Eyjafjallajokull Volcanic Ash Cloud: NCAS FGAM Instruments

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.

Date (Publication): 2014-09-19T13:24:43

Date (Creation): 2014-09-19T13:24:43

Citation identifier: https://catalogue.ceda.ac.uk/uuid/7de58a079598413481ac3055d71db95f

Citation identifier: NCAS British Atmospheric Data Centre (NCAS BADC) / 7de58a079598413481ac3055d71db95f

Point of contact

Organisation name	Electronic mail address	Role
National Centre for Atmospheric Science (NCAS)	admin@ncas.ac.uk	Author
NCAS British Atmospheric Data Centre (NCAS BADC)	badc@rl.ac.uk	Custodian
NCAS British Atmospheric Data Centre (NCAS BADC)	badc@rl.ac.uk	Distributor
European Facility for Airborne Research (EUFAR)	unknown	Principal investigator
Met Office	enquiries@metoffice.gov.uk	Principal investigator
National Centre for Atmospheric Science (NCAS)	admin@ncas.ac.uk	Principal investigator
NCAS British Atmospheric Data Centre (NCAS BADC)	badc@rl.ac.uk	pointofContact
NCAS British Atmospheric Data Centre (NCAS BADC)	badc@rl.ac.uk	Publisher

Maintenance and update frequency: Not planned

Update scope: Dataset

Keywords

Eyjafjallajokull
FGAM Instruments

GEMET - INSPIRE themes, version 1.0

atmospheric conditions

Access constraints: Other restrictions

Other constraints: Access to these data is available to any registered CEDA user. Please Login or Register for a CEDA account to gain access.

Use constraints: Other restrictions

Other constraints: 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.

Spatial representation type: Grid

Language: English

Topic category

Climatology, meteorology, atmosphere

Begin date: 2010-04-09T23:00:00

End date: 2010-08-29T23:00:00

Unique resource identifier: WGS 84

Distribution format

Name	Version
Images are PNG formatted

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
NCAS British Atmospheric Data Centre (NCAS BADC)		badc@rl.ac.uk	Distributor

OnLine resource

Protocol	Linkage	Name
	https://catalogue.ceda.ac.uk/uuid/7de58a079598413481ac3055d71db95f	CEDA Data Catalogue Page

OnLine resource

Protocol	Linkage	Name
	http://data.ceda.ac.uk/badc/eyjafjallajokull/data/ncas-fgam-instruments/	DOWNLOAD

Hierarchy level: Dataset

Conformance result

Title: 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

Date (Publication): 2010-12-08

Statement: 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.