Concentrations and properties of atmospheric ice nucleating particles (INPs)

Aerosol particles that can initiate ice formation in the atmosphere are called ice nucleating particles (INPs). These particles play an important role in climate by modifying the formation conditions and properties of clouds. Still, the magnitude of this effect is uncertain due to our poor understanding of INPs. To address this lack of knowledge, we are conducting laboratory and field measurements of INP. In the laboratory, we investigate the ice nucleating properties of various aerosol types, including mineral dust and microplastics. In the field (i.e., atmosphere), we measure the concentrations and properties of INPs. Recently, we developed a new method based on density gradient centrifugation that can separate and measure the concentrations of inorganic and organic INPs. After further development, we hope to use this method to measure inorganics and organic INPS concentrations at many sites worldwide and use the measurements to test and improve atmosphere models. As part of the NETCARE Project, previous field measurements of atmospheric INPs have been carried out in the Arctic, the marine boundary layer, and a high-elevation site.