An Improved Mellor–Yamada Level-3 Model: Its Numerical Stability and Application to a Regional Prediction of Advection Fog
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This note describes a numerically stable version of the improved Mellor–Yamada (M–Y) Level-3 model proposed by Nakanishi and Niino [Nakanishi, M. and Niino, H.: 2004, Boundary-Layer Meteorol. 112, 1–31] and demonstrates its application to a regional prediction of advection fog. In order to ensure the realizability for the improved M–Y Level-3 model and its numerical stability, restrictions are imposed on computing stability functions, on L/q, the temperature and water-content variances, and their covariance, where L is the master length scale and q2/2 the turbulent kinetic energy per unit mass. The model with these restrictions predicts vertical profiles of mean quantities such as temperature that are in good agreement with those obtained from large-eddy simulation of a radiation fog. In a regional prediction, it also reasonably reproduces the satellite-observed horizontal distribution of an advection fog.
KeywordsAdvection fog Level-3 model Realizability Regional prediction Turbulence closure model
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- Janjić, Z. I.: 2001, Nonsingular Implementation of the Mellor–Yamada Level 2.5 Scheme in the NCEP Meso Model, Office Note No. 437, National Centers for Environmental Prediction, 61 pp.Google Scholar
- Japan Meteorological Agency.: 2002, Outline of the Operational Numerical Weather Prediction at the Japan Meteorological Agency, Appendix to the WMO Numerical Weather Prediction Progress Report, Japan Meteorological Agency, Tokyo, 158 pp.Google Scholar
- Katayama A. (1972). A Simplified Scheme for Computing Radiative Transfer in the Troposphere, Numerical Simulation of Weather and Climate. Technical Report No. 6, University of California, Los Angeles, 77 pp.Google Scholar
- Nakanishi M. (2002). ‘A Lateral Boundary Condition Suitable for the One-Way Nesting Scheme’. Tenki 49:117–128 (in Japanese).Google Scholar