One of the objectives of CleanCloud is to get a better understanding of aerosol-cloud interactions in European climate hotspots. This will be achieved, on top of studying available observations, by tailored field campaigns that will conduct closure experiments studying the vertical profiles of aerosol and cloud properties.
In April 2024, the first of such CleanCloud campaigns will take place at the Villum Research Station (VRS), which is an ACTRIS site, coordinated by the Department of Environmental Science at Aarhus University, it is located in Northeast Greenland. VRS is the second most northern atmospheric research station in the world.
The campaign will bring together several of the CleanCloud partners including Aarhus University (AU), Foundation for Research and Technology Hellas (FORTH), Leibniz Institute for Tropospheric Research (TROPOS), and Ecole Polytechnique Federale De Lausanne (EPFL). In CleanCloud closure experiments, we will employ ground-based remote-sensing including aerosol lidars (FORTH) and cloud radars (EPFL) as well as satellite observations, supported by in-situ surface (AU) and vertical aerosol-cloud observations using wind lidar and ceilometer (AU) and helikites (TROPOS) to characterize the size distribution, hygroscopicity, chemical composition, optical properties, and CCN/INP properties of the aerosols.
On top of providing a better understanding for processes driving aerosol-cloud interactions, these experiments will also be used to develop new retrieval algorithms to obtain less uncertain key cloud properties in diverse geographic and climatic conditions. This will help us differentiate between different classes of bioaerosol (pollen, fungi, bacterial), biomass burning and dust aerosol using lidar observations, further improve cloud radar remote sensing algorithms that can provide insights on the microphysical processes, as well as vertical air motions will be incorporated in the parameter space of the obtained aerosol and cloud statistics, paving the way to an improved disentanglement of dynamical and aerosol-related effects on cloud processes. These observations will also be instrumental in the validation of the upcoming satellite missions (e.g. ESA-EarthCARE and NASA-PACE).
