Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application

Abstract

Abstract.A characterization of the ultra-fine aerosol particle counter COPAS (COndensation PArticle counting System) for operation on board the Russian high altitude research aircraft M-55 Geophysika is presented. The COPAS instrument consists of an aerosol inlet and two dual-channel continuous flow Condensation Particle Counters (CPCs) operated with the chlorofluorocarbon FC-43. It operates at pressures between 400 and 50 hPa for aerosol detection in the particle diameter (d p ) range from 6 nm up to 1 µm. The aerosol inlet, designed for the M-55, is characterized with respect to aspiration, transmission, and transport losses. The experimental characterization of counting efficiencies of three CPCs yields d p50 (50% detection particle diameter) of 6 nm, 11 nm, and 15 nm at temperature differences ( T ) between saturator and condenser of 17 • C, 30 • C, and 33 • C, respectively. Non-volatile particles are quantified with a fourth CPC, with d p50 =11 nm. It includes an aerosol heating line (250 • C) to evaporate H 2 SO 4 -H 2 O particles of 11 nm<d p <200 nm at pressures between 70 and 300 hPa. An instrumental in-flight inter-comparison of the different COPAS CPCs yields correlation coefficients of 0.996 and 0.985. The particle emission index for the M-55 in the range of 1.4-8.4×10 16 kg −1 fuel burned has been estimated based on measurements of the Geophysika's own exhaust.

Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

“…The aerosol number concentration of ambient aerosol particles with size diameters between 6 nm and roughly 1 µm was measured using two independent COndensation PArticle counter Systems (COPAS, Weigel et al, 2009), each having two channels. Three of the four channels sample the ambient aerosol with cut-off diameters (in terms of 50% detection efficiency) of 6, 10 and 14 nm, respectively.…”

“…For the M-55 "Geophysica" this is the COPAS (COndensation PArticle counter System; see Weigel et al, 2009) while an NMASS instrument was operated by the University of Denver on the NASA DC-8 and NASA WB-57F. Similar instruments were implemented on the German DLR Falcon-20 and a balloon borne CPC was utilised by the University of Wyoming.…”

Chemical analysis of refractory stratospheric aerosol particles collected within the arctic vortex and inside polar stratospheric clouds

“…According to Weigel et al (2009) the inlet efficiency can be compared with the similarly designed and operated inlet system presented by Hermann et al (2001). For submicron particles, the transmission efficiency of the COPAS aerosol inlet is 90 % or higher.…”

“…A self-match of the Geophysica aircraft can be excluded. During RECON-CILE one self-match flight was performed (30 January 2010; see Suminska-Ebersoldt et al, 2012) and it was shown that such a self-match becomes directly visible in the data of diverse Geophysica measuring devices like the COPAS system (Weigel et al, 2009). …”

“…All aerosol samples during the RECONCILE campaign were taken from the inlet line of COPAS (COndensation PArticle counting System; Curtius et al, 2005;Weigel et al, 2009;Borrmann et al, 2010) with a Y-shaped manifold.…”