Skip to content

Research at St Andrews

The moist parcel-in-cell method for modelling moist convection

Research output: Contribution to journalArticle

DOI

Open Access permissions

Open

Author(s)

D. G. Dritschel, S. J. Böing, D. J. Parker, A. M. Blyth

School/Research organisations

Abstract

We describe a promising alternative approach to modelling moist convection and cloud development in the atmosphere. Rather than using a conventional grid‐based approach, we use Lagrangian “parcels” to represent key dynamical and thermodynamical variables. In the prototype model considered, parcels carry vorticity, mass, specific humidity, and liquid‐water potential temperature. In this first study, we ignore precipitation, and many of these parcel “attributes” remain unchanged (i.e. are materially conserved). While the vorticity does change following the parcel motion, the vorticity tendency is readily computed and, crucially, unwanted numerical diffusion can be avoided. The model, called “Moist Parcel‐In‐Cell” (MPIC), is a hybrid approach which uses both parcels and a fixed underlying grid for efficiency: advection (here moving parcels) is Lagrangian whereas inversion (determining the velocity field) is Eulerian. The parcel‐based representation of key variables has several advantages: (a) it allows an explicit subgrid representation; (b) it provides a velocity field which is undamped by numerical diffusion all the way down to the grid scale; (c) it does away with the need for eddy viscosity parametrizations and, in their place, it provides for a natural subgrid parcel mixing; (d) it is exactly conservative (i.e. there can be no net loss or gain of any theoretically conserved attribute); and (e) it dispenses with the need to have separate equations for each conserved parcel attribute; attributes are simply labels carried by each parcel. Moreover, the latter advantage increases as more attributes are added, such as the distributions of microphysical properties, chemical composition and aerosol loading.    
Close

Details

Original languageEnglish
JournalQuarterly Journal of the Royal Meteorological Society
VolumeEarly View
Early online date4 Oct 2018
DOIs
StateE-pub ahead of print - 4 Oct 2018

    Research areas

  • Clouds, Convection, Numerical method

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Scale-invariant singularity of the surface quasigeostrophic patch

    Scott, R. K. & Dritschel, D. G. 28 Jan 2019 In : Journal of Fluid Mechanics. 863, 12 p., R2

    Research output: Contribution to journalArticle

  2. Imperfect bifurcation for the quasi-geostrophic shallow-water equations

    Dritschel, D. G., Hmidi, T. & Renault, C. 12 Oct 2018 In : Archive for Rational Mechanics and Analysis. 231, 3, p. 1853-1915 63 p.

    Research output: Contribution to journalArticle

  3. Circulation conservation and vortex breakup in magnetohydrodynamics at low magnetic Prandtl number

    Dritschel, D. G., Diamond, P. H. & Tobias, S. M. 25 Dec 2018 In : Journal of Fluid Mechanics. 857, p. 38-60

    Research output: Contribution to journalArticle

Related by journal

  1. Quarterly Journal of the Royal Meteorological Society (Journal)

    Scott, R. K. (Editor)
    2011 → …

    Activity: Publication peer-review and editorial workEditor of research journal

  2. Quarterly Journal of the Royal Meteorological Society (Journal)

    Dritschel, D. G. (Editor)
    2005 → …

    Activity: Publication peer-review and editorial workEditor of research journal

Related by journal

  1. A new class of vacillations of the stratospheric polar vortex

    Scott, R. K. Jul 2016 In : Quarterly Journal of the Royal Meteorological Society. 142, 698, p. 1948-1957 10 p.

    Research output: Contribution to journalArticle

  2. A test case for the inviscid shallow-water equations on the sphere

    Scott, R. K., Harris, L. M. & Polvani, L. M. Jan 2016 In : Quarterly Journal of the Royal Meteorological Society. 142, 694, p. 488-495 8 p.

    Research output: Contribution to journalArticle

  3. The onset of the barotropic sudden warming in a global model

    Liu, S. & Scott, R. K. 2015 In : Quarterly Journal of the Royal Meteorological Society. Early view

    Research output: Contribution to journalArticle

ID: 252962614