For Ny Alesund, samples from spring and summer months were examined, while a yearly coverage existed for the other stations. Differing values of NINP were observed during the year, and in general during summer and fall, particles were more ice active than during winter and early spring, indicating that different sources of ice nucleating particles contributed to the pan-arctic area, their influence varying with season. The lowest values determined for the Arctic samples were about 1 order of magnitude lower than NINP determined from precipitation samples collected in North America and Europe (Petters & Wright 2015), but the highest values were comparable, pointing at a biogenic origin from either the biosphere (e.g., from fungal spores or bacteria) or from marine sea spray (e.g., from algae or bacteria). These biogenic ice nucleating particles might become more abundant as the Arctic warms, with potential influences on cloud properties as e.g., the lifetime of the persistent Arctic stratiform clouds.
This study gives first insights into yearly cycles of ice nucleating particles in the Arctic, but it also reveals open questions and suggests future pathways concerning their examination.
Conen et al., 2012, Atmos. Meas. Tech., doi: 10: .5194/amt-5-321-2012.
Peters & Wright, 2015, Geophys. Res. Lett., doi: 10.1002/2015gl065733.