Details of Award
NERC Reference : NE/J01754X/1
A Prototype Optical Instrument for the Analysis of Single Aerosol Particles
Training Grant Award
- Lead Supervisor:
- Professor JP Reid, University of Bristol, Chemistry
- Grant held at:
- University of Bristol, Chemistry
- Science Area:
- Atmospheric
- Overall Classification:
- Atmospheric
- ENRIs:
- Environmental Risks and Hazards
- Global Change
- Science Topics:
- None
- Abstract:
- New techniques for aerosol analysis on a single-particle basis have reached maturity for providing snapshots of the chemical composition of atmospheric particles, the classification of particle morphology and shape, the signature of certain biological markers and identification of ice particle shape, to highlight but a few. When considered alongside conventional ensemble measurements, these single particle tools have provided crucial new insights into the role of aerosols and clouds in the atmosphere. However, aerosols are dynamic, evolving with time, and new analytical tools must be developed and deployed in the field to explore their time-varying properties and the processes connecting these snapshots in physical and chemical properties. Optical tools for isolating and characterising single particles have now become sufficiently advanced that an instrument capable of studying the dynamic changes of atmospheric aerosol in the field can now be conceived. This studentship will develop a prototype analytical instrument for this purpose, building on very recent preliminary work funded by the NERC Technology Proof of Concept programme. The new instrument will combine novel light beams for isolating single accumulation mode aerosol with spectroscopic tools for characterising chemical composition, particle size and morphology. We have shown previously that a zeroth order Bessel beam (BB) can be used to confine and guide aerosol particles over macroscopic distances. A BB consists of a bright pseudo non-diffracting core of light a few micrometres in diameter that can propagate for millimetres. Numerous particles can be simultaneously captured and manipulated, allowing parallel analysis of many particles on an individual basis. We have also shown that a BB can be combined with cavity ringdown spectroscopy (CRDS) for characterising light extinction due to a single particle. CRDS has become a widely used technique for retrieving the complex refractive index of atmospheric aerosol through ensemble average measurements. Combining CRDS with the BB approach for manipulating aerosol now allows the optical properties to be retrieved on a single particle basis. In addition, more conventional elastic light scattering techniques can be used to interrogate particle size and morphology. The new instrument will allow the transient properties of single particles to be analysed (eg. size, composition and morphology) over a period of time, building on many conventional analytical techniques that are able to provide only a single snapshot. This will allow key properties such as aerosol hygroscopicity, the volatility of organic components, the time-response of particles to change in environmental conditions (such as water condensation) and the change in optical properties with aging to be analysed directly. This will provide a unique tool for interrogating accumulation mode aerosol, offering new analytical capabilities that are currently unavailable through conventional techniques.
- NERC Reference:
- NE/J01754X/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Analytical Sci and Tech
This training grant award has a total value of £67,596
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £13,812 | £5,500 | £48,285 |
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