Following the eruption of the Eyjafyallajokull volcano in April and May of 2010, the Met Office is involved in a number of projects and activities to improve the detection of volcanic ash and the forecasting of its movement.
Met Office volcanic ash related development activities
Following the eruption of the Eyjafyallajokull volcano in April and May of 2010, the Met Office is involved in a number of projects and activities to improve the detection of volcanic ash and the forecasting of its movement. Many of these activities are taking place in collaboration with other international bodies and organisations such as the World Meteorological Organisation Volcanic Ash Scientific Advisory Group and the International Civil Aviation Organisation Volcanic Ash Task Force.
1. New Weather Radar for Iceland
An accurate assessment of the height of the initial eruptive volcanic ash plume is critical for predicting the subsequent movement and dispersion of a volcanic ash plume. Traditional weather radar technology is able to provide such an assessment, because volcanic ash in the eruptive plume is highly reflective. However, the quality of the information can be significantly affected by rain and/or snow and the distance of the radar from the actual volcano. The Met Office has been involved in a project that successfully resulted in the loan to Iceland, of a mobile and 'state-of-the-art' 'Civil Contingency' weather radar from Italy. The new radar is more suitable for identifying the difference between ash and rain. This coupled with the flexibility to position this radar closer to an erupting volcano will enable an improved and more detailed assessment of the eruptive volcanic ash plume height.
The Met Office has also helped to develop the specification for the procurement by the Iceland Met Office of its own mobile radar. This radar is scheduled to be in position in Iceland in autumn 2011.
2. Volcanic Ash Observations
The development of integrated volcanic ash observing systems are of fundamental importance. They provide the real time assessment of the horizontal and vertical extent of volcanic ash and where possible, associated volcanic ash concentration levels. The Met Office is playing a leading role both nationally and through EUMETNET (European network of European Meteorological Services) in Europe in both developing new technologies and in reviewing existing observational capabilities:
Aircraft-based Observations - The Met Office has placed a contract with Cranfield Aerospace and DO Systems for the provision of the Met Office 'Civil Contingency' aircraft. This twin piston engine Cessna aircraft is being equipped with a range of specialist instrumentation to measure the concentration of volcanic ash and to remotely sense the ash with lidar. The aircraft is currently being modified and will become operational in April 2011.
The Met Office continues to liaise and advise British Airways who are looking at the possibility of installing 'state-of-the-art' ash measuring instrumentation on a couple of their aircraft. In addition to this, the Met Office is working with the Norwegian Institute for Air Research (NILU), to investigate options for fitting their Airborne Volcanic Object Identifier and Detector (AVOID) system. This would be fitted on the FAAM BAe146 Atmospheric Research Aircraft for flight trials in spring 2011. Options are also currently being explored for the collaborative development of a suitably instrumented Unmanned Airborne Vehicle (UAV) capability.
Satellite Observations - Work being undertaken by the Met Office during 2011 continues to focus on the development of new derived satellite imagery for the location of volcanic ash plumes. Research is also continuing on the development of satellite derived products to determine "total column" volcanic ash density and also volcanic ash height.
Ground-based Observations - Laser Cloud Base Recorders (LCBRs), are used routinely by the Met Office at sites across the UK for cloud base height measurements. Under favourable meteorological conditions, LCBRs are also capable of detecting aerosol layers in the atmosphere, and with supporting evidence these aerosols could be identified as volcanic ash. The Met Office now automatically collects and plots LCBR data centrally from some of these cloud reporting stations, enabling near real-time analysis of volcanic ash observations. This monitoring capability is being made fully operational, providing a robust system in the event of future volcanic incidents. An additional 14 LCBRs with an extended maximum height range of 15 km will also be added to the network during summer 2011. Research and development activities are being undertaken by the Met Office, in order to provide some automation of the LCBR plot analysis.
Developments by the Met Office include the development during the first half of 2011 of a mobile Lidar and radiosonde (instrumentation carried by weather balloon) launching capability. A vehicle is being modified to allow a Lidar to remotely sense ash, by pointing its laser out of an aperture in the top of the vehicle. This will be done whilst the vehicle is moving, allowing the distribution of the ash to be characterised. In addition the stationary vehicle will be able to launch conventional radiosondes and recently developed aerosol sondes.
Aerosol radiosonde Observations - Studies are continuing on measurements of volcanic ash concentration levels using aerosol radiosondes. The radiosondes have been developed by the University of Hertfordshire and the University of Reading and are due for further testing by the Met Office during the spring and summer of 2011.
ATD-net Observations - The UK Met Office owns and operates a long-range lightning location network (called ATDnet) which consists of eleven operational sensors across Europe and Asia including one in Iceland. Research has shown that the lightning flashes generated in ash clouds above a volcano, can provide an instant alert for forecasters of potential increases in eruptive activity. This capability is already being used operationally by the London VAAC.
3. Volcanic Ash Transport and Dispersion Model
A highly sophisticated computer model, NAME, is used by the Met Office to forecast the movement and dispersion of volcanic ash. During early 2011 the Met Office will be making further improvements to the definition of the volcanic eruptive source term used in NAME as well as making refinements to the way in which peak and average ash concentrations in vertical layers are calculated. Research and international collaboration will continue throughout 2011 into the complex issue of model assimilation of real time volcanic ash observational data, the generation of probabilistic volcanic ash forecasts and the inclusion of other chemicals and gases into the modelled volcanic ash plume. The Met Office is also working on a comprehensive analysis of historic eruptions, previous ash encounters and in depth climatological studies to better quantify and understand the risks posed by volcanic ash.
The introduction of new and optimised systems for forecasters will be made in the first half of 2011. These changes will allow forecaster's to modify the ash concentration charts that are currently produced as raw model output.
Meanwhile, as a result of the development of new operational and guidance products to meet customer user requirements, the Met Office continues to improve its product range.