Ice nucleating particles (INPs) are important for ice formation within mixed phase clouds and so impact processes such as the radiative budget and the global hydrological cycle. Desert dust is known to be a very important type of INP in the atmosphere, even many thousands of kilometres from the source regions. The ice nucleating activity of desert dust is thought to be related to the K-feldspar mineral component.

However, the effect of ageing of K-feldspar and the contribution of other mineral constituents to the number of INPs in the atmosphere is poorly understood. Desert dust can spend many days lofted in the atmosphere where it can undergo a number of ageing processes and so this poses the question of whether or not desert dust will lose its activity as an INP during transport.