Competing effects of elevated vertical mixing and increased freshwater input on the stratification and sea ice cover in a changing Arctic Ocean

Davis, P; Lique, C; Johnson, H; Guthrie, J

Journal article

Competing effects of elevated vertical mixing and increased freshwater input on the stratification and sea ice cover in a changing Arctic Ocean

Abstract:: The Arctic Ocean is undergoing a period of rapid transition. Freshwater input is projected to increase, and the decline in Arctic sea ice is likely to drive periodic increases in vertical mixing during ice-free periods. Here, a 1D model of the Arctic Ocean is used to explore how these competing processes will affect the stratification, the stability of the cold halocline, and the sea-ice cover at the surface. Initially, stronger shear leads to elevated vertical mixing which causes the mixed layer to warm. The change in temperature, however, is too small to affect the sea-ice cover. Most importantly, in the Eurasian Basin, the elevated shear also deepens the halocline and strengthens the stratification over the Atlantic Water thermocline, reducing the vertical heat flux. After about a decade this effect dominates, and the mixed layer begins to cool. The sea-ice cover can only be significantly affected if the elevated mixing is sufficient to erode the stratification barrier associated with the cold halocline. Whilst freshwater generally dominates in the Canadian Basin (further isolating the mixed layer from the Atlantic Water layer), in the Eurasian Basin elevated shear reduces the strength of the stratification barrier, potentially allowing AtlanticWater heat to be directly entrained into the mixed layer during episodic mixing events. Therefore, although most sea ice retreat to date has occurred in the Canadian Basin, our results suggest that in future decades elevated vertical mixing may play a more significant role in sea ice melt in the Eurasian Basin.

Publication status:: Published

Peer review status:: Peer reviewed

Actions

Email

Email this record

Send the bibliographic details of this record to your email address.

Your Email
Please enter the email address that the record information will be sent to.

-
Your message (optional)
Please add any additional information to be included within the email.
Cite

Cite this record

APA Style

Davis, P., Lique, C., Johnson, H., & Guthrie, J. (2016). Competing effects of elevated vertical mixing and increased freshwater input on the stratification and sea ice cover in a changing Arctic Ocean. Journal of Physical Oceanography, 46, 1531–1553.

MLA Style

Davis, P., et al. “Competing Effects of Elevated Vertical Mixing and Increased Freshwater Input on the Stratification and Sea Ice Cover in a Changing Arctic Ocean.” Journal of Physical Oceanography, vol. 46, American Meteorological Society, 2016, pp. 1531–53.

Chicago Style

Davis, P, C Lique, H Johnson, and J Guthrie. 2016. “Competing Effects of Elevated Vertical Mixing and Increased Freshwater Input on the Stratification and Sea Ice Cover in a Changing Arctic Ocean.” Journal of Physical Oceanography 46: 1531–53.
Share
Print