Cloud Microphysics

This project provides the opportunity to participate in the development of balloon-borne optical instruments to investigate super-cooled liquid water in the atmosphere, and its effect on weather and climate models.

Clouds are, unsurprisingly, an integral part of the climate system, but perhaps surprisingly there are many puzzles regarding their formation and evolution. One such puzzle is around the presence of super-cooled liquid water (SLW) – why is there so much and why is it so persistent?

One part of the world where there is more SLW than expected is the atmosphere over the southern ocean. This discrepancy is one of the most important sources of uncertainty in weather and climate models which predict the net heating/cooling of the earth, and whether water in clouds is liquid or solid has a large effect on the transport of radiative heat through the atmosphere.

We are addressing this question by developing balloon-borne optical instruments to measure the amount of liquid water, compared to ice, in a cloud, and where there is ice, to see what crystal form the ice particles adopt. There is quite a bit of work to do in characterising the instrument, both in balloon flights and fixed instruments on towers/masts.

There will be opportunities to deploy the instruments in the field, and/or to analyse data from a deployment on the new CSIRO ship RV Investigator, and from Macquarie Island.

As a side note, a holographic microscope was developed at the University of Adelaide to help in the characterisation of the above instrument.

An interesting spin-off application is in characterising pollen for the pollen count warnings that some weather services offer to hay fever sufferers. There is also scope for a project to further develop this microscope.

Supervisor