Search from over 60,000 research works

Advanced Search

The “ABC model”: a non-hydrostatic toy model for use in convective-scale data assimilation investigations

[thumbnail of Open access]
Preview
gmd-10-4419-2017.pdf - Published Version (6MB) | Preview
Available under license: Creative Commons Attribution
[thumbnail of ABC_model_Sub3_CopernicusTemplate.pdf]
ABC_model_Sub3_CopernicusTemplate.pdf - Accepted Version (3MB)
Restricted to Repository staff only
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email

Petrie, R. E., Bannister, R. N. orcid id iconORCID: https://orcid.org/0000-0002-6846-8297 and Cullen, M. J. P. (2017) The “ABC model”: a non-hydrostatic toy model for use in convective-scale data assimilation investigations. Geoscientific Model Development, 10. pp. 4419-4441. ISSN 1991-959X doi: 10.5194/gmd-10-4419-2017

Abstract/Summary

In developing methods for convective-scale data assimilation (DA) it is necessary to consider the full range of motions governed by the compressible Navier-Stokes equations (including non-hydrostatic and ageostrophic flow). These equations describe motion on a wide range of time-scales with non-linear coupling. For the purpose of developing new DA techniques that suit the convective-scale problem it is helpful to use so-called ‘toy models’ that are easy to run, and contain the same types of motion as the full equation set. Such a model needs to permit hydrostatic and geostrophic balance at large-scales, but to allow imbalance at small-scales, and in particular, it needs to exhibit intermittent convection-like behaviour. Existing ‘toy models’ are not always sufficient for investigating these issues. A simplified system of intermediate complexity derived from the Euler equations is presented, which supports dispersive gravity and acoustic modes. In this system the separation of time scales can be greatly reduced by changing the physical parameters. Unlike in existing toy models, this allows the acoustic modes to be treated explicitly, and hence inexpensively. In addition, the non-linear coupling induced by the equation of state is simplified. This means that the gravity and acoustic modes are less coupled than in conventional models. A vertical slice formulation is used which contains only dry dynamics. The model is shown to give physically reasonable results, and convective behaviour is generated by localised compressible effects. This model provides an affordable and flexible framework within which some of the complex issues of convective-scale DA can later be investigated. The model is called the “ABC model” after the three tunable parameters introduced: A (the pure gravity wave frequency), B (the modulation of the divergent term in the continuity equation), and C (defining the compressibility).

Altmetric Badge

Item Type Article
URI https://reading-clone.eprints-hosting.org/id/eprint/75739
Item Type Article
Refereed Yes
Divisions Science > School of Mathematical, Physical and Computational Sciences > National Centre for Earth Observation (NCEO)
Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher European Geosciences Union
Download/View statistics View download statistics for this item

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Search Google Scholar