IMPACT OF CLOUDS ON THE SHORTWAVE RADIATION BUDGET OF THE SURFACE ATMOSPHERE SYSTEM FOR SNOW-COVERED SURFACES

Recent data from the Earth Radiation Budget Experiment (ERBE) have rai sed the question as to whether or not the addition of clouds to the at mospheric column can decrease the top-of-the-atmosphere (TOA) albedo o ver bright snow-covered sur-faces. To address this issue, ERBE shortwa ve pixel measurements have been collocated with surface insolation mea surements made at two snow-covered locations: the South Pole and Saska toon, Saskatchewan. Both collocated datasets show a negative correlati on (with solar zenith angle variability removed) between TOA albedo an d surface insolation. Because increased cloudiness acts to reduce surf ace insolation, these negative correlations demonstrate that clouds in crease the TOA albedo at both snow-covered locations.