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Southern Hemisphere Lidar Measurements of the Aerosol Clouds from Mt. Pinatubo and Mt. HudsonOn 19 Jul., 1991, during tests to determine the ability of the newly-modified CSIRO Ns:YAG lidar to measure signals from the stratosphere before the arrival of dust from the eruption of Mt. Pinatubo, a strongly scattering layer was detected at an altitude of 2 km. That evening, the spectacular sunset and twilight were typical of volcanically disturbed conditions. Lidar measurements at 532 nm were made between 1400 and 1500 EST (0400-0500 UT) on 19 Jul. through broken cloud. Approximately 3800 laser firings were averaged in 256 shot blocks. These and subsequent data have been analyzed to produce profiles of aerosol volume backscatter function and scattering ratio. Clouds again prevented a clear view of the twilights on the next two nights, although there was some evidence for an enhanced glow. The evidence suggested that the aerosol layer had disappeared. An explanation for this disappearance and the earlier than expected arrival of the layer over Melbourne was required. Nimbus 7 TOMS data for 23 Jun. showed that the SO2 from the eruption had extended at least 11000 km to the west and that the southern boundary of the cloud had reached 15 degrees S just 8 days after the climactic eruption. It can be assumed that this cloud also contained dust and sulphuric acid aerosol. It was proposed that a section had then been broken away from the main cloud and carried south by a large scale eddy between the low latitude easterlies and the strong mid-latitude westerlies which finally carried the aerosol cloud over southern Australia. Accompanying 30 mb wind data showed a counter clockwise circulation, responsible for the transport, located in the South Atlantic Ocean.
Document ID
19920019987
Document Type
Conference Paper
Authors
Young, Stuart A. (Commonwealth Scientific and Industrial Research Organization Mordialoc, Australia)
Manson, Peter J. (Commonwealth Scientific and Industrial Research Organization Mordialoc, Australia)
Patterson, Graeme R. (Commonwealth Scientific and Industrial Research Organization Mordialoc, Australia)
Date Acquired
September 6, 2013
Publication Date
July 1, 1992
Publication Information
Publication: NASA. Langley Research Center, Sixteenth International Laser Radar Conference, Part 1
Subject Category
ENVIRONMENT POLLUTION
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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