Clouds have a significant effect on the global albedo; play a key role in the hydrological cycle and offer an important loss route for aerosol particles through precipitation. To encapsulate such effects accurately in regional and global models it is necessary that the key microphysical processes in the cloud, and their interaction with aerosol particles and dynamics, are well understood. Whilst there has been some progress on developing knowledge of such processes in warm clouds and cirrus, mixed phase clouds are far less well understood, yet they are important, as often they are the main precipitating clouds and they cover a substantial fraction of the Earth's surface. Further, mixed phase cloud processes are key to precipitation development.
NCAS Weather provides co-ordination and support for investigations of the microphysics of mixed and ice phase clouds, and the interaction of aerosols with such clouds. These activities encompass:
- developing and using detailed analysis methods to interpret data obtained from current and future cloud microphysics and aerosol instrumentation;
- interfacing these with current and future models of mixed phase clouds being developed through NCAS and associated activities (specifically explicit microphysics models linking aerosol composition and size to the microphysics and dynamics of the cloud); and
- further advancing detailed process and cloud scale models of mixed phase and cold clouds.
Current activity includes supporting DIAMET (DIAbatic influences on Mesoscale structures in ExTractopical storms), a NERC funded project funded through the Storm Risk Mitigation research programme. This consists of obtaining measurements of cloud microphysical properties in conjunction with dynamical information to establish the influence of various processes (condensation, evaporation, melting, freezing etc) on large scale structures. This is done through comparisons of measurement and model simulations, and via model sensitivity test. Ongoing work as part of the APPRIASE-Clouds programme is looking at the detailed microphysical structure of cold fronts and the processes which can affect precipitation intensity. Recent activity has also included support of the VOCALS-UK project, looking at the properties of widespread persistent stratocumulus in the South East Pacific. Looking forward, our research forms important aspects of the NERC funded ACCACIA and MICROSCOPE projects, which aim to look at Arctic boundary layer clouds and intense convective systems respectively.
Staff involved in this activity are:
Dr. Jonathan Crosier, Prof Tom Choularton and Dr Paul Connolly (University of Manchester).