Abstract
A previous study by the author of January temperatures in the mid-stratosphere at several arctic stations near 80W has been extended to include stations in other sectors of the Arctic and the additional months of December and February. Distinctly bimodal temperature frequency distributions are evidently confined to the general area of the Canadian Archipelago and northern Greenland, and are characteristic of this region throughout the winter. Mean 25-mb charts and mean cross-sections are used to illustrate two quite dissimilar thermal and circulation regimes that tend to dominate the arctic stratosphere for long periods during the polar night.
