Influence of grid aspect ratio on planetary boundary layer turbulence in large-eddy simulations

By Seiya Nishizawa, Hisashi Yashiro, Yousuke Sato, Y. Miyamoto, Hirofumi Tomita. 2015

154 citations recorded by the source corpus.

Abstract. We examine the influence of the grid aspect ratio of horizontal to vertical grid spacing on turbulence in the planetary boundary layer (PBL) in a large-eddy simulation (LES). In order to clarify and distinguish them from other artificial effects caused by numerical schemes, we used a fully compressible meteorological LES model with a fully explicit scheme of temporal integration. The influences are investigated with a series of sensitivity tests with parameter sweeps of spatial resolution and grid aspect ratio. We confirmed that the mixing length of the eddy viscosity and diffusion due to sub-grid-scale turbulence plays an essential role in reproducing the theoretical −5/3 slope of the energy spectrum. If we define the filter length in LES modeling based on consideration of the numerical scheme, and introduce a corrective factor for the grid aspect ratio into the mixing length, the theoretical slope of the energy spectrum can be obtained; otherwise, spurious energy piling appears at high wave numbers. We also found that the grid aspect ratio has influence on the turbulent statistics, especially the skewness of the vertical velocity near the top of the PBL, which becomes spuriously large with large aspect ratio, even if a reasonable spectrum is obtained.

Subfields: Atmospheric Science, Environmental Engineering, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/64fb0b8c9d99bf0553e34cccec6bf769bc1ad49f

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atmospheric Science

1. Hisashi Yashiro
2. Y. Miyamoto
3. Y. Kajikawa
4. Yousuke Sato
5. Seiya Nishizawa
6. Hirofumi Tomita
7. David L. Williamson

In Environmental Engineering

1. Hisashi Yashiro
2. Y. Miyamoto
3. Hirofumi Tomita

In Global and Planetary Change

1. Hisashi Yashiro
2. Yousuke Sato
3. Seiya Nishizawa
4. Y. Kajikawa
5. Y. Miyamoto
6. Hirofumi Tomita

Citations in the corpus

• Impacts of cloud microphysics on trade wind cumulus: which cloud microphysics processes contribute to the diversity in a large eddy simulation? (2015, methodology): “Based on the rough estimation of Nishizawa et al. (2015), the non-dimensional coefficient (γ) should be smaller than O (10)–O (10) for n = 4.”