A one-dimensional sea ice model with an ice thickness distribution is presented to examine the disposition of the incoming surface shortwave radiation within the sea ice and the upper ocean. The sea ice model consists of 15 different ice thickness categories and an open water (leads) category. Ice growth, melting on horizontal and vertical surfaces, meltwater pond growth and drainage, and snow accumulation evolve independently for each of the ice categories. Leads, melt ponds, and thinner ice categories are of particular interest, as these features account for nearly all of the solar energy that is transmitted into the upper ocean beneath the ice pack. Also examined is the surface reflection and absorption, internal ice absorption, and lateral melting for ponded and pond-free ice. Area-averaged results show that 69% of the total annual solar energy is reflected, 15% is absorbed by the snow cover, 12% is absorbed by the ice, and 4% is transmitted to the ocean mixed layer through thin ice and leads. ¿ American Geophysical Union 1995