Simulation of Freshwater Processes Associated with the Canadian Arctic Archipelago

• Author / Creator

  Hu, Xianmin

• This thesis presents the numerical simulations related to freshwater processes within the Canadian Arctic Archipelago (CAA) using a coupled ocean and sea ice pan-Arctic model based on NEMO v3.1.

  In this study, two major routes for the export of Pacific water to the North Atlantic, via either Fram Strait or the CAA, are identified using three dimensional (3D) Lagrangian particle tracking. More than 70% of the Pacific water is exported out of the Arctic Ocean within 10 years using either the Transpolar route or the Alaskan route. About 50% of the above water is delivered to the North Atlantic through the central CAA. The proportion of Pacific water transported along the two routes is found to be associated with the spatial distribution of freshwater within the Canadian Basin.

  The impacts of Greenland melt are studied through a series of sensitivity experiments that add different amounts of freshwater along the coast of Greenland. Compared to the control run, enhanced Greenland melt significantly increases the freshwater content within Baffin Bay, raising the dynamic heights and further weakening the CAA throughflows. Meanwhile, a strengthened outflow through Fram Strait is produced to compensate for the reductions in volume and freshwater transport through the CAA.

  Using forcing data from global climate models under the IPCC 20C3M and A1B climate scenarios, sea ice and surface ocean conditions within the CAA and adjacent regions are studied in detail. Remarkable changes in sea ice (concentration and thickness) are shown in the simulation from the mid 2020s to the mid 2060s. A shrinking of 65% in concentration and a thinning of 75% in thickness are estimated over the 40 years. Lower albedo results in more heat absorbed by the ocean, increasing the sea surface temperature, especially in summer. However, sea surface salinity within the CAA does not become fresher under the context of ice melting but demonstrates a strong decadal oscillation. Also an increase in the Arctic Ocean freshwater storage is simulated. Change in the sea surface height in Baffin Bay and Canadian Basin impacts the central CAA throughflow and pathway of Pacific water in the Arctic Ocean in the future.

• Subjects / Keywords

  • Caa
  • Sea ice
  • Oceanography
  • Arctic ocean circulation
  • Canadian arctic archipelago
  • Freshwater
  • Pacific water route
  • Beaufort gyre

• Graduation date

  Fall 2013

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R30H4J

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.