Lidar data from Fukuoka, Japan and Hampton, Virginia showed generally weaker stratospheric aerosol backscattering in April. On 22 April, the lidar profile at Fukuoka showed a broad single layer that decreased gradually upward from 17 km. At Hampton, integrated backscattering on 25 and 26 April was only half that on the 11th, and lower than values measured in previous months. Lava from the March-April eruption of Mauna Loa cut electric power lines to Mauna Loa Observatory and no lidar data has been collected there since 21 March.

Edward Brooks reported that dawn and dusk colors at Jeddah, Saudi Arabia were variable but generally unimpressive in April, continuing the trend of recent months. Dawn colors were bright 1-3 April and remained bright on the 4th and 5th, but no late dusk colors were observed, indicating the absence of high-altitude aerosols. Dawn was colorless 7 April and faint 8-11 April. A bright dusk 11 April and dawn the next morning were followed by cloudy weather through the 14th. Dawn and dusk were colorless on the 15th, but moderately strong from the 16th through dawn on the 21st.

Information Contacts: W. Fuller, NASA; M. Fujiwara and M. Hirono, Kyushu Univ., Japan; E. Brooks, Saudi Arabia.