A tracer study of the Arctic Ocean's liquid freshwater export variability

• Published in: Journal of Geophysical Research
• Other Authors: Jahn, Alexandra (author), Tremblay, Bruno (author), Newton, Robert (author), Holland, Marika (author), Mysak, Lawrence (author), Dmitrenko, Igor (author)
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2010
• Subjects: freshwater export; tracers; modeling; Arctic; Canadian Arctic Archipelago; Pacific; Arctic Archipelago; Fram Strait
• Online Access: http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-000-941; https://doi.org/10.1029/2009JC005873

We present an analysis of the variability of the liquid Arctic freshwater (FW) export, using a simulation from the Community Climate System Model Version 3 (CCSM3) that includes passive tracers for FW from different sources. It is shown that the FW exported through the western Canadian Arctic Archipelago (CAA) comes mainly from the Pacific and from North American runoff. The variability of the FW export from both of these sources is generally in phase, due to the strong influence of variations of the velocity anomaly on the CAA FW export variability. The velocity anomaly in the CAA is in turn mainly governed by variations in the large-scale atmospheric circulation (i.e., the Arctic Oscillation). In Fram Strait, the FW export is mainly composed of Eurasian runoff and FW of Pacific origin. The variability of the Fram Strait FW export is governed both by changes in the velocity and in the FW concentration, and the variability of the FW concentration from the two largest sources is not in phase. The Eurasian runoff export through Fram Strait depends strongly on the release of FW from the Eurasian shelf, which occurs during years with an anticyclonic circulation anomaly (negative Vorticity index) and takes 3 years to reach Fram Strait after leaving the shelf. In contrast, the variability of the Pacific FW export through Fram Strait is mainly controlled by changes in the Pacific FW storage in the Beaufort Gyre, with an increased export during years with a cyclonic circulation anomaly (positive Vorticity index). National Science Foundation (NSF): OPP‐0230325 Arctic Science Program Grant: ARC‐ 0520496 National Science Foundation (NSF): OPP‐0230264