The spectral distribution of light beneath first‐year sea ice in the Arctic Ocean1

Abstract

Spectral transmission data in the 400–1,000‐nm range were obtained from about 60 sites beneath first‐year sea ice near Point Barrow, Alaska. The amount of energy reaching the ocean depended strongly on the nature of the upper surface. Maximum transmission occurred in the 450–550‐nm region, regardless of surface conditions or ice thickness. Initial results were influenced by the presence of interstitial algae in the lower part of the ice. The characteristic signature of these algae was a secondary peak at about 540 nm. Results are generalized to provide estimates of the magnitude and composition of downwelling irradiance beneath the types of ice typically encountered in coastal portions of the Arctic Ocean.