Effect of environmental conditions on volcanic plume rise

Graf, Hans‐F.; Herzog, Michael; Oberhuber, Josef M.; Textor, C.

doi:10.1029/1999jd900498

Cited by 78 publications

(76 citation statements)

References 20 publications

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“…In the moist tropics, we would expect that entrainment of water vapor and the higher tropopause will increase the height of maximum ascent of otherwise small to moderate sized eruptions, resulting in high eruption clouds with high water vapor but relatively less ash (Graf et al, 1999;Woods, 1993), and therefore a proportionally lower chance of detection than an eruption of the same height at high latitudes. Rabaul Volcano Observatory has observed convective growth over small eruptions in Papua New Guinea (Ima Itikarai, personal communication, 2002), and show large cumulus forming over passive degassing in a moist environment at Sakurajima, Japan.…”

Section: Eruptions and Moist Convectionmentioning

confidence: 99%

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Tupper

Carn

Davey

et al. 2004

Remote Sensing of Environment

108

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We examined recent volcanic cloud events in the Western Pacific and Indonesian area, to validate the performance of remote sensing techniques used to support the International Airways Volcano Watch (IAVW). Five events were considered, during which eruptions from eight volcanoes injected ash into the upper troposphere or lower stratosphere. For one of the eruptions, at Miyakejima, Japan, at least five aircraft encountered volcanic ash clouds, and the cost to three operators alone exceeded US $12,000,000 in aircraft repairs, diversions, and lost operating time. We performed 'reverse' absorption and 'pattern analysis' using GMS-5/VISSR, MODIS and AVHRR data, and we examined TOMS SO 2 and Aerosol Index data, surface-based observations, pilot reports, and dispersion model output. Our results verify that the introduction of 'reverse' absorption using the geostationary GMS-5 platform significantly enhanced our capacity to monitor volcanic ash clouds in the region. In one case, we tracked an eruption cloud for approximately 80 hours. The primary impediment to remote monitoring is the presence of overlying cloud, or substantial amounts of ice within the volcanic clouds. TOMS data showed success in identifying volcanic clouds during these conditions, but was limited by the infrequency of observations. More effective future operation of the IAVW relies on developing complementary methods of volcanic cloud remote sensing, and greatly increasing the amount and quality of available surface and air observations, including observations of precursor activity. An understanding of the likely future limitations of remote sensing techniques will aid in the refining of IAVW procedures.

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Section: Eruptions and Moist Convectionmentioning

confidence: 99%

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Tupper

Carn

Davey

et al. 2004

Remote Sensing of Environment

108

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“…Veitch and Woods (2001) According to Textor and Ernst (2004) the plume model considered by Veitch and Woods (2001) provides an overly-simplistic description of the aggregation process as it does not consider microphysical processes crucial for the aggregation of ash in the presence of water. Textor et al (2006a, b) presented a more sophisticated model of wet aggregation using ATHAM (Active Tracer High-resolution Atmospheric Model, Graf et al 1999;Herzog et al 2003;Oberhuber et al 1998) which accounts for the formation of liquid and solid hydrometeors and the effect on the plume dynamics from the latent heat generated by water phases changes. During rapid rise to high cold altitudes, ice is dominant in typical Plinian plumes relative to liquid water.…”

Section: Empirical and Numerical Studies On Aggregationmentioning

confidence: 99%

A review of volcanic ash aggregation

Brown

Bonadonna

Durant

2012

Physics and Chemistry of the Earth, Parts A/B/C

237

298

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. (2012) 'A review of volcanic ash aggregation.', Physics and chemistry of the earth, parts A/B/C., 45-46 . pp. 65-78. Further information on publisher's website:http://dx.doi.org/10.1016/j.pce. 2011.11.001 Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractMost volcanic ash particles with diameters < 63 µm settle from eruption clouds as particle aggregates that cumulatively have larger sizes, lower densities, and higher terminal fall velocities than individual constituent particles. Particle aggregation reduces the atmospheric residence time of fine ash, which results in a proportional increase in fine ash fallout within 10s km to 100s km from the volcano and a reduction in airborne fine ash mass concentrations 1000s km from the volcano. Aggregate characteristics vary with distance from the volcano: proximal aggregates are typically larger (up to cm size) with concentric structures, while distal aggregates are typically smaller (sub-millimetre size). Particles comprising ash aggregates are bound through hydro-bonds (liquid and ice water) and electrostatic forces, and the rate of particle aggregation correlates with cloud liquid water availability. Eruption source parameters (including initial particle size distribution, erupted mass, eruption column height, cloud water content and temperature) and the eruption plume temperature lapse rate, coupled with the environmental parameters, determines the type and spatiotemporal distribution of aggregates. Field studies, lab experiments and modelling investigations have already provided important insights on the process of particle aggregation. However, new integrated observations that combine remote sensing studies of 2 ash clouds with field measurement and sampling, and lab experiments are required to fill current gaps in knowledge surrounding the theory of ash aggregate formation. Abstract word count: 222

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“…The three-dimensional model ATHAM (Active Tracer High resolution Atmospheric Model) is able to simulate intense forms of atmospheric convection induced by volcanic eruptions or intense forest fires (Oberhuber et al, 1998;Graf et al, 1999;Textor et al, 2006;Tupper et al, 2009). The model solves the complete Navier-Stokes equations including sound waves, which cannot be excluded due to the possible supersonic flow around the vent of a volcano (Herzog et al, 2003).…”

Section: Model Descriptionmentioning

confidence: 99%

3-D model simulations of dynamical and microphysical interactions in pyroconvective clouds under idealized conditions

et al. 2014

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Abstract. Dynamical and microphysical processes in pyroconvective clouds in mid-latitude conditions are investigated using idealized three-dimensional simulations with the Active Tracer High resolution Atmospheric Model (ATHAM). A state-of-the-art two-moment microphysical scheme building upon a realistic parameterization of cloud condensation nuclei (CCN) activation has been implemented in order to study the influence of aerosol concentration on cloud development. The results show that aerosol concentration influences the formation of precipitation. For low aerosol concentrations (N CN = 200 cm −3 ), rain droplets are rapidly formed by autoconversion of cloud droplets. This also triggers the formation of large graupel and hail particles, resulting in an early onset of precipitation. With increasing aerosol concentration (N CN = 1000 cm −3 and N CN = 20 000 cm −3 ) the formation of rain droplets is delayed due to more but smaller cloud droplets. Therefore, the formation of ice crystals and snowflakes becomes more important for the eventual formation of graupel and hail, which is delayed at higher aerosol concentrations. This results in a delay of the onset of precipitation and a reduction of its intensity with increasing aerosol concentration. This study is the first detailed investigation of the interaction between cloud microphysics and the dynamics of a pyroconvective cloud using the combination of a high-resolution atmospheric model and a detailed microphysical scheme.

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Effect of environmental conditions on volcanic plume rise

Cited by 78 publications

References 20 publications

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

A review of volcanic ash aggregation

3-D model simulations of dynamical and microphysical interactions in pyroconvective clouds under idealized conditions

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