Japan Geoscience Union Meeting 2018

Presentation information

[EE] Evening Poster

A (Atmospheric and Hydrospheric Sciences) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS01] High performance computing for next generation weather, climate, and environmental sciences

Sun. May 20, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Hiromu Seko(Meteorological Research Institute), Chihiro Kodama(Japan Agency for Marine-Earth Science and Technology), Masayuki Takigawa(独立行政法人海洋研究開発機構, 共同), Takemasa Miyoshi(RIKEN Advanced Institute for Computational Science)

[AAS01-P09] Numerical simulation of a heavy rain event in Hiroshima city on 19-20 August 2014

*Tsutao OIZUMI1, Kazuo Saito2, Le Duc1, Junshi Ito2 (1.Japan Agency for Marine-Earth Science and Technology, 2.Meteorological Research Institute)

Keywords:Heavy rain, High resolution, Numerical weather prediction

In Hiroshima, heavy rainfall caused debris flows on 19-20 August 2014. The heavy rain was a line-shaped rainband caused by “back-building formation” in a relatively narrow region. To predict and mitigate this kind of disaster, an accurate numerical prediction is necessary.

In this study, we investigated important factors in a numerical weather prediction (NWP) model that impact on a performance of heavy rainfall forecast. The investigated factors were grid spacings (5 km to 250 m), planetary boundary layer (PBL) schemes, model domain sizes, lateral boundary conditions in nesting simulations, and terrain representations.

Results indicated that ultra-high-resolution (500-250 m grid spacing) experiments showed better performance than coarser-resolution experiments (5 and 2 km grid spacing) in the rainfall cases. The differences of grid spacings had a larger impact on the position of rainband. These results demonstrate that the ultra-high-resolution NWP model has the possibility to improve predictions of heavy rainfall.