The main issues are the pristine ice number concentration, snow evolution leading to surface precipitation, mixed-phase and cold cloud length scales.
The main goals in order of priority are:
* To provide statistical datasets to act as a critical holistic test of three phase microphysics as RICO did for warm cloud microphysics (e.g. cold air outbreak).
* To test whether the background aerosol concentration active as ice nuclei can be used to predict the pristine ice concentration in cases where there is limited ice multiplication.
* To test detailed microphysical assumptions in model, which include capacitance, aggregation efficiency vs temperature (conversion rate from 'ice' to 'snow' categories), mass-dimension relations and area-dimension relations (these combine to give fall-speed).
* To investigate small ice (sub 100 microns) concentration controversy.