A5020056749- Radioactive contamination and transfer
- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Radioactivity and Radon Measurements
- Atmospheric Ozone and Climate
- Isotope Analysis in Ecology
- Radioactive element chemistry and processing
- Nuclear and radioactivity studies
- Atmospheric and Environmental Gas Dynamics
- Groundwater and Isotope Geochemistry
- Toxic Organic Pollutants Impact
- Air Quality Monitoring and Forecasting
- Marine and coastal ecosystems
- Radiation Detection and Scintillator Technologies
- Soil and Water Nutrient Dynamics
- Methane Hydrates and Related Phenomena
- Vehicle emissions and performance
- Mercury impact and mitigation studies
- Hydrology and Watershed Management Studies
- Heavy metals in environment
- Smart Materials for Construction
- Particle Dynamics in Fluid Flows
- Oceanographic and Atmospheric Processes
- Environmental DNA in Biodiversity Studies
Kanazawa University
2006-2024
Meteorological Research Institute
2005-2021
Japan Meteorological Agency
2007-2021
Asia Center for Air Pollution Research
2010-2019
Japan Agency for Marine-Earth Science and Technology
2018
Niigata Institute of Technology
2015
Nagoya University
1999-2006
The emission, concentration levels, and transboundary transport of particulate polycyclic aromatic hydrocarbons (PAHs) in Northeast Asia were investigated using PAH measurements, the newly developed emission inventory (Regional Emission ASia for Persistent Organic Pollutants version, REAS-POP), chemical model Air Quality Model ver2 POPs RAQM2-POP). simulated concentrations nine PAHs agreed well with measured concentrations, results firmly established efficacy REAS/RAQM2-POP. It was found...
This article summarizes and discusses mass balance calculations of the activities Fukushima-derived 137Cs released to atmosphere ocean prior 2018 as well inventories on land in ocean, biota, sediment. We propose that consensus value total amount was 15-21 PBq; atmospheric deposition 3-6 North Pacific 12-15 direct discharge PBq. also evaluated movement from one domain another for several years after accident. calculated transported by rivers might be 40 TBq. The annual due resuspension at...
Abstract. A new aerosol chemical transport model, the Regional Air Quality Model 2 (RAQM2), was developed to simulate Asian air quality. We implemented a simple version of triple-moment modal dynamics model (MADMS) and achieved completely dynamic (non-equilibrium) solution gas-to-particle mass transfer over wide range diameters from 1 nm super-μm. To consider variety atmospheric properties, category approach utilized in which aerosols were distributed into four categories: particles Aitken...
Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from Tokyo Electric Power Company Fukushima Daiichi Nuclear Plant (FNPP1) accident. From end March early April 2011, extremely high activities were observed in coastal surface seawater near FNPP1. The spread a region 165°E western North Pacific Ocean, with latitudinal center 40°N. Atmospheric deposition also caused between 180° 130°W Ocean. inventory FNPP1-released Ocean...
The model performance of a regional-scale meteorology-chemistry (NHM-Chem) has been evaluated for the consistent predictions chemical, physical, and optical properties aerosols. These are essentially important accurate assessment air quality health hazards, contamination land ocean ecosystems, regional climate changes due to aerosol-cloud-radiation interaction processes. Currently, three optional methods available: five-category non-equilibrium method, three-category bulk equilibrium method....
Anthropogenic radionuclides were released into the world's oceans as a result of large-scale weapons testing in late 1950s and early 1960s. These anthropogenic have long lifetimes are still present today. The behavior long-lived is useful for seawater circulation global ocean.In this study, we focus on spatiotemporal variations 137Cs 90Sr activity concentrations surface vertical distributions. Most data included database, Historical Artificial radioactivity database Marine environment,...
Seasonal changes in the vertical structure of free tropospheric aerosols over east Asia, on basis aircraft‐borne and lidar measurements, pathway long‐range transport Asian dust particles inferred from isentropic trajectory analysis are discussed. Aircraft‐borne measurements held situ troposphere central Japan 2000–2001 revealed a small scale yet steady lower‐middle (2–6 km altitude) during spring including days with no evident outbreak. Such dust, found as background, was observed even...
We investigated spatial and temporal variations in 137Cs concentrations the surface waters of global ocean for period from 1957 to 2005 using "HAM database – a version". Based on 0.5-y average value water each sea area, we classified into four types. (1) In North Pacific Ocean where there was high fallout atmospheric nuclear weapons tests, rates decrease changed over five decades: rate 1950s 1970s much faster than that after 1970s, were almost constant 1990s. Latitudinal differences became...
Abstract. A regional-scale meteorology – chemistry model (NHM-Chem v1.0) has been developed. Three options for aerosol representations are currently available: the 5-category non-equilibrium (Aitken, soot-free accumulation, accumulation internally mixed with soot, dust, and sea-salt), 3-category coarse), bulk equilibrium (submicron, sea-salt) methods. These three methods suitable predictions of regional climate, air quality, operational forecasts, respectively. The total CPU times were 91 %...
Benzo[ a ]pyrene (BaP), polycyclic aromatic hydrocarbon in the air, triggers pulmonary inflammation. This study focused on BaP-induced inflammation alveolar epithelium. A549 cells were stimulated with BaP for four days. treatment markedly increased NLRP1 expression but slightly decreased NLRP3. Furthermore, aryl receptor (AhR) knockdown displayed no increase expression. Similar results also observed by blocking reactive oxygen species (ROS), which is mediated through AhR, suggesting that...
This study delved into the complex interplay between nanostructural characteristics of nanoparticles and their efficacy in surface-enhanced Raman scattering (SERS) for sensitive detection trace chemical substances. Silver were prepared SERS substrate by combining laser ablation, postannealing processes (up to 500 °C), electrostatic mobility classification, allowing high-purity silver with controlling sizes (40–100 nm) aggregate structures. These then inertially deposited on substrates create...
Abstract. This study investigated the spatio-temporal variations in activity concentrations Sea of Japan (SOJ) 137Cs and these transport process from North Pacific Ocean to SOJ through East China (ECS) during 2012–2016. The have been increasing since 2012–2013 reached a maximum 2015–2016 approximately 3.4 Bq m−3, more than twice pre-Fukushima accident concentration ∼1.5 m−3. 134Cs ∕ ratios ranged 0.36 0.51 2016. After taking into account radioactive decay ocean mixing, we concluded that were...
Since the 1980s, Japan has been affected by transboundary air pollution from Asian continent due to northwesterly seasonal winds in winter. However, after peaks 2006 and 2011/2012, sulfur dioxide (SO2) nitrogen oxide (NOx) emissions began decreasing, respectively. To assess biogeochemical response of forest ecosystems changing atmospheric deposition, flux observations rainfall outside canopies (RF), throughfall stemflow (TF + SF), stream water (SW) chemistry were conducted a Japanese cedar...
Abstract. This study provides comparisons of aerosol representation methods incorporated into a regional-scale nonhydrostatic meteorology–chemistry model (NHM-Chem). Three options for representations are currently available: the five-category non-equilibrium (Aitken, soot-free accumulation, soot-containing dust, and sea salt), three-category coarse), bulk equilibrium (submicron, salt) methods. The method is widely used in three-dimensional air quality models. method, standard NHM-Chem, an...
Abstract. We conducted a regional-scale simulation over Northeast Asia for the year 2006 using an aerosol chemical transport model, with time-varying lateral and upper boundary concentrations of gaseous species predicted by global stratospheric tropospheric chemistry-climate model. The present one-way nested global-through-regional-scale model is named Meteorological Research Institute–Passive-tracers Model system atmospheric Chemistry (MRI-PM/c). evaluated model's performance respect to...
The interactions of aerosol-radiation-stratification-turbulence-cloud processes during a severe haze event in Beijing January 2013 were studied using numerical model. For the clear days, solar radiation flux was reduced by approximately 15% and surface temperature slightly decreased from 0 to 0.5 K throughout day night, except for 1.4 decrease around sunrise when fog presented. longwave cooling intensified or drizzle droplets near top layer. Thus, Beijing, both daytime at air pollutants. In...
Seasonal intensive sampling was undertaken for two weeks during each of four seasons from May 2015 to February 2017 at Niigata-Maki station in Niigata, eastern Japan. Daily mean concentrations PM2.5 ranged 4.2 µg m–3 33.4 the observation period, which were lower than Japanese Environmental Quality Standard (35 m–3). The higher SO42−, NH4+ and OC observed spring summer, may result photochemical activity secondary production. major chemical components site NO3−, NH4+, OCM, EC crustal elements....