Characterisation of the Near-Field Eyjafjallajökull Volcanic Plume and its Long-range Influence

Lead Research Organisation: University of Leeds
Department Name: School of Earth and Environment

Abstract

The volcanic plume from the Eyjafjallajökull eruption has caused significant disruption to air transport across Europe. The regulatory response, ensuring aviation safety, depends on dispersion models. The accuracy of the dispersion predictions depend on the intensity of the eruption, on the model representation of the plume dynamics and the physical properties of the ash and gases in the plume. Better characterisation of these processes and properties will require improved understanding of the near-source plume region. This project will bring to bear observations and modelling in order to achieve more accurate and validated dispersion predictions. The investigation will seek to integrate the volcanological and atmospheric science methods in order to initiate a complete system model of the near-field atmospheric processes. This study will integrate new modelling and insights into the dynamics of the volcanic plume and its gravitational equilibration in the stratified atmosphere, effects of meteorological conditions, physical and chemical behaviour of ash particles and gases, physical and chemical in situ measurements, ground-based remote sensing and satellite remote sensing of the plume with very high resolution numerical computational modelling. When integrated with characterisations of the emissions themselves, the research will lead to enhanced predictive capability. The Eyjafjallajökull eruption has now paused. However, all three previous historical eruptions of Eyjafjallajökull were followed by eruptions of the much larger Katla volcano. At least two other volcanic systems in Iceland are 'primed' ready to erupt. This project will ensure that the science and organisational lessons learned from the April/May 2010 response to Eyjafjallajökull are translated fully into preparedness for a further eruption of any other volcano over the coming years. Overall, the project will (a) complete the analysis of atmospheric data from the April/May eruption, (b) prepaor future observations and forecasting and (c) make additional observations if there is another eruption during within the forthcoming few years.

Publications

10 25 50

publication icon
Ilyinskaya E (2018) Globally Significant CO 2 Emissions From Katla, a Subglacial Volcano in Iceland in Geophysical Research Letters

publication icon
Marenco F (2011) Airborne lidar observations of the 2010 Eyjafjallajökull volcanic ash plume in Journal of Geophysical Research

 
Description 1. Spreading of Neutrally Buoyant Volcanic Plumes
Volcanic eruptions commonly produce buoyant ash-laden plumes that initially rise through the atmosphere and then spread horizontally at a level of neutral buoyancy. This spreading is what results in long-range influences of plumes, such as those on aviation. The VANAHEIM consortium has carried out mathematical modelling of the dynamics of this plume spreading. This has demonstrated that plumes spread rather faster than previously thought - at a rate proportional to time to the power 3/4 rather than the power 2/3. Our results emphasise the important role of buoyancy-driven plume spreading, even at large distances from the volcano, in the formation of the flowing thin horizontally extensive layers of ash that form in the atmosphere. It is these thin layers which predominantly make up the primary hazard for aviation.
Two papers have been published:
Johnson, C.G., Hogg, A.J., Huppert, H.E., Sparks, R.S.J., Phillips, J.C., Slim, A.C. and Woodhouse, M.J. 2015 Modelling intrusions through quiescent and moving ambients. J. Fluid Mech. 771, 370-406. doi:10.1017/jfm.2015.180.
Ungarish, M., Johnson, C.G. and Hogg, A.J. 2015 A novel hybrid model for the motion of sustained axisymmetric gravity currents and intrusions. Euro. J. Mech. B/Fluids 49, 108--120, ooi:10.1016/j.euromechflu.2014.07.007

2. Modelling Topographic Influences on Volcanic Emissions
In support of the above observations of the Bárðarbunga eruption, a modified version of the WRF (Weather Research and Forecasting) numerical prediction model has been implemented at high resolution. This allows complex topographical features to be incorporated in the dispersion modelling process. A representation of the Bárðarbunga fissure and surface SO2 emissions were included in the simulation. Simulations have been performed for the May 2015 FAAM aircraft flights over this region. Work is ongoing to compare the simulations with the flight data. Additional comparisons will be made with the daily, automated NCAS HYSPLIT forecasts which were performed for the duration of the eruption.
A paper has been submitted to Meteorological Applications.
This work has been carried out by VANAHEIM consortium members Ralph Burton and Stephen Mobbs.

3. Ash Refractive Index
Interpretation of satellite observations of volcanic ash is crucially dependent on the optical properties of the ash. In science terms this means the refractive index of the ash particles and the absorption properties of the ash. Lack of knowledge of these properties is the greatest single obstacle to deducing ash concentrations and properties from satellites. Our consortium has included the most comprehensive measurements of ash refractive indices to date. A new technique has been developed to estimate the real part of the refractive index at the optical wavelength of 635 nm. This has been applies to a sample of Eyjafjallajökull ash and is reported in the following paper:
Reed, B.E., R.G. Grainger, D.M. Peters and A.J.A. Smith, Retrieving the real refractive index of mono- and polydisperse colloids from reflectance near the critical angle, Optics Express, 24, 1953-1972, 2016. (doi:10.1364/OE.24.001953).
Exploitation Route The outcomes of the project are being taken forward by the consortium team in multiple ways, including academic communication, collaboration with operational agencies and commercialisation.
Sectors Environment,Transport

 
Description This has been reported to NERC via regular 6-monthly reporting. The project funding has now ended except for one component. This concerns planned flights by the FAAM aircraft over Iceland. In the original project plan the flying over Iceland was only to take place in the event of another ash eruption and this opportunity has not arisen. However, in the light of the other research under the project which has been completed during the past four years, it has been possible to develop revised airborne research plans which do not require an active ash eruption. Essentially the research is concerned with trace gas emission which could be an indicator of a future eruption. On the basis of these new plans, permission has been granted by NERC to extend the project and to carry out the airborne research. This is likely to happen late in 2016, so it is unlikely that it will be reported on in July 2016. In the meantime, although the other funding has ended, further highlights continue to emerge from the project research. Six notable examples are given below. 1. Airborne Observations of the Bárðarbunga Volcano and the Hekla Volcano A fissure eruption took place close to the Bárðarbunga volcano in Iceland from August 2014 to February 2015. At the end of this period the FAAM aircraft became available (it was previously fully engaged on other projects). A short trip to Iceland was made to fly over the lava field. Unfortunately low cloud meant that it was not possible to fly sufficiently close to detect the emitted gases. However the same flight was combined with observations of the non-erupting volcano Hekla. Recent ground-based work at Hekla has raised the possibility that gaseous emissions from the flanks of the volcano may be a pre-cursor of an eruption. Airborne observations of trace gases provide a much more comprehensive way of surveying such emissions. The flight revealed elevated levels of trace gases, especially ozone, close to Hekla. The data is currently being analysed in detail. A further flight later in 2015 is possible. This work has been carried out by VANAHEIM consortium members James Lee, Ruth Purvis, Alastair Lewis, Stephen Mobbs, Ralph Burton and Evgenia Ilyinskaya. 2. Modelling Topographic Influences on Volcanic Emissions In support of the above observations of the Bárðarbunga eruption, a modified version of the WRF (Weather Research and Forecasting) numerical prediction model has been implemented at high resolution. This allows complex topographical features to be incorporated in the dispersion modelling process. A representation of the Bárðarbunga fissure and surface SO2 emissions were included in the simulation. Simulations have been performed for the May 2015 FAAM aircraft flights over this region. Work is ongoing to compare the simulations with the flight data. Additional comparisons will be made with the daily, automated NCAS HYSPLIT forecasts which were performed for the duration of the eruption. A paper has been submitted to Meteorological Applications. This work has been carried out by VANAHEIM consortium members Ralph Burton and Stephen Mobbs. 3. Spreading of Neutrally Buoyant Volcanic Plumes Volcanic eruptions commonly produce buoyant ash-laden plumes that initially rise through the atmosphere and then spread horizontally at a level of neutral buoyancy. This spreading is what results in long-range influences of plumes, such as those on aviation. The VANAHEIM consortium has carried out mathematical modelling of the dynamics of this plume spreading. This has demonstrated that plumes spread rather faster than previously thought - at a rate proportional to time to the power 3/4 rather than the power 2/3. Our results emphasise the important role of buoyancy-driven plume spreading, even at large distances from the volcano, in the formation of the flowing thin horizontally extensive layers of ash that form in the atmosphere. It is these thin layers which predominantly make up the primary hazard for aviation. Two papers have been published: Johnson, C.G., Hogg, A.J., Huppert, H.E., Sparks, R.S.J., Phillips, J.C., Slim, A.C. and Woodhouse, M.J. 2015 Modelling intrusions through quiescent and moving ambients. J. Fluid Mech. 771, 370-406. doi:10.1017/jfm.2015.180. Ungarish, M., Johnson, C.G. and Hogg, A.J. 2015 A novel hybrid model for the motion of sustained axisymmetric gravity currents and intrusions. Euro. J. Mech. B/Fluids 49, 108--120, ooi:10.1016/j.euromechflu.2014.07.007 This work has been carried out by VANAHEIM consortium members Andrew Hogg, Stephen Sparks and Mark Woodhouse. 4. Satellite Observations of Volcanic SO2 in Near Real Time A website has been developed and deployed displaying data produced by the Infrared Atmospheric Sounding Instrument (IASI) satellite instruments. The data are analysed in near real time and are available to view within 3 hours of the satellite first making the measurement. A model of the atmosphere is compared to measurements made by IASI, allowing us to determine any changes in the composition of the atmosphere. From this, we can establish which compounds and particles have caused the change. The website currently displays the presence of SO2 within the atmosphere, which is often an indicator of volcanic activity. In those situations, the SO2 is often co-located with volcanic ash plumes, the location of which is of crucial importance to the aviation industry. The addition of indicators for other atmospheric contaminants, including volcanic ash, is planned for the near future. This work has been carried out by VANAHEIM consortium members Don Grainger and Elisa Carboni. 5. Ash Refractive Index Interpretation of satellite observations of volcanic ash is crucially dependent on the optical properties of the ash. In science terms this means the refractive index of the ash particles and the absorption properties of the ash. Lack of knowledge of these properties is the greatest single obstacle to deducing ash concentrations and properties from satellites. Our consortium has included the most comprehensive measurements of ash refractive indices to date. A new technique has been developed to estimate the real part of the refractive index at the optical wavelength of 635 nm. This has been applies to a sample of Eyjafjallajökull ash and is reported in the following paper: Reed, B.E., R.G. Grainger, D.M. Peters and A.J.A. Smith, Retrieving the real refractive index of mono- and polydisperse colloids from reflectance near the critical angle, Optics Express, 24, 1953-1972, 2016. (doi:10.1364/OE.24.001953). Related laboratory work has enabled both the refractive index and the absorption coefficient to be measures for 11 different ash samples at three wavelengths. This is reported in the following paper: Ball, J.G.C., B.E. Reed, R.G. Grainger, D.M. Peters, T.A. Mather and D.M. Pyle, Measurements of the complex refractive index of volcanic ash at 450, 546.7, and 650 nm, Journal of Geophysical Research, 120, 7747-7757, 2015. (doi:10.1002/2015JD023521) . 6. Dynamics of Volcanic Plumes The consortium has focused much of its research on developing a better understanding of how volcanic plumes spread and disperse over large distances. The most recent work has concentrated on extending models in which the ash is intruded into an already stratified atmosphere to now include the effects of the Earth's rotation. The resulting predictions have been tested against satellite images of ash clouds. Of significant practical importance is the conclusion that this approach can be used to deduce eruption source strength and mixing parameters. This work is reported in 4 papers: Johnson, C.G., Hogg, A.J., Huppert, H.E., Sparks, R.S.J., Phillips, J.C., Slim, A.C. and Woodhouse, M.J. 2015 Modelling intrusions through quiescent and moving ambients. J. Fluid Mech. 771, 370-406. doi:10.1017/jfm.2015.180. Woodhouse, M.J., Hogg, A.J., Phillips, J.C. and Rougier, J.C. 2015 Uncertainty analysis of a model of wind-blown volcanic plumes. Bull. Volcanol. 77 doi:10.1007/s00445-015-0959-2. Pouget, S., Bursik, M., Johnson, C.G., Hogg, A.J., Phillips, J.C. and Sparks, R.S.J 2016 Interpretation of umbrella cloud growth and morphology: implications for flow regimes of short-lived and long-lived eruptions. Bull. Volcanol. 78 doi:10.1007/s00445-015-0993-0. Ungarish, M., Johnson, C.G and Hogg, A.J. 2016 Sustained axisymmetric intrusions in a rotating system Euro. J. Fluid Mech, B. 56, 110-119 doi:10.1016/j.euromechflu.2015.10.008. In earlier reports we described the online tool PlumeRise developed under the consortium (https://www.plumerise.bris.ac.uk/). PlumeRise continues to be used quite widely. We have been running the model for recent eruptions in Indonesia to provide information for the Volcanic Ash Advisory Centre at Darwin.
First Year Of Impact 2011
Sector Aerospace, Defence and Marine,Environment,Transport
Impact Types Economic,Policy & public services

 
Description KTP partnership with Markes International on atmospheric sensing technologies 
Organisation Markes International
Country United Kingdom 
Sector Private 
PI Contribution A project to jointly develop trace gas sensors which will have wide application, including volcanic trace gases.
Start Year 2012
 
Title Aerosol Detection 
Description Aerosol detection apparatus comprises an aircraft having a dielectric member, such as a window (10), comprised in the body (12) thereof such that a surface of the dielectric member forms part of the exterior surface of the aircraft. Detection means (16), such as a static monitor is located on the inside of the aircraft and arranged to detect an electric field resulting from polarisation of the dielectric member. The output of the static monitor, or the rate of change thereof, correlates closely to particle density as the aircraft is flown though an aerosol, such as a volcanic ash cloud. The apparatus is simple and relatively inexpensive, and may comprise any general purpose aircraft. Aerosol particles may be detected and mapped using apparatus of the invention more easily and quickly than by use of devices such as optical spectrometers mounted on dedicated research aircraft, or static monitors mounted on the exterior of an aircraft. 
IP Reference 20130193978 
Protection Patent application published
Year Protection Granted 2013
Licensed No
Impact The invention is being further developed for commercial use on passenger aircraft.
 
Title Aerosol Detection 
Description Aerosol detection apparatus comprises an aircraft having a dielectric member, such as a window (10), comprised in the body (12) thereof such that a surface of the dielectric member forms part of the exterior surface of the aircraft. Detection means (16), such as a static monitor is located on the inside of the aircraft and arranged to detect an electric field resulting from polarisation of the dielectric member. The output of the static monitor, or the rate of change thereof, correlates closely to particle density as the aircraft is flown though an aerosol, such as a volcanic ash cloud. The apparatus is simple and relatively inexpensive, and may comprise any general purpose aircraft. Aerosol particles may be detected and mapped using apparatus of the invention more easily and quickly than by use of devices such as optical spectrometers mounted on dedicated research aircraft, or static monitors mounted on the exterior of an aircraft. 
IP Reference CA2812752 
Protection Patent application published
Year Protection Granted 2013
Licensed No
Impact The invention is being further developed for commercial use on passenger aircraft.
 
Title Aerosol Detection 
Description Aerosol detection apparatus comprises an aircraft having a dielectric member, such as a window (10), comprised in the body (12) thereof such that a surface of the dielectric member forms part of the exterior surface of the aircraft. Detection means (16), such as a static monitor is located on the inside of the aircraft and arranged to detect an electric field resulting from polarisation of the dielectric member. The output of the static monitor, or the rate of change thereof, correlates closely to particle density as the aircraft is flown though an aerosol, such as a volcanic ash cloud. The apparatus is simple and relatively inexpensive, and may comprise any general purpose aircraft. Aerosol particles may be detected and mapped using apparatus of the invention more easily and quickly than by use of devices such as optical spectrometers mounted on dedicated research aircraft, or static monitors mounted on the exterior of an aircraft. 
IP Reference EP2622387 
Protection Patent application published
Year Protection Granted 2013
Licensed No
Impact The invention is being developed for commercial use on passenger aircraft
 
Title Aerosol detection 
Description A new technique for detecting volcanic ash outside of an aircraft has been developed. The key discovery is that when an aircraft flies through volcanic ash an electric field is induced within the aircraft cabin. This field can be detected and used to warn of the presence of ash. 
IP Reference WO2012042242 
Protection Patent application published
Year Protection Granted 2012
Licensed No
Impact Prototype ash sensor instruments are flying on Flybe and British Airways aircraft as well as on the NERC FAAM research aircraft
 
Description Stakeholders meeting 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Workshop led to greater understanding and exchanges between policymakers and the scientists in the VANAHEIM project.

Members of the VANAHEIM team have been asked to provide additional advice to policymakers and government.
Year(s) Of Engagement Activity 2014