Dynamics of biological ice nucleating particles during a phytoplanktonic bloom in the Arctic

With raising temperatures in the Arctic, the extent of sea ice is decreasing dramatically resulting in a larger fraction of the Arctic ocean surface being exposed to the atmosphere. Therefore, the ice-free ocean and in particular the sea surface microlayer (SML), which represents the upper 1 mm of the water column is becoming of increasing interest as a source of bioaerosols with ice nucleating properties. These biological ice nucleating particles (INPs) can be aerosolized by wave breaking and bubble bursting. In the atmosphere, they may trigger the freezing of cloud droplets and thus affect the lifetime of clouds as well as their radiative properties. Recent studies proposed a link between biological ice nucleating aerosols in the Arctic sea water and phytoplanktonic blooms.

Thus, we examined the concentration and characteristics of INPs in both, the sea bulk water, and the surface microlayer for two locations in southwest Greenland throughout a phytoplankton bloom. Further, we investigated possible links between INP concentrations in the sea water, the abundance and community composition of bacteria and algae, as well as the phytoplanktonic growth season derived from satellite data and in-situ chlorophyll concentrations. Preliminary results will be presented.