A large surface high pressure system occupied the Beaufort Sea to the east of Barrow. The upper air pattern showed a ridge on the west side of the surface high over Barrow. This ridge had dense cirrus cloud cover on the satellite images. The cirrus were both reflective in the visible and cold in the infrared indicating their density. The cirrus extended from Barrow and the coast to the north and appeared to be nearly absent to the south over Alaska's North Slope. The satellite images also indicate other lower cloud layers which were probably broken.
The trajectories to SHEBA ship show air coming from a variety of directions depending on the level in the vertical. The surface and 1.0 km air came from the Beaufort Sea to the southeast along the Alaskan coast. Slightly above at 1.5 to 3.0 km, the air came from Alaska's western coast on the Chukchi Sea and the Bering Straight. The higher air, 6-9 km came from Siberia to the southwest.
The trajectories to Barrow also are complicated. The surface air came from Alaska's coast on the Beaufort Sea to the east. Just above, from 1.0 to 1.5 km, the air appears to have come only a short distance from Northwestern Alaska across land. The 3.0 km trajectory indicates stronger winds and air coming from the North Pacific Ocean across Alaska. The higher trajectories, 6-9 km indicate light winds and the air coming from the Chukchi Sea to the west of Barrow.
