Mean and eddy induced transport in the ocean region adjacent to the Greenland-Scotland Ridge

• Main Author: Lundrigan, Sarah
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2019
• Subjects: Arctic; Arctic Ocean; Greenland; Fram Strait; Greenland-Scotland Ridge; Nordic Seas; North Atlantic Deep Water; North Atlantic; Sea ice
• Online Access: https://research.library.mun.ca/14316/; https://research.library.mun.ca/14316/1/thesis.pdf

The circulation and transport in the ocean region adjacent to the Greenland- Scotland Ridge (GSR) are crucial for maintaining heat, freshwater, and sea-ice exchange between the Nordic Seas and Subpolar North Atlantic Ocean. The Nordic Seas receive low-density Atlantic Water and transform it into dense water. The dense water overflow contributes to the North Atlantic Deep Water mass formation, which feeds the lower limb of the Atlantic Meridional Overturning Circulation. The thesis presents results from a study of the temperature and salinity transport in the ocean region adjacent to the GSR consisting of three sub-projects. The first sub-project is focused on model simulations of interannual to decadal variability of the exchange through the GSR and its impact on the variability of the temperature and salinity in the Nordic Seas. The model results demonstrate that the increase in the transport of fresh and cold waters through Fram Strait in the 1960s was concurrent with a reduction in the exchange over the GSR. The resulting imbalance in salinity and heat fluxes through the strait and over the ridge contributed to the freshening of the water masses of the Nordic Seas and intensified the Great Salinity Anomaly in the 1960s. In the late 1980s the AW transport over the GSR was stronger than normal while the exchange through Fram Strait was close to normal. The related imbalance in the lateral heat fluxes through the strait and over the ridge warmed the Nordic Seas and caused an increase in the temperature of the AW inflow to the Arctic Ocean in the late 1980s (i.e., about a decade earlier than the warming of the subpolar North Atlantic Ocean in the mid-1990s). The second sub-project is focused on observational estimates of the heat flux convergence of the ocean region adjacent to the GSR. Along-track altimeter and sea surface temperature satellite observations and ARGO in-situ measurements of temperature and salinity are used to investigate the heat transport by mean currents and eddies in the ocean region adjacent ...