Measuring of Hetrogenenous Ice Nucleating Particles (INPs) Concentrations in the Atmosphere Using Impingers

Atmospheric aerosols have an impact on the climate through direct and indirect interactions with solar radiations. Ice nucleating particles on in the atmosphere has an influence on cloud radiative properties and the hydrological cycle^{1, 2}. Ice nucleating particles (INPs), which are a small fraction of the total aerosol population, are capable of catalyzing ice formation under atmospheric conditions.  We introduced aerosol species which have been identified in the past as potentially important INP and address their ice nucleating abilities when immersed in the supercooled droplets and comparison were made with the literature and existing parameterizations which are describing ice nucleation according to the singular approximation. We found that they type of aerosol that makes INP in Leeds dominates soot and K-feldspar. It is also quite striking that our observations showed that significant day-to-day variability in the INP concentration. For example, at an activation temperature of -20 ^oC the INP concentration varies by nearly 2 orders of magnitude.  We note that the days on which we measured the highest INP concentrations were windy days. It indicates that INP concentration depends on the local metrological variables like wind speed, humidity and origin of air mass.