An objective of the Surface Heat Budget of the Arctic (SHEBA) was to obtain a complete annual cycle of the terms of the surface energy budget over the pack ice in the Beaufort Sea (about 76°N), and understand the important and sometimes subtle processes. An important period in the annual cycle is the onset of surface melting, at which time the surface albedo may decrease significantly, providing positive feedback for the melting. During SHEBA, the significant melting began in late May or early June, apparently in conjunction with low clouds and drizzle, despite the fact that strong solar insolation had been occurring for several weeks prior to this time. This presentation will examine the surface energy budget in detail using the measurements made at the 20-m tall meteorological tower operated by NOAA/ETL and CRREL, and will try to focus on the important surface energy transfers occurring before the onset of melting and during the melting. This should indicate which process(es) were important for the onset of melting. The measurements made at this site include 5-level profiles (2-18 m) of temperature, wind, humidity, and turbulent fluxes; broad-band shortwave and longwave upwelling and downwelling radiation, snow depth, snow-surface temperature, ice-snow interface temperature, and precipitation. Most of this data is available as 1-minute averages, but longer averages will generally be used. The flux calculations are made using 53 minutes of 10 Hz measurements. Additional formation may be used from thermistor strings through the snow and ice pack located within 100 m of this site, and cloud radar, lidar, and balloon sounding measurements made about 400 m away