Description
New particle formation by gas-to-particle conversion could account for more than 50 % of global cloud condensation nuclei concentrations and therefore directly impacts climate. After nucleation of small molecular clusters, high initial growth rates are required that the newly formed particles reach sizes where they can act as cloud condensation nuclei. The vapors responsible for that growth in the atmosphere are sulfuric acid and maybe more important, organics produced by the oxidation of volatile organic compounds (VOCs). This oxidation process and the subsequent nanoparticle growth might be heavily influenced by ambient conditions, e.g. by temperature. Here we present results from the CERN CLOUD experiments, where a PTR3-TOF-MS was combined with a Nitrate-CIMS in order to identify the organic species responsible for growth at warm (+25°C) and cold temperatures (-25°C). We observe that the lesser extend of autoxidation at cold temperatures is compensated by the decrease of volatility of all oxidation products. Organics might therefore be responsible for initial growth over a wide range of tropospheric conditions and could for example contribute to upper tropospheric new particle formation over areas with high biogenic VOC emissions like the Amazon Basin.| Period | 7 Feb 2019 |
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| Event title | 8th International PTR-MS Conference |
| Event type | Conference |
| Location | Innsbruck, AustriaShow on map |