Service National d’Observation CLAP-PdM

At PDM, the chemical composition of aerosols has been measured since 2002. Weekly filter samples are taken from a pumped volume of air of approximately 400 m3 . They are then analysed to provide the concentrations of elemental carbon (EC) and organic carbon (OC) through a thermo-optical analytical technique (EUSAAR protocol; Cavalli et al., 2010) on the one hand and the concentrations of major inorganic ions (calcium, magnesium, sulfate, nitrate, potassium, chlorine, ammonium) through analysis by ion chromatography on the other hand. Aerosol optical properties have been measured since 2013.

Scattering measurements were implemented for one wavelength from 2013 to 2018 (Nephelometer Ecotech M9003) and then for three wavelengths from 2018 to present (Nephelometer Ecotech AURORA 3000). Aerosol absorption properties were measured first (2013–2017) for one wavelength and then for seven wavelengths (2017–present) with a Magee AE16 and then with an AE33 Aethalometer, respectively.

The total aerosol number concentration was measured from 2008 by a condensation particle counter (TSI CPC 3010) until 2020 and then by a CPC 3750 thereafter.

Finally, the aerosol size distribution measurement was initially performed only in the coarse mode (0.5–10 μm) from 2010 to 2021 thanks to the implementation of an optical particle sizer (TSI OPS 3330), and then, from 2020, the aerosol size distribution from 10 nm to 0.8 μm was performed by the implementation of a size mobility particle spectrometer (model 4S from Paolo Vilani société 4S).