Studies of the Mass Budget of Arctic Pack-Ice Floes

Abstract The processes of melting, freezing, precipitation, evaporation and condensation were considered in the computation of the mass budget of an ice floe in the northern Chukchi Sea. It was bound that condensation and evaporation contribute negligible amounts, and that melting accounted for the largest loss from the upper surface of the floe. From an original mass of 270 g. cm. −2 a unit ice column lost 9.2 g. cm. −2 by melting of snow and 35.2 g. cm. −2 by melting of ice during the melt season. During the freezing period 5.8 g. cm. −2 were regained by the accumulation of snow and frost. Measurements at the bottom of the ice indicate an estimated net loss of 5 g. cm. −2 over a seven-month study. A comparison of six summers at three stations shows no obvious correlation of ablation and latitude, and an average loss of ice at the surface of 40 g. cm. −2 .