organic aerosol; mixed-phase clouds; atmospheric chemistry; photochemistry; ice nucleation; cloud condensation nuclei
Borduas-Dedekind Nadine, Nizkorodov Sergey, McNeill Kristopher (2020), UVB-irradiated Laboratory-generated Secondary Organic Aerosol Extracts Have Increased Cloud Condensation Nuclei Abilities: Comparison with Dissolved Organic Matter and Implications for the Photomineralization Mechanism, in CHIMIA International Journal for Chemistry
, 74(3), 142-148.
Brennan Killian P., David Robert O., Borduas-Dedekind Nadine (2020), Spatial and temporal variability in the ice-nucleating ability of alpine snowmelt and extension to frozen cloud fraction, in Atmospheric Chemistry and Physics
, 20(1), 163-180.
Borduas-Dedekind Nadine, Ossola Rachele, David Robert O., Boynton Lin S., Weichlinger Vera, Kanji Zamin A., McNeill Kristopher (2019), Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals, in Atmospheric Chemistry and Physics
, 19(19), 12397-12412.
Manfrin Alessandro, Nizkorodov Sergey A., Malecha Kurtis T., Getzinger Gordon J., McNeill Kristopher, Borduas-Dedekind Nadine (2019), Reactive Oxygen Species Production from Secondary Organic Aerosols: The Importance of Singlet Oxygen, in Environmental Science & Technology
, 53(15), 8553-8562.
|Persistent Identifier (PID)
ETH Zurich Research Collection
CCN and INP data of photo oxidized DOM samples.
To have clouds in the sky, three ingredients are necessary: convection, water and tiny particles called aerosols. We are particularly interested in these aerosols because they activate into water droplets, termed cloud condensation nuclei (CCN), and nucleate ice crystals, termed ice nucleating particles (INPs). Furthermore, aerosol-cloud interactions are difficult to predict and yet have a highly uncertain effect on the planet’s radiative balance and climate. Organic aerosols represent a subset of aerosols able to act as CCN and as, recently found, INPs, and affect the types of clouds in which liquid water co-exists with ice crystals, called mixed phase clouds, common in Switzerland. Between the location where organic aerosols are emitted and/or formed and where they act as CCN and INP in mixed phase clouds, they will undoubtedly undergo atmospheric processing including sunlight exposure. Chemical and physical changes caused by sunlight exposure, or photochemistry, during an aerosol’s approximately one-week lifetime in the atmosphere are expected to alter its ability to form mixed phase clouds.This collaborative project uniquely combines organic chemistry methods and analytical techniques, available in the Environmental Chemistry Group of Prof. McNeill, with state-of-the-art cloud nucleation instrumentation, available in the Atmospheric Physics Group of Prof. Lohmann, both at ETH. My group serves as a bridge to bring a unique environmental chemistry perspective to atmospheric science. The project objectives are three-fold. Firstly, we identify and characterize organic polymers present in organic aerosols that are efficient CCN and INPs. Secondly, we quantify the effect of atmospheric processing of organic atmospheric polymers on CCN and INP efficiency. And thirdly, we identify the key chemical and physical parameters required to adequately predict organic aerosol fractions able to act as CCN and INPs.The anticipated results will improve our understanding of the role of chemistry in predicting aerosol-cloud interactions and will have implications on the fields of atmospheric chemistry, aerosol science, and climate modelling.