Growth of volcanic ash aggregates in the presence of liquid water and ice: an experimental approach

Eaton, Alexa R. Van; Muirhead, James D.; Wilson, C. J. N.; Cimarelli, C.

doi:10.1007/s00445-012-0634-9

Cited by 79 publications

(87 citation statements)

References 58 publications

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“…namics, volcanic lightning, sequestration of gaseous species, and the transport of these species to the stratosphere (Brown et al, 2012;McNutt and Williams, 2010;Kolb et al, 2010;Van Eaton et al, 2012). Further, fine ash from plumes can stay suspended in the upper troposphere for weeks to months and travel 1000s of kilometers; if these particles are efficient depositional ice nuclei, they could represent a widespread source of cold-cloud ice nuclei not currently parameterized in global models .…”

Section: G P Schill Et Al: Deposition and Immersion-mode Nucleatiomentioning

confidence: 99%

“…For the immersion freezing experiments, the Raman microscope cold stage was validated using the same, standard kaolinite sample (Murray et al, 2011;Pinti et al, 2012). Using this validated system, we determined the ice nucleation active surface site densities of each volcanic ash sample by utilizing the singular description (Vali, 1994(Vali, , 2008Vali and Stansbury, 1966). The results and implications of these findings for cloud glaciation in volcanic plumes and the atmosphere are discussed.…”

Section: G P Schill Et Al: Deposition and Immersion-mode Nucleatiomentioning

confidence: 99%

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Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

2015

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Abstract. Ice nucleation of volcanic ash controls both ash aggregation and cloud glaciation, which affect atmospheric transport and global climate. Previously, it has been suggested that there is one characteristic ice nucleation efficiency for all volcanic ash, regardless of its composition, when accounting for surface area; however, this claim is derived from data from only two volcanic eruptions. In this work, we have studied the depositional and immersion freezing efficiency of three distinct samples of volcanic ash using Raman microscopy coupled to an environmental cell. Ash from the Fuego (basaltic ash, Guatemala), Soufrière Hills (andesitic ash, Montserrat), and Taupo (Oruanui eruption, rhyolitic ash, New Zealand) volcanoes were chosen to represent different geographical locations and silica content. All ash samples were quantitatively analyzed for both percent crystallinity and mineralogy using X-ray diffraction. In the present study, we find that all three samples of volcanic ash are excellent depositional ice nuclei, nucleating ice from 225 to 235 K at ice saturation ratios of 1.05 ± 0.01, comparable to the mineral dust proxy kaolinite. Since depositional ice nucleation will be more important at colder temperatures, fine volcanic ash may represent a global source of cold-cloud ice nuclei. For immersion freezing relevant to mixed-phase clouds, however, only the Oruanui ash exhibited appreciable heterogeneous ice nucleation activity. Similar to recent studies on mineral dust, we suggest that the mineralogy of volcanic ash may dictate its ice nucleation activity in the immersion mode.

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Section: G P Schill Et Al: Deposition and Immersion-mode Nucleatiomentioning

confidence: 99%

Section: G P Schill Et Al: Deposition and Immersion-mode Nucleatiomentioning

confidence: 99%

Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

2015

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“…"Plume" lightning produces the longest discharge channels and is considered the most similar to thunderstorm lightning, where volcanic ash may act as ice nuclei, leading to tribocharging from ice-ice or ice-ash collisions [2,[5][6][7]. Ice collisions can only be an effective charging mechanism once the ash has reached an altitude at which ice nucleation can occur, between the −10 • C and −20 • C isotherms [8,9]. The altitude of isotherms above erupting volcanoes will vary based on the latitude and the meteorological conditions of the day.…”

Section: Introductionmentioning

confidence: 99%

“…The altitude of isotherms above erupting volcanoes will vary based on the latitude and the meteorological conditions of the day. Remote sensing studies of volcanic lightning have determined the altitude of the −20 • C isotherm Heterogeneous ice nucleation will occur on volcanic ash particles between the −10 °C and −20 °C isotherm [8,9], the latter of which is the highest temperature examined in this study using both deposition-mode and immersion-mode experiments. Based upon remote sensing studies of volcanic lightning, the −20 °C isotherm occurs at an altitude ranging from 4 to 10 km [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Compositional and Mineralogical Effects on Ice Nucleation Activity of Volcanic Ash

et al. 2018

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Volcanic ash produced during explosive eruptions may serve as ice nuclei in the atmosphere, contributing to the occurrence of volcanic lightning due to tribocharging from ice-ice or ice-ash collisions. Here, different ash samples were tested using deposition-mode and immersion-mode ice nucleation experiments. Results show that bulk composition and mineral abundance have no measurable effect on depositional freezing at the temperatures tested, as all samples have similar ice saturation ratios. In the immersion mode, there is a strong positive correlation between K 2 O content and ice nucleation site density at −25 • C and a strong negative correlation between MnO and TiO 2 content at temperatures from −35 to −30 • C. The most efficient sample in the immersion mode has the highest surface area, smallest average grain size, highest K 2 O content, and lowest MnO content. These results indicate that although ash abundance-which creates more available surface area for nucleation-has a significant effect on immersion-mode freezing, composition may also contribute. Consequently, highly explosive eruptions of compositionally evolved magmas create the necessary parameters to promote ice nucleation on grain surfaces, which permits tribocharging due to ice-ice or ice-ash collisions, and contribute to the frequent occurrence of volcanic lightning within the eruptive column and plume during these events.

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“…Behnke et al, 2014;Woodhouse and Behnke, 2014) and aggregation of ash (e.g. Brown et al, 2012;Van Eaton et al, 2012.…”

Section: Discussionmentioning

confidence: 99%

A global sensitivity analysis of the PlumeRise model of volcanic plumes

Woodhouse

Hogg

Phillips

2016

Journal of Volcanology and Geothermal Research

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Integral models of volcanic plumes allow predictions of plume dynamics to be made and the rapid estimation of volcanic source conditions from observations of the plume height by model inversion. Here we introduce PlumeRise, an integral model of volcanic plumes that incorporates a description of the state of the atmosphere, includes the effects of wind and the phase change of water, and has been developed as a freely available web-based tool. The model can be used to estimate the height of a volcanic plume when the source conditions are specified, or to infer the strength of the source from an observed plume height through a model inversion. The predictions of the volcanic plume dynamics produced by the model are analysed in four case studies in which the atmospheric conditions and the strength of the source are varied. A global sensitivity analysis of the model to a selection of model inputs is performed and the results are analysed using parallel coordinate plots for visualisation and variance-based sensitivity indices to quantify the sensitivity of model outputs. We find that if the atmospheric conditions do not vary widely then there is a small set of model inputs that strongly influence the model predictions. When estimating the height of the plume, the source mass flux has a controlling influence on the model prediction, while variations in the plume height strongly effect the inferred value of the source mass flux when performing inversion studies. The values taken for the entrainment coefficients have a particularly important effect on the quantitative predictions. The dependencies of the model outputs to variations in the inputs are discussed and compared to simple algebraic expressions that relate source conditions to the height of the plume.

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Growth of volcanic ash aggregates in the presence of liquid water and ice: an experimental approach

Cited by 79 publications

References 58 publications

Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

Deposition and immersion-mode nucleation of ice by three distinct samples of volcanic ash

Compositional and Mineralogical Effects on Ice Nucleation Activity of Volcanic Ash

A global sensitivity analysis of the PlumeRise model of volcanic plumes

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