A5046205613- Tropical and Extratropical Cyclones Research
- Climate variability and models
- Meteorological Phenomena and Simulations
- Ocean Waves and Remote Sensing
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Geophysics and Gravity Measurements
- Atmospheric chemistry and aerosols
- 3D IC and TSV technologies
- Electronic Packaging and Soldering Technologies
- Coastal wetland ecosystem dynamics
- Copper Interconnects and Reliability
- Aeolian processes and effects
- Reservoir Engineering and Simulation Methods
- Japanese History and Culture
- Underground infrastructure and sustainability
- Landslides and related hazards
- Computational Physics and Python Applications
- Precipitation Measurement and Analysis
- Cryospheric studies and observations
- Flood Risk Assessment and Management
- Advanced Data Storage Technologies
- Urban and spatial planning
- Oceanographic and Atmospheric Processes
- Hydrology and Drought Analysis
Yokohama National University
2019-2024
RIKEN Center for Computational Science
2012-2022
Kobe University
2016-2022
University of Colorado Boulder
2018-2022
NOAA Earth System Research Laboratory
2018-2022
Cooperative Institute for Research in Environmental Sciences
2018-2022
NOAA Chemical Sciences Laboratory
2020-2021
RIKEN
2015-2018
University of Miami
2016
Japan Agency for Marine-Earth Science and Technology
2016
Deep moist atmospheric convection is a key element of the weather and climate system for transporting mass, momentum, thermal energy. It has been challenging to simulate realistically in global models because large gap spatial scales between (10 0 km) motions 4 km). We conducted first ever subkilometer simulation described features convection. Through series grid‐refinement resolution testing, we found that an essential change statistics occurred around 2 km grid spacing. The structure,...
Abstract Japan’s new geostationary satellite Himawari-8, the first of a series third-generation meteorological satellites including GOES-16, has been operational since July 2015. Himawari-8 produces high-resolution observations with 16 frequency bands every 10 min for full disk, and 2.5 local regions. This study aims to assimilate all-sky every-10-min infrared (IR) radiances from regional numerical weather prediction model investigate its impact on real-world tropical cyclone (TC) analyses...
Following the invention of telegraph, electronic computer, and remote sensing, "big data" is bringing another revolution to weather prediction. As sensor computer technologies advance, orders magnitude bigger data are produced by new sensors high-precision simulation or simulation." Data assimilation (DA) a key numerical prediction (NWP) integrating real-world into simulation. However, current DA NWP systems not designed handle from next-generation big Therefore, we propose assimilation"...
Abstract The flow environment associated with tropical cyclone genesis (TCG) over the western North Pacific was assessed via categorization into five patterns: monsoon shear line (SL), confluence region (CR), gyre (GY), easterly wave (EW), and preexisting (PTC). Using reanalysis data an objective algorithm, authors defined “contribution scores” for patterns. Each score represents contribution to TCG from each pattern, scores were calculated 908 cases 1979 2008 (30 yr). Of major patterns, SL...
Abstract The intraseasonal variability of tropical cyclogenesis in the western North Pacific (WNP) basin is explored this study. relation each five large-scale patterns identified recent work by Yoshida and Ishikawa associated with Madden–Julian oscillation (MJO). Confirming previous results, more events are found during active MJO phase WNP. Furthermore, results indicate that most monsoon shear line pattern phase. genesis potential index (GPI) its individual components used to evaluate...
With a goal of real-time, high-resolution, short-term prediction heavy rainfall systems, the SCALE-LETKF was developed implementing local ensemble transform Kalman filter with Scalable Computing for Advanced Library and Environment-Regional Model (SCALE-RM). The system has been running in near real time experimentally since May 2015, configured weather analyses forecasts at 18-km resolution 5760 × 4320 km area around Japan. Among data more than one year, near-real-time 3-km downscaling...
The impact of intraseasonal oscillation on tropical cyclone genesis (TCG) over the western North Pacific during boreal summer was examined in association with categorized synoptic-scale low-level flow patterns. Five patterns were considered as environment connecting large-scale and meso-scale TCG: a shear line, confluence region, an easterly wave, monsoon gyre, pre-existing cyclone. phase amplitude (BSISO) used. It is found that 7 favorable for TCG associated phases 8 also region. During...
The success of sub-kilometer global atmospheric simulation opens the door for resolving deep convections, which are fundamental elements cloudy disturbances that drive circulation. A previous study found essential change in simulated convection properties occurred at a grid spacing about 2 km as mean. In grid-refinement experiments, we conducted further comprehensive analysis global-mean state and characteristics convection, to clarify difference by location environment. We was different...
Resolution dependence was found in the simulated diurnal precipitation cycle over land tropics. We conducted a series of grid refinement experiments atmosphere from 14 km to 0.87 using global high-resolution model without any convection parameterizations. In experiment, peak earlier and at higher. The characteristics changed spacing around 2-3 km. started increase morning experiments, suggesting that small-scale moist became active late morning. lower-resolution began afternoon. As well as...
Abstract The characteristics of tropical cyclones (TCs) in the summer and autumn seasons over western North Pacific that are associated with different environmental factors influence TC genesis (TCG) were studied. authors objectively categorized into five TCG classified by Ritchie Holland: monsoon shear line (SL), confluence region (CR), gyre (GY), easterly wave (EW), Rossby energy dispersion from a preexisting (PTC). GY-TCs tended to develop slowly, highest rates occurrence rapid...
Abstract. This paper describes the splitting supercell idealized test case used in 2016 Dynamical Core Model Intercomparison Project (DCMIP2016). These storms are useful beds for global atmospheric models because horizontal scale of convective plumes is O(1 km), emphasizing non-hydrostatic dynamics. The simulates a on reduced-radius sphere with nominal resolutions ranging from 4 to 0.5 km and based work Klemp et al. (2015). Models initialized an environment conducive formation forced small...
We summarize the optimization and performance evaluation of Nonhydrostatic ICosahedral Atmospheric Model (NICAM) on two different types supercomputers: K computer TSUBAME2.5. First, we evaluated improved several kernels extracted from model code computer. did not significantly change loop data ordering for sufficient usage features computer, such as hardware-aided thread barrier mechanism relatively high bandwidth memory, i.e., a 0.5 Byte/FLOP ratio. Loop optimizations cleaning reduction in...
Abstract Deep moist convection is an element of cloud disturbances such as Madden‐Julian oscillation ( MJO ), tropical cyclones TCs mid‐latitudinal low depressions MDL and fronts FRT ). However, differences in characteristics remain unclear. We first clarified the statistical features (structure, intensity, environmental parameters) various simulated by a global simulation with sub‐kilometre grid spacing. The TC ) was tall strong (weak) upward motion, driven large convective available...
Large-scale fields and inner-core processes relevant to the formation intensification of Typhoon Fengshen (2008) were examined by simulations using a global nonhydrostatic model with cloud-permitting resolution. Five runs performed varying cloud microphysics or initial condition settings. In three out five runs, middle tropospheric trough developed within few days following large-scale latent heat release, which enabled successive occurrence deep convective events 50-km radius incipient...
The environmental conditions for tropical cyclone genesis are examined by numerical experiment.We focus on the case of a non-developing disturbance showed features in Pacific Area Long-term Atmospheric observation Understanding climate change 2010 (PALAU2010) campaign over western North Pacific.We clarify importance presence abundant moisture around continuous convection and demonstrate that collocation mid-level vortex low-level vortex, i.e., persistence an upright structure vortices, is...
Future changes in large-scale climatology and perturbation may have different impacts on regional climate change. It is important to understand the of terms both thermodynamic dynamic changes. Although many studies investigated influence climate, significance still debated. The nonlinear effect these two also unknown. We propose a systematic procedure that extracts influences three factors: climatology, resulting effect. then demonstrate usefulness procedure, applying it future...
Regional climate projections inevitably inherit uncertainties from general circulation models (GCMs). We therefore propose a new approach for identifying the dominant uncertainties. This employs downscaling procedure by Adachi et al. to uncertainty problem using multiple GCM projections. The mean state of large‐scale atmospheric states and deviation this are two factors considered here, which provided GCM. These referred as climatology perturbation components, respectively. To demonstrate...
Abstract. This paper describes and analyzes the Reed–Jablonowski (RJ) tropical cyclone (TC) test case used in 2016 Dynamical Core Model Intercomparison Project (DCMIP2016). intermediate-complexity evolution of a weak vortex into TC an idealized environment. Reference solutions from nine general circulation models (GCMs) with identical simplified physics parameterization packages that participated DCMIP2016 are analyzed this study at 50 km horizontal grid spacing, five these also providing 25...
Abstract Atmospheric deep moist convection can organize into cloud systems, which impact the Earth's climate significantly. High‐resolution simulations that correctly reproduce organized systems are necessary to understand role of in system. However, there remain issues regarding convergence with respect grid spacing. To investigate resolution for a reasonable simulation convection, we conducted grid‐refinement experiments using state‐of‐the‐art atmospheric models. We found structure an...
This study investigated the atmospheric and oceanic contributions to genesis of Typhoon Faxai in 2019. Our statistical analysis using tropical cyclone score (TGS) attributed disturbance that developed into (Pre-Faxai) easterly waves (EWs). The EW evaluated by a grid version TGS (Grid-EW) averaged around occurrence Pre-Faxai was approximately twice as large climatological mean, it second largest value past 38 years. area with high Grid-EW scores could be traced back eastern North Pacific...
This study examined the statistical characteristics of tropical cyclones (TCs) for which cyclogenesis (TCG) process was modulated by upper tropospheric cold lows (UCLs) over western North Pacific during 38 years from 1979 to 2016. Among 965 TCs, 90 TCs (9 %, 2.4 per year) were defined as having TCG influenced UCLs in northwest quadrant TC region (UL-TCs). Most UL-TCs occurred summer, with large variability annual occurrence rate June October, ranging 0 approximately 30 %. The variation...
We propose a cost-effective online nesting procedure (CONeP) for regional atmospheric models to improve computational efficiency. The conventional of is ineffective because computations are executed sequentially each domain, and it does not enable users freely determine the number nodes. However, CONeP can completely avoid this limitation through three actions: 1) splitting processes into multiple subgroups; 2) making subgroup manage just one domain; 3) executing domain simultaneously. Since...