THE IMPACT OF CLOUDS ON THE SHORTWAVE RADIATION BUDGET OF THE SURFACEATMOSPHERE SYSTEM - INTERFACING MEASUREMENTS AND MODELS

Two datasets have been combined to demonstrate how the availability of more comprehensive datasets could serve to elucidate the shortwave ra diative impact of clouds on both the atmospheric column and the surfac e. These datasets consist of two measurements of net downward shortwav e radiation: one of near-surface measurements made at the Boulder Atmo spheric Observatory tower, and the other of collocated top-of-the-atmo sphere measurements from the Earth Radiation Budget Experiment. Output from the European Centre for Medium-Range Weather Forecasts General C irculation Model also has been used as an aid in interpreting the data , while the data have in turn been employed to validate the model's sh ortwave radiation code as it pertains to cloud radiation properties. C ombined, the datasets and model demonstrate a strategy for determining under what conditions the shortwave radiative impact of clouds leads to a heating or cooling of the atmospheric column. The datasets also s how, in terms of a linear slope-offset algorithm for retrieving the ne t downward shortwave radiation at the surface from satellite measureme nts, that the clouds present during this study produced a modest negat ive bias in the retrieved surface flux relative to that inferred from a clear-sky algorithm.