Aerosol Chemical Composition Within the Paris Region, France: What Can We Learn from 13 Years of Continuous Online Measurements?

JEAN-EUDES PETIT, Juliette Brochet, Yunjiang Zhang, Hasna Chebaicheb, Olivier Favez, LSCE

     Abstract Number: 238
     Working Group: Urban Aerosols

Abstract
The SIRTA observatory is a multi-instrumented observatory located around 20km South-West of Paris. Since 2011, continuous aerosol mass spectrometer (ACSM) measurements have been carried out, gathering essential knowledge of submicron aerosol chemical composition, its pluri-annual trends and behaviours which can be linked to mitigation policies as well as changing meteorological conditions.

Here, we present the long-term features of one of the longest ACSM time series worldwide. We will especially highlight :

- A phenomenology analysis of haze episodes. We will discuss their temporal evolution, their seasonal features, and the influence of climatological variability.
- First insights of a very long-term Organic Aerosols source apportionment, discussing the changes of the fractions of OA linked to its oxidation properties, and also how long-term measurements and trajectory analysis can help to provide additional information.
- The changes induced by COVID-19-related lockdowns, put in the context of long-term trends. We will discuss the efforts needed in order to further mitigate pollution sources within the Paris region.