DECOMBIO - Contribution de la combustion de la biomasse aux PM10 en vallée de l’Arve : mise en place et qualification d’un dispositif de suivi

National audienc

DECOMBIO - Contribution de la combustion de la biomasse aux PM10 en vallée de l’Arve : mise en place et qualification d’un dispositif de suivi

National audienc

Evidence of major secondary organic aerosol contribution to lensing effect black carbon absorption enhancement

International audienceAtmospheric black carbon (BC) has a strong positive, but still controversial, effect on global warming. In particular, BC absorption enhancement (E abs) due to internal mixing with other chemical species-so-called lensing effect-is poorly assessed. This bottleneck partly relies on the lack of long-term in situ measurements of both the optical and chemical properties of BC-containing particles. Here, we present experimental and computational results showing a significant E abs increase with the aerosol photochemical aging. This was associated with the production of highly oxidized secondary organic aerosols (SOA), especially at summertime. The 3-year-long continuous aerosol chemical and optical measurements used for the present study was obtained in the Paris region, France, which might be representative of near-future air quality within developing countries. These findings suggest that SOA could represent one of the most critical chemical species to be considered within climate models