Factors contributing to interannual variability in CERES radiation flux

This study examines anomalies in CERES radiation flux and related datasets to understand what factors cause variability in Earth's energy budget on interannual to decadal time scales. The impacts of temperature, greenhouse effect, cloud fraction, effective cloud height and additional factors are explored with satellite and other observational datasets. Preliminary results indicate that changes in cloud fraction are the largest contributors to year-to-year variability in reflected shortwave flux and changes in surface and atmospheric temperature are the largest contributors to year-to-year variability in longwave flux. Variability in global mean temperature is related to ENSO, but no single factor appears to be responsible for variability in global mean cloud fraction. Changes in midlatitude cloudiness tend to compensate changes in tropical cloudiness. A comparison of broadband and window channel longwave radiation flux shows a 10-year trend toward a stronger clear-sky greenhouse effect from increased water vapor in the atmosphere.