Online single particle analysis of ice particle residuals from mountain-top mixed-phase clouds using laboratory derived particle type assignment

Abstract

In situ single particle analysis of ice particle residuals (IPRs) and out-of-cloud aerosol particles was conducted by means of laser ablation mass spectrometry during the intensive INUIT-JFJ/CLACE campaign at the high alpine research station Jungfraujoch (3580 m a.s.l.) in January–February 2013. During the 4-week campaign more than 70 000 out-of-cloud aerosol particles and 595 IPRs were analyzed covering a particle size diameter range from 100 nm to 3 µm. The IPRs were sampled during 273 h while the station was covered by mixed-phase clouds at ambient temperatures between −27 and −6 °C. The identification of particle types is based on laboratory studies of different types of biological, mineral and anthropogenic aerosol particles. The outcome of these laboratory studies was characteristic marker peaks for each investigated particle type. These marker peaks were applied to the field data. In the sampled IPRs we identified a larger number fraction of primary aerosol particles, like soil dust (13 ± 5 %) and minerals (11 ± 5 %), in comparison to out-of-cloud aerosol particles (2.4 ± 0.4 and 0.4 ± 0.1 %, respectively). Additionally, anthropogenic aerosol particles, such as particles from industrial emissions and lead-containing particles, were found to be more abundant in the IPRs than in the out-of-cloud aerosol. In the out-of-cloud aerosol we identified a large fraction of aged particles (31 ± 5 %), including organic material and secondary inorganics, whereas this particle type was much less abundant (2.7 ± 1.3 %) in the IPRs. In a selected subset of the data where a direct comparison between out-of-cloud aerosol particles and IPRs in air masses with similar origin was possible, a pronounced enhancement of biological particles was found in the IPRs

Composition of ice particle residuals in mixed phase clouds at Jungfraujoch (Switzerland): Enrichment and depletion of particle groups relative to total aerosol

“…Both parameters will be discussed in the following. Complex secondary aerosol 20 particles and soot were not found in the IPR fraction, in contrast to previous work at Jungfraujoch (Cozic et al, 2008a;Ebert et al, 2011;Worringen et al, 2015;Schmidt et al, 2017), even though these groups dominate the total aerosol fraction. Thus, their ice nucleating ability can be assumed to be very low.…”

“…These groups included silicates, Ca-rich particles, carbonaceous particles, metal/ metal oxide and soot. Using single particle mass spectrometry, Schmidt et al (2017) considered all particles observed in the IPR fraction as INP (biological, soil dust, minerals, sea salt/ cooking, aged material, engine exhaust, soot, lead-containing, industrial metals, NaK and others). Kamphus et al (2010) report mineral dust and fly ash (with and without some volatiles), metallic particles and black carbon 20 as the most ice active particles, measured with two different mass spectrometers behind the Ice-CVI.…”

“…In contrast to previous work (Worringen et al, 2015;Ebert et al, 2011;Kamphus et al, 2010;Schmidt et al, 2017), IPR and total aerosol were collected in parallel. This allows us to examine the ice nucleation efficiency of the various particle groups, and to investigate the dependence on temperature, particle size and air mass history.…”

Particulate trimethylamine in the summertime Canadian high Arctic lower troposphere

“…Fragmentation depends on laser wavelength and energy. Ion markers of many species are already well known from laboratory measurements with the ALABAMA (Schmidt et al, 2017) and additionally from the literature of other single particle mass spectrometers (SPMSs) using the same ablation laser wavelength. Table 1 lists ion markers of substances used in this study to identify the external and internal mixing states of particles.…”

“…It is known from previous SPMS laboratory studies on sea spray particles produced from biologically active waters that organic nitrogen species present in inorganic salts arise from biological activity (Prather et al, 2013;Guasco et al, 2014). In particular, organic nitrogen fragments together with calcium, sodium and phosphate have been linked to signatures of biological species (e.g., Pratt et al, 2009a;Schmidt et al, 2017). SPMS spectra of biological particles presented in Pratt et al (2009a) 2 )) in ambient SPMS spectra and attributed them to organic-containing sea salt particles.…”