Measuring atmospheric marine ice nucleating particles using cryopreservatin technologies (CryoINC)

Lead Research Organisation: University of Leeds
Department Name: School of Earth and Environment

Abstract

Despite oceans covering over 70% of the planet and sea spray being one of the dominant aerosol types in the atmosphere, its role in the formation of ice in clouds remains poorly understood. At present we do not know if Ice Nucleating Particles (INPs) in the oceanic atmosphere are derived from local marine biogenic sources or from long range transport from the continents. In this proposal the student will measure oceanic INP with an instrument recently developed for use in cryopreservation applications.
The student will work in close collaboration with Asymptote Ltd who are an SME company specialising in cryopreservation and crystallisation and have a strong track record with Murray. They have recently developed a new system for the controlled freezing of biological samples which could be easily adapted for atmospheric INP research. The student will work at Asymptote's laboratories in Cambridge in order to learn how to use this instrument and make minor adaptations to it for the measurement of atmospheric INP (CryoINC). The Asymptote controlled rate freezing equipment uses Stirling cryocoolers to achieve low temperatures and only needs an electrical supply making it portable and ideal for field work, whereas conventional systems use inconvenient liquid nitrogen or fluids cooled using mechanical compressors. An earlier version has been successfully used on cruises to the Arctic and Atlantic by Murray's team. Asymptote's instrument is compatible with a wide range of robotic and automation technologies, which with additional investment (possibly from the Technology Strategy Board) will allow us to develop a commercial autonomous INP measurement system.
The student will deploy CryoINC in several marine environments in collaboration with our project partners. The first will be at the well-established Mace Head atmospheric observatory on the West Coast of Ireland which is an ideal land-based site for sampling marine air. The second will be on board a research ship, facilitated by the British Antarctic Survey, in the remote marine environment possibly on a cruise to Antarctica via the Atlantic. Risk to the student's project is reduced by making use of an established atmospheric observatory, while also offering highly valuable ship based fieldwork training in the more challenging remote oceanic environment.

Publications

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Description My first piece of work looked at the effect of the feldspar mineral on ice nucleation. Ice nucleation is important for atmospheric processes and effects things from the radiation budget to the hydrological cycle. In this work I identified that the feldspar minerals were not as consistent in their nucleating efficiency as previously thought and build up a hypothesis as to why the K-feldspar mineral in particular shows high activity. This hypothesis has since been expanded on with further evidence supporting its credibility. We believe that microtexture which is commonly found in K-feldspar leads to more defects in the crystal which in turns acts as a site for nucleation to occur. Another piece of work I am close to submitting is the construction of an instrument making use of an infrared camera to detect freezing events in an ice nucleation experiment. This new instrument is semi-automated with the potential to e fully automated. with further work the hope is to be able to deploy a fully automated system for field data collection which would massively improve our spatial and temporal data coverage. Further to this I led a campaign to Barbados to investigate how desert may effect ice nucleation. It is known that desert dust is one of the major components in the atmosphere capable of forming ice in clouds, however we do not know how it's efficiency is effected with processing in the atmosphere. we have already collected samples in Cape Verde and the idea was to contrast this data with samples collected from the other side of the Atlantic after the dust emissions have been transported. The data is still preliminary but it is surprising that the dust concentrations seem to be so low in Barbados. This would be consistent with some atmospheric processing of the dust on transport which reduces the ice nucleating ability of the material. Further work will probe this.
Exploitation Route We hope to commercialize the instrument once it is developed so that other communities can make ice nucleation measurements which are vital for global models.The instrument also lends itself to uses in cryopreservation and a small amount of work has already been conducted using the instrument in this field. The field collected data will help refine our global model as Ice nucleating particles are still one of the major uncertainties in these. The work on minerals I have conducted is not only atmospherically relevant but also builds on our fundamental knowledge of ice nucleation. This work has led to further studies which are now starting to really probe into what an active site is on a nucleants surface.
Sectors Education,Environment,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology

URL https://www.atmos-chem-phys.net/16/10927/2016/