Laboratory studies of cloud microphysical processes using a state of the art particle generation system (NERC EAO Doctoral Training Partnership)

Clouds have a considerable effect on the climate system. They interact with both solar radiation and terrestrial radiation, leading to changes in surface heating rates, moisture content, and large scale dynamics. Clouds are also a key component of the water cycles, as the control the distribution of precipitation to the surface. In order to understand the formation, evolution and eventually the dissipation of clouds, a detailed understanding of the microphysical processes of how cloud particles interact is crucial. For example, understanding the interactions between clouds droplets is crucial for predicting the onset of warm rain. Other important microphysical process include riming (the collection/freezing of supercooled water droplets on the surface of impinging ice particles), aggregation (the collision and sticking together of multiple ice particles), and ice multiplication processes (a single particle interacts with its environment to produce several additional ice particles. Many of these processes are deemed to be important in influencing cloud lifetime and precipitation formation, but are highly uncertain

A particle generation system is being developed to allow detailed studies of particle properties and processes. The system allows for the formation of liquid and ice particle at precise location, and at a known time. Coupled to a high speed microscope imaging system, detailed studies of particle processes can be undertaken in real-time on the single particle level. The student will use this new system to obtain details of ice particle and liquid droplet properties at an unprecedented level. This research will shed light
on some of the most important microphysical processes in the atmosphere, processes which remain largely unobserved due to the small temporal and spatial scale under which they occur. The student will develop skills in the areas of instrumentation, calibration, experimental design and data analysis.