Roar Articles

‘Sharpening’ computer models may improve weather predictions

Research conducted by:

Aaron Wang, assistant professor of meteorology and atmospheric science, Penn State, Ying Pan, assistant professor of meteorology and atmospheric science, Penn State, Paul M. Markowski, Distinguished Professor of Meteorology, Penn State


advection Department of Meteorology and Atmospheric Science meteorology weather weather forecasting prediction weather models weather predictions

Research Summary:

How Roar played a role in this research:

Computations for this research were performed on Penn State's Institute for Computational and Data Sciences’ Roar supercomputer.

Publication Details

Article Title:

The Influence of WENO Schemes on Large-Eddy Simulations of a Neutral Atmospheric Boundary Layer

Published In:

Journal of Atmospheric Sciences


This work explores the influence of Weighted Essentially Non-Oscillatory (WENO) schemes on Cloud Model 1 (CM1) large-eddy simulations (LES) of a quasi-steady, horizontally homogeneous, fully developed, neutral atmospheric boundary layer (ABL). An advantage of applying WENO schemes to scalar advection in compressible models is the elimination of acoustic waves and associated oscillations of domain-total vertical velocity. Applying WENO schemes to momentum advection in addition to scalar advection yields no further advantage, but has an adverse effect on resolved turbulence within LES. As a tool designed to reduce numerically generated spurious oscillations, WENO schemes also suppress physically realistic instability development in turbulence-resolving simulations. Thus, applying WENO schemes to momentum advection reduces vortex stretching, suppresses the energy cascade, reduces shear-production of resolved Reynolds stress, and eventually amplifies the differences between the surface-layer mean wind profiles in the LES and the mean wind profiles expected in accordance with the filtered law of the wall (LOTW). The role of WENO schemes in adversely influencing surface-layer turbulence has inspired a concept of anti-WENO (AWENO) schemes to enhance instability development in regions where energy-containing turbulent motions are inadequately resolved by LES grids. The success in reproducing the filtered LOTW via AWENO schemes suggests that improving advection schemes is a critical component toward faithfully simulating near-surface turbulence and dealing with other "Terra Incognita" problems.

View article on publisher's website

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