Comparison of MISR and CERES top-of-atmosphere albedo

The Clouds and the Earth's Radiant Energy System (CERES) and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra satellite measure the Earth's top-of-atmosphere (TOA) albedo in broadband and narrowband, respectively. This study presents the first direct comparison of the CERES and MISR albedos. An algorithm for converting the MISR spectral albedos to broadband is derived. The MISR and CERES albedos for overcast ocean scenes are compared between 75 degrees S-75 degrees N for solar zenith angles <= 75 degrees. For overcast 1 degrees x 1 degrees ocean regions, the relative differences and the relative root-mean-square (RMS) differences between the MISR and CERES albedos are similar to 0.8% and similar to 4.3%, respectively. Accounting for a similar to 2.0% error in the MISR albedos due to narrow-to-broadband albedo conversion errors, the RMS difference between the MISR and CERES albedos due to angular distribution model (ADM) differences is estimated to be similar to 3.8%. The remarkable consistency between the CERES and MISR albedos for overcast oceans suggests that both instrument teams have derived accurate corrections for the radiance anisotropy of cloud scenes. This consistency will strongly enhance the confidence in the temporal trends of cloud albedo measured by the CERES and have significant impact on climate studies.