An assessment of climate feedback processes using satellite observations of clear-sky OLR

Abstract

Clear-sky longwave radiative feedback processes depicted in climate models prepared for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are investigated using satellite observations of the clear-sky outgoing longwave radiation (OLR). Estimates of clear-sky longwave radiative damping are derived from regional, seasonal, and interannual sources of variability. In spite of well-known biases of tropospheric temperature and humidity in climate models, comparisons indicate that the intermodel range in the rate of clear-sky radiative damping are small despite large intermodel variability in the mean clear-sky OLR. Moreover, the model-simulated rates of radiative damping are consistent with those obtained from satellite observations and are indicative of a strong positive correlation between temperature and water vapor variations over a broad range of spatiotemporal scales. © Copyright 2010 by the American Geophysical Union.