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Development of a volcanic ash forecasting model - Damien Martin

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Development of a volcanic ash forecasting model - Damien Martin

  1. 1. Development of avolcanic ashforecasting modelDamien Martin28th June 2012 School Institute Name to go here
  2. 2. Background Icelandic volcano Eyjafjallajökull (first started on the 20 March 2010 – second eruptive phase 15th until 20th April 2010) The total loss for the airline industry was estimated at US$1.7 billion (IATA)What made this volcanic activity so disruptive to air travel? 1.The volcanos location is directly under the jet stream. 2.The direction of the jet stream was unusually stable at the time of the eruptions second phase, maintaining a continuous south easterly heading 3.The volcanos explosive power was sufficient to inject ash directly into the Jet Stream School Institute Name to go here
  3. 3. Background4. The second eruptive phase took place under 200 m(660 ft) of glacial ice. The resulting melt water flowed backinto the erupting volcano which created two specificphenomena:The rapidly vaporising water significantly increased theeruptions explosive powerThe erupting lava cooled very rapidly, which created a cloudof highly abrasive, glass-rich ash, this caused a largeamount of flights to be cancelled in Ireland. Typically an encounter every year- average of ~3 School Institute Name to go here
  4. 4. Volcanic Ash Advisory Centre (VAAC) A Volcanic Ash Advisory Centre (VAAC) is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation. The individual VAACs are run as part of national weather forecasting organisations Met Office London Volcanic Ash Advisory Centre (VAAC) provides forecast guidance up to 24 hours ahead to support decision-making School Institute Name to go here
  5. 5. Regulatory response – London VAAC output 4mg/m3 –no fly zone 2-4mg/m3 – risk assessment required 0.2-2 mg/m3 Calculated at 3 flight levels ‘All concentrations are subject to a level of uncertainty relative to errors in the estimations of the eruption strength’ School Institute Name to go here
  6. 6. What is that uncertainty? Factor of 4-5 uncertaintyHeight (km) in this method! Log eruption strength (kg/sec) School Institute Name to go here
  7. 7. Motivation‘ Questions have been raised about the level of sophistication of the VAAC models used since much ash micro-physical and chemical evolution processes are typically not present in VAAC models. The development of an accurate and timely forecasting model represents an important tool for Irish government and policy makers in order to respond quickly and efficiently to the impacts associated with volcanic ash emissions. A more accurate forecasting may also lessen the economic impact of such emissions.’ School Institute Name to go here
  8. 8. Model descriptionThree-dimensional on-line climate chemistry/aerosol model called REMOTE(Regional Model with Tracer Extension)Model Specifications•81x 91x19 vertical grid boxes•0.5 grid resolution (approx. 50 km2)•6 h input and 3 h output resolution.•Ash size distribution is constrained by the model to a lognormal Model Domain distributionPM10 emission rate data used for the simulations described here have been taken from theEuropean Monitoring and Evaluation Programme (EMEP, 2011) estimations. These data wereoriginally based on tephra estimates derived from preliminary thickness data obtained which wasmeasured on the 17th April at two locations 20 and 50 km east of the volcano. School Institute Name to go here
  9. 9. Model Outputs Low resolution mobilestandard spatial plot Vertical profile device version School Institute Name to go here
  10. 10. ModelAutomation School Institute Name to go here
  11. 11. Verification- remote sensing and in-situ measurementsLIDAR (Light DetectionAnd Ranging) is an opticalremote sensingtechnology that measuresproperties of scatteredlight to find range and/orother information of adistant target. Plume entered the boundary layer at 22 UTC 19 April 2010, SO4 increased from 23 UTC. Ground measurements with HR-ToF AMS School Institute Name to go here
  12. 12. Model performance? School Institute Name to go here
  13. 13. 20 year climatology study – (1990 – 2010) Changing meteorological patterns and increased rates of deposition over the winter period. •Number of total column execeedances for each of the prescribed regulatory ash limits. •Seasonal changes in ash height profiles and its associated relationship to exceedance of internationally recognised flight levels. •Calculation and tabulation of regulatory exceedances at a number of airports. School Institute Name to go here
  14. 14. Irish responseIrish Aviation Authority (IAA)MACCII project - Europes Global Monitoring forEnvironment and Security initiative 4-node (North-South-East- West) ash detection network covering the primary pollution entry directions around Irish airspace and airports. Ireland is ideally positioned to develop, test and implement a ground- based remote-sensing ash detection pilot network due to its proximity to major Icelandic volcanic sources School Institute Name to go here
  15. 15. Volcanic Ash Strategic-initiative Team (VAST) (funded by ESA) Norwegian Institute for Air Research (NILU), Norway Finnish Meteorological Institute (FMI), Finland National University of Ireland Galway (NUIG), Ireland ZentralAnstalt für Meteorolgie und Geodynamik (ZAMG), Austria S&TCorp AS, NorwayTo investigate satellite retrievals for volcanic ashTo evaluate and improve ash dispersionTo integrate Earth Observation Data and ModelsTo develop and introduce a volcanic ash prediction system School Institute Name to go here
  16. 16. Satellite retrieval They can be divided into two main types: low-earth orbiting satellites in polar configurations that provide global coverage with rather limited temporal coverage (typically twice per day) and good spatial resolution (~1 km2), and geosynchronous satellites that provide very good temporal coverage (up to 96 per day for some instruments) but limited spatial coverage (70° total field of view) and lower spatial resolution (typically 10 km2). For the aviation problem, the geosynchronous satellites are much better suited because the need for high temporal resolution outweighs the need for high spatial resolution. School Institute Name to go here
  17. 17. NUIG component• Validation of eruption source Information• Evaluate specific source term models The efficacy of utilising a one-dimensional volcanic plume model such as PLUMERIA which incorporates inputs as vent temperature, radius and velocity, and the effects of water/ice phase changes will be investigated. PLUMERIA outputs graphs of velocity (from which eruption height is apparent), log density, plume radius, temperature, and water/ice mass fraction as functions of elevation and these values can be used to constrain the source term. This approach will then be evaluated against more typical used empirical considerations of the source term which may be subject to a high degree of uncertainty• Validation of satellite retrievals• Validation of modelling results• Development of a certification process of ash products School Institute Name to go here
  18. 18. Summary An automated volcanic ash dispersion model was developed and verified using both in situ and remote sensing techniques. Further work has being instigated in order to better characterise ash by improved modelling techniques and more in situ measurements. School Institute Name to go here
  19. 19. Acknowledgements Colin O’Dowd, Harald BerresheimRemote sensing In- situ measurements ModellingGiovanni Martucci Darius Ceburnis Liz ColemanTomas Grigas Jurgita Ovadnevaite Saji Varghese Jakub Bialek Robert Flanagan Ciaran Monaghan Damien Martin Aditya VaishyaICHEC (Alistair McKinstry) and the EPA for funding thiswork School Institute Name to go here