Mechanisms controlling the SST air-sea heat flux feedback and its dependence on spatial scale
MetadataShow full item record
KeywordSea surface temperature; Air-sea interaction; Feedback; Variability; Southern Ocean; North Atlantic
The turbulent air-sea heat flux feedback (α, in W m-2 K-1) is a major contributor to setting the damping timescale of sea surface temperature (SST) anomalies. In this study we compare the spatial distribution and magnitude of α in the North Atlantic and the Southern Ocean, as estimated from the ERA-Interim reanalysis dataset. The comparison is rationalized in terms of an upper bound on the heat flux feedback, associated with \fast" atmospheric export of temperature and moisture anomalies away from the marine boundary layer, and a lower bound associated with "slow" export. It is found that regions of cold surface waters (≤10°C) are best described as approaching the slow export limit. This conclusion is not only valid at the synoptic scale resolved by the reanalysis data, but also on basin scales. In particular, it applies to the heat flux feedback acting as circumpolar SST anomaly scales are approached in the Southern Ocean, with feedbacks of ≤10 W m-2 K-1. In contrast, the magnitude of the heat flux feed-back is close to that expected from the fast export limit over the Gulf Stream and its recirculation with values on the order of ≈40 W m-2 K-1. Further analysis suggests that this high value reflects a compensation between a moderate thermo-dynamic adjustment of the boundary layer, which tends to weaken the heat flux feedback, and an enhancement of the surface winds over warm SST anomalies, which tend to enhance the feedback.
Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Climate Dynamics 48 (2017): 1297–1307, doi:10.1007/s00382-016-3142-3.
Showing items related by title, author, creator and subject.
Pullen, Julie; Doyle, James D.; Haack, Tracy; Dorman, Clive E.; Signell, Richard P.; Lee, Craig M. (American Geophysical Union, 2007-02-13)A two-way interacting high resolution numerical simulation of the Adriatic Sea using the Navy Coastal Ocean Model (NCOM) and Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) was conducted to improve forecast ...
Mahowald, Natalie M.; Randerson, James T.; Lindsay, Keith; Munoz, Ernesto; Doney, Scott C.; Lawrence, Peter; Schlunegger, Sarah; Ward, Daniel S.; Lawrence, David; Hoffman, Forrest M. (John Wiley & Sons, 2017-01-23)Using the Community Earth System Model, we explore the role of human land use and land cover change (LULCC) in modifying the terrestrial carbon budget in simulations forced by Representative Concentration Pathway 8.5, ...
Ecosystem feedbacks and cascade processes : understanding their role in the responses of Arctic and alpine ecosystems to environmental change Wookey, Philip A.; Aerts, Rien; Bardgett, Richard D.; Baptist, Florence; Bråthen, Kari Anne; Cornelissen, Johannes H. C.; Gough, Laura; Hartley, Iain P.; Hopkins, David W.; Lavorel, Sandra; Shaver, Gaius R. (2008-09-11)Global environmental change, related to climate change and the deposition of airborne N-containing contaminants, has already resulted in shifts in plant community composition among plant functional types in arctic and ...