Radiative Feedback Signatures in AMSR - E Sea Surface Temperatures Versus

Radiative feedbacks in the climate system are the primary uncertainty affecting estimates of anthropogenic global warming and climate change (Knutti & Hergerl, 2008; IPCC, 2007). While the feedbacks of most interest are on the long time scales associated with anthropogenic greenhouse gas forcing – decadal or longer – our most accurate satellite measurements of global radiative fluxes are closer to ten years in length. As a result, only short term climate variability can be analyzed and related to short term variability in climate models as part of the model testing and validation process. But as time scales are decreased, the observed behavior of the climate system – at least in terms of identifying and quantifying feedbacks-changes markedly. Feedbacks are traditionally referenced to surface temperature changes. But AMSR-E data shows that as time scales are shortened, there exists very little correlation between global, monthly average SST data and radiative fluxes measured by CERES on NASA's Aqua or Terra satellites. This decorrelation is due to the fact that there are episodic variations in global-average convective heat transport from the surface to the troposphere (Spencer et al., 2007). These variations, which are usually on the order of weeks to a few months, exhibit either SST warming and tropospheric cooling during less convective periods, or SST cooling and tropospheric warming during more active periods. This negatively correlated behavior means that when radiative flux changes are quantitatively divided by temperature changes in order to estimate a feedback parameter, results with opposite signs can be experienced depending upon which temperature is used. Obviously, as time