Turbulent ship wakes and their spatiotemporal extent
Licentiate thesis, 2021
When a ship moves through water, the turbulence induced by the propeller and hull, will create a turbulent wake that remains and expands after the ship passage. The turbulence in the wake will govern the spread of contaminants and affect gas exchange in the wake water, physically perturb plankton, and potentially impact local biogeochemistry through increased vertical mixing.
To be able to assess the environmental impact of ship-induced turbulence in areas with intense ship traffic, knowledge of the spatiotemporal extent and development of the turbulent wake is necessary. The aim of this thesis is to increase that knowledge, by conducting in situ observations of turbulent ship wakes, which can be used to estimate the spatiotemporal extent of the turbulent wake.
By using a collection of methods, the thesis work has resulted in a first estimate of the spatiotemporal extent of the turbulent ship wake, based on more than 200 field observations of different real-size ships in natural conditions. The observed turbulent wakes showed large variation in their spatiotemporal extent, and further studies are needed to fully disentangle how environmental conditions and vessel specifications affect the intensity and extent of the turbulent wake.
The results and experiences gained from the in situ observations, give an indication of the complexity entailed in characterising the development of the turbulent wake, and provide valuable input regarding the relevant parameters and spatiotemporal scales to include in future studies. The work of this thesis constitutes the first step in addressing the knowledge gap regarding the environmental impact of ship-induced turbulence and can be used as a road map for further studies within the field.
Chalmers, Mechanics and Maritime Sciences (M2), Maritime Studies
Deep learning for deep waters: An expert-in-the-loop machine learning framework for marine sciences
Journal of Marine Science and Engineering,; Vol. 9(2021)p. 1-18
Pre-study: Deep Learning for Deep Water
Chalmers, 2019-10-01 -- 2019-12-31.
Effects of ship induced vertical mixing in ship lanes
Chalmers, 2017-11-06 -- 2022-05-08.
Effects of ship emissions on plankton communities
University of California at Irvine (UCI), 2019-01-15 -- 2020-12-31.
The Swedish Agency for Marine and Water Management, 2020-04-01 -- 2020-12-31.
Areas of Advance
Earth and Related Environmental Sciences
Oceanography, Hydrology, Water Resources
Thesis for the degree of Licentiate – Department of Mechanics and Maritime Sciences: 2021:10
Omega, Hörselgången 5
Opponent: Cynthia Juyne Beegle-Krause, SINTEF, Norway