The surface energy budget was investigated during a cruise through the pack ice in the Southern Ocean. The time of observation was close to mid-summer. Some of the more important findings were:
The mean albedo varied from 11 % for open water to 59% for 10/10 ice cover. Hourly values span the range from 6% (open water) to 76% (total ice cover).
The net heat flux into the ocean (B) was on average 109 W m−2, If this energy were used solely for melting of sea ice, 30 mm could be melted each day.
For low surface albedos (ice concentration below 7/10), the net radiation increased with decreasing cloudiness. However, the opposite was the case for a high surface albedo.
The last point shows the importance of clouds on the surface energy budget. Not only should their presence or absence be known but also the reflectivity of the underlying surface, as it might change the net radiation in opposite ways.