Measuring and identifying ice nucleating particles in the atmosphere

Overview
We are looking for an enthusiastic and ambitious student to make measurements of ice nucleating aerosol particles from the UK research aircraft and in remote oceanic air from a research ship. Clouds and their radiative properties are very sensitive to the presence of rare particles which are capable of triggering the formation of an ice crystal. These special particles are known as ice nucleating particles (INPs), but their abundance, identity and distribution in the atmosphere is very poorly constrained. Typically only one in a million aerosol particles is capable of nucleating ice. This makes their measurement in the atmosphere challenging. We are in the strong position that we have made enormous progress in understanding INPs in the laboratory and now want to apply these techniques and our expertise to the measurement of INP in the atmosphere.

Objectives
In this PhD project your overall objective will be to quantify the concentration of and identify atmospheric ice nucleating particles. You will:
o Collect aerosol filter samples from the UK’s FAAM research aircraft and our new mobile laboratory which will be placed on the foredeck of a research ship and at coastal stations.
o Use our laboratory based instrumentation to quantify INP concentrations on the filters.
o Develop the technique with a robust methodology, reducing background contamination and improving uncertainty.
o Analyse the aerosol particles on the filters for size distribution, shape and chemical composition using scanning electron microscopy.
o Develop a new laboratory based method of establishing what is special about the few aerosol particles which nucleate ice. This will be using both Raman microscopy and Environmental scanning electron microscopy.
o Compare your results with the predictions of our global aerosol model.