Editorial Type:
Article
Article Type:
Research Article

The Effect of Spurious Cloud Edge Supersaturations in Lagrangian Cloud Models: An Analytical and Numerical Study

F. Hoffmann Institute of Meteorology and Climatology, Leibniz Universität Hannover, Hannover, Germany

Search for other papers by F. Hoffmann in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Jan 2016
DOI:
https://doi.org/10.1175/MWR-D-15-0234.1
Page(s):
107–118
Restricted access

Abstract

This study analyzes the production and the effect of spurious cloud edge supersaturations in Lagrangian cloud models (LCMs), which simulate droplets and aerosols explicitly as Lagrangian particles. By applying an idealized one-dimensional setup, it is shown that the production of spurious cloud edge supersaturations in LCMs and Eulerian cloud models is identical. In LCMs, however, the effect of spurious supersaturations on the number of activated/deactivated particles is decreased due to (i) a physically more appropriate representation of the activation process, and (ii) the LCM’s ability to represent the distribution of liquid water on the subgrid scale. Additionally, an analytic solution for the production of spurious supersaturations in both Lagrangian and Eulerian cloud models is derived, enabling the identification of the upper limit of spurious supersaturations and the conditions under which they occur.

Corresponding author address: Fabian Hoffmann, Institute of Meteorology and Climatology, Leibniz Universität Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany. E-mail: hoffmann@muk.uni-hannover.de

Abstract

This study analyzes the production and the effect of spurious cloud edge supersaturations in Lagrangian cloud models (LCMs), which simulate droplets and aerosols explicitly as Lagrangian particles. By applying an idealized one-dimensional setup, it is shown that the production of spurious cloud edge supersaturations in LCMs and Eulerian cloud models is identical. In LCMs, however, the effect of spurious supersaturations on the number of activated/deactivated particles is decreased due to (i) a physically more appropriate representation of the activation process, and (ii) the LCM’s ability to represent the distribution of liquid water on the subgrid scale. Additionally, an analytic solution for the production of spurious supersaturations in both Lagrangian and Eulerian cloud models is derived, enabling the identification of the upper limit of spurious supersaturations and the conditions under which they occur.

Corresponding author address: Fabian Hoffmann, Institute of Meteorology and Climatology, Leibniz Universität Hannover, Herrenhäuser Straße 2, 30419 Hannover, Germany. E-mail: hoffmann@muk.uni-hannover.de
Save
Cover Monthly Weather Review
Monthly Weather Review

  • Andrejczuk, M., J. M. Reisner, B. Henson, M. K. Dubey, and C. A. Jeffery, 2008: The potential impacts of pollution on a nondrizzling stratus deck: Does aerosol number matter more than type? J. Geophys. Res., 113, D19204, doi:10.1029/2007JD009445.

    • Search Google Scholar
    • Export Citation

  • Andrejczuk, M., W. W. Grabowski, J. M. Reisner, and A. Gadian, 2010: Cloud-aerosol interactions for boundary layer stratocumulus in the Lagrangian Cloud Model. J. Geophys. Res., 115, D22214, doi:10.1029/2010JD014248.

    • Search Google Scholar
    • Export Citation

  • Arabas, S., and S.-I. Shima, 2013: Large-eddy simulations of trade wind cumuli using particle-based microphysics with Monte Carlo coalescence. J. Atmos. Sci., 70, 2768–2777, doi:10.1175/JAS-D-12-0295.1.

    • Search Google Scholar
    • Export Citation

  • Árnason, G., and P. S. Brown, 1971: Growth of cloud droplets by condensation: A problem in computational stability. J. Atmos. Sci., 28, 72–77, doi:10.1175/1520-0469(1971)028<0072:GOCDBC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Grabowski, W. W., 1989: Numerical experiments on the dynamics of the cloud-environment interface: Small cumulus in a shear-free environment. J. Atmos. Sci., 46, 3513–3541, doi:10.1175/1520-0469(1989)046<3513:NEOTDO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Grabowski, W. W., and P. K. Smolarkiewicz, 1990: Monotone finite-difference approximations to the advection-condensation problem. Mon. Wea. Rev., 118, 2082–2098, doi:10.1175/1520-0493(1990)118<2082:MFDATT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Grabowski, W. W., and H. Morrison, 2008: Toward the mitigation of spurious cloud-edge supersaturation in cloud models. Mon. Wea. Rev., 136, 1224–1234, doi:10.1175/2007MWR2283.1.

    • Search Google Scholar
    • Export Citation

  • Grabowski, W. W., M. Andrejczuk, and L.-P. Wang, 2011: Droplet growth in a bin warm-rain scheme with Twomey CCN activation. Atmos. Res., 99, 290–301, doi:10.1016/j.atmosres.2010.10.020.

    • Search Google Scholar
    • Export Citation

  • Hoffmann, F., S. Raasch, and Y. Noh, 2015: Entrainment of aerosols and their activation in a shallow cumulus cloud studied with a coupled LCM-LES approach. Atmos. Res., 156, 43–57, doi:10.1016/j.atmosres.2014.12.008.

    • Search Google Scholar
    • Export Citation

  • Margolin, L., J. M. Reisner, and P. K. Smolarkiewicz, 1997: Application of the volume-of-fluid method to the advection-condensation problem. Mon. Wea. Rev., 125, 2265–2273, doi:10.1175/1520-0493(1997)125<2265:AOTVOF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Mordy, W., 1959: Computations of the growth by condensation of a population of cloud droplets. Tellus, 11, 16–44, doi:10.1111/j.2153-3490.1959.tb00003.x.

    • Search Google Scholar
    • Export Citation

  • Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, 1996: Numerical Recipes in Fortran 90: The Art of Parallel Scientific Computing. 2nd ed. Cambridge University Press, 1495 pp.

  • Riechelmann, T., Y. Noh, and S. Raasch, 2012: A new method for large-eddy simulations of clouds with Lagrangian droplets including the effects of turbulent collision. New J. Phys., 14, 065008, doi:10.1088/1367-2630/14/6/065008.

    • Search Google Scholar
    • Export Citation

  • Rogers, R. R., and M. K. Yau, 1989: A Short Course in Cloud Physics. Pergamon Press, 293 pp.

  • Schumann, U., 1975: Subgrid scale model for finite difference simulations of turbulent flows in plane channels and annuli. J. Comput. Phys., 18, 376–404, doi:10.1016/0021-9991(75)90093-5.

    • Search Google Scholar
    • Export Citation

  • Shima, S.-I., K. Kusano, A. Kawano, T. Sugiyama, and S. Kawahara, 2009: The super-droplet method for the numerical simulation of clouds and precipitation: A particle-based and probabilistic microphysics model coupled with a non-hydrostatic model. Quart. J. Roy. Meteor. Soc., 135, 1307–1320, doi:10.1002/qj.441.

    • Search Google Scholar
    • Export Citation

  • Sölch, I., and B. Kärcher, 2010: A large-eddy model for cirrus clouds with explicit aerosol and ice microphysics and Lagrangian ice particle tracking. Quart. J. Roy. Meteor. Soc., 136, 2074–2093, doi:10.1002/qj.689.

    • Search Google Scholar
    • Export Citation

  • Stevens, B., R. L. Walko, W. R. Cotton, and G. Feingold, 1996: The spurious production of cloud-edge supersaturations by Eulerian models. Mon. Wea. Rev., 124, 1034–1041, doi:10.1175/1520-0493(1996)124<1034:TSPOCE>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Thouron, O., J.-L. Brenguier, and F. Burnet, 2012: Supersaturation calculation in large eddy simulation models for prediction of the droplet number concentration. Geosci. Model Dev., 5, 761–772, doi:10.5194/gmd-5-761-2012.

    • Search Google Scholar
    • Export Citation

  • Twomey, S., 1959: The nuclei of natural cloud formation. Part II: The supersaturation in natural clouds and the variation of cloud droplet concentration. Pure Appl. Geophys., 43, 243–249, doi:10.1007/BF01993560.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 262 96 6
PDF Downloads 189 77 10