14106 research outputs found
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The Baltic storm surges of 1872 and 2023 – what do they have in common?
No full textDie Ostseesturmflut vom 20. Oktober 2023 war eine der höchsten, die an der Ostküste Schleswig-Holsteins beobachtet wurde. Der Sturm vom 13. November 1872 ist nach wie vor die höchste beobachtete Sturmflut in der westlichen Ostsee in den letzten zwei Jahrhunderten. In Flensburg wurde im November 1872 ein Wasserstand von 3.31 m gemessen und im Oktober 2023 wurden 2.27 m maximaler Wasserstand gemessen. Beide Sturmereignisse ereigneten sich im Herbst und sind durch eine ähnliche atmosphärische Wetterlage mit einem stationären Hochdruckgebiet über Skandinavien und einem Tiefdruckgebiet über Mitteleuropa gekennzeichnet. Diese Situationen erzeugten einen starken Luftdruckgradienten, welcher zu starkem Ostwind mit bis zu 30 m/s am Leuchtturm Kiel sowie über der westlichen Ostsee mit hohem Windstau führten, die den Küstenschutz im Osten Schleswig-Holsteins herausforderten
Combined technologies for 3D cable tracking. Integrated data acquisition of a 3D sub-bottom profiler and an array of magnetometers
No full textWith an increasing number of offshore cables being installed, depth of burial (DOB) surveys are an important and regular task. DOB surveys determine the exact position and burial depth of the cable immediately after dredging and later at regular intervals throughout its lifetime. Innomar and Aquadyne have combined forces and technologies to use the positioning and real-time guidance information provided by Aquadyne’s MagTrack magnetic cable tracking system to efficiently acquire acoustic data using Innomar’s sixpack sub-bottom profiler (SBP) to produce a three-dimensional visualisation of the subsea environment around a cable in a single pass along the target. This paper summarises user requirements for DOB surveys, discusses the technologies used and presents encouraging field data from initial trials. The application of the methods presented is not limited to cable DOB surveys, they can also be used for pipeline surveys or other activities during construction and maintenance of offshore structures
Calibration of tidal model parameters by data assimilation with Particle Swarm Optimisation
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Bathymetry estimation using airborne remote sensing RGB image data of the tidal flats of the North Sea
No full textReliable bathymetric data are essential for safe navigation, as inaccuracies can pose risks for vessels dependent on precise depth information. This study investigates whether a combined approach using colour-based remote sensing systems and wave kinematic methods can improve the temporal resolution of bathymetric information in the Wadden Sea of the North Sea and provide a cost-efficient method for targeting regions with highly variable bathymetry for acoustic measurement techniques
HyFiVe: hydrography on fishing vessels. A new monitoring system enables cost effective and scalable ocean monitoring
No full textWhether for modelling climate change or understanding fish stocks, ocean data is essential across many disciplines. Traditionally, such data has been collected by research vessels, which are costly and limited in scope. To enhance data resolution, the concept of ships-of-opportunity presents a scalable alternative, utilising vessels originally financed for non-scientific purposes. Fishing vessels, in particular, offer unique advantages as they operate in deep waters, allowing access to the entire water column for attached measuring systems. We developed a highly flexible, autonomous measuring system within the HyFiVe project over the past three years. This system comprises three main components: a sensor carrier mounted on fishing gear for underwater data collection, a deck unit for geo-referencing and data transfer, and an onshore server for automatic quality control and data storage. In this article, we provide an overview of the HyFiVe measuring system, summarise the results of measurement campaigns to date, and discuss the system’s benefits to the community
