ACTRIS ACSM intercomparison – Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

Abstract

Abstract. Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December 2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2).Published by Copernicus Publications on behalf of the European Geosciences Union. R. Fröhlich et al.: Intercomparison of ME-2 organic source apportionmentExcept for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f 44 ), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f 44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbonlike organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the factors (HOA: 14.3 ± 2.2 %, COA: 15.0 ± 3.4 %, OOA: 41.5 ± 5.7 %, BBOA: 29.3 ± 5.0 %). Factors which tend to be subject to minor factor mixing (in this case COA) have higher relative uncertainties than factors which are recognised more readily like the OOA. Averaged over all factors and instruments the relative first SD from the mean of a source extracted with ME-2 was 17.2 %.

Chemical characteristics of submicron particles at the central Tibetan Plateau: insights from aerosol mass spectrometry

“…Cimone (4.5 µg m −3 ; Rinaldi et al, 2015), Puy de Dôme (5-27 µg m −3 ), and Mt. Bachelor (15.1 µg m −3 ; Zhou et al, 2017), but higher than those in some other sites, such as subAntarctic (0.46 µg m −3 ; Schmale et al, 2013) and Jungfraujoch (0.55 µg m −3 ; Fröhlich et al, 2015), similar to that at Table 1 and Fig. S3).…”

Collocated observations of cloud condensation nuclei, particle size distributions, and chemical composition

“…In addition, all Q-ACSMs operated within ACTRIS participated in an intercomparison exercise 59,62 (marked with ‘*’ in Table 3) at the Aerosol Chemical Monitor Calibration Center. Generally, the latest acquisition and analysis software were used.…”

Aerosol characterization over the North China Plain: Haze life cycle and biomass burning impacts in summer

“…The two secondary OA (SOA) factors were both characterized by high m/z 44, and their mass spectra resemble those of standard OOA and LV-OOA reported previously [Ng et al, 2011a], yet with overall higher f 44 . One of the reasons is that the ACSM measurements are subject to produce higher m/z 44 than those from HR-AMS [Fröhlich et al, 2015]. LV-OOA showed higher f 44 than SV-OOA, indicating that LV-OOA was a more aged OA factor.…”