UV Lidar Measurement of Stratospheric Aerosol Layer Observational Results at Fukuoka (33.6°N) during October 1982 through May 1983

Abstract

After the volcanic eruptions of Mt. El Chichon in Mexico, increase of stratospheric aerosols has been measured by a UV lidar at a wavelength of 340.5nm at Fukuoka (33.65*N, 130.35*E) since October 1982. The altitude of the maximum backscattering ratio (Rmax* 3.5) was 24km in October 1982, and it decreased to 20km in January 1983. The value of Rmax-1 decreased by a factor of 2.4, but large changes of aerosol backscattering coefficient integrated over an altitude range of 15-30km were not recognized during this period. A brief consideration is given on this lowering of the aerosol layer.

Ruby Lidar Observatiens of the E1 Chichon Dust Clouds at Tsukuba (36.1°N) and Comparisons with UV Lidar Measurements at Fukuoka (33.6°N)

“…1982 to January 1983 was remarkable. The lowering of Zmax from 27km to 21.5km observed at Mauna Loa Observatory during June 1982 through 1983 was monotonous and represented characteristics of the particle sedimentation with an apparent radius of 0.4*0.5 * m (Uchino et al, 1984). On the other hand, Zmax at Langley Research Center, Hampton lowered from 25km to 18km with fluctuations of 1-2km during July 1982 through September 1983.…”

“…This increase of temperature is believed to be due to the absorption of terrestrial infrared radiation by enhanced stratospheric aerosol burdens at 30-mb level, while these aerosols reflect the solar radiation and decrease the direct solar insulation. Scattered solar radiation by the aerosol particles may have enhanced the photodissociation rates to affect minor atmospheric species such as Ox, HOx, and NOx (Yamamura et al, 1983).…”

On the Long Term Variation of Stratospheric Aerosol Content After the Eruption of Volcano El Chichón: Lidar Measurements at Nagoya, Japan

“…Since the descent of the peak height was possibly not only due to gravitational fall but also due to downward motion, the mean radius of particles around the peak height could be regarded as about 0.6-0.7*m for the earlier Oberbeck et al (1983) N0 is the number of particles, r0 is the median radius and * is the standard deviation with respect to in r. The total surface area and the backscattering coeficent are shown for each distribution functions. decay period (Uchino et al, 1984).…”