ANR MABCaM  » Multi-channel wavelength-resolved Albedometer for Black Carbon Measurement  » (2017-2020)
Laboratoire de Physicochimie de l’Atmosphère (Weidong Chen (PI), Eric Fertein, Cécile Coeur, Thomas Fagniez), ULCO
Laboratoire d’Optique Atmosphérique (Suzanne Crumeyrolle), Lille 1
Environnement S.A (Rony Akiki)

Résumé (non confidentiel) du projet en anglais

Black carbon (BC), one of the most important SLCPs with an atmospheric lifetime of about one week, warms the atmosphere by absorbing sunlight. BC is considered as the third most powerful climate-forcing agent in the atmosphere after CO2 and CH4 [IPCC 2013]. The uncertainties associated to BC radiative forcing are, for now, larger than 70% and are mainly related to actual measurement techniques that provide limited information to distinguish BC from other aerosols and to its optical properties [Bond 2013]. BC has been also identified as the most harmful air pollutant in terms of its adverse impacts on human health [WHO 2013].
Despite intensive efforts over the past decades, no widely accepted standard measurement method exists for the determination of BC. The most widely used methods are filter-based online aethalometry and off line thermal optical analysis. However all filter-based photometers suffer from non linearity due to the loading of the filter, which may lead to a large measurement bias [Lack 2008].

In this proposal, we propose to develop a novel Black Carbone Analyzer based on an innovative multi-channel aerosol albedometer for direct and filter-free simultaneous measurements of wavelength-dependent optical extinction and absorption of BC (and other aerosols) in the major spectral region of the solar radiation (300-2000 nm). This all integrated compact photonic albedometer consists of two main devices : (1) an innovative broadband optical cavity coupled to a high-sensitivity CCD spectrometer to form a BroadBand Cavity enhanced Extinctiometer (BBCE) for wavelength-resolved extinction measurements; (2) a multi-microphone enhanced Photoacoustic Absorptionmeter (PA) for wavelength-dependent integrated absorption measurements. Both devices are coupled to a single broadband high-brightness photonic light source.

The developed 2 in 1 BBCE-PA albedometer will be used in synergy with mono/multi-wavelength Lidar, sun photometer, and in-situ instruments (particle sizer, humidified nephelometer, aethalometer and cavity attenuated phase shift) to improve the number and the accuracy of the retrieved parameters. This will contribute to both National ORAURE and European ACTRIS observing systems, and to the activity of « Aerosol observations: Instrumentation and intensive field campaigns – Monitoring from networks and satellites » (WP-3) of the LABEX CaPPA project (