Flow Constraints on Pathways through the Canadian Arctic Archipelago

Abstract

To identify flow pathways through the Canadian Arctic Archipelago, numerical model results were examined using two configurations of the Nucleus for European Modelling of the Ocean (NEMO). After correcting for shortwave radiation, the models captured much of the observed spatiotemporal structure of the sea-ice and ocean circulation in the Canadian Arctic Archipelago, especially the southward flow in M'Clintock Channel and the cyclonic circulation in eastern Lancaster Sound. The southward flow in M'Clintock Channel is driven by ageostrophic accelerations and is controlled by topography. Vorticity dynamics analysis showed that both stratification and bathymetry have a strong impact on the circulation in eastern Lancaster Sound.

RÉSUMÉ Pour identifier les trajets d’écoulement à travers l'archipel Arctique canadien, nous avons examiné les résultats de modèles numériques en utilisant deux configurations du NEMO (Nucleus for European Modelling of the Ocean). Après avoir appliqué une correction visant à tenir compte du rayonnement de courtes longueurs d'onde, les modèles capturent la majeure partie de la structure spatiotemporelle de la glace de mer et de la circulation océanique dans l'archipel Arctique canadien, en particulier l’écoulement vers le sud dans le détroit de M'Clintock et la circulation cyclonique dans l'est du détroit de Lancaster. L’écoulement vers le sud dans le détroit de M'Clintock est dû à des accélérations agéostrophiques et est contrôlé par la topographie. L'analyse de la dynamique tourbillonnaire a montré que tant la stratification que la bathymétrie ont un effet marqué sur la circulation dans l'est du détroit de Lancaster.

Keywords:

• Canadian Arctic Archipelago
• circulation
• sea ice
• numerical model

Acknowledegements

The authors would like to acknowledge Dr. Z. Wang for sharing his ocean model output with us. The authors also wish to thank C. Haas, S.J. Prinsenberg, C.G. Hannah, Y. Lu and F. Dupont for discussions on the flow in the CAA and sea-ice boundary conditions. This work was supported by the Natural Sciences and Engineering Research Council (NSERC) and Government of Canada International Polar Year awards to PGM, as well as an NSERC graduate scholorship awarded to QW. We are grateful to Westgrid for computational resources. The NCEP/NCAR reanalysis data were provided by the National Oceanic and Atmospheric Administartion/office of Oceanic and Atmospheric Research/ Earth System Research Laboratory: Physical Sciences Division (NOAA/OAR/ESRL:PSD), Boulder, CO, USA. The sea-ice concentration data were provided by NSIDC,Boulder, CO, USA. The PIOMAS output were provided by the University of Washington, Seattle, USA. We thank two anonymous reviewers for their comments which helped improve the manuscript significantly.