A three‐dimensional positivity‐preserving and conservative multimoment finite‐volume transport model on a cubed‐sphere grid. (2nd November 2022)

• Record Type: Journal Article
• Authors: Tang, Jie; Chen, Chungang; Shen, Xueshun; Xiao, Feng; Li, Xingliang
• Is Part Of: Quarterly journal of the Royal Meteorological Society. Volume 148:Number 749(2022)
• Page Start: 3622
• Page End: 3638
• Publication Date: 2022-11-02
• Subjects: 3D global transport model -- cubed‐sphere grid -- mass conservation -- multimoment finite‐volume method -- positive‐definite -- reactive chemistry test -- semi‐Lagrangian method; Meteorology -- Periodicals; 551.5
• DOI: 10.1002/qj.4377
• Languages: English
• ISSNs: 0035-9009

Abstract

Abstract: A three‐dimensional positivity‐preserving and conservative transport model on a cubed‐sphere grid is presented using a multimoment finite‐volume (MMFV) method. The three‐point fourth‐order MMFV method with boundary gradient switching projection is utilized to ensure nonoscillatory numerical solutions in the horizontal, while the simple and computationally efficient semi‐Lagrangian piecewise rational method is used to allow a large time step in the vertical. By means of horizontal and vertical separation, a Strang‐type splitting technique is adopted to advance the numerical solutions in time. Non‐negative corrections are made to achieve positive‐definite preservation exactly. The resulting transport model is inherently conservative, high‐accuracy, and positive‐definite, and allows a large Courant number no matter how dense the vertical grid is. Various benchmark test cases, including three representative advection tests and an idealized terminator chemistry test, are conducted to validate the performance of the model presented. The numerical results indicate that the model is quite competitive in comparison with the existing models in the literature and looks very promising in real atmospheric simulations. Abstract : Schematic of a cubed‐sphere grid with 6 N 2 = 864 $$ 6{N}^2=864 $$ meshes ( N = 12 $$ N=12 $$ ) and the relative position arrangement of the six local coordinates.