Data for 'The study of atmospheric ice-nucleating particles via microfluidically generated droplets'

Ice-nucleating particles (INPs) play a significant role in the climate and hydrological cycle by triggering ice formation in supercooled clouds thereby causing precipitation and affecting cloud lifetimes and their radiative properties. However, despite their importance they often comprise only 1 in 103 to 106 ambient particles, making it difficult to ascertain and predict their type, source and concentration. The typical techniques for quantifying INP concentrations tend to be highly labour intensive, suffer from poor time resolution or are limited in sensitivity to low concentrations. Here, we present the novel application of microfluidic devices to the study of atmospheric INPs via the simple and rapid production of monodisperse droplets and their subsequent freezing on a cold stage. This device offers the potential for the testing of INP concentrations in aqueous samples with high sensitivity and high counting statistics. Various INP were tested for validation of the platform, including mineral dust and biological species, with results compared to literature values. We also describe a methodology for sampling atmospheric aerosol in a manner that minimises sampling biases and which is compatible with the microfluidic device. We present results for INP concentrations in air sampled during two field campaigns: (i) from a rural location in the UK, and (ii) during the UK’s annual Bonfire Night festival. These initial results will provide a route for deployment of the microfluidic platform for the study and quantification of INPs in upcoming field campaigns around the globe, whilst providing a benchmark for future lab-on-a-chip based INP studies.