A5103080779- Atmospheric aerosols and clouds
- Radioactive contamination and transfer
- Atmospheric chemistry and aerosols
- Radioactivity and Radon Measurements
- Aeolian processes and effects
- Meteorological Phenomena and Simulations
- Nuclear and radioactivity studies
- Climate variability and models
- earthquake and tectonic studies
- Seismology and Earthquake Studies
- Atmospheric and Environmental Gas Dynamics
- Solar Radiation and Photovoltaics
- Risk Perception and Management
- Geological formations and processes
- Air Quality and Health Impacts
- Radioactive element chemistry and processing
- Nuclear reactor physics and engineering
- Geology and Paleoclimatology Research
- Earthquake and Tsunami Effects
- Human Pose and Action Recognition
- Enhanced Oil Recovery Techniques
- Tropical and Extratropical Cyclones Research
- Wind and Air Flow Studies
- Graphite, nuclear technology, radiation studies
- Methane Hydrates and Related Phenomena
National Institute for Environmental Studies
2020-2024
The University of Tokyo
2014-2020
University of Washington Applied Physics Laboratory
2007-2010
University of Washington
2010
Kumamoto University
2008
The effect of cloud droplet sedimentation on the entrainment rate and liquid water path a nocturnal nondrizzling stratocumulus layer is examined using large‐eddy simulations (LES) with bulk microphysics. In agreement prior study by Ackerman et al. (2004), found to decrease thereby increase path. They suggested this due reduction boundary‐layer turbulence. Our suggest otherwise. Instead, reduces removing from zone. This inhibits two mechanisms that promote sinking entrained air into...
In marine stratocumulus‐capped boundary layers under strong inversions, the timescale for thermodynamic adjustment is roughly a day, much shorter than multiday inversion height adjustment. Slow‐manifold analysis introduced to exploit this separation when layer air columns experience only slow changes in their conditions. Its essence that structure of remains approximately slaved its and instantaneous conditions; determines entrainment rate hence evolution can be regarded as one‐dimensional...
In this study, a new method is proposed for the depiction of atmospheric transportation 137Cs emitted from Fukushima Daiichi Nuclear Power Station accident. This employs combination results two aerosol model ensembles and hourly observed concentration at surface level during 14–23 March 2011 90 sites in suspended particulate matter monitoring network. The elucidates accurate transport routes distribution surface-level relevant to eight plume events that were previously identified. ensemble...
Abstract A model intercomparison of the atmospheric dispersion cesium‐137 ( 137 Cs) emitted after Fukushima Daiichi Nuclear Power Plant accident in Japan was conducted to understand behavior Cs greater detail. The same meteorological data with a fine spatiotemporal resolution and an emission inventory were applied all models exclude differences among originating from data. used for initial, boundary, nudging or offline field. Furthermore, horizontal grid as that adopted models. This setup...
This study presents an intercomparison of single‐column model simulations a nocturnal heavily drizzling marine stratocumulus‐topped boundary layer. Initial conditions and forcings are based on flight observations off the coast California during DYCOMS‐II field experiment. Differences in turbulent microphysical parameterizations between models were isolated by slightly idealizing standardizing specification surface radiative fluxes. For most participating models, case was run at both typical...
Abstract. An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the and target domains are simulated single model, which includes fine meshes covering region to calculate meso-scale circulations. The stretched involves lower computational costs simulate atmospheric aerosols horizontal resolutions compared uniform whereas it may require higher general regional models, because calculates inside outside domain. As opposed requires...
The third model intercomparison project (MIP) for investigating the atmospheric behavior of caesium-137 (137Cs) emitted from Fukushima Daiichi Nuclear Power Plant (FDNPP) (3rd FDNPP-MIP), Japan, in March 2011, was conducted. A finer horizontal grid spacing (1 km) used than previous FDNPP-MIP (2nd FDNPP-MIP, Sato et al., 2018; 3 to evaluate models' performance high-concentration events measured near FDNPP. Nine models 2nd were also 3rd and all identical source terms meteorological fields....
Abstract The Weather Research and Forecasting (WRF) Model the Nonhydrostatic Icosahedral Atmospheric (NICAM) are forced with Global Forecast System (GFS) data run over United Arab Emirates (UAE) for two 4-day periods: one in cold season (16–18 December 2017) another warm (13–15 April 2018). models’ performance is evaluated against four observational datasets: weather station observations, eddy-covariance flux measurements at Al Ain, microwave radiometer–derived temperature profile,...
Abstract A nonhydrostatic stretched-grid (SG) model is used to analyze the large-scale errors generated by stretching horizontal grids and their influence on a region of interest. Simulations fully compressible, global atmospheric model, Nonhydrostatic Icosahedral Atmospheric Model (NICAM), its SG regional stretched-NICAM, were performed for months March, April, May 2011 using various resolutions factors. comparison week-long accumulative precipitation amounts between Tropical Rainfall...
A nonhydrostatic, regional climate limited-area model (LAM) was used to analyze lateral boundary condition (LBC) errors and their influence on the uncertainties of models. Simulations using fully compressible nonhydrostatic LAM (D-NICAM) were compared against corresponding global quasi-uniform-grid Nonhydrostatic Icosahedral Atmospheric Model (NICAM) a stretched-grid counterpart (S-NICAM). By this approach sharing same dynamical core physical schemes, possible causes bias LBC are isolated....
Abstract. The sensitivity of a stratocumulus-capped mixed layer to change in cloud droplet concentration is evaluated with large-eddy simulation (LES) and model (MLM). strength the second aerosol indirect effect simulated by two types agrees within 50% for cases which LES-simulated boundary remains well mixed, if MLM entrainment closure includes effects sedimentation. To achieve this agreement, parameters drizzle parameterization must be retuned match LES. This because LES advection scheme...
Abstract. Great efforts have been made to simulate atmospheric pollutants, but their spatial and temporal distributions are still highly uncertain. Observations can measure concentrations with high accuracy cannot estimate due the sporadic locations of sites. Here, we propose an ensemble method by applying a linear minimum variance estimation (LMVE) between multi-model (MME) simulations measurements derive more realistic distribution pollutants. The LMVE is classical basic version data...
The Fukushima Dai-ichi Nuclear Power Plant accidents following the March 11, 2011 Tohoku earthquake, and subsequent tsunami released radioactive materials into atmosphere caused significant public health concerns, particularly thyroid cancers in children. However, lack of measurement data for atmospheric concentrations 131I has persistent widespread uncertainty. This study estimated maximum potential doses inhaled early post-accident phase between 12 23, by using hourly measured 137Cs at 101...
The process of an aerosol rainout in wet deposition induces large uncertainties among atmospheric simulations, especially for particles the fine mode. In this study, we performed intercomparison study four different schemes on model (the nonhydrostatic icosahedral or NICAM) to simulate particulate Cs-137 emission scenario March 2011 accident at Fukushima Dai-ichi Nuclear Power Plant. include global climate models (GCMs) approach with a simple tuning parameter determine scavenging...
Abstract. An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the and target domains are simulated single model, which includes fine meshes covering region to calculate meso-scale circulations. The stretched involves relatively low computational costs simulate atmospheric aerosols horizontal resolutions compared uniform model. As opposed general regional models, neither nesting technique nor boundary conditions required. In this...
Abstract The computational balance between the model grid resolution and complexity of data assimilation technique is essential for accurate aerosol forecasting obtaining reanalysis sets. This study aimed to develop a high‐resolution system. A 2‐dimensional variational method (2DVar) was implemented in non‐hydrostatic icosahedral atmospheric (NICAM). new (NICAM/2DVar), with global size 56 km, assimilated observed optical depth (AOD) that estimated by combining multiple products geostationary...