Measurement of ultrafine aerosol size distributions by a combination of diffusion screen separators and condensation particle counters

Feldpausch, Philipp; Fiebig, Markus; Fritzsche, Lutz; Petzold, A.

doi:10.1016/j.jaerosci.2005.04.009

Cited by 43 publications

(29 citation statements)

References 14 publications

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“…The second CPC used on the Egrett was fitted with three diffusion disks to increase the lower size cut-off by removing smaller aerosol from the flow. As shown by Feldpausch et al (2006) this cut-off is in fact very gradual, and the instrument remained sensitive to particles down to 20-30 nm in diameter, despite the nominal cut-off (50 % point) in detection efficiency of 100 nm at 200 mb.…”

Section: Aircraft and Payloadmentioning

confidence: 96%

Aerosol observations and growth rates downwind of the anvil of a deep tropical thunderstorm

et al. 2012

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Abstract. We present a case study of Aitken and accumulation mode aerosol observed downwind of the anvil of a deep tropical thunderstorm. The measurements were made by condensation nuclei counters flown on the Egrett high-altitude aircraft from Darwin during the ACTIVE campaign, in monsoon conditions producing widespread convection over land and ocean. Maximum measured concentrations of aerosol with diameter greater than 10 nm were 25 000 cm −3 (STP). By calculating back-trajectories from the observations, and projecting onto infrared satellite images, the time since the air exited cloud was estimated. In this way a time scale of about 3 hours was derived for the Aitken aerosol concentration to reach its peak. We examine the hypothesis that the growth in aerosol concentrations can be explained by production of sulphuric acid from SO 2 followed by particle nucleation and coagulation. Estimates of the sulphuric acid production rate show that the observations are only consistent with this hypothesis if the particles coagulate to sizes >10 nm much more quickly than is suggested by current theory. Alternatively, other condensible gases (possibly organic) drive the growth of aerosol particles in the TTL.

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Section: Aircraft and Payloadmentioning

confidence: 96%

Aerosol observations and growth rates downwind of the anvil of a deep tropical thunderstorm

et al. 2012

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“…This method allowed a classification of the aerosol in volatile, semi-volatile, and non-volatile (refractory) compounds and provided a crude but fast characterization of its chemical habit: sulfuric acid aerosol is volatile above 125 • C and ammonium sulfate above 250 • C (semi-volatile), while soot (black carbon), mineral dust, and sea salt remain non-volatile above 250 • C (Burtscher et al, 2001). For about 15 min every day a diffusion screen separator (Particle Size Selector Model 376060, TSI; further information see Feldpausch et al, 2006) was switched in front of the heated inlet to assess the volatility of particles below a defined diameter (in our case D p <40 nm). Periodic comparative measurements with both CPC 3022 instruments simultaneously connected with an unheated inlet showed a typical scatter between both signals within 5 % to 10 % but did not indicate any significant bias.…”

Section: Site Description and Instrumentationmentioning

confidence: 99%

“…Although photo-oxidation of algae derived dimethylsulfide (DMS) is a potential secondary aerosol source in the MBL, new particle formation seems to be mainly connected with entrainment of free tropospheric air but seems marginal within the remote MBL itself due to permanently present large aerosol surface areas (primarily by already present sulfate aerosol and sea spray) acting as a condensation sink for low volatile supersaturated gases (Raes, 1995;Covert et al, 1996;Capaldo et al, 1999;Heintzenberg et al, 2004). Nevertheless, there is some observational evidence of considerable particle nucleation within the MBL in regions with enhanced DMS flux (Davison et al, 1996;O'Dowd et al, 1997;Clarke et al, 1998). In this context, the Southern Ocean surrounding the Antarctic continent shows striking biological activity during polar spring and summer (Gabric et al, 2005;Korhonen et al, 2008;Lana et al, 2011), provoking pronounced formation of biogenic sulfur aerosol (Minikin et al, 1998;Preunkert et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Characterization of the inter-annual, seasonal, and diurnal variations of condensation particle concentrations at Neumayer, Antarctica

et al. 2011

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“…It consisted of four condensation particle counters (CPC) operated at different lower cutoff diameters (Schröder and Ström, 1997) (Feldpausch et al, 2006), one thermodenuder with two channels operated at 20 • C and 250 • C (Engler et al, 2006), and two optical particle counters (passive cavity aerosol spectrometer probe (PCASP 100X); forward scattering spectrometer probe (FSSP 300)). The number concentrations of nucleation mode, Aitken mode and accumulation mode particles were determined from CPC and PCASP-100X data.…”

Section: Instrumentationmentioning

confidence: 99%

“…CPC instruments were operated with nominal minimum threshold diameters (50% response probability) of 4 and 10 nm for the total aerosol and of 14 and 80 nm for the non-volatile aerosol. The latter cut-off diameter of 80 nm was achieved by a CPC equipped with a diffusion screen separator containing three screens (Feldpausch et al, 2006). Size distributions of the accumulation and coarse mode were inferred from a combined analysis of PCASP-100X and FSSP-300 data.…”

Section: Instrumentationmentioning

confidence: 99%

Aircraft measurements over Europe of an air pollution plume from Southeast Asia – aerosol and chemical characterization

et al. 2007

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Abstract. An air pollution plume from Southern and Eastern Asia, including regions in India and China, was predicted by the FLEXPART particle dispersion model to arrive in the upper troposphere over Europe on 24-25 March 2006. According to the model, the plume was exported from Southeast Asia six days earlier, transported into the upper troposphere by a warm conveyor belt, and travelled to Europe in a fast zonal flow. This is confirmed by the retrievals of carbon monoxide (CO) from AIRS satellite measurements, which are in excellent agreement with the model results over the entire transport history. The research aircraft DLR Falcon was sent into this plume west of Spain on 24 March and over Southern Europe on 25 March. On both days, the pollution plume was found close to the predicted locations and, thus, the measurements taken allowed the first detailed characterization of the aerosol content and chemical composition of an anthropogenic pollution plume after a nearly hemispheric transport event. The mixing ratios of CO, reactive nitrogen (NO y ) and ozone (O 3 ) measured in the Asian plume were all clearly elevated over a background that was itself likely elevated by Asian emissions: CO by 17-34 ppbv on average (maximum 60 ppbv) and O 3 by 2-9 ppbv (maximum 22 ppbv). Positive correlations existed between these species, and a O 3 / CO slope of 0.25 shows that ozone was formed in this plume, albeit with moderate efficiency. Nucleation mode and Aitken particles were suppressed in the Asian plume, whereas accumulation mode aerosols were strongly elevated and correlated with CO. The suppression of the nucleation mode was likely due to the large pre-existing aerosol surface of the transported larger particles. Supermicron particles, likely desert dust, were found in part of the Asian pollution plume and also in surrounding cleaner air. The aerosol light absorption coefficient was enhanced in the plume (average values for individual plume encounters Correspondence to: A. Stohl (ast@nilu.no) 0.25-0.70 Mm −1 ), as was the fraction of non-volatile Aitken particles. This indicates that black carbon (BC) was an important aerosol component. During the flight on 25 March, which took place on the rear of a trough located over Europe, a mixture of Asian pollution and stratospheric air was found. Asian pollution was mixing into the lower stratosphere, and stratospheric air was mixing into the pollution plume in the troposphere. Turbulence was encountered by the aircraft in the mixing regions, where the thermal stability was low and Richardson numbers were below 0.2. The result of the mixing can clearly be seen in the trace gas data, which are following mixing lines in correlation plots. This mixing with stratospheric air is likely very typical of Asian air pollution, which is often lifted to the upper troposphere and, thus, transported in the vicinity of stratospheric air.

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Measurement of ultrafine aerosol size distributions by a combination of diffusion screen separators and condensation particle counters

Cited by 43 publications

References 14 publications

Aerosol observations and growth rates downwind of the anvil of a deep tropical thunderstorm

Aerosol observations and growth rates downwind of the anvil of a deep tropical thunderstorm

Characterization of the inter-annual, seasonal, and diurnal variations of condensation particle concentrations at Neumayer, Antarctica

Aircraft measurements over Europe of an air pollution plume from Southeast Asia – aerosol and chemical characterization

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