Examining the origins of ocean heat content variability in the eastern North Atlantic subpolar gyre

• Published in: Geophysical Research Letters
• Main Authors: Foukal, Nicholas P., Lozier, M. Susan
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley & Sons 2018
• Subjects: Subpolar gyre; Heat budget; Ocean heat content; Subtropical gyre; Overturning circulation; Lagrangian trajectories; North Atlantic
• Online Access: https://hdl.handle.net/1912/10788

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 11,275-11,283, doi:10.1029/2018GL079122. We analyze sources of ocean heat content (OHC) variability in the eastern North Atlantic subpolar gyre from both Eulerian and Lagrangian perspectives within two ocean simulations from 1990 to 2015. Heat budgets reveal that while the OHC seasonal cycle is driven by air‐sea fluxes, interannual OHC variability is driven by both air‐sea fluxes and the divergence of ocean heat transport, the latter of which is dominated by the oceanic flux through the southern face of the study area. Lagrangian trajectories initialized along the southern face and run backward in time indicate that interannual variability in the subtropical‐origin volume flux (i.e., the upper limb of the overturning circulation) drives variability in the temperature flux through the southern face. As such, the heat carried by the imported subtropical waters is an important component of the eastern subpolar gyre heat budget on interannual time scales. NSF. Grant Number NSF‐OCE‐12‐59102; NASA Grant Number: NNX13AO21H 2019-04-27