School of Earth, Atmospheric and Environmental Sciences
Centre for Atmospheric Science, University of Manchester
We are offering a fully funded (for UK/EU applicants) studentship, to be affiliated with the newly
founded Manchester-Liverpool-National Oceanic Centre Doctoral Training Programme.
The primary objective of this project is to investigate aerosol-cloud interactions in a variety of cloud
types. The work will focus on the understanding of ice and mixed-phase clouds, which are least well
understood in terms of how they form precipitation and how they develop in time. Rich datasets of
cloud-aerosol and remotely sensed products will be used to advance the field.
This project is part of BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds
and Climate see http://www.bacchus-env.eu), a European Union collaborative project aiming to
quantify key processes and feedbacks controlling aerosol cloud interactions, and is closely aligned
with related research funded by NERC in the clouds and aerosols research group within the Centre for
Atmospheric Science. BACCHUS will establish datasets of advanced measurements of cloud and
aerosol properties in unprecedented detail in combination with state-of-the-art numerical modelling.
This project has opportunities to develop collaborative research in a consortium of 20 leading
international partners, including Universities of Leeds, Oxford, ETH Zurich, the Max Planck Institute
for Meteorology and the UK Met Office.
The closing date for applications is March 6th 2014. Please direct enquiries to Dr Paul Connolly
(p.connolly@manchester.ac.uk).
Project description (microphysics of mixed-phase clouds)
The role that atmospheric aerosol particles (APs) have on liquid clouds is relatively well understood.
A subset of APs behave as Cloud Condensation Nuclei (CCN), which are the nuclei on which liquid
clouds form. Large number concentrations of CCN result in clouds with large numbers, and smaller
sizes of droplets in them, and vice-versa. There are climate and weather relevant impacts of such
interactions, which again are well understood: clouds with large numbers of drops tend to reflect a lot
of sunlight and thus have a negative radiative effect, but they also result in less precipitation since
smaller drops do not collide and coalesce to form the embryos of rain.
The climate and weather relative impacts of clouds that contain ice particles are potentially very large,
yet are not well understood: we know that a very small subset of APs behave as Ice Nuclei (IN) and
are the nuclei on which ice crystals form. Investigations into which particles behave as IN is a very
dynamic field of research and advances have been made in the last 10 years. However, there are
complex interactions within mixed-phase clouds that make the interpretation challenging: in certain
environments high concentrations of IN produce more precipitation and in other environmental can
produce less precipitation.
The successful applicant will therefore further the knowledge of how aerosols affect mixed-phase
clouds in a variety of environments. This will require a detailed physical science basis, to understand
how the cloud microphysics influences the cloud macrophysics, and also will result in the
development of a conceptual understanding / summary of the effects. There will be the potential to
work with leading international scientists for example from European Institutes and the Met Office
and to use state-of-the-science analysis tools and models. If the student so chooses there may also be
opportunity for field work, laboratory measurement and postgraduate teaching within the School.