Observed and Simulated Global Surface Heat Flux Feedback

The global surface heat flux responses to sea surface temperature anomalies (SSTAs), the surface heat flux feedback, are estimated using two observation-based global heat flux datasets, the Objectively Analyzed Air-Sea Fluxes [OAFLUX; Yu et al. 2008] and the turbulence heat fluxes estimated from the available individual ship observations (archived from Extended Edited Cloud Report Archive [Hahn and Warren 1999]), by using a conventional lag regression analysis and an Linear Inverse Model (LIM) since the dawn of satellite observations (yrs 1985-2007). Two approaches largely confirm the previous estimation of dominant negative feedback in the extratropics, with somewhat weaker feedback in the LIM estimation relative to that in the lag regression analysis. The difference is more pronounced in the Tropics where the influence of stochastic term is not negligible. The estimated heat flux feedbacks from the observation-based products are also compared to the results from recent coupled climate model simulations.