Ocean Science www.ocean-sci.net 1812-0784 1812-0792 5 2 2009 10.5194/os-5-59-2009 http://www.ocean-sci.net/5/59/2009/ http://www.ocean-sci.net/5/59/2009/os-5-59-2009.html http://www.ocean-sci.net/5/59/2009/os-5-59-2009.pdf 59 72 2009-04-22 Towards closure of regional heat budgets in the North Atlantic using Argo floats and surface flux datasets N. C. Wells n.wells@noc.soton.ac.uk S. A. Josey R. E. Hadfield National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK The upper ocean heat budget (0–300 m) of the North Atlantic from 20°–60° N is investigated using data from Argo profiling floats for 1999–2005 and the NCEP/NCAR and NOC surface flux datasets. Estimates of the different terms in the budget (heat storage, advection, diffusion and surface exchange) are obtained using the methodology developed by Hadfield et al. (2007a, b). The method includes optimal interpolation of the individual profiles to produce gridded fields with error estimates at a 10°×10° grid box resolution. Closure of the heat budget is obtained within the error estimates for some regions – particularly the eastern subtropical Atlantic – but not for those boxes that include the Gulf Stream. Over the whole range considered, closure is obtained for 13 (9) out of 20 boxes with the NOC (NCEP/NCAR) surface fluxes. The seasonal heat budget at 20–30° N, 35–25° W is considered in detail. Here, the NCEP based budget has an annual mean residual of −55±35 Wm^−2 compared with a NOC based value of −4±35 Wm^−2. For this box, the net heat divergence of 36 Wm^−2 (Ekman=−4 Wm^−2, geostrophic=11 Wm^−2, diffusion=29 Wm^−2) offsets the net heating of 32 Wm^−2 from the NOC surface heat fluxes. 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