A5018018178- Tropical and Extratropical Cyclones Research
- Climate variability and models
- Meteorological Phenomena and Simulations
- Ocean Waves and Remote Sensing
- Geophysics and Gravity Measurements
- Oceanographic and Atmospheric Processes
- Atmospheric Ozone and Climate
- Geological and Geophysical Studies
- Atmospheric and Environmental Gas Dynamics
- Precipitation Measurement and Analysis
- Atmospheric aerosols and clouds
- Earthquake Detection and Analysis
- Arctic and Antarctic ice dynamics
- Seismology and Earthquake Studies
- Ionosphere and magnetosphere dynamics
- Coastal and Marine Dynamics
- Wind and Air Flow Studies
- Building Energy and Comfort Optimization
- Earthquake and Tsunami Effects
- Methane Hydrates and Related Phenomena
- Flood Risk Assessment and Management
- Trauma and Emergency Care Studies
- earthquake and tectonic studies
- Case Reports on Hematomas
- Urban Heat Island Mitigation
Japan Agency for Marine-Earth Science and Technology
2016-2025
Yokohama National University
2023-2025
The University of Tokyo
2022
National Institute of Information and Communications Technology
2022
Chiba University
2022
Meteorological Research Institute
1953-2022
National Institute for Environmental Studies
2022
RIKEN Center for Computational Science
2022
Kyushu University
2004
Abstract Toward the achievement of reliable global kilometer‐scale (k‐scale) climate simulations, we improve Nonhydrostatic ICosahedral Atmospheric Model (NICAM) by focusing on moist physical processes. A goal model improvement is to establish a configuration that can simulate realistic fields seamlessly from daily‐scale variability climatological statistics. Referring two representative configurations present NICAM, each which has been used for climate‐scale and sub‐seasonal‐scale...
Future changes in tropical cyclone (TC) activity and structure are investigated using the outputs of a 14-km mesh climate simulation. A set 30-yr simulations was performed under present-day warmer conditions nonhydrostatic icosahedral atmospheric model with explicitly calculated convection. The projected that global frequency TCs is reduced by 22.7%, ratio intense increased 6.6%, precipitation rate within 100 km TC center 11.8% conditions. These tendencies consistent previous studies...
We propose a deep learning approach for identifying tropical cyclones (TCs) and their precursors. Twenty year simulated outgoing longwave radiation (OLR) calculated using cloud-resolving global atmospheric simulation is used training two-dimensional convolutional neural networks (CNNs). The CNNs are trained with 50,000 TCs precursors 500,000 non-TC data binary classification. Ensemble CNN classifiers applied to 10 independent OLR detecting TCs. performance of the investigated various basins,...
Recent progress in computing and model development has initiated the era of global storm-resolving modeling, with it potential to transform weather climate prediction. Within general theme vetting this new class models, present study evaluates nine global-storm resolving models their ability simulate tropical cyclones (TCs). Results indicate that, broadly speaking, produce realistic TCs remove longstanding issues known from such as deficiency accurately simulating TC intensity. However, are...
Abstract We used observations and model simulation to examine the atmospheric pulses that dominate far field in hours after January 2022 Tonga eruption. analyzed radiance taken from Himawari-8 geostationary satellite showed both a Lamb wave front with expected horizontal phase speed ∼315 m s −1 distinct ∼245 can be detected. The slower is consistent for global internal resonant mode had been proposed by Pekeris 1937 other idealized theoretical studies over past century, but which never...
Abstract. The Nonhydrostatic ICosahedral Atmospheric Model (NICAM), a global model with an icosahedral grid system, has been under development for nearly two decades. This paper describes NICAM16-S, the latest stable version of NICAM (NICAM.16), modified Coupled Intercomparison Project Phase 6, High Resolution (HighResMIP). Major updates NICAM.12, previous used climate simulations, included cloud microphysics scheme and land surface model, introduction natural anthropogenic aerosols...
Abstract The transport and accumulation of moisture played an essential role in the extremely heavy rainfall July 2020 Japan. To better understand this event terms sources routes, backward particle trajectory analysis was conducted. We found two major sources: from tropics uptake subtropics. A narrow channel along edge western Pacific Subtropical High (WPSH), transporting to Baiu front. However, most lost due precipitation, their contributions were reduced about 15%. In contrast, subtropical...
Abstract Thirty‐one successive daily experiments for extended‐range (30 day) forecasts are conducted using a global nonhydrostatic atmospheric model without convective parameterization. The successfully reproduces tropical cyclogenesis (TCG) in six out of eight cases the western North Pacific August 2004, up to 2 weeks prior cyclone formation. Detailed analyses reveal that Typhoon Songda's genesis is related eastward extension monsoon trough associated with intraseasonal variability (ISV)....
This review article summarizes recent (2014–2019) advances in our understanding of tropical cyclogenesis, stemming from activities at the ninth International Workshop on Tropical Cyclones. cyclogenesis involves interaction dynamic and thermodynamic processes multiple spatio-temporal scales. Studies have furthered how may be affected by external processes, such as intraseasonal oscillations, monsoon circulations, intertropical convergence zone, midlatitude troughs cutoff lows. Additionally,...
In relation to projections of tropical cyclone (TC) frequency in a future warmer climate, there is debate on whether the global TC seeds (weak pre-storm vortices) will increase or not. We examined changes by occurrence analysis (OFA) vortex intensity (vorticity maximum wind speed). directly counted number vortices with various intensities high resolution atmospheric model simulations for present and climates. By using OFA we showed clear reduction relatively weak (category 2 weaker) TCs an...
Abstract Previous projections of the frequency tropical cyclone genesis due to global warming, even in terms sign change, depends on chosen model simulation. Here, we systematically examine projected changes cyclones using six atmospheric models with medium-to-high horizontal resolutions included sixth phase Coupled Model Intercomparison Project/High-Resolution Project. Changes could be broken down into contributions from (i) seed, a depression having closed contour sea level pressure warm...
Abstract Reducing the computational cost of weather and climate simulations would lower electric energy consumption. From standpoint reducing costs, use reduced precision arithmetic has become an active area research. Here impact using single-precision on simulation accuracy is examined by conducting Jablonowski Williamson’s baroclinic wave tests dynamical core a global fully compressible nonhydrostatic model. The model employs finite-volume method discretized icosahedral grid system its...
Future changes in precipitation and the vertical structure of frontal zone around Japan during Baiu season are investigated using regional climate experiments with a 5-km-mesh non-hydrostatic model, driven for present-day (1979-2003) future (2075-2099) climates by output from global warming 20-km-mesh atmospheric circulation model under SRES-A1B scenario.Significant increases projected relative to daily amounts western late season. The percentage occurring intense (over 100 mm day-1)...
A 5-km-mesh nonhydrostatic cloud-system-resolving regional climate model (NHM-5km) has been developed at the Meteorological Research Institute (MRI) of Japan Agency (JMA) by improving upon JMA operational mesoscale (MSM). Three major changes have made to MSM: Kain-Frisch convective parameterization scheme improved reduce incidence false predictions rainfall areas along coastlines during warm season, a spectral nudging method introduced avoid phase-gap between inner and outer model, Simple...
This article reviews the major outcomes of a 5-year (2011–2016) project using K computer to perform global numerical atmospheric simulations based on non-hydrostatic icosahedral model (NICAM). The was made available public in September 2012 and used as primary resource for Japan's Strategic Programs Innovative Research (SPIRE), an initiative investigate five strategic research areas; NICAM fell under area climate weather simulation sciences. Combining with high-performance computing has...
Abstract. Recent advances in high-performance computers facilitate operational numerical weather prediction by global hydrostatic atmospheric models with horizontal resolutions of ∼ 10 km. Given further such and the fact that balance approximation becomes invalid for spatial scales < km, development nonhydrostatic high accuracy is urgently required. The Global 7 km mesh Model Intercomparison Project improving TYphoon forecast (TYMIP-G7) designed to understand statistically quantify...
Peculiar tsunami waves p roduced by the eruption of a submarine volcano at Myojinsho Reef on March 11,1953 were recorded wave gauges installed Hachijojima Island, Cape Ornaezaki and Jogashima which are distant from 130,336 356 km, respectively. Moreover, 11th to 25th about fifty times Island. From these data we could make clear features variation with distance as well time, it was proved that theory Cauchy-Poisson explains satisfactorily. It also shown caused an initial impulse rather than...
Tide gauge data indicated that ocean waves were generated by the eruption of Hunga Tonga-Hunga Ha'apai volcano on January 15, 2022. These high-amplitude reached Japanese coast earlier than expected for free waves. fluctuations in sea level reasonably reproduced an model, with realistic bottom topography forced sea-level pressure perturbations well atmospheric general circulation models. While early arrival times are associated Lamb waves, amplitude changes cannot be fully explained resonance...
In order to study changes in the regional climate vicinity of Japan during summer rainy season due global warming, preliminary experiments by a semi-cloud resolving non-hydrostatic model with horizontal resolution 5 km (NHM-5km) are conducted from June October between 2002 and 2006 using 20-km grid operational analysis data Meteorological Agency (JMA) as initial boundary conditions.The total precipitation amount appearance frequency for daily simulated NHM-5km show notable agreement those...
We studied the role of planetary boundary layer (PBL) in intensity and inner core structure extremely intense tropical cyclones (TC) using a 2 km mesh nonhydrostatic atmospheric model (NHM2) developed for operational use by Japan Meteorological Agency. To investigate effects PBL on simulated TCs, we used four schemes: level 2.5 3 Mellor‐Yamada‐Nakanishi‐Niino closure schemes, nonlocal scheme, Deardorff‐Blackadar scheme. The numerical results indicated that subgrid‐scale mixing length...
This review describes advances in understanding and forecasting tropical cyclone (TC) subseasonal variability during the past four years. A large effort by scientific community has been sources of predictability at timescales beyond well-known modulation TC activity Madden-Julian Oscillation (MJO). In particular, strong over western North Pacific Boreal Summer Intra-Seasonal (BSISO) documented. Progress also realized role tropical-extratropical interactions improving forecasts. addition,...
The representations of extreme weather during the landfall Typhoon Songda (2004) in regional simulations at 1-km resolution are described and compared for two cloud-resolving models: Non-hydrostatic Model (NHM) Weather Research Forecasting model (WRF). Both models, using same 5-km-mesh outputs from NHM as their initial boundary conditions, successfully reproduced observed typhoon track intensity. comparison surface winds indicated that WRF evaluates more enhanced extremes than NHM; on other...