University weather balloon measures volcanic plume
Release Date : 20 April 2010
More accurate data about the potential danger to aircraft from volcanic plumes is being gathered by scientists from the University of Reading.
As another plume is due to sweep across the UK in the next few days, researchers are using a newly-developed weather balloon to feed back important information to the Met Office about the make-up of the volcanic ash.
This is the first time that direct measurements of the plume over Scotland have been available.
The measurement technique being used was originally developed to study the properties of Saharan dust clouds for climate models, but has turned out to be ideally suited to measuring a volcanic cloud.
The instrument measures the particle size and concentration using a miniature laser system carried by the balloon. It was specifically designed to take electric charge measurements too, which, as television images of volcanic lightning show, can be an important property of volcanic plumes. The weather balloon technique provides detailed information on the ash plume position, extent and structure.
As well as the particle size and concentration data, the balloon system also reports its position using GPS.
Giles Harrison, Professor of Atmospheric Physics in the Department of Mereorology, and Keri Nicoll, whose PhD project included developing the charge sensor, set up a ground station at Stranraer under the dust cloud.
The RAF helicopter scrambled at the weekend to transport the scientists and equipment to fly to Scotland at low level under the ash plume had to be grounded, forcing a long journey through the night by road.
Professor Harrison said: "To get good measurements of the ash we needed to be both under the ash plume, but in cloud free air. Fortunately the Met Office predictions for an ideal observation window at a site near Stranraer were bang on, allowing us to launch our balloon to pass directly through the volcanic plume.
"Despite the beguilingly blue sky at Stranraer, the weather balloon measurements showed a layer of volcanic dust at 4km aloft. The plume was about 500m thick, with very abrupt edges. Most of the particles sampled were around one millionth of a meter in (1 micron) diameter."
The results will also provide vital data about haazards to aircraft should there be similar events in the future.
See video of the balloon being launched - http://www.reading.ac.uk/researchdownloads/weather-balloon.avi (right-click link to download, avi – 6MB)
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Notes to editor
The weather balloon instrument was orginally developed in the Meteorology Department in collaboration with the University of Hertfordshire led by Professor Giles Harrison, under NERC funding. Electrical alignment of dust is thought to change the amount of solar radiation which can pass through.
The Department of Meteorology is internationally renowned for its excellent teaching and research in atmospheric, oceanic and climate science. Established in 1965, it is the only UK university which offers a full range of undergraduate and postgraduate courses in meteorology.
In 2005 Meteorology at Reading was awarded the Queen's Anniversary Prize for Higher and Further Education.
In the 2008 Research Assessment Exercise, 75% of our research was graded as world-leading or internationally excellent. Our weighted score places it third in the country in the "Earth Systems and Environmental Science" category, and makes it the highest-graded department focusing on the fundamental science of weather and climate.
University of Reading is rated as one of the top 200 universities in the world (THE-QS World Rankings 2009).
- The University of Reading is one of the UK's top research-intensive universities. The University is ranked in the top 20 UK higher education institutions in securing research council grants worth nearly £10 million from EPSRC, ESRC, MRC, NERC, AHRC and BBSRC. In the RAE 2008, over 87% of the university's research was deemed to be of international standing. Areas of particular research strength recognised include meteorology and climate change, typography and graphic design, archaeology, philosophy, food biosciences, construction management, real estate and planning, as well as law.
- Standards of teaching are excellent - the University scored highly in the National Student Survey 2009. 87% of Reading students responding to the survey stated they were satisfied with the quality of their course.
- The University is estimated to contribute £600 million to the local economy annually.
- University of Reading is a member of the 1994 Group of 19 leading research-intensive universities. The Group was established in 1994 to promote excellence in university research and teaching. Each member undertakes diverse and high-quality research, while ensuring excellent levels of teaching and student experience. www.1994group.ac.uk