79 research outputs found
Revealing Physical and Ecological Dynamics at an Ice Edge – a Robotic Approach
No full textRevealing Physical and Ecological Dynamics at an Ice Edge – a Robotic Approach
Wulff, T. (1) ; Lehmenhecker, S. (1) ; Hagemann, J. (1) ; Busack, M. (1) ; Tippenhauer, S. (1) ; Strohmeier, M. (2) ; Rothe, J. (2)
1: Alfred Wegener Institute, Bremerhaven, Germany
2: University of Wuerzburg, Wuerzburg, Germany
Marginal ice zones (MIZs) are characterized by the complex and dynamic interaction between the atmosphere, the ice, and the ocean. This high dynamics put MIZs among the – biologically – most productive regions of our planet and make them an ideal place to investigate the coupling between physics and ecology. Fostered by the last decades´ technological progress in robotics and sensor technology, marine sciences are increasingly able to monitor and understand these processes, which occur on very small scales – both temporal and spatial.
The German Alfred Wegener Institute (AWI) has regularly operated an Autonomous Underwater Vehicle (AUV) in the Arctic and especially in the MIZ of the Fram Strait since 2009. Starting in 2011 / 2012 AWI has also used Unmanned Aerial Vehicles (UAVs) to support AUV operations and gather a holistic picture of the investigated area. In our talk we will give an overview on the equipment and infrastructure used to support our AUV dives including an UAV for operations at high latitudes. We will present technical details of our vehicle´s scientific payload which is specifically designed to investigate the physical dynamics of the marginal ice zone and its ecological response
The coupling between physical and ecological processes - fine scale investigations with an AUV in the Arctic
No full textAUV based study on physical and ecological processes at fronts
No full textAUV based study on physical and ecological processes at fronts
Sandra Tippenhauer, Thorben Wulff, Wilken-Jon Von Appen
Small-scale processes and their effects get more and more attention when it comes to understanding processes and changes in the (Arctic) ocean. Here we present a study on physical processes and ecological responses at submesoscale frontal systems in the Fram Strait investigated using an autonomous underwater vehicle (AUV). The AUV is equipped with physical and biogeochemical sensors such as an acoustic Doppler current profiler, a turbulence probe, a conductivity-temperature-depth probe, and sensors for Oxygen, Nitrate, Chlorophyll a, and photosynthetically active radiation (PAR).
The study is designed such that the AUV covers tracks of several kilometers length in cross-frontal direction with the front roughly located in the middle of the track. On its way, the AUV records high-resolution vertical or zigzag profiles of the physical and biogeochemical properties in the upper 50 m which includes the euphotic zone. In both, physical and biogeochemical terms, the measurements revealed a complex structure of the water column. At the fronts the distribution of phytoplankton and nutrients was highly inhomogeneous, possibly due to wind-driven frontogenesis or the growth of mixed layer eddies. To set the observations into a larger context we also examine ship-based and satellite data. We investigate how the observed patterns of the potential vorticity and the biogeochemical properties may be formed and which processes could lead to a smoothing of the observed gradients
Physics and Ecology in the Marginal Ice Zone of the Fram Strait : a Robotic Approach
No full textThis thesis describes operations of an autonomous underwater vehicle (AUV) to investigate the complex interaction between physical forcing and ecological response in the marginal ice zone of the Fram Strait. The vehicle was equipped with instruments collecting physical, chemical, and biological data in the euphotic zone (0 - 50 m depth). After an introductory part, the thesis consists of six studies. The first four studies have a technical focus and they describe the integration of a water sample collector, sensors and a payload control computer. Additionally, supporting technologies such as flying drones and a filter to correct the AUV s navigation data are described. The fifth study tackles the issue of the purity and safety of the water samples inside the AUV. The last study has a scientific focus and presents the first direct observations of wind driven frontogenesis along a melt water front. Vehicle data were complemented by means of ship and model based data to explain the observed hydrographic structures and the distribution of chlorophyll a. In the final section of this thesis, open scientific questions and possible technological upgrades are presented
Vertical profiles of physical and biogeochemical parameters obtained by AWI's AUV "PAUL" during a dive in the vicinity of an ice tongue in the Fram Strait in 2013
No full textAWI's autonomous underwater vehicle "PAUL" covered two 10 km long transects in the Fram Strait on July 2nd / 3rd 2013 to investigate the physical-ecological coupling at an ice edge. The dive was orientated perpendicular to a meltwater front. The meltwater front was associated to a large ice tongue extending from the main ice edge. Every 800 - 1000 m, the vehicle ascended vertically from 50 m water depth to a minimal depth of 3 m to gather a high resolution profile of the following parameters: Temperature, Conductivity, Pressure, Chlorophyll a, CDOM, Dissolved Oxygen, Photosynthetically Active Radiation, and Nitrate.
The dataset contains the data of the vertical ascends only. Due to the correction process, which takes into account the pitch angle of the vehicle, pump times, and the position of the respective instrument inside the vehicle, each parameter has an individual depth stamp
Entwicklung eines Wasserprobennahmesystems als wissenschaftliche Nutzlast eines autonomen Tauchfahrzeugs
No full textPhysik und Ökologie des Eisrandbereichs der Framstraße : eine robotische Betrachtung
No full textThis thesis describes operations of an autonomous underwater vehicle (AUV) to investigate the complex interaction between physical forcing and ecological response in the marginal ice zone of the Fram Strait. The vehicle was equipped with instruments collecting physical, chemical, and biological data in the euphotic zone (0 - 50 m depth). After an introductory part, the thesis consists of six studies. The first four studies have a technical focus and they describe the integration of a water sample collector, sensors and a payload control computer. Additionally, supporting technologies such as flying drones and a filter to correct the AUV s navigation data are described. The fifth study tackles the issue of the purity and safety of the water samples inside the AUV. The last study has a scientific focus and presents the first direct observations of wind driven frontogenesis along a melt water front. Vehicle data were complemented by means of ship and model based data to explain the observed hydrographic structures and the distribution of chlorophyll a. In the final section of this thesis, open scientific questions and possible technological upgrades are presented
Design of a Launch and Recovery System for an AUV, developed for the research vessel FK Uthörn
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