Variation of Ice Nucleating Particles in the European Arctic Over the Last Centuries

The historical development of ice nucleating particle concentrations (N-INP) is still unknown. Here, we present for the first time N-INP from the past 500 years at two Arctic sites derived from ice core samples. The samples originate from the EUROCORE ice core (Summit, Central Greenland) and from the Lomo09 ice core (Lomonosovfonna, Svalbard). No long-term trend is obvious in the measured samples, and the overall range of N-INP is comparable to present-day observations. We observe that the short-term variations in N-INP is larger than the long-term variability, but neither anthropogenic pollution nor volcanic eruptions seem to have influenced N-INP in the measured temperature range. Shape and onset temperature of several INP spectra suggest that INP of biogenic origin contributed to the Arctic INP population throughout the past.