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Numerical modelling of the Arctic and North Atlantic exchanges with NEMO: Focus on freshwater and dynamics

  • Author / Creator
    Grivault, Jonathan
  • The Arctic is currently undergoing significant changes due to increasing anthropogenic greenhouse gases causing atmospheric warming. The impact of this warming is clearly visible in the Arctic: reduced sea-ice cover, enhanced land-ice melting, increased frequency of extreme weather, etc. Understanding the current dynamics of the Arctic Ocean and its exchange with the North Atlantic is the first step in understanding how it may change in the future. In this thesis, I focused on key regions where exchange between the Arctic Ocean and the North Atlantic occurs: Baffin Bay, the Canadian Arctic Archipelago, and the Arctic gateways. I used a numerical model with several domains, resolutions, atmospheric forcings, and runoff datasets to evaluate how Arctic outflow dynamics change or are impacted by the warming climate. I demonstrated (1) that enhanced Greenland melt significantly impacts the steric height in Baffin Bay, which changes the circulation in Baffin Bay, reducing the Arctic outflow through Baffin Bay. (2) The Canadian Arctic Archipelago throughflow is significantly impacted by sea-ice motion as sea-ice has a significant impact on the surface stress. In particular, I showed that more mobile ice enhanced the freshwater transport. (3) The main frequencies acting on the Arctic outflow variability are the seasonal cycle, and the 6-month, 3 year, 6 year, 8.5 year, and 21 year cycles. Variability on short timescales are associated with the atmospheric circulation via the Arctic Oscillation, while longer timescales are related to the variability of the sea surface height gradient between the Beaufort Gyre and Baffin Bay.

  • Subjects / Keywords
  • Graduation date
    Fall 2018
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/R3222RN5Z
  • License
    Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.