EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evaluating performances of one-year simulation by using 3.5 km mesh global nonhydrostatic model

Yohei Yamada1, Chihiro Kodama1, Akira Noda1, Masaki Satoh2, Masuo Nakano1, Tomoki Miyakawa2, Hisashi Yashiro3, and Tomoe Nasuno1
Yohei Yamada et al.
  • 1Japan Agency for Marine-Earth Science and Technology,Yokohama, Japan (
  • 2Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan (
  • 3National Institute for Environmental Studies, Tsukuba, Japan (

Recent advancement of supercomputing enables us to conduct a climate simulation by using a global model with horizontal grid spacing of a few kilometers. We may need to tune the model in order to conduct a reliable simulation. In order to test feasibility of a few kilometer climate simulation in near future, we conducted one-year simulation from June 2004 to May 2005 by using Nonhydrostatic Icosahedral Atmospheric Model (NICAM) with horizontal grid spacing of 28 km, 14 km, 7 km, and 3.5 km, and evaluated their simulation performances. In general, global models have shown weak wind speed of tropical cyclones compared to its central sea level pressure due to insufficient horizontal resolution. As expected, the 3.5 km simulation showed improvement of this bias. As for simulated mean state, globally annual mean precipitation tended to be decreased with finer horizontal resolution in NICAM. Compared with observation (Global Precipitation Climatology Project V2.2; 2.71 mm day-1), 7 km and 3.5 km simulations underestimated the global mean precipitation (2.54 mm day-1 and 2.67 mm day-1), while 14 km and 28 km simulations overestimated (2.84 mm day-1 and 2.78 mm day-1). The 3.5 km simulation showed the best performance for reproducing globally annual mean precipitation. However, the 3.5 simulation showed underestimation of the South Pacific Convergence Zone. In order to conduct a reliable simulation, we need to improve performance of the 3.5 km global model. This demands extensive computing resources. The supercomputer Fugaku will give us extensive computing resources for addressing this issue.

How to cite: Yamada, Y., Kodama, C., Noda, A., Satoh, M., Nakano, M., Miyakawa, T., Yashiro, H., and Nasuno, T.: Evaluating performances of one-year simulation by using 3.5 km mesh global nonhydrostatic model, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15452,, 2021.


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