@article{186146, author = {Timothy Andrews and Alejandro Bodas-Salcedo and Jonathan Gregory and Yue Dong and Kyle Armour and David Paynter and Pu Lin and Angshuman Modak and Thorsten Mauritsen and Jason Cole and Brian Medeiros and James Benedict and Herve Douville and Romain Roehrig and Tsuyoshi Koshiro and Hideaki Kawai and Tomoo Ogura and Jean-Louis Dufresne and Rcihard Allan and Chunlei Liu}, title = {On the effect of historical SST patterns on radiative feedback}, abstract = {

We investigate the dependence of radiative feedback on the pattern of sea-surface temperature (SST) change in 14 Atmospheric General Circulation Models (AGCMs) forced with observed variations in SST and sea-ice over the historical record from 1871 to near-present. We find that over 1871{\textendash}1980, the Earth warmed with feedbacks largely consistent and strongly correlated with long-term climate sensitivity feedbacks (diagnosed from corresponding atmosphere-ocean GCM\ abrupt-4xCO2\ simulations). Post 1980, however, the Earth warmed with unusual trends in tropical Pacific SSTs (enhanced warming in the west, cooling in the east) and cooling in the Southern Ocean that drove climate feedback to be uncorrelated with{\textemdash}and indicating much lower climate sensitivity than{\textemdash}that expected for long-term CO2\ increase. We show that these conclusions are not strongly dependent on the Atmospheric Model Intercomparison Project (AMIP) II SST data set used to force the AGCMs, though the magnitude of feedback post 1980 is generally smaller in nine AGCMs forced with alternative HadISST1 SST boundary conditions. We quantify a {\textquotedblleft}pattern effect{\textquotedblright} (defined as the difference between historical and long-term CO2\ feedback) equal to 0.48\ {\textpm}\ 0.47 [5\%{\textendash}95\%]\ W m-2\ K-1\ for the time-period 1871{\textendash}2010 when the AGCMs are forced with HadISST1 SSTs, or 0.70\ {\textpm}\ 0.47 [5\%{\textendash}95\%]\ W m-2\ K-1\ when forced with AMIP II SSTs. Assessed changes in the Earth{\textquoteright}s historical energy budget agree with the AGCM feedback estimates. Furthermore satellite observations of changes in top-of-atmosphere radiative fluxes since 1985 suggest that the pattern effect was particularly strong over recent decades but may be waning post 2014.

}, year = {2022}, journal = {Journal of Geophysics Research Atmosphere}, volume = {127}, pages = {e2022JD036675}, url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JD036675}, }