Thesis (M.A.)--Boston University / Introduction The purpose of the thesis is; to develop and explain the location and extent of sea ice in the Beaufort Sea, and to describe methods in use and proposed by the science of ice forecasting to aid ship movements in the area. Much of the data in the thesis camas from unpublished or widely scattered papers, and the thesis is an attempt to assimilate such data into cohesive form. Chapter I. The Newly Acquired Importance of the Beaufort Sea Region and the Status of Ice Forecasting. Prior to World War II the area of the Beaufort Sea was little known or exploited. A few explorers occasionally had joined the native eskimos as inhabitants of the area. After the war, a program of oil exploration was undertaken on the southern shores of the Sea by the U.S. Navy. Discovery of oil and the newly feasible means of making trans-polar flights across the Arctic waters suddenly catipulated the area into a position of strategic importance to our national defense. Research programs devoted to gathering data on how to live in such a hostile climate bacame a natural outgrowth of this new importance. With the construction and resupply of the DEW line a vital necessity, methods of coping with sea ice had to be developed. In this respect, the Russians were far advanced over the Western Allies, having devoted much time and effort on the problem since the 1920's. Nonetheless, U.S. and Canadian scientists, under an accelerating research program, are well on the way to equality in the fields surrounding sea ice research. [TRUNCATED]