[A-AS05] Weather, Climate, and Environmental Science Studies using High-Performance Computing

[AAS05-P05] Season-scale large ensemble simulation with a high-resolution nonhydrostatic model, NICAM

*Yohei Yamada¹, Masuo Nakano¹, Tomoki Miyakawa², Chihiro Kodama¹, Akira Yamazaki¹, Tomoe Nasuno¹, Hisashi Yashiro³, Masaki Satoh² (1.Japan Agency for Marine-Earth Science and Technology, 2.Atmosphere and Ocean Research Institute, The University of Tokyo, 3.National Institute for Environmental Studies)

Keywords:Large ensamble simulation, high resolution global nonhydrostatic model, Tropical cyclone

A tropical cyclone activity has interannual variability which internal atmospheric variability contributes. A large ensemble simulation is required to evaluate a model capability in reproducing interannual variability of tropical cyclone frequency. The large ensemble simulation (64 members) was conducted for the boreal summer (June-September) during 2009-2019 by using Nonhydrostatic ICosahedral Atmospheric Model, NICAM with a horizontal grid spacing of 14 kilometers. NICAM has the highest correlation coefficient with the interannual variability of tropical cyclone frequency in September in observation over the eastern North Pacific (0.72-0.9). It is important to note that there is a large variation of tropical cyclone frequency among ensemble members. For instance, some members show no tropical cyclones. We will report the capability of NICAM in reproducing interannual variability of tropical cyclone frequency and its relation to environmental condition. This work was supported by MEXT as “Program for Promoting Researches on the Supercomputer Fugaku” (JPMXP1020200305) and used computational resources provided by the RIKEN Center for Computational Science (Project ID: hp200128, hp210166).