During NPF-PANDA we performed measurements of cluster formation and growth with an unprecedented array of instruments at two locations: Hyytiälä, Finland to resemble clean conditions and San Pietro di Capofiume, Italy to resemble highly polluted conditions. We further analyzed data from our measurement station in Beijing and related chamber experiments at the CERN CLOUD chamber to investigate particle formation under polluted conditions in more detail and under controlled laboratory conditions. We further worked on the implementation of novel computational analysis tools: 1) we developed approaches to combine several instruments for cluster measurements to best exploit our field results 2) we developed software packages to better describe the cluster growth process, especially better capturing the contributions of ions and organic molecules 3) we simulated clsuter dynamics in chamber experiments and tried to reproduce the cluster growth patterns.
NPF-PANDA convincingly showed that rapid cluster growth in urban and polluted environments can indeed explain the observed survival of clusters besides their high losses towards pre-existing particles. We showed that increasing precision in cluster measurements through our analyis tools, the application of several instruments and novel instrumental developement point indeed towards the fact that clusters in highly polluted conditions grow faster than previously thought. We further demonstrated that this can result in the necessary survival of these clusters both in chamber experiments and the ambient. Beyond that, we showed that new particle formation is indeed a crucial contributor to air pollution patterns. Furthermore, we could clarify how it changed under the Covid-19 lockdown periods, potentially giving a glance towards a future, less-polluted atmosphere and the role of new particle formation within it.
We disseminated our findings in 13 peer-reviewed scientfic journal articles (with another 5 articles being already submitted, accepted or published as preprints) and on three international conferences. We also brought our results to a wider public by participation in workshops and outreach events, the maintainance of a blog and twitter account and within a nation-wide Austrian newspaper article.
