Project Description:
Clouds play a crucial role in Earth’s climate system due their interactions with radiation. In mixed-phase clouds, which contain both supercooled water droplets (water that is below 0°C yet remains liquid) and ice crystals, heterogeneous ice nucleation by suspended particles is a major factor controlling cloud glaciation. Sub-micron (D < 1 um) mineral dust particles can remain suspended in the atmosphere for extended durations. Recent modelling work suggests that these very small particles may have a dominant, previously unrecognised, influence on the glaciation processes of mixed-phase clouds in the Arctic and Antarctic, in turn affecting the cloud radiative properties and precipitation patterns. There are physical reasons to think that such small dust particles may nucleate ice differently to large dust particles, yet existing parameterizations used to model the ice-nucleating effectiveness of mineral dusts are based on measurements of samples containing many large particles.
In this project the student will work in the ICE lab of the Institute of Climate and Atmospheric Science (ICAS). You will use a combination of sieving, filtration and centrifugation to produce samples of mineral dusts with defined size distributions. Ice nucleation measurements will be conducted on the various size fractions allowing generation of parameterisations of ice nucleating effectiveness for varying mineral particle sizes. You will then work with modellers to simulate the impact of our revised understanding of ice nucleation by small dust particles on polar mixed-phase clouds in the Met Office Earth System Model. The project will play a key role in improving understanding of the impact of mineral dust particles on weather and climate.
Pre-requisites:
Supervisory Team:
Thomas Whale
Contact:
Thomas Whale: t.f.whale@leeds.ac.uk
How to apply:
- Complete the online REP application form one for each project of interest.
- Email a copy of your CV to yes-dtn@leeds.ac.uk (only once is needed).
- Complete the EDI Form (only one is needed). Although this is optional, if places are over-subscribed, preference will be given to under-represented groups, as defined above.