A5073152357- Tropical and Extratropical Cyclones Research
- Meteorological Phenomena and Simulations
- Climate variability and models
- Aeolian processes and effects
- Solar and Space Plasma Dynamics
- Flood Risk Assessment and Management
- Ocean Waves and Remote Sensing
- Precipitation Measurement and Analysis
- Coastal and Marine Dynamics
- Fluid Dynamics and Turbulent Flows
- Nonlinear Dynamics and Pattern Formation
- Air Quality Monitoring and Forecasting
- Functional Brain Connectivity Studies
- Complex Systems and Time Series Analysis
- Island Studies and Pacific Affairs
- Wind and Air Flow Studies
- Oceanographic and Atmospheric Processes
The University of Tokyo
2014-2024
Meteorological Research Institute
2019-2024
Japan Meteorological Agency
2019-2024
Sphere Institute
2017-2024
National Research Institute for Earth Science and Disaster Resilience
2021-2023
Kyushu University
2012-2017
Abstracts The history of severe thunderstorm research and forecasting over the past century has been a remarkable story involving interactions between technological development observational modeling capabilities, into physical processes, phenomena with goal reducing loss life property. Perhaps more so than any other field meteorology, relationship researchers forecasters particularly close in domain, both groups depending on improved capabilities. advances that have made depended observing...
Abstract The structural and environmental characteristics of extratropical cyclones that cause tornado outbreaks [outbreak (OCs)] do not [nonoutbreak (NOCs)] are examined using the Japanese 55-year Reanalysis dataset (JRA-55). Composite analyses show differences between OCs NOCs: for OCs, storm relative helicity (SREH) convective available potential energy (CAPE) notably larger, areas in which these parameters have significant values wider warm sector than they NOCs. larger CAPE is due to...
A tornado hit Nobeoka city on the southeast coast of Kyushu Island, Japan 22 September 2019 when Typhoon Tapah was located about 500 km to southwest Island and moving northeastward. Triply-nested numerical simulations are performed reproduce typhoon, a parent storm, associated tornadoes. The simulation with coarsest resolution reasonably reproduces outer rainbands at several east its center, where environment around rainband is found be favorable for mini-supercells. finest train...
This work investigates development processes of Baiu frontal depressions (BFDs) using a reanalysis data set in June and July from 2000 to 2007. On the basis deepening magnitude, 140 BFDs detected analysis period are categorized into developed non-developed BFDs. Developed further classified W-BFDs E-BFDs; (E-BFDs) peak region west (east) 140°E.A composite many case studies reveal that vertical coupling between lower- upper-level disturbances latent heating key factors for both It is also...
Abstract On 12–13 April 2020, an extreme heavy rainfall event associated with extratropical cyclone occurred over the eastern coastal region of Kii Peninsula, Japan, when unusual warm sea surface temperature anomalies (SSTAs) a Kuroshio large meander (KLM) was observed. Here, we carry out numerical experiments to examine impact SSTAs on this event. The enhanced low‐level moisture that transported toward by cyclone, resulting in increase precipitation. In particular, maximum 3‐hour...
Characteristics of extratropical cyclones that cause tornadoes in Italy are investigated. Tornadoes between 2007 and 2016 analyzed, statistical analysis the associated cyclone structures environments is performed using JRA-55 reanalysis. distributed sporadically around location within a window 10° × 10°. The difference tracks partially explains seasonal variability distribution tornadoes. highest number occur south centers, mainly warm sector, while few observed along cold front. Composite...
Abstract Convective available potential energy (CAPE) is known to lack skill in discussing the environments of tornadic and nontornadic storms, or those tornado outbreaks nonoutbreaks. In this paper, a composite analysis extratropical cyclones that caused 15 more tornadoes [outbreak (OCs)] 5 fewer [nonoutbreak (NOCs)] United States April May between 1995 2012 shows entraining-CAPE (E-CAPE), which considers effects entrainment environmental air, useful OCs NOCs. E-CAPE warm sector larger than...
Abstract To clarify the effects of horizontal shear jet stream on structure and environment extratropical cyclones that are accompanied by tornado outbreaks (OCs) those not (NOCs), two idealized numerical experiments performed. The (OC-CTL NOC-CTL) adopt basic states taken from corresponding composites reanalysis data (JRA-55), except humidity field in both cases is OC composite. simulated cyclone OC-CTL exhibits a more meridionally elongated stronger low-level wind southeast quadrant...
In this article, the global climatology of tornadoes and current understanding synoptic- meso-scale environments tornado outbreaks are reviewed. The study involves investigation atmospheric processes at global- to micro-scales has advanced multiscale processes. Global-scale circulation controls synoptic-scale such as extratropical cyclones, upper-level jets, anticyclonic circulation; affect mesoscale that cause severe thunderstorms tornadoes. Studies near-storm environment over decades have...
This study used the JRA-55 reanalysis dataset for analyzing structure and environment of extratropical cyclones (ECs) that spawned tornadoes (tornadic ECs: TECs) between 1961 2011 in Japan. Composite analysis findings indicated differences TECs, those ECs did not spawn (non-tornadic NTECs), vary with seasons. In spring (March–May), TECs are associated stronger upper-level potential vorticity colder mid-level temperature than NTECs. The air at mid level contributes to increase convective...
Abstract Strong gusty winds in a weak maritime extratropical cyclone (EC) over the Tsushima Strait southwestern Sea of Japan capsized several fishing boats on 1 September 2015. A C-band Doppler radar recorded spiral-shaped reflectivity pattern associated with convective system and velocity vortex diameter 30 km [meso- β -scale (MBV)] near location wreck. high-resolution numerical simulation horizontal grid interval 50 m successfully reproduced precipitation MBV tornado-like strong vortices...
The influence of an upper-level trough on a Baiu frontal depression (BFD) that caused heavy rainfall event in southern Kyushu, Japan, July 4, 2020, was examined using numerical simulations with and without the trough. simulation (CNTL) reproduced reasonable well-developed BFD Kyushu. Conversely, (NOUT) produced weaker notable southward shift compared situation CNTL. for NOUT due to convection than CNTL over mainland China. Thus, strong China essential formation development Additional...
In Part I of this study, the development processes Baiu frontal depressions (BFDs) have been examined through case-study numerical experiments. The simulations revealed that latent heating is dominant for BFDs in western part zone (W-BFDs), west approximately 140°E, while both and baroclinicity are important eastern (E-BFDs), east 140°E. idealized with zonally homogeneous basic fields conducted to obtain a more generalized perspective BFDs.
Abstract Tropical transition (TT) is a cyclogenesis process in which baroclinic disturbance transformed into tropical cyclone. Many studies have analyzed TT events over the North Atlantic. This study assesses processes from possible subtropical cyclone to Storm Kirogi at relatively high latitude western Pacific an environment of enhanced baroclinicity August 2012. Analyses based on satellite observations, JRA-55 reanalysis, and simulation with 2.5-km horizontal grid spacing demonstrate three...
Abstract The frontal structures of extratropical cyclones developing in the northwestern Pacific storm track are relatively poorly understood compared with those Europe and Atlantic Ocean, for which representative conceptual models have been developed. In this paper, their associated fronts (NP), as well Okhotsk Sea Japan (OJ), examined at mature stages using Japanese 55-year Reanalysis dataset. Furthermore, NP (NA). At time maximum deepening rate, accompanied by strong warm cold fronts,...
Abstract The structure and environment of extratropical cyclones around East Asia that are accompanied by split fronts (SFs), hereafter referred to as SF cyclones, examined using the Japanese 55‐year reanalysis dataset. SFs objectively automatically detected with a thermal front parameter equivalent potential temperature (). Previous statistical studies have shown dry intrusion in northern hemisphere occurs most frequently winter; however, occur more spring autumn. In winter, tend at lower...
This paper summarizes the current challenges in climate and weather research provides suggestions for future directions global observing systems, modelling prediction, academic environment education systems.
Abstract Baiu frontal depressions (BFDs) are the major cyclones that form and develop along baiu fronts. The structure environment of BFDs examined using Japanese 55-year Reanalysis dataset. detected automatically were categorized into four groups based on region where peaked: East China Sea (ES), off south coast islands (SC), Yellow (YS), Japan (SJ). A BFD-centered composite analysis demonstrates that, for YS-BFDs SJ-BFDs, compared to ES-BFDs SC-BFDs, strength upper-level troughs is...
Ensemble forecasts with 101 members, including one ensemble mean, using Kalman filter analysis were performed to understand the atmospheric conditions favorable for development of a meso-β-scale vortex (MBV) that caused shipwrecks as result sudden gusty winds in southwestern part Sea Japan on 1 September 2015. A composite was conducted reveal differences structure MBV and around between strongest 8 (STRG) weakest 10 (WEAK) members. Two ten members developed much earlier than other excluded...
Abstract The environmental characteristics and formation process of a tornado spawned by quasi-linear convective system (QLCS) over Kanto Plain, Japan, are examined using observations, reanalysis dataset, high-resolution numerical simulation with horizontal grid spacing 50 m. QLCS environment responsible for tornadogenesis was characterized small available potential energy large storm-relative helicity due to strong vertical shear associated low-level jet. jet zonal pressure gradient between...