ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-9-14901-2009 Numerical simulations of contrail-to-cirrus transition – Part 1: An extensive parametric study Unterstrasser S. 1 Gierens K. 1 Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany 09 07 2009 9 4 14901 14953 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/9/14901/2009/acpd-9-14901-2009.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/9/14901/2009/acpd-9-14901-2009.pdf

Simulations of contrail-to-cirrus transition over up to 6 h were performed using a LES-model. The sensitivity of microphysical, optical and geometric contrail properties on relative humidity RH<sub><i>i</I></sub>, temperature <I>T</I> and vertical wind shear <I>s</I> was investigated in an extensive parametric study. The dominant parameter for contrail evolution is relative humidity. Substantial spreading is only visible for RH<sub><I>i</I></sub>&#x2273;120%. Vertical wind shear has a smaller effect on most contrail properties than human observers might expect from the visual impression. Our model shows that after a few hours the water vapour removed by falling ice crystals from the contrail layer can be several times higher than the ice mass that is actually present in the contrail at any instance.

 References Appleman, H.: The formation of exhaust condensation trails by jet aircraft, B. Am. Meteorol. Soc., 34, 14–20, 1953. Burkhardt, U., Kärcher, B., Ponater, M., and Sausen, R.: A Parameterization for Contrail Cirrus for GCMs, AGU Fall Meeting, EOS Trans., 87, San Francisco, CA (USA), 2006. Chlond, A.: Large-Eddy Simulation of Contrails, Journal of the Atmospheric Sciences, 55, 796–819, 1998. CIAP: The Stratosphere perturbed by Propulsion Effluents, Monograph 3, US Dep. of Transport, Washington, D.C., 1975. Dürbeck, T. and Gerz, T.: Dispersion of aircraft exhausts in the free atmosphere, J. Geophys. Res., 101, 26007–26016, 1996. Ebert, E. and Curry, J.: A parameterization of ice cloud optical properties for climate models, J. Geophys. Res., 97, 3831–3836, 1992. Elliott, W. and Gaffen, D.: On the utility of radiosonde humidity archives for climate studies, B. Am. Meteorol. Soc., 72, 1507–1520, 1991. Forster, P., Ramaswamy, V., Artaxo, P., et~al.: Changes in atmospheric constituents and in radiative forcing, Climate Change 2007 The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the IPCC, Climate Change 2007 The Physical Science Basis, Contribution of Working Group I to the Fourth Assessment Report of the IPCC edited by: Solomon, S., Quin, D., Manning, M., et al., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 129–234, 2007. Freudenthaler, V., Homburg, F., and Jäger, H.: Contrail observations by ground-based scanning lidar: Cross-sectional growth, Geophys. Res. Lett., 22, 3501–3504, 1995. Fusina, F., Spichtinger, P., and Lohmann, U.: Impact of ice supersaturated regions and thin cirrus on radiation in the midlatitudes, J. Geophys. Res., 112, D24S14, doi:10.1029/2007JD008449, 2007. Gerz, T., Dürbeck, T., and Konopka, P.: Transport and effective diffusion of aircraft emissions, J. Geophys. Res., 103, 905–25, 1998. Gierens, K.: Numerical Simulations of Persistent Contrails, J. Atmos. Sci., 53, 3333–3348, 1996. Gierens, K. and Bretl, S.: Analytical treatment of ice sublimation and test of sublimation parameterisations in two-moment ice microphysics models, Atmos. Chem. Phys. Discuss., 9, 10549–10574, 2009. Gierens, K. and Jensen, E.: A numerical study of the contrail-to-cirrus transition, Geophys. Res. Lett., 25, 4341–4344, 1998. Gierens, K., Schumann, U., Helten, M., Smit, H., and Marenco, A.: A distribution law for relative humidity in the upper troposphere and lower stratosphere derived from three years of MOZAIC measurements, Ann. Geophys., 17, 1218–1226, 1999. Harrington, J., Meyers, M., Walko, R., and Cotton, W.: Parameterization of ice crystals conversion processes due to vapor deposition for mesoscale models using double-moment basis functions. I- Basic formulation and parcel model results, J. Atmos. Sci., 52, 4344–4366, 1995. Hendricks, J., Kärcher, B., Lohmann, U., and Ponater, M.: Do aircraft black carbon emissions affect cirrus clouds on the global scale, Geophys. Res. Lett., 32, L12814, doi:10.1029/2005GL022740, 2005. Heymsfield, A. and Iaquinta, J.: Cirrus Crystal Terminal Velocities, J. Atmos. Sci., 57, 916–938, 2000. ICAO: Environmental Report 2007, Environmental Unit of the International Civil Aviation Organzation, pp. 1–231, 2007. Jensen, E., Ackerman, A., Stevens, D., Toon, O., and Minnis, P.: Spreading and growth of contrails in a sheared environment, J. Geophys. Res., 103, 31557–31568, 1998. Kärcher, B., Mayer, B., Gierens, K., Burkhardt, U., Mannstein, H., and Chatterjee, R.: Aerodynamic contrails: Microphysics and optical properties, J. Atmos. Sci., 66, 227–243, 2009. Marquart, S., Ponater, M., Mager, F., and Sausen, R.: Future Development of Contrail Cover, Optical Depth and Radiative Forcing: Impacts of Increasing Air Traffic and Climate Change, J. Climate, 16, 2890–2904, 2003. Nash, J. and Schmidlin, F.: International Radiosonde Intercomparison, WMO/TD-195, 102 pp, 1987. Paugam, R.: Simulation numerique de l'evolution d'une trainee de condensation et de son interaction avec la turbulence atmospherique, PhD thesis, CERFACS Toulouse MAS Ecole Centrale Paris, 2008. Ponater, M., Brinkop, S., Sausen, R., and Schumann, U.: Simulating the global atmospheric response to aircraft water vapour emissions and contrails: a first approach using a GCM, Ann. Geophys., 14, 941–960, 1996. Ponater, M., Marquart, S., and Sausen, R.: Contrails in a comprehensive global climate model: Parameterization and radiative forcing results, J. Geophys. Res., 107, 941–960, 2002. Ponater, M., Marquart, S., Sausen, R., and Schumann, U.: On Contrail Cimate Sensitivity, Geophys. Res. Lett., 32, L10706–1–L10706–5, \doi10.1029/2005GL022580, prefixhttp://elib.dlr.de/10340, 2005. Pratt, R.: Review of Radiosonde Humidity and Temperature Errors, J. Atmos. Oceanic Technol., 2, 404–407, 1985. Schmidt, E.: Die Entstehung von Eisnebel aus den Auspuffgasen von Flugmotoren, Schriften der Deutschen Akademie der Luftfahrtforschung, 44, 1–15, 1941. Schröder, F., Kärcher, B., Duroure, C., Ström, J., Petzold, A., Gayet, J., Strauss, B., Wendling, P., and Borrmann, S.: On the Transition of Contrails into Cirrus Clouds, J. Atmos. Sci., 57, 464–480, 2000. Schumann, U.: On the effect of emissions from aircraft engines on the state of the atmosphere, Ann. Geophys., 12, 365–384, 1994. Schumann, U.: On conditions for contrail formation from aircraft exhausts, Meteorologische Zeitschrift, NF, 5, 4–23, 1996. Schumann, U., Schlager, H., Arnold, F., Baumann, R., Haschberger, P., and Klemm, O.: Dilution of aircraft exhaust plumes at cruise altitudes, Atmos. Environ., 32, 3097–3103, 1998. Smolarkiewicz, P. and Margolin, L.: On Forward-in-Time Differencing for Fluids: an Eulerian/Semi-Lagrangian Non-Hydrostatic Model for Stratified Flows, Numerical Methods in Atmospheric and Oceanic Modelling: The André J. Robert Memorial Volume, 1997. Smolarkiewicz, P. and Margolin, L.: MPDATA: A Finite-Difference Solver for Geophysical Flows, J. Comput. Phys., 140, 459–480, 1998. Spichtinger, P.: Eisübersättigte Regionen, Ph.D. thesis, LMU München, prefixhttp://elib.dlr.de/10241, 2004. Spichtinger, P. and Gierens, K. M.: Modelling of cirrus clouds – Part 1a: Model description and validation, Atmos. Chem. Phys., 9, 685–706, 2009. Spichtinger, P., Gierens, K., and Read, W.: The statistical distribution law of relative humidity in the global tropopause region, Meteorologische Zeitschrift, 11, 83–88, 2002. Ström, J. and Ohlsson, S.: In situ measurements of enhanced crystal number densities in cirrus clouds caused by aircraft exhaust, J. Geophys. Res., 103, 11355–11362, 1998. Unterstrasser, S. and Gierens, K.: Numerical simulations of contrail-to-cirrus transition – Part 2: Impact of initial ice crystal number, radiation, stratification, secondary nucleation and layer depth, Atmos. Chem. Phys. Discuss., 9, 14955–14993, 2009. Unterstrasser, S., Gierens, K., and Spichtinger, P.: The evolution of contrail microphysics in the vortex phase, Meteorologische Zeitschrift, 17, 145–156, 2008.