The parameters of the agent-based model are fitted to available archaeological information. A simulation tool is proposed for computing the evolution of the spreading process in time and space, offering a way to study qualitative effects of different aspects affecting speed and spatial evolution of the spreading process