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The evolution of microphysical and optical properties of an A380 contrail in the vortex phase

Gayet, J.-F. and Shcherbakov, V. and Voigt, C. and Schumann, Ulrich and Schäuble, Dominik and Jeßberger, Philipp and Petzold, Andreas and Minikin, Andreas and Schlager, Hans and Dubovik, O. and Lapyonok, T. (2012) The evolution of microphysical and optical properties of an A380 contrail in the vortex phase. Atmospheric Chemistry and Physics, 12, pp. 6629-6643. DOI: 10.5194/acp-12-6629-2012.

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Official URL: http://www.atmos-chem-phys.net/12/6629/2012/acp-12-6629-2012.html

Abstract

A contrail from a large-body A380 aircraft at cruise in the humid upper troposphere has been probed with in-situ instruments onboard the DLR research aircraft Falcon. The contrail was sampled during 700 s measurement time at contrail ages of about 1â��4 min. The contrail was in the vortex regime during which the primary wake vortices were sinking 270 m below the A380 flight level while the secondary wake remained above. Contrail properties were sampled separately in the primary wake at 90 and 115 s contrail age and nearly continously in the secondary wake at contrail ages from 70 s to 220 s. The scattering phase functions of the contrail particles were measured with a polar nephelometer. The asymmetry parameter derived from these data is used to distinguish between quasi-spherical and aspherical ice particles. In the primary wake, quasi-spherical ice particles were found with concentrations up to 160 cmâ��3, mean effective diameter Deff of 3.7 �¼m, maximum extinction of 7.0 kmâ��1, and ice water content (IWC) of 3 mg mâ��3 at slightly ice-subsaturated conditions. The secondary and primary wakes were separated by an almost particle-free wake vortex gap. The secondary wake contained clearly aspherical contrail ice particles with mean Deff of 4.8 �¼m, mean (maximum) concentration, extinction, and IWC of 80 (350) cmâ��3, 1.6 (5.0) kmâ��1, and 2.5 (10) mg mâ��3, respectively, at conditions apparently above ice-saturation. The asymmetry parameter in the secondary wake decreased with contrail age from 0.87 to 0.80 on average indicating a preferential aspherical ice crystal growth. A retrieval of ice particle habit and size with an inversion code shows that the number fraction of aspherical ice crystals increased from 2% initially to 56% at 4 min contrail age. The observed crystal size and habit differences in the primary and secondary wakes of an up to 4 min old contrail are of interest for understanding ice crystal growth in contrails and their climate impact. Aspherical contrail ice particles cause less radiative forcing than spherical ones.

Document Type:Article
Title:The evolution of microphysical and optical properties of an A380 contrail in the vortex phase
Authors:
AuthorsInstitution or Email of Authors
Gayet, J.-F.Univ. Blaise Pascal, Clermont-Ferrand, F
Shcherbakov, V.Univ. Blaise Pascal, Clermont-Ferrand, F
Voigt, C.UNSPECIFIED
Schumann, UlrichUNSPECIFIED
Schäuble, DominikUNSPECIFIED
Jeßberger, PhilippUNSPECIFIED
Petzold, AndreasUNSPECIFIED
Minikin, AndreasUNSPECIFIED
Schlager, HansUNSPECIFIED
Dubovik, O.Univ. des Sciences et Technologies de Lille, Villeneuve d'Ascq, F
Lapyonok, T.Univ. des Sciences et Technologies de Lille, Villeneuve d'Ascq, F
Date:2012
Journal or Publication Title:Atmospheric Chemistry and Physics
Refereed publication:Yes
In Open Access:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:12
DOI:10.5194/acp-12-6629-2012
Page Range:pp. 6629-6643
Status:Published
Keywords:climate impact, Falcon
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:ATM and Operation
DLR - Research area:Aeronautics
DLR - Program:L AO - Air Traffic Management and Operation
DLR - Research theme (Project):L - Climate, Weather and Environment
Location: Oberpfaffenhofen
Institutes and Institutions:Institute of Atmospheric Physics
Institute of Atmospheric Physics > Atmospheric Trace Species
Deposited By: Jana Freund
Deposited On:01 Aug 2012 11:06
Last Modified:12 Dec 2013 21:44

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