Ground based in situ measurements of arctic cloud microphysical and optical properties at Mount Zeppelin, Svalbard

Abstract : Climate simulations suggest that cloud feedback plays an important role in the arctic warming. Moreover, the high seasonal variability of arctic aerosol properties is expected to significantly impact the cloud properties during the winter-summer transition. Field measurements are needed for improved understanding and representation of cloud-aerosol interactions in climate models. Within the CLIMSLIP project (CLimate IMpacts of Short-LIved Pollutants and methane in the arctic), a two months (March-April 2012) ground-based cloud measurement campaign was performed at Mt Zeppelin station, Ny-Alesund, Svalbard. The experimental set-up comprised a wide variety of instruments. A CPI (Cloud Particle Imager) was used for the microphysical and morphological characterization of ice particles. Measurements of sized-resolved liquid cloud parameters were performed by the FSSP-100 (Forward Scattering Spectrometer Probe). The Nevzorov Probe measured the bulk properties of clouds. The Polar Nephelometer was used to assess the single scattering properties of an ensemble of cloud particles. This cloud instrumentation combined with the aerosol properties continuously measured at the station allowed us to study the variability of the microphysical and optical properties of low level Mixed Phase Clouds (MPC) as well as the aerosol- cloud interaction in the Arctic. Typical properties of MPC, snow precipitation and blowing snow will be presented. First results suggest that liquid water is ubiquitous in spring arctic low level clouds. Carbon monoxide measurements allow us to compare polluted with clean cases. The cloud-aerosol interactions processes which take place during the transport of polluted air masses from mid-latitude to the Arctic is thus assessed.