Dust Radiation, Electrification and Alignment in the Middle East (DREAME)

Lead Research Organisation: University of Hertfordshire
Department Name: Science and Technology RI

Abstract

Mineral dusts in the atmosphere, originating primarily from dry regions like the Sahara desert, have significant influence on climate. Because of this they need to be accurately represented in climate and weather prediction models. Recent observations of atmospheric Saharan dust by UK scientists provide strong evidence for the existence in mineral dust layers of particles that are predominantly vertically aligned. This alignment is thought to be due to atmospheric electricity associated with the dust layers. Computer modelling indicates that the alignment can significantly change the properties of the dust layers, including the amount of light they transmit, absorb and reflect. This has been termed a 'Venetian blind effect' from the way the tilted particles influence the amount of transmitted light and heat. Change in this and other properties can have significant impact on measurements of dust clouds from satellites, and possibly also on dust movement through the atmosphere. The proposed project will answer urgent questions concerning the precise origin, magnitude, extent and impact of this phenomenon by the use of a variety of measurements from the ground, balloons and aircraft, carried out in the Middle East. The project will result in improved understanding of dust and has the potential to solve a long-standing enigma concerning the movement of dust clouds on the continental scale. The proposal takes advantage of a major opportunity offered by the UK Met Office MEVEX flight campaign, to carry out this project at little additional cost. Therefore it provides excellent value for money.

Publications

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Harrison R (2010) Self-charging of the Eyjafjallajökull volcanic ash plume in Environmental Research Letters

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Nicoll K (2011) Observations of Saharan dust layer electrification in Environmental Research Letters

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Ulanowski Z. (2014) Profiling of atmospheric volcanic ash layers using an aerosol radiosonde in InternatIonal Conference on Atmospheric Dust, Book of Abstracts

 
Description We showed that airborne desert dust is electrically charged, to levels that can explain previous observations of the alignment of dust particles in the atmosphere. A byproduct of the project has been an aerosol radiosonde for launching on meteorological balloons.
Exploitation Route The radiosondes have already been used for detecting ash from the Eyafjallajokull eruption. The Met Office stocks them for use during future volcanic events. The aerosol radiosondes developed by this project can be used for atmospheric aerosol, including volcanic ash. A project is due to start shortly where a commercial version of the radiosonde will be developed.
Sectors Aerospace, Defence and Marine,Environment,Transport

URL http://www.herts.ac.uk/research/stri/research-areas/cair/LSRP/atmospheric-dust
 
Description The dust radiosondes developed during the project were used in 2010 and 2011 to verify the presence of volcanic ash from Icelandic volcanoes. The data was then used to justify airspace closure. The sondes are now kept by the Met Office as a contingency measure in case of future eruptions. The radiosondes then led to the development of particle counters that have become the subject of several further development and research projects. These have included installation of measurement systems on two research aircraft in the UK and Germany.
Sector Aerospace, Defence and Marine
Impact Types Societal

 
Title Low-cost optical particle counters 
Description The project led to a range of low-cost optical particle counters, the first of which were deployed during DREAME on meteorological balloons, as non-returnable atmospheric aerosol sondes. 
Type Of Material Improvements to research infrastructure 
Year Produced 2010 
Provided To Others? Yes  
Impact The optical particle counters were used during the 2010 Eyjafjallajokull volcanic eruption, to show the presence of airborne ash, and thus to verify ash dispersion models. This justified the closure of European airspace. 
URL https://www.herts.ac.uk/research/centres-and-groups/cacp/particle-instruments-and-diagnostics/low-co...
 
Description Ash sondes 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Academic/University 
PI Contribution We have provided the Met Office with radiosondes for detecting volcanic ash in the atmosphere.
Collaborator Contribution The Met Office paid for constructing the radiosondes and collaborated in testing them.
Impact The sondes were used to verify ash dispersion model results during Icelandic volcano eruptions.
Start Year 2010
 
Title An improved low-cost apparatus and method for the detection of a fluid-borne particle 
Description Detection and sizing of a fluid (e.g. air) borne particle is accomplished using a two-element detector. The detector allows defining a sensing volume within an illuminating laser beam, and produces a signal proportional to the size of the particle. 
IP Reference GB2484930 
Protection Patent granted
Year Protection Granted 2012
Licensed Yes
Impact The AirSensa project is creating a UK-wide network of urban air quality monitors that include OPC-N2 technology. They are starting in Greater London, to monitor and visualise air quality right down to individual street level. Up to 10,000 sensors are to be placed in schools, public and commercial buildings to monitor and feed back data to the cloud where it will be made available online and via smart-phone apps.