7de58a079598413481ac3055d71db95f English 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646 e6f5502c687f25a6c7009d4704b124b4 dataset NCAS British Atmospheric Data Centre (NCAS BADC) +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk pointOfContact 2026-05-10T02:06:06 UK GEMINI 2.3 WGS 84 Eyjafjallajokull Volcanic Ash Cloud: NCAS FGAM Instruments 2014-09-19T13:24:43 publication 2014-09-19T13:24:43 creation https://catalogue.ceda.ac.uk/uuid/7de58a079598413481ac3055d71db95f 7de58a079598413481ac3055d71db95f NCAS British Atmospheric Data Centre (NCAS BADC) The Icelandic Volcano, Eyjafjallajokull, started erupting on 14th April 2010. The volcanic ash cloud produced covered much of Northern Europe for several weeks causing extensive disruption to air travel. The UK and European atmospheric communities had many instruments - both airborne and ground-based, remote sensing and in-situ - taking measurements of the ash cloud throughout this period. This dataset contains images from Aberystwyth elight and water-vapour lidars, FGAM lidar situated at Cardington and Salford Urban Built-Environment Research Base lidar. Ash was seen frequently over Capel Dewi and Cardington during the periods 13th - 23rd April 2010 and 11th - 17th May. The ash tended to occur in single, narrow, uniform layers during the first period but in multiple, thicker, patchy layers during the second period. Work has begun on trying to determine the properties of the ash from the lidar observations. A comparison of the Raman lidar returns at 355 and 387 nm gives the lidar (optical extinction to backscatter) ratio. The unexpectedly (and controversially) large mean values for the April period (182) suggest that the ash particles were much larger and darker than those associated with eruptions of Mount Etna (mean lidar ratio values of 55). DK confirmed that similarly large values were found for observations made by an airborne lidar system. The ultimate aim of this type of work is to be able to define the ash source function, which is required to initiate the dispersion model. For example, how much mass was ejected and to what heights? Moreover, how did the ash particles behave one they are airborne? For example, how quickly, did they start to sediment? DK clarified that high pressure over the British Isles appeared to be the driving force which caused the ash to enter the BL - not sedimentation. In order to improve the interpretation of remote sensing data, more will need to be known about the properties of the ash particles, e.g. their complex refractive index. It may be necessary to improve the lidar scattering models for this type of particle, e.g. to encompass Mie scattering. National Centre for Atmospheric Science (NCAS) author +44 (0)113 3436408 School of Earth and Environment University of Leeds Leeds LS2 9JT United Kingdom admin@ncas.ac.uk author NCAS British Atmospheric Data Centre (NCAS BADC) custodian +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk custodian NCAS British Atmospheric Data Centre (NCAS BADC) distributor +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk distributor European Facility for Airborne Research (EUFAR) principal_investigator unknown principalInvestigator Met Office principal_investigator 0370 900 0100 Met Office FitzRoy Road Exeter EX1 3PB enquiries@metoffice.gov.uk principalInvestigator National Centre for Atmospheric Science (NCAS) principal_investigator +44 (0)113 3436408 School of Earth and Environment University of Leeds Leeds LS2 9JT United Kingdom admin@ncas.ac.uk principalInvestigator NCAS British Atmospheric Data Centre (NCAS BADC) point_of_contact +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk pointofContact NCAS British Atmospheric Data Centre (NCAS BADC) publisher +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk publisher notPlanned dataset Eyjafjallajokull FGAM Instruments atmospheric conditions theme GEMET - INSPIRE themes, version 1.0 2008-06-01 publication otherRestrictions Access to these data is available to any registered CEDA user. Please Login or Register for a CEDA account to gain access. otherRestrictions Under the following licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/, appropriate use of these data may fall under any use. This message is intended as guidance, always read the full licence. When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. grid English climatologyMeteorologyAtmosphere -20.0 10.0 40.0 70.0 2010-04-09T23:00:00 2010-08-29T23:00:00 Images are PNG formatted NCAS British Atmospheric Data Centre (NCAS BADC) Data Center Contact +44(0)1235 446432 British Atmospheric Data Centre STFC Rutherford Appleton Laboratory Harwell Oxford OX11 0QX UK badc@rl.ac.uk distributor https://catalogue.ceda.ac.uk/uuid/7de58a079598413481ac3055d71db95f CEDA Data Catalogue Page Detail and access information for the resource information http://data.ceda.ac.uk/badc/eyjafjallajokull/data/ncas-fgam-instruments/ DOWNLOAD Download Data download dataset Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 A copy of these data were made available to the British Atmospheric Data Centre (BADC) to assist the academic community during this volcanic ash event.