In the Tucson, Arizona area (32.25°N, 110.95°W), Marjorie and Aden Meinel report strongly enhanced sunset glows beginning 24 August. That evening, silvery, undulate striae, similar to phenomena associated with the 1974 Fuego eruption, were seen at sunset against a glowing background. As the sun set, striae and background passed simultaneously through the same sequence of colors, indicating that they were at the same altitude, calculated by the Meinels to be about 19 km. The striae were not visible the following evening, but the strong background glow recurred and a secondary glow was visible until about 70 minutes after sunset, as after the eruptions of Krakatau in 1883 and Agung in 1963. The glow became fainter on succeeding evenings, but a strong enhancement occurred 16 September and the glow was still nearly as bright several days later. The Meinels believe that the August phenomena were probably caused by material injected into the upper atmosphere by the 17 August eruption of Hekla, while the September enhancement could have been due either to a return of the Hekla material or normal seasonal trends in glow intensity.

In England, H.H. Lamb observed a week or more of reddened sunsets, culminating in a colored ring around the sun seen from Ketteringham, Norfolk before sunset on 12 June. The same evening lidar observations confirmed the presence of a dust veil over Garmisch-Partenkirchen, West Germany (47.5°N, 11.0°W). Lamb saw no apparent abnormal coloring the following week, nor was any observed during the few breaks in bad weather from late June through mid-July. On 14 July, unusual light diffusion in brownish layers above cumulonimbus clouds was followed by a shower that deposited russet-colored mud. Meteorological data suggest transit from the Arctic. By early September, clear skies showed a brownish coloration at sunset and more than usually diffused light around the sun, interpreted by Lamb to indicate a rather thin dust veil.

Information Contacts: Marjorie Meinel and Aden Meinel; H. Lamb, Univ. of East Anglia, England.