Inverse Analysis Adjustment of the SOC Air–Sea Flux Climatology Using Ocean Heat Transport Constraints

Abstract

Results are presented from a linear inverse analysis of the Southampton Oceanography Centre (SOC) air–sea flux climatology using 10 hydrographic ocean heat transport constraints distributed throughout the Atlantic and North Pacific Oceans. A solution is found that results in an adjusted set of fluxes that is consistent with all of the available constraints within their estimated error bounds. The global mean net ocean heat loss to the atmosphere with these adjustments is –5 W m–2, compared with a gain of 30 W m–2 for the original climatology. The primary changes to the net heat flux arise from an increase of 15% to the latent heat and reduction of 9% to the shortwave flux. The analysis has been extended to include the additional constraint that the global mean net heat flux lies in the range 0 ± 2 W m–2. In the latter case, the solution is modified such that the adjustment of the latent heat increases to 19%, the reduction of the shortwave decreases to 6%, and the global mean net heat flux is –2 W m–2. The adjusted SOC fluxes with both solutions agree to within 7 W m–2 with independent large-scale area average heat flux estimates obtained from a hydrographic section at 32°S that was withheld from the analysis. Good agreement is also found with recent estimates of the global ocean heat transport obtained using residual techniques and from atmospheric model reanalyses. However, additional comparisons of the adjusted fluxes with measurements made by various Woods Hole Oceanographic Institute research buoys indicate that further improvements to the inverse analysis are still required. Modifications to the analysis scheme are suggested that may lead to further improvements to the adjusted fluxes, in particular, the explicit use of the buoy measurements as constraints.