The Eyjafjallajökull volcanic ash plume over central Europe: Lidar Observations of aerosol composition and ash-induced cloud modification

Abstract. Airborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla volcano between 19 April and 18 May 2010. Flight planning and measurement analyses were supported by a refined Meteosat ash product and trajectory model analysis. The volcanic ash plume was observed with lidar directly over the volcano and up to a distance of 2700 km downwind, and up to 120 h plume ages. Aged ash layers were between a few 100 m to 3 km deep, occurred between 1 and 7 km altitude, and were typically 100 to 300 km wide. Particles collected by impactors had diameters up to 20 μm diameter, with size and age dependent composition. Ash mass concentrations were derived from optical particle spectrometers for a particle density of 2.6 g cm−3 and various values of the refractive index (RI, real part: 1.59; 3 values for the imaginary part: 0, 0.004 and 0.008). The mass concentrations, effective diameters and related optical properties were compared with ground-based lidar observations. Theoretical considerations of particle sedimentation constrain the particle diameters to those obtained for the lower RI values. The ash mass concentration results have an uncertainty of a factor of two. The maximum ash mass concentration encountered during the 17 flights with 34 ash plume penetrations was below 1 mg m−3. The Falcon flew in ash clouds up to about 0.8 mg m−3 for a few minutes and in an ash cloud with approximately 0.2 mg m−3 mean-concentration for about one hour without engine damage. The ash plumes were rather dry and correlated with considerable CO and SO2 increases and O3 decreases. To first order, ash concentration and SO2 mixing ratio in the plumes decreased by a factor of two within less than a day. In fresh plumes, the SO2 and CO concentration increases were correlated with the ash mass concentration. The ash plumes were often visible slantwise as faint dark layers, even for concentrations below 0.1 mg m−3. The large abundance of volatile Aitken mode particles suggests previous nucleation of sulfuric acid droplets. The effective diameters range between 0.2 and 3 μm with considerable surface and volume contributions from the Aitken and coarse mode aerosol, respectively. The distal ash mass flux on 2 May was of the order of 500 (240–1600) kg s−1. The volcano induced about 10 (2.5–50) Tg of distal ash mass and about 3 (0.6–23) Tg of SO2 during the whole eruption period. The results of the Falcon flights were used to support the responsible agencies in their decisions concerning air traffic in the presence of volcanic ash.

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Volcanic ash particulate matter from the 2010 Eyjafjallajökull eruption in dust deposition at Prague, central Europe

Aeolian Research ◽

10.1016/j.aeolia.2012.12.002 ◽

2013 ◽

Vol 9 ◽

pp. 191-202 ◽

Cited By ~ 11

Author(s):

Tomáš Navrátil ◽

Jindřich Hladil ◽

Ladislav Strnad ◽

Leona Koptíková ◽

Roman Skála

Keyword(s):

Particulate Matter ◽

Central Europe ◽

Volcanic Ash ◽

Dust Deposition

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Evaluating the structure and magnitude of the ash plume during the initial phase of the 2010 Eyjafjallajökull eruption using lidar observations and NAME simulations

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jd015608 ◽

2011 ◽

Vol 116 ◽

Cited By ~ 80

Author(s):

H. F. Dacre ◽

A. L. M. Grant ◽

R. J. Hogan ◽

S. E. Belcher ◽

D. J. Thomson ◽

...

Keyword(s):

Initial Phase ◽

Ash Plume ◽

Lidar Observations

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Lidar observations of volcanic aerosol over the UK since June 2019

10.5194/egusphere-egu2020-5653 ◽

2020 ◽

Author(s):

Geraint Vaughan ◽

David Wareing ◽

Hugo Ricketts

Keyword(s):

Volcanic Ash ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Raman Lidar ◽

Lidar System ◽

Elastic Channel ◽

Enhanced Sensitivity ◽

Volcanic Cloud ◽

The Uk ◽

Lidar Observations

<p>On 22 June 2019, the Raikoke volcano in the Kuril Islands erupted, sending a plume of ask and sulphur dioxide into the stratosphere. A Raman lidar system at Capel Dewi, UK (52.4&#176;N, 4.1&#176;W) has been used to measure the extent and optical depth of the stratospheric aerosol layer following the eruption. The lidar was modified to give it much enhanced sensitivity in the elastic channel, allowing measurements up to 25 km, but the Raman channel is only sensitive to the troposphere. Therefore, backscatter ratio profiles were derived by comparison with aerosol-free profiles derived from nearby radiosondes, corrected for aerosol extinction. Small amounts of stratospheric aerosol were measured prior to the arrival of the volcanic cloud, probably from pyroconvection over Canada. Volcanic ash began to arrive as a thin layer at 14 km late on 3 July, extending over the following month to fill the stratosphere below around 19 km. Aerosol optical depths reached around 0.03 by mid-August and continued at this level for the remainder of the year. The location of peak backscatter varied considerably but was generally around 15 km. However, on one notable occasion on August 25, a layer around 300 m thick with peak lidar backscatter ratio around 1.5 was observed as high as 21 km.</p>

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Airborne in-situ investigations of the Eyjafjallajökull volcanic ash plume on Iceland and over north-western Germany with light aircrafts and optical particle counters

Atmospheric Environment ◽

10.1016/j.atmosenv.2011.10.030 ◽

2012 ◽

Vol 48 ◽

pp. 9-21 ◽

Cited By ~ 44

Author(s):

K. Weber ◽

J. Eliasson ◽

A. Vogel ◽

C. Fischer ◽

T. Pohl ◽

...

Keyword(s):

Volcanic Ash ◽

Western Germany ◽

Ash Plume ◽

North Western

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Ash plume top height estimate using AATSR

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-3863-2014 ◽

2014 ◽

Vol 7 (4) ◽

pp. 3863-3913

Author(s):

T. H. Virtanen ◽

P. Kolmonen ◽

E. Rodríguez ◽

L. Sogacheva ◽

A.-M. Sundström ◽

...

Keyword(s):

Volcanic Ash ◽

Quality Parameters ◽

Height Estimate ◽

Brightness Temperatures ◽

In Situ Data ◽

Estimate Method ◽

Ash Plume ◽

Along Track

Abstract. An algorithm is presented for estimation of volcanic ash plume top height using the stereo view of the Advanced Along Track Scanning Radiometer (AATSR) aboard ENVISAT. The algorithm is based on matching the top of atmosphere (TOA) reflectances and brightness temperatures of the nadir and 55° forward views, and using the resulting parallax to obtain the height estimate. Various retrieval parameters are discussed in detail, several quality parameters are introduced, and post-processing methods for screening out unreliable data have been developed. The method is compared against other satellite observations and in-situ data. The proposed algorithm is designed to be fully automatic, and can be implemented into operational retrieval algorithms. Combined with automated ash detection using the brightness temperature difference between the 11 μm and 12 μm channels, the algorithm allows simultaneous retrieval of horizontal and vertical dispersion of volcanic ash efficiently. A case study on the eruption of the Icelandic volcano Eyjafjallajökull in 2010 is presented. The height estimate method results are validated against available satellite and ground based data.

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Ash plume top height estimation using AATSR

Atmospheric Measurement Techniques ◽

10.5194/amt-7-2437-2014 ◽

2014 ◽

Vol 7 (8) ◽

pp. 2437-2456 ◽

Cited By ~ 15

Author(s):

T. H. Virtanen ◽

P. Kolmonen ◽

E. Rodríguez ◽

L. Sogacheva ◽

A.-M. Sundström ◽

...

Keyword(s):

Volcanic Ash ◽

Quality Parameters ◽

Brightness Temperatures ◽

In Situ Data ◽

Vertical Dispersion ◽

Fully Automatic ◽

Ash Plume ◽

Along Track

Abstract. An algorithm is presented for the estimation of volcanic ash plume top height using the stereo view of the Advanced Along Track Scanning Radiometer (AATSR) aboard Envisat. The algorithm is based on matching top of the atmosphere (TOA) reflectances and brightness temperatures of the nadir and 55° forward views, and using the resulting parallax to obtain the height estimate. Various retrieval parameters are discussed in detail, several quality parameters are introduced, and post-processing methods for screening out unreliable data have been developed. The method is compared to other satellite observations and in situ data. The proposed algorithm is designed to be fully automatic and can be implemented in operational retrieval algorithms. Combined with automated ash detection using the brightness temperature difference between the 11 and 12 μm channels, the algorithm allows efficient simultaneous retrieval of the horizontal and vertical dispersion of volcanic ash. A case study on the eruption of the Icelandic volcano Eyjafjallajökull in 2010 is presented.

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