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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.
- Graduation date
- Fall 2019
- Type of Item
- Doctor of Philosophy
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