Strange high-level haze in the arctic

Every March and April, the supposedly pristine air of Alaska is defiled by a peculiar haze concentrated at about 10,000 feet. The sky has a whitish, diffuse look; from an airplane the horizon seems to disappear entirely. Is the haze due to pollutants in this remote region? Recent studies indicate two components in the haze:

(1) Dust, and (2) Sulfuric acid droplets.

Both of these must be imported because there are no sources of such materials in the arctic.

Violent wind storms in the Gobi Desert may carry some dust into the arctic. Strong winds might also transport sulphuric acid from Japanese industries to Alaska. These are speculations, though, and no one is sure where this haze comes from or how far it extends beyond Alaska into the stable, stagnant air over the Arctic Ocean.

(Anonymous; "Alaska's Imported Haze," Mozaic, 9:41, September/October 1978.)