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Report on Atmospheric Effects (1980-1989) — February 1986

Scientific Event Alert Network Bulletin, vol. 11, no. 2 (February 1986)
Managing Editor: Lindsay McClelland.

Atmospheric Effects (1980-1989) Stratospheric aerosols persist

Please cite this report as:

Global Volcanism Program, 1986. Report on Atmospheric Effects (1980-1989) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 11:2. Smithsonian Institution.

Atmospheric Effects (1980-1989)

All times are local (unless otherwise noted)

Lidar data from Mauna Loa, Hawaii on 5 February showed continued development of the aerosol layer centered at about 20 km (figure 22). The entire profile was depressed on the 12th, but a week later the 20 km layer had strengthened and backscattering was slightly enhanced above 25 km. By 28 February, the higher layer had become prominent, the first significant enhancements detected at that altitude over Mauna Loa since 26-27 November (probably from Ruiz). From Hampton, VA (37.1°N, 76.3°W), lidar data on 14 February showed a layer centered around 20 km that was at a similar altitude but weaker than layers observed in Japan in January. Lidar profiles from the segments of the NASA airborne mission W of Thule, Greenland (about 77.5°N, 69.5°W) were similar to profiles from Tsukuba, Japan, 9-10 January.

Figure with caption Figure 22. Lidar profiles from Mauna Loa, Hawaii, 5-28 February 1986. The dotted line superimposed on each profile represents the average data 5-22 November, before the arrival of new aerosols over Hawaii. Courtesy of Thomas DeFoor.

Balloon flights over Laramie, WY on 3 and 22 February detected no layers of optically active areosols (radius > 0.15 µm) or condensation nuclei (CN, radius > 0.01 µm) that could be associated with recent volcanic activity. An increase in CN at 25 km on 3 February was attributed to evaporation and recondensation of older aerosols, rather than a new volcanic event.

From Millville, New Jersey (39.4°N, 74.9°W), Fred Schaaf observed an unusual sunrise on 11 January. Glow reached 15° altitude at 0702 and visible NE-SW horizontal striations seemed to be at higher altitudes than normal weather clouds. The intensity of the effects were similar to those observed after the 1980 St. Helens eruption, but much weaker than those that followed the eruption of El Chichón in 1982.

Information Contacts: Thomas DeFoor, Mauna Loa Observatory, P.O. Box 275, Hilo, HI 96720 USA; William Fuller, NASA Langley Research Center, Hampton, VA 23665 USA; J.M. Rosen and D.J. Hofmann, Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 USA; Fred Schaaf, R. D. 2, Box 248, Millville, New Jersey 08332 USA.