The Operational JMA Nonhydrostatic Mesoscale Model

Abstract

An operational nonhydrostatic mesoscale model has been developed by the Numerical Prediction Division (NPD) of the Japan Meteorological Agency (JMA) in partnership with the Meteorological Research Institute (MRI). The model is based on the MRI/NPD unified nonhydrostatic model (MRI/NPD-NHM), while several modifications have been made for operational numerical weather prediction with a horizontal resolution of 10 km. A fourth-order advection scheme considering staggered grid configuration is implemented. The buoyancy term is directly evaluated from density perturbation. A time-splitting scheme for advection has been developed, where the low-order (second order) part of advection is modified in the latter half of the leapfrog time integration. Physical processes have also been revised, especially in the convective parameterization and PBL schemes. A turbulent kinetic energy (TKE) diagnostic scheme has been developed to overcome problems that arise to predict TKE. The model performance for mesoscale NWP has been verified by comparison with a former operational hydrostatic mesoscale model of JMA. It is found that the new nonhydrostatic mesoscale model outperforms the hydrostatic model in the prediction of synoptic fields and quantitative precipitation forecasts.

Projection of Future Climate Change over Japan in Ensemble Simulations with a High-Resolution Regional Climate Model

“…The NHRCM developed by Sasaki et al (2008) is a climate version of the Japan Meteorological Agency Nonhydrostatic Model (JMA-NHM; Saito et al 2006), which is used operationally by JMA in numerical weather prediction. Sasaki et al (2008) and Nakano et al (2012) describe the specifications of NHRCM except for recent improvements that include a revised version of the Kain-Fritsch convection parameterization, developed by one of the present authors (T. Kato).…”

Ground-Based Microwave Radiometer Variational Analysis during No-Rain and Rain Conditions

“…Note that the zenith and off-zenith observations are separately used as observation vectors in this study. The numerical model used in this study was the JMA nonhydrostatic model (NHM; Saito et al 2006). Numerical experiments with a horizontal grid spacing of 5 km and a domain covering Japan were performed.…”

“…1c, d) at a 15° elevation angle. At frequencies between similar to that of the JMA operational mesoscale model (Saito et al 2006). The time step of the NHM was 20 s, and the results were output at 10-min intervals.…”

“…The time step of the NHM was 20 s, and the results were output at 10-min intervals. Other setups were the same as those used in Saito et al (2006). Vertical profiles averaged over 25 × 25 km 2 squares centered at Tateno were interpolated to the MWR observation times and used for the 1DVAR retrievals.…”

Summertime Temperature Extremes over Japan in the Late 21st Century Projected by a High-Resolution Regional Climate Model

“…The RCM used in this study is a climate extension of the Japan Meteorological Agency Nonhydrostatic Model (JMA-NHM; Saito et al 2006Saito et al , 2007. The extended model (referred to NHM) is able to simulate the regional climate (e.g., Kurihara et al 2005;Kanada et al 2008;Sasaki et al 2008;Ishizaki and Takayabu 2009;Nakano et al 2010).…”