Observations of “Arctic Haze” during the “Ptarmigan” weather reconnaissance flights, 1948-1961

114 “Ptarmigan” weather reconnaissance flights over the Alaskan Arctic during 1948-1961 were analyzed for reports of “Arctic Haze” (∼400 reports). Arctic Haze can reduce horizontal visibility significantly and is most frequently reported during late winter and spring, but is also found during early winter and summer. Haze is reported everywhere within the Alaskan Arctic at altitudes between the surface and 6 km. Anticyclonic surface pressure conditions are characteristic of Arctic Haze; “clear skies” weather conditions were predominantly present with haze observations during the winter months, “cloudy skies” were predominantly present with haze observations during the summer months. We hypothesize that Arctic Haze has a dual character of origin: it is pollution-derived during winter and early spring, and desert dust-derived during late spring and summer.