Particle size distributions of Mount Etna's aerosol plume constrained by Sun photometry

Watson, I. Matthew; Oppenheimer, Clive

doi:10.1029/2000jd900042

Cited by 40 publications

(48 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…greater than 1.0, are associated with non-ash-bearing volcanic plumes (e.g. Watson and Oppenheimer, 2000;Mather et al, 2004). In particular, the Ångström exponent values observed at Lampedusa (average value of 1.61 ± 0.06 for the period 26-29 October) are consistent with those measured in the Mount Etna near-source plume in the past.…”

Section: Role Of Sulfate Aerosols and Ash At Lampedusasupporting

confidence: 74%

“…Sun photometric measurements (see e.g. Watson and Oppenheimer, 2000) performed at Mount Etna have shown a tri-modal lognormal aerosol size distribution, with a coarser mode with a mean radius greater than 5 µm, which is partially attributed to ash during relatively weak activity phases. Coarse modes with higher mean radii, greater than 10 µm, are observed in eruptive size distributions, (e.g.…”

Section: Cloud Top Pressure Observations From Spinningmentioning

confidence: 99%

“…6a of Watson and Oppenheimer, 2000;Fig. 4a of Watson and Oppenheimer, 2001), thus generating a size distribution characterised by markedly increasing concentrations for very small radii.…”

Section: Role Of Sulfate Aerosols and Ash At Lampedusamentioning

confidence: 99%

See 2 more Smart Citations

Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

et al. 2016

View full text Add to dashboard Cite

Abstract. In this paper we combine SO 2 and ash plume dispersion modelling with satellite and surface remote sensing observations to study the regional influence of a relatively weak volcanic eruption from Mount Etna on the optical and micro-physical properties of Mediterranean aerosols. We analyse the Mount Etna eruption episode of 25-27 October 2013. The evolution of the plume along the trajectory is investigated by means of the FLEXible PARTicle Lagrangian dispersion (FLEXPART) model. The satellite data set includes true colour images, retrieved values of volcanic SO 2 and ash, estimates of SO 2 and ash emission rates derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations and estimates of cloud top pressure from SEVIRI (Spinning Enhanced Visible and InfraRed Imager). Surface remote sensing measurements of aerosol and SO 2 made at the ENEA Station for Climate Observations (35.52 • N, 12.63 • E; 50 m a.s.l.) on the island of Lampedusa are used in the analysis. The combination of these different data sets suggests that SO 2 and ash, despite the initial injection at about 7.0 km altitude, reached altitudes around 10-12 km and influenced the column average aerosol particle size distribution at a distance of more than 350 km downwind. This study indicates that even a relatively weak volcanic eruption may produce an observable effect on the aerosol properties at the regional scale. The impact of secondary sulfate particles on the aerosol size distribution at Lampedusa is discussed and estimates of the clear-sky direct aerosol radiative forcing are derived. Daily shortwave radiative forcing efficiencies, i.e. radiative forcing per unit AOD (aerosol optical depth), are calculated with the LibRadtran model. They are estimated between −39 and −48 W m −2 AOD −1 at the top of the atmosphere and between −66 and −49 W m −2 AOD −1 at the surface, with the variability in the estimates mainly depending on the aerosol single scattering albedo. These results suggest that sulfate particles played a large role in the transported plume composition and radiative forcing, while the contribution by ash particles was small in the volcanic plume arriving at Lampedusa during this event.

show abstract

Section: Role Of Sulfate Aerosols and Ash At Lampedusasupporting

confidence: 74%

Section: Cloud Top Pressure Observations From Spinningmentioning

confidence: 99%

See 1 more Smart Citation

Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Etna is not an arc volcano; we use the data from Gerlach [2004] not to compare them to field data but to show the differences in the plume evolution in the model for different types of volcanoes. The initial composition of the aerosol is taken from Allen et al [2006], whereas the aerosol size distribution is taken from Watson and Oppenheimer [2000].…”

Section: Model Description and Setupmentioning

confidence: 99%

Reactive halogen chemistry in volcanic plumes

Bobrowski¹,

Glasow²,

Aiuppa³

et al. 2007

J. Geophys. Res.

151

173

View full text Add to dashboard Cite

[1] Bromine monoxide (BrO) and sulphur dioxide (SO 2 ) abundances as a function of the distance from the source were measured by ground-based scattered light Multiaxis Differential Optical Absorption Spectroscopy (MAX-DOAS) in the volcanic plumes of Mt. Etna on Sicily, Italy, in August-October 2004 and May 2005 and Villarica in Chile in November 2004. BrO and SO 2 spatial distributions in a cross section of Mt. Etna's plume were also determined by Imaging DOAS. We observed an increase in the BrO/SO 2 ratio in the plume from below the detection limit near the vent to about 4.5 Â 10 À4 at 19 km (Mt. Etna) and to about 1.3 Â 10 À4 at 3 km (Villarica) distance, respectively. Additional attempts were undertaken to evaluate the compositions of individual vents on Mt. Etna. Furthermore, we detected the halogen species ClO and OClO. This is the first time that OClO could be detected in a volcanic plume. Using calculated thermodynamic equilibrium compositions as input data for a one-dimensional photochemical model, we could reproduce the observed BrO and SO 2 vertical columns in the plume and their ratio as function of distance from the volcano as well as vertical BrO and SO 2 profiles across the plume with current knowledge of multiphase halogen chemistry, but only when we assumed the existence of an ''effective source region,'' where volcanic volatiles and ambient air are mixed at about 600°C (in the proportions of 60% and 40%, respectively).

show abstract

“…Thanks to their small size and weight, these hand-held instruments are very well suited to field measurement of volcanic plumes near the source, in difficult access areas. In the past, Microtops-II "Sun Photometer" systems (hereafter referred to as MIISP), have been used to characterise the optical properties of plumes, i.e., to observe the spectral AOD in the visible and near infrared (NIR) spectral ranges, and to derive the Ångström coefficients α and β, from volcanoes such as Mount Etna [9,10], Kilauea [11], Masaya [12], Lascar and Villarica [13,14] and Eyjafjallajökull [15]. Recently, ultraviolet (UV) AOD and UV-to-NIR Ångström coefficient observations have been derived at Mount Etna by means of a Microtops-II "Ozone Monitor" system (hereafter referred to as MIIOM) [16].…”

Section: Introductionmentioning

confidence: 99%

Aerosol Optical Properties of Pacaya Volcano Plume Measured with a Portable Sun-Photometer

et al. 2018

View full text Add to dashboard Cite

Abstract:In this paper, Sun-photometer multichannel measurements of aerosol optical depths (AODs) in the visible and near-infrared spectral ranges, and Ångström parameters of the plume issued from the Pacaya volcano, Guatemala, are presented for the first time. These observations, made during a short-term campaign carried out on 29 and 30 January 2011, indicate a diluted (AODs lower than 0.1) volcanic plume composed of small particles (Ångström exponent ∼1.0 on 29 January and ∼1.4 on 30 January). Results are consistent with an ash-free plume. Finally, the impact of the choice of different wavelength pairs for the calculation of the Ångström parameters from the spectral AOD observations is tested and critically discussed.

show abstract

Particle size distributions of Mount Etna's aerosol plume constrained by Sun photometry

Abstract: Abstract.Near simultaneous instrument calibration and volcanic aerosol measurement were performed near the summit of Mount Etna, Sicily, in October 1997 using an eight channel Sun-tracking photometer. Three objectives were achieved using this methodology:

Cited by 40 publications

References 30 publications

Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25–27 October 2013

Reactive halogen chemistry in volcanic plumes

Aerosol Optical Properties of Pacaya Volcano Plume Measured with a Portable Sun-Photometer

Contact Info

Product

Resources

About