Observations of Arctic haze during polar flights from Alaska to Norway

Arctic haze observed during polar flights from Anchorage, Alaska, to Thule, Greenland, and Thule to Bodo, Norway, during March 1983, was widespread over the entire Arctic region flown. The distribution of this haze exhibited strong horizontal and vertical variability resulting from the synopticmeteorological situations encountered: e.g. the presence of fronts and haze transport zones. Condensation nuclei concentrations of about 500 cm⁻³ and aerosol scattering extinction values of about 4 × 10⁻⁵m⁻¹ were typical for Arctic haze layers. Intrusions of stratospheric air into the Arctic troposphere through tropopause folds were observed twice, suggesting that these events might occur quite frequently in the springtime Arctic atmosphere.