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www.atmos-meas-tech-discuss.net/1/321/2008/
doi:10.5194/amtd-1-321-2008
© Author(s) 2008. This work is distributed
under the Creative Commons Attribution 3.0 License.
Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application
1Max Planck Institute for Chemistry, Particle Chemistry Department, Mainz, Germany
2Leibniz Institute for Tropospheric Research, Leipzig, Germany
3Institute for Atmospheric Physics, Johannes Gutenberg-University, Mainz, Germany
4Inst. for Atmosphere and Environment, Johann Wolfgang Goethe Univ., Frankfurt, Germany
5Deutsches Zentrum fuer Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
6Myasishchev Design Bureau, Moscow, Russia
*now at: Lab. de Météorologie Physique, Univ. Blaise Pascal, Clermont-Ferrand, France
Abstract. This study aims at a detailed characterization of an ultra-fine aerosol particle counting system for operation on board the Russian high altitude research aircraft M-55 "Geophysica" (maximum ceiling of 21 km). The COndensation PArticle counting Systems (COPAS) consists of an aerosol inlet and two dual-channel continuous flow Condensation Particle Counters (CPCs).
The aerosol inlet, adapted for COPAS measurements on board the M-55 "Geophysica", is described concerning aspiration, transmission, and transport losses. The counting efficiencies of the CPCs using the chlorofluorocarbon FC-43 as the working fluid are studied experimentally at two pressure conditions, 300 hPa and 70 hPa. Three COPAS channels are operated with different temperature differences between the saturator and the condenser block yielding smallest detectable particle sizes (dp50 – as 50% detection "cut off" diameters) of 6 nm, 11 nm, and 15 nm, respectively, at ambient pressure of 70 hPa. The fourth COPAS channel is operated with an aerosol heating line (250°C) for a determination of the non-volatile number of particles. The heating line is experimentally proven to volatilize pure H2SO4-H2O particles for a particle diameter (dp) range of 11 nm<dp<200 nm.
Additionally this study includes investigation to exclude auto-nucleation of the working fluid inside the CPCs. An instrumental inter-comparison (cross-correlation) has been performed for several measurement flights and mission flights in the Arctic and the Tropics are discussed. Finally, COPAS measurements are used for an aircraft plume crossing analysis.
Discussion Paper (PDF, 4996 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (AMT)
Notice on Discussion StatusCitation: Weigel, R., Hermann, M., Curtius, J., Voigt, C., Walter, S., Böttger, T., Lepukhov, B., Belyaev, G., and Borrmann, S.: Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application, Atmos. Meas. Tech. Discuss., 1, 321-374, doi:10.5194/amtd-1-321-2008, 2008. Bibtex EndNote Reference Manager XML
