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A physics‐based diffusion scheme for numerical models
Author(s) -
Liu Chongjian,
Liu Ying,
Xu Hui
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl025781
Subject(s) - spurious relationship , dissipation , dissipative system , nonlinear system , numerical diffusion , numerical weather prediction , discretization , statistical physics , hydrostatic equilibrium , mathematics , meteorology , physics , forcing (mathematics) , mesoscale meteorology , computer science , mechanics , thermodynamics , mathematical analysis , atmospheric sciences , quantum mechanics , machine learning
A proper description of the dissipation in a forcing‐dissipative system, such as the atmosphere, is very important when the system is discretized. Atmospheric dissipation is generally treated as diffusion in numerical weather prediction (NWP) models. The commonly used fourth‐order diffusion scheme (linear and nonlinear) generates spurious upgradient mass or heat transport, which violates the entropy constraint posed by non‐equilibrium thermodynamics. The second law of thermodynamics is used in this paper to re‐construct the diffusion scheme to ensure downgradient transport. The new physics‐based scheme is applied to the Penn State/NCAR non‐hydrostatic mesoscale model. A hurricane case simulation demonstrates that the new scheme improves the model accuracy in predicting the strength of the hurricane.