Surface radiation budget at Barrow,Alaska

Summary At Barrow, the most northerly point in the U.S., radiation measurements were carried out. It was found that multiple reflection between the ground and stratus clouds, due to high surface albedo in winter, enhances the global radiation. These measurements are in agreement with model results. This, together with cloud amount, makes effective transmittance of the atmosphere highest in spring, resulting in the highest values of irradiation in May. For the same cloud amount, the effective transmittance of the atmosphere is always larger in winter, when there is a highly reflective surface, than in summer.Irradiation on a south slope, inclined to latitude (71°) and south wall was higher in spring and fall, but lower than the horizontal in summer. The annual mean was not substantially different for all three surfaces.The net radiation was positive for only three months (June, July, and August). May, with the largest amount of global radiation, displayed values around zero. The high surface albedo reflects most of the incoming radiation back to space, indicating that the net radiation is more controlled by the albedo than by the incoming global radiation.With 11 Figures