Spatial distribution of aerosol properties in the lower troposphere upon Ny-Ålesund

The primary objective of this long-term research activity is to build a climatology of vertical aerosol profiles in and above the Arctic Boundary Layer. To this aim since 2011, an international research team has performed yearly field campaigns at the Ny-Ålesund super-site thanks the support of the Italian CNR Arctic Station Dirigibile Italia and the German-French AWIPEV station. We employed various aerosol payloads and tethered balloons systems (TBS) and recorded, up to date, about 500 aerosol profiles in the first 2 km, providing detailed information on black carbon (BC) concentration, aerosol size distribution, aerosol scattering coefficients, and chemical composition. These pieces of information are necessary for the understanding of the aerosol formation, long-range transport, and fate in the Arctic troposphere. Case studies will be highlighted describing the influence of ship emissions, Arctic haze and new particle formation events on the vertical aerosol structure. In situ TBS activities have been often accompanied by simultaneous lidar profiling and a closure study of aerosol microphysical property retrieval is in progress based on this data and also on a full chemical aerosol characterization both at a bulk level on filter samples and on single particles by scanning electron microscopy. Complementary information has also been obtained from extensive computational studies of air mass transport utilizing Eulerian and Gaussian models. Since 2016 the study of the horizontal distribution of BC and nanoparticles has been initiated and performed along transects of the main glaciers around Ny-Ålesund exploiting portable instrumentation with the primary goal of studying the processes at the atmosphere/snow boundary. More recently in summer 2018 a TBS campaign has been performed in Longyearbyen for investigating pollution due to ship emission, and during the winter 2018/2019, for the first time, vertical aerosol profiles have been measured during the polar night. These scientific activities have been accompanied by constant development of the instrumentation and payload performances as well as by regular intercomparison campaigns with ground-based measurements performed at the Gruvebadet laboratory and the CCT. The next generation of aerosol payloads, currently under development and test, will include the possibility of characterizing the Arctic thin clouds, with dedicated measurements of cloud droplet size distribution, cloud chemistry, and cloud microbiology, within the framework of collaborations with the Korean polar research Institute (KOPRI) institute and other national research teams.