www.atmos-chem-phys-discuss.net/9/14901/2009/ doi:10.5194/acpd-9-14901-2009 © Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Numerical simulations of contrail-to-cirrus transition – Part 1: An extensive parametric study Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany Abstract. 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 RHi, temperature T and vertical wind shear s was investigated in an extensive parametric study. The dominant parameter for contrail evolution is relative humidity. Substantial spreading is only visible for RHi≳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. Discussion Paper (PDF, 5951 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (ACP) Citation: Unterstrasser, S. and Gierens, K.: Numerical simulations of contrail-to-cirrus transition – Part 1: An extensive parametric study, Atmos. Chem. Phys. Discuss., 9, 14901-14953, doi:10.5194/acpd-9-14901-2009, 2009. Bibtex EndNote Reference Manager XML |