Characterisation of the Manchester Aerosol Chamber facility

Abstract

Abstract. This study describes the design of the Manchester Aerosol Chamber (MAC), initially developed in 2005 and presents for the first time its comprehensive characterisation. The MAC is designed to investigate multi-phase chemistry and the evolution of aerosol physico-chemical properties from the real-world emissions (e.g. diesel engine, plants) or of secondary organic aerosol (SOA) produced from pure volatile organic compounds (VOCs). Additionally, the generated aerosol particles in the MAC can be transferred to the Manchester Ice Cloud Chamber (MICC), which enables investigation of cloud formation in warm, mixed-phase, and fully glaciated conditions (with temperature, T, as low as −55 ∘C). The MAC is an 18 m3 fluorinated ethylene propylene (FEP) Teflon chamber with the potential to conduct experiments at controlled temperature (15–35 ∘C) and relative humidity (RH; 25 %–80 %) under simulated solar radiation or dark conditions. Detailed characterisations were conducted at common experimental conditions (25 ∘C, 50 % RH) for actinometry and determination of background contamination, wall losses of gases (NO2, O3, and selected VOCs), aerosol particles at different sizes, chamber wall reactivity, and aerosol formation. In addition, the influences of chamber contamination on the wall loss rate of gases and particles and the photolysis of NO2 were estimated.

The influence of the addition of isoprene on the volatility of particles formed from the photo-oxidation of anthropogenic–biogenic mixtures

“…Prior to and after each experiment the chamber was flushed with a high flow rate (∼ 3 m 3 min −1 ) of purified air. The initial concentrations in the clean chamber were particle number concentrations ≤ 15 cm −3 , O 3 ≤ 1 ppb, NO x ≤ 8 ppb (NO ≤ 6 ppb; NO 2 ≤ 2 ppb), and VOC ∼ 0 ppb (Shao et al, 2022).…”

“…All the experiments were conducted at the 18 m 3 fluorinated ethylene propylene (FEP) MAC, operating as a batch reactor (Shao et al, 2022). The MAC is enclosed in a temperature and relative humidity-controlled housing.…”

Combined application of online FIGAERO-CIMS and offline LC-Orbitrap mass spectrometry (MS) to characterize the chemical composition of secondary organic aerosol (SOA) in smog chamber studies

“…Experiments were performed in the Manchester Aerosol Chamber located at the University of Manchester to investigate SOA formation using a broad suite of instrumentation. A full description of the MAC and its characterization can be found in Shao et al (2022). Briefly, the chamber has a volume of 18 m 3 (3 m (L) ×2 m (W ) ×3 m (H )) and consists of a fluorinated ethylene Teflon bag, which is suspended in the enclosure and supported by three rectangular aluminium frames.…”

“…The experiments reported here used two arc lamps with quartz glass filters in front of them and five rows of halogen lamps to simulate the solar spectra over the wavelength range of 290-800 nm (Alfarra et al, 2012). The reported calculated photolysis rate of NO 2 (j NO 2 ), investigated from the steady-state actinometry experiments, was ∼ 0.11-0.18 min −1 (Shao et al, 2022).…”

“…During experiments, photolysis of ozone and unsaturated VOC ozonolysis (or potentially via OH recycling) can also generate OH source. The irradiance for photolysis of both NO 2 and O 3 is provided by two 6 kW xenon arc lamps and five rows of halogen lamps as described in Shao et al (2022). A 1 h stabilization period was utilized for measurement of the background conditions in the chamber after injection of the precursors and seed particles but before illumination of the chamber and the onset of photooxidation.…”