HR: 09:00h
AN: V21E-05 INVITED    [Abstracts]
TI: Volcanic Ash Clouds: Modelling for Aviation Safety
AU: * Graf, H
EM: hfg21@cam.ac.uk
AF: University of Cambridge, Centre for Atmospheric Sciences, Dept. Geography, Downing Place, Cambridge, CB2 3EN, United Kingdom
AU: Tupper, A
EM: A.Tupper@bom.gov.au
AF: Australian Bureau of Meteorology, PO Box 40050, Northern Territory Regional Office., Casuarina, NT 0811, Australia
AU: Herzog, M
EM: mh526@cam.ac.uk
AF: University of Cambridge, Centre for Atmospheric Sciences, Dept. Geography, Downing Place, Cambridge, CB2 3EN, United Kingdom
AU: Textor, C
EM: christiane.textor@lsce.ipsl.fr
AF: Service d'Aeronomie, CNRS/UPMC/IPSL, Paris, 91371, France
AB: Ash clouds of volcanic origin pose a serious safety problem to aviation. Simplistic models often give inaccurate estimates of the dispersion height of these clouds and observational methods have problems if these clouds consist of a mixture of ice, water and ash, as is often the case in moist environments. In this talk results are presented of a sophisticated 3-D numerical model that show the effects of environmental conditions on plume rise and dispersion height for eruptions reaching from small sub-plinian to large co-ignimbrite eruptions. The model not only predicts injection heights, but also the rapid spread of the umbrella, mixing with ice and rain-out or freeze-out of the ash particles and gases. Also sedimentation is simulated realistically. These predictions may be useful for improved remote sensing and detection of hazardous ash plumes and lead to improved initial conditions for simpler dispersion models used at weather services providing ash warnings to the aviation industry.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0370 Volcanic effects (8409)
DE: 0545 Modeling (4255)
DE: 8488 Volcanic hazards and risks
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting