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ON THE DRIVING SOURCES AND VARIABILITY OF NORTH ATLANTIC DEEP WATER

  • Author / Creator
    Yarisbel Garcia Quintana
  • The rising concentration of anthropogenic heat-trapping gasses has resulted in an energy imbalance in the Earth's climate system. As a consequence of it, an enhanced hydrological cycle and the continuous decline of the ice sheets are expected to increase the freshwater input into the Arctic and Sub-Arctic basins. The input of cold and fresh waters limits vertical mixing processes in the upper ocean, and there is currently a rising concern on how these future changes might impact open ocean deep convection regions. To understand the implications of the global warming related changes on the basins and the waters formed within, it is imperative
    to have a better understanding of the processes involved in deep water formation. By using a numerical model with horizontal resolutions of 1/4 and 1/12, I investigated the sensitivity and variability of two components of the North Atlantic Deep Water under climate change like and present-day scenarios. I found that: (I) increased Greenland melt and precipitation impact denser Labrador Sea Water (LSW) replenishment; (II) potential decreases in Labrador
    Sea winter heat loss due to global warming may be a bigger threat to LSW formation than freshwater increase; (III) strong light-to-dense Atlantic Water (AW) transformation driven by
    heat loss occurs in the boundary currents of the Nordic Seas, with densities reaching that of the overflow waters; (IV) AW entering the Nordic Seas is transformed into overflow waters
    in the shelf system of the basin within 6 years; (V) along the north Icelandic shelfbreak the transformation is faster with export of the transformed waters occurring in the North Icelandic Jet (NIJ) within 1 year; (VI) a new overturning loop is proposed in this thesis with the North Icelandic Irminger Current (NIIC) being the upper limb and the NIJ the lower limb. Contrary to what has been thought, I found that the transformation of the NIIC waters occurs on and
    along the west/northwest portion of the Icelandic shelf.

  • Subjects / Keywords
  • Graduation date
    Fall 2019
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/r3-cjja-eb52
  • 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.