Units are o C .
The 1000 m . Units are o C . The 1000 m . This simple adjustment allows an excellent reconstruction of the annually averaged temperature distribution over the ice sheet. Because summer temperatures determine directly the ablation and runoff predicted by the positive degree-day and linear models and indirectly the melting calculated by the snowpack model through their control of the snow albedo, they play a much more important role than the annual average temperature on the Greenland ice sheet.