How does the difference between low- and high-latitude climate sensitivity affect climate feedback diagnosis?

Abstract:

The magnitude of climate feedback has been estimated by using radiative fluxes and sea surface temperature time series from satellite observations. The time-varying radiative forcings, however, hinder one from estimating firmly reliable climate feedbacks. Recent studies have tried to interpret these internal uncertainties using simple forcing-feedback models. As an extension of previous studies, this study aimed to examine the effect of different low- and high-latitude climate sensitivity on climate feedback diagnosis. In this study, we assess whether both the regional and global climate feedbacks are well estimated according to the heat transport strengthening by prescribing latitudinally different climate feedback (2.26 W m^-2 K^-1 in the low-latitude, 1.11 W m^-2 K^-1 in the high-latitude as a default). In the presence of the meridional heat transport, model simulated low-latitudinal climate feedback is underestimated by 0.5 W m^-2 K^-1 while high-latitudinal one is overestimated by similar scale from transient climate simulations. Globally, therefore, no significant variations are caused by the heat transport. Moreover, uncertainties of regional and global estimates slightly decrease with the increasing heat transport. The results of this study possibly provide support for the researches interpreting meridional satellite observational signals.