Spatial distribution of air-sea heat fluxes over the sub-polar North Atlantic Ocean
Figure S1: Winter mean climatology of the sea surface temperature from the ERAI 1979-2012. (1.088Mb)
Figure S2: Composite monthly mean Bowen Ratio for winter months during which the total turbulent heat flux at the Iceland Sea site is in the 10th or 90th percentile. (779.8Kb)
Table S1: Months in which the monthly total turbulent heat flux at the Iceland Sea site is in the 10th percentile. (31.5Kb)
Table S1: Months in which the monthly total turbulent heat flux at the Iceland Sea site is in the 10th percentile. (27.81Kb)
Table S2: Months in which the monthly total turbulent heat flux at the Iceland Sea site is in the 90th percentile. (37Kb)
Moore, G. W. K.
Renfrew, Ian A.
Pickart, Robert S.
MetadataShow full item record
On a variety of spatial and temporal scales, the energy transferred by air-sea heat and moisture fluxes plays an important role in both atmospheric and oceanic circulations. This is particularly true in the sub-polar North Atlantic Ocean, where these fluxes drive water-mass transformations that are an integral component of the Atlantic Meridional Overturning Circulation (AMOC). Here we use the ECMWF Interim Reanalysis to provide a high-resolution view of the spatial structure of the air-sea turbulent heat fluxes over the sub-polar North Atlantic Ocean. As has been previously recognized, the Labrador and Greenland Seas are areas where these fluxes are large during the winter months. Our particular focus is on the Iceland Sea region where, despite the fact that water-mass transformation occurs, the winter-time air-sea heat fluxes are smaller than anywhere else in the sub-polar domain. We attribute this minimum to a saddle point in the sea-level pressure field, that results in a reduction in mean surface wind speed, as well as colder sea surface temperatures associated with the regional ocean circulation. The magnitude of the heat fluxes in this region are modulated by the relative strength of the Icelandic and Lofoten Lows, and this leads to periods of ocean cooling and even ocean warming when, intriguingly, the sensible and latent heat fluxes are of opposite sign. This suggests that the air-sea forcing in this area has large-scale impacts for climate, and that even modest shifts in the atmospheric circulation could potentially impact the AMOC.
Author Posting. © American Geophysical Union, 2012. 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 39 (2012): L18806, doi:10.1029/2012GL053097.