Yayoi Inomata

Asia Center for Air Pollution Research, Niahi-niigata, Niigata, Japan

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Publications (37)75.04 Total impact

  • Y. Inomata · M. Aoyama · T. Tsubono · D. Tsumune · K. Hirose
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    ABSTRACT: Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (FNPP1) accident. From the end of March to early April 2011, extremely high activities were observed in the coastal surface seawater near the FNPP1. The high activities spread to a region near 165°E in the western North Pacific Ocean, with a latitudinal center of 40°N. Atmospheric deposition also caused high activities in the region between 180° and 130°W in the North Pacific Ocean. The inventory of FNPP1-released (134)Cs in the North Pacific Ocean was estimated to be 15.3 ± 2.6 PBq. About half of this activity (8.4 ± 2.6 PBq) was found in the coastal region near the FNPP1. After 6 April 2011, when major direct releases ceased, the FNPP1-released (134)Cs in the coastal region decreased exponentially with an apparent half-time of about 4.2 ± 0.5 days and declined to about 2 ± 0.4 PBq by the middle of May 2011. Taking into account that the (134)Cs/(137)Cs activity ratio was about 1 just after release and was extremely uniform during the first month after the accident, the amount of (137)Cs released by the FNPP1 accident increased the North Pacific inventory of (137)Cs due to bomb testing during the 1950s and early 1960s by 20%.
    No preview · Article · Jan 2016 · Environmental Sciences: Processes and Impacts
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    ABSTRACT: We estimated the inventories of radiocaesium released by the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident to the North Pacific Ocean by using compiled data and model simulations. By comparing the observed inventories with model-simulated results, we obtained 12–15 PBq of 137Cs for the atmospheric deposition released by the FNPP1 accident in the North Pacific Ocean. Before the Fukushima accident, 137Cs activity in the North Pacific Ocean was about 69 PBq. Therefore, the 12–15 PBq of 137Cs newly added by atmospheric deposition together with the 3.5 ± 0.7 PBq added by direct discharge increased the total 137Cs inventory in the North Pacific Ocean by 22–27 %. We also estimated the total amount of 137Cs released to the atmosphere to be 15–20 PBq, and the total amount of 137Cs released to the environment to be 19–24 PBq, respectively. Observed 134Cs to 137Cs activity ratio at the time of accident was close to 1 and extremely uniform, therefore, the total amount of 134Cs deposition in the North Pacific Ocean, that of released to the atmosphere, that of direct discharge to the ocean and that of released to the environment were the same amounts as those of 137Cs.
    Full-text · Article · Nov 2015 · Journal of Oceanography
  • Y. Inomata · M Chiba · Y Igarashi · M Aoyama · K Hirose
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    ABSTRACT: 場所:東京大学弥生講堂,共催:文部科学省21世紀COE「環日本海域の環境計測と長期・短期変動予測」,大気環境学会
    No preview · Conference Paper · Jan 2015
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    ABSTRACT: In South East Asia an increase in emissions of sulfur (S) into the atmosphere may introduce new risks for the plant, soil and inland-water through acidification. However, the effect of the atmospheric S deposition on acidification by an increase in SO 4 2-is poorly understood in tropical forests with pedogenic and lithological S sources in the internal cycles. Sulfur isotopic ratio (δ34S) could be a good indicator to identify the source of SO 4 2-in soil and inland-water. Our objective is to clarify the contribution of atmospheric S deposition to S dynamics in the tropical forests by determining δ34S (‰) distribution from rainfall to stream water. Study catchments are lowland dipterocarp forest in Danum valley, Sabah (DNV), rehabilitation forest in Bintulu, Sarawak (BTL) and dry evergreen forest in Sakaerat, Nakhon Ratchasima (SKT). Anion-exchange-resin columns were installed in each site through a year (ca. 6-months × 2) to collect and concentrate SO 4 2-in the field. SO 4 2-retained in the resin was extracted by NaCl and precipitated as BaSO 4. We determined 34S / 32S of the BaSO4 by mass spectrometer and calculated δ34S (‰) using the reference material (Canyon Diablo Troilite). Annual weighted-mean δ34S was calculated from SO 4 2-fluxes (kg ha-1 6-month-1) and δ34S in each period. Annual weighted-mean δ34S in rainfall were 10.1, 7.9 and 4.1‰ in DNV, BTL and SKT respectively, whereas S depositions were 2.6, 6.1 and 6.4 kg ha-1 year-1. The δ34S vertically decreased from rainfall to subsoil in DNV although δ34S increased in subsoil in BTL. In DNV and BTL arithmetic mean δ34S in streamwater were lower than that in rainfall, which implied the existence of pedogenic or lithological S source. Those internalS sources should be considered to examine the effect of atmospheric deposition on soil and inland-water ecosystems in this area. Acknowledgements The project is supported by the grant from APN (ARCP2012-18NMY-Sase:
    Full-text · Conference Paper · Dec 2014
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    ABSTRACT: We investigated the distribution in seawater of anthropogenic radionuclides from the Fukushima Daiichi Nuclear Power Plant (FNPP1) as preliminary attempt using a rapid aerial radiological survey performed by the U.S. Department of Energy National Nuclear Security Administration on 18 April 2011. We found strong correlations between in-situ activities of 131I, 134Cs, and 137Cs measured in surface seawater samples and gamma-ray peak count rates determined by the aerial survey (correlation coefficients were 0.89 for 131I, 0.96 for134Cs, and 0.92 for137Cs). The offshore area of high radionuclide activity extended south and southeast from the FNPP1. The maximum activities of 131I, 134Cs, and 137Cs were 329, 650, and 599 Bq L−1, respectively. The 131I/137Cs ratio in surface water of the high-activity area ranged from 0.6 to 0.7. Considering the radioactive decay of 131I (half-life 8.02 d), we determined that the radionuclides in this area were directly released from FNPP1 to the ocean. We confirm that aerial radiological surveys can be effective for investigating the surface distribution of anthropogenic radionuclides in seawater. Our model reproduced the distribution pattern of radionuclides derived from the FNPP1, although results simulated by a regional ocean model were underestimated.
    Full-text · Article · May 2014 · Journal of Nuclear Science and Technology
  • Mizuo Kajino · Keiichi Sato · Yayoi Inomata · Hiromasa Ueda
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    ABSTRACT: We conducted a source-receptor relationship (SRR) analysis of the total deposition of nitrate (TDN; dry + wet, gas + aerosol) in Northeast Asia using an aerosol chemical transport model. Six regions were included in the study: North China, Central China, South China, South Korea, Japan, and Ocean. More than 95% of the TDN across China consisted of contributions from Chinese emissions. The largest intra-regional contributions and the second largest contributions were attributed to the Central China region. The contribution of the three China regions accounted for approximately 50-60% of the TDN in South Korea and Japan and 75% of the TDN in the Ocean region, respectively. The spatial distributions of the SRR indicated that the sub-regional high was more than twice the regional averages of the TDN. We also investigated the effects of sea salt on the transport and deposition of nitrate. During the long-range transport from the Asian continent over the ocean, nitric acid gas condenses on sea-salt particles to form NaNO3. The presence of sea-salt particles increased the TDN over the downwind regions of the Asian continent by approximately 10-25% in South Korea and Japan and by up to 40% in the Ocean region. However, the sea-salt effects on the SRR of the TDN were small (the absolute differences were smaller than approximately 10%).
    No preview · Article · Nov 2013 · Atmospheric Environment
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    ABSTRACT: We analyzed the source-receptor relationships for particulate polycyclic aromatic hydrocarbon (PAH) concentrations in northeastern Asia using an aerosol chemical transport model. The model successfully simulated the observed concentrations. In Beijing (China) benzo[a]pyren (BaP) concentrations are due to emissions from its own domain. In Noto, Oki and Tsushima (Japan), transboundary transport from northern China (>40°N, 40-60%) and central China (30-40°N, 10-40%) largely influences BaP concentrations from winter to spring, whereas the relative contribution from central China is dominant (90%) in Hedo. In the summer, the contribution from Japanese domestic sources increases (40-80%) at the 4 sites. Contributions from Japan and Russia are additional source of BaP over the northwestern Pacific Ocean in summer. The contribution rates for the concentrations from each domain are different among PAH species depending on their particulate phase oxidation rates. Reaction with O3 on particulate surfaces may be an important component of the PAH oxidation processes.
    No preview · Article · Aug 2013 · Environmental Pollution
  • Tetsu Sakai · Tomohiro Nagai · Yuzo Mano · Yuji Zaizen · Yayoi Inomata
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    ABSTRACT: Collocated and simultaneous measurements of aerosols near the ground were conducted using a lidar and aerosol sampler at Tsukuba, Japan, to clarify the relationship between lidar-derived optical properties and in-situ microphysical properties. The total linear particle depolarization ratio (δp) ranged from 14% to 18% when nonspherical mineral dust particles were predominant in the supermicrometer range on May 7–8, 2008, whereas it ranged from 6% to 7% when spherical sea-salt particles were predominant in that range on September 3–4, 2008. Sulfates and nitrates were predominant in the submicrometer range for these two periods. Water-dialysis analysis on May 6–7 indicated that 29% of the coarse particles were water insoluble, whereas 70% were water soluble or nearly soluble on September 3–4. The ratio of dry mass concentration to the backscattering coefficient (M/βp) was 34–39 g m−2 sr on May 7–8 and 6.2–6.3 g m−2 sr on September 3–4. Our results provide evidence that lidar-derived βp and δp capture the aerosol mass concentration and relative abundance of the spherical and nonspherical particles although the microphysical properties vary significantly for individual particles.
    No preview · Article · Dec 2012 · Atmospheric Environment
  • Y Inomata · M Aoyama · D Tsumune · T Motoi · H Nakano
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    ABSTRACT: (137)Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of (137)Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of (137)Cs that revealed the basin-scale circulation of (137)Cs in surface seawater in the North Pacific Ocean: (137)Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, (137)Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre.
    No preview · Article · Nov 2012 · Journal of Environmental Monitoring
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    M. Kajino · M. Deushi · T. Maki · N. Oshima · Y. Inomata · K. Sato · T. Ohizumi · H. Ueda
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    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 a global stratospheric and tropospheric chemistry-climate model. The present one-way nested global-through-regional-scale model is named the Meteorological Research Institute-Passive-tracers Model system for atmospheric Chemistry (MRI-PM/c). We evaluated the model's performance with respect to the major anthropogenic and natural inorganic components, SO42-, NH4+, NO3-, Na+ and Ca2+ in the air, rain and snow measured at the Acid Deposition Monitoring Network in East Asia (EANET) stations. Statistical analysis showed that approximately 40-50 % and 70-80 % of simulated concentration and wet deposition of SO42-, NH4+, NO3-and Ca2+ are within factors of 2 and 5 of the observations, respectively. The prediction of the sea-salt originated component Na+ was not successful at near-coastal stations (where the distance from the coast ranged from 150 to 700 m), because the model grid resolution (Δx=60 km) is too coarse to resolve it. The simulated Na+ in precipitation was significantly underestimated by up to a factor of 30.
    Preview · Article · Nov 2012 · Geoscientific Model Development
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    M. Kajino · M. Deushi · T. Maki · N. Oshima · Y. Inomata · K. Sato · T. Ohizumi · H. Ueda
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    ABSTRACT: We conducted a regional-scale simulation (with grid spacing = 60 km) over Northeast Asia for the entire year of 2006 by using an aerosol chemical transport model, the lateral and upper boundary concentrations of which we predicted with a global stratospheric and tropospheric chemistry-climate model, with a horizontal resolution of T42 (grid spacing ~300 km) and a time resolution of 1 h. The present one-way nested global-through-regional-scale model is called the Meteorological Research Institute - Passive-tracers Model system for atmospheric Chemistry (MRI-PM/c). We evaluated the model performance with respect to the major inorganic components in rain and snow measured by stations of the Acid Deposition Monitoring Network in East Asia (EANET). Through statistical analysis, we show that the model successfully reproduced the regional-scale processes of emission, transport, transformation, and wet deposition of major inorganic species derived from anthropogenic and natural sources, including SO42-, NH4+, NO3-, Na+ and Ca2+. Interestingly, the only exception was Na+ in precipitation at near-coastal stations (where the distance from the coast was from 150 to 700 m), concentrations of which were significantly underestimated by the model, by up to a factor of 30. This result suggested that the contribution of short-lived, super-large sea salt droplets (SLSD; D > 10-100 μm) was substantial in precipitation samples at stations near the coast of Japan; thus samples were horizontally representative only within the traveling distances of SLSD (from 1 to 10 km). Nevertheless, the calculated effect of SLSD on precipitation pH was very low, a change of about +0.014 on average, even if the ratio of SLSD to all sea salt in precipitation was assumed to be 90%.
    Preview · Article · Jun 2012 · Geoscientific Model Development Discussions
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    ABSTRACT: A new aerosol chemical transport model, the Regional Air Quality Model 2 (RAQM2), was developed to simulate the Asian air quality. We implemented a simple version of a triple-moment modal aerosol dynamics model (MADMS) and achieved a completely dynamic (nonequilibrium) solution of a gas-to-particle mass transfer over a wide range of aerosol diameters from 1 nm to super-μm. To consider a variety of atmospheric aerosol properties, a category approach was utilized in which the aerosols were distributed into four categories: particles in the Aitken mode (ATK), soot-free particles in the accumulation mode (ACM), soot aggregates (AGR), and particles in the coarse mode (COR). The aerosol size distribution in each category is characterized by a single mode. The condensation, evaporation, and Brownian coagulations for each mode were solved dynamically. A regional-scale simulation (1x = 60 km) was performed for the entire year of 2006 covering the Northeast Asian region. The modeled PM1/bulk ratios of the chemical components were consistent with observations, indicating that the simulated aerosol mixing types were consistent with those in nature. The non–sea-salt SO42− mixed with ATK + ACM was the largest at Hedo in summer, whereas the SO42− was substantially mixed with AGR in the cold seasons. Ninety-eight percent of the modeled NO3− was mixed with sea salt at Hedo, whereas 53.7% of the NO3− was mixed with sea salt at Gosan, which is located upwind toward the Asian continent. The condensation of HNO3 onto sea salt particles during transport over the ocean accounts for the difference in the NO3− mixing type at the two sites. Because the aerosol mixing type alters the optical properties and cloud condensation nuclei activity, its accurate prediction and evaluation are indispensable for aerosol-cloud-radiation interaction studies.
    Full-text · Article · May 2012 · Atmospheric Chemistry and Physics
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    ABSTRACT: The emission, concentration levels, and transboundary transport of particulate polycyclic aromatic hydrocarbons (PAHs) in Northeast Asia were investigated using particulate PAH measurements, the newly developed emission inventory (Regional Emission inventory in ASia for Persistent Organic Pollutants version, REAS-POP), and the chemical transport model (Regional Air Quality Model ver2 for POPs version, RAQM2-POP). The simulated concentrations of the nine particulate PAHs agreed well with the measured concentrations, and the results firmly established the efficacy of REAS/RAQM2-POP. It was found that the PAH concentrations in Beijing (China, source region), which were emitted predominantly from domestic coal, domestic biofuel, and other transformations of coal (including coke production), were approximately 2 orders of magnitude greater than those monitored at Noto (Japan, leeward region). In Noto, the PAH concentrations showed seasonal variations; the PAH concentrations were high from winter to spring due to contributions from domestic coal, domestic biofuel, and other transformations of coal, and low in summer. In summer, these contribution were decrease, instead, other sources, such as the on-road mobile source, were relatively increased compared with those in winter. These seasonal variations were due to seasonal variations in emissions from China, as well as transboundary transport across the Asian continent associated with meteorological conditions.
    Full-text · Article · Mar 2012 · Environmental Science & Technology
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    ABSTRACT: We developed a new emission inventory for polycyclic aromatic hydrocarbons (9PAHs; fluorene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene) in ASia (Regional Emission inventory in Asia for POP version, REAS-POP) at 0.5x0.5 grid for the period from 2000 to 2005. By using the REAS-POP, spatial distributions of PAHs in East Asia were simulated by Regional Air Quality Model for POP version (RAQM-POP). In REAS-POP, estimated annual emission of 9PAHs in East Asia was increased from 7.61 Gg yr-1 in 2000 to 10.79 Gg yr-1 in 2005. The China is the dominant PAHs emission country in East Asia during this period. Area where considerable high emissions as well as rapid increase rate was found in the northern central region, North China Plain, Guizhou, Sichuan Basin, and North East in China. The contribution from various sources for PAHs emission was different by each country. In the developing country (China, Democratic People's Republic of Korea, Mongolia, and Russia), dominant sources of PAHs were domestic coal, domestic biofuel, and other transformation of coal including cokes production, although contribution from open biomass burning was relatively large in Russia and Mongol. In Japan and Taiwan, the road traffic source was identified as the major source for the 9PAHs emissions. At Beijing, China, simulated PAHs concentrations were quantitatively agreed with the measured concentrations during the period from 8 March to 26 May, 2005. In the case of Wajima, coastal site of the Sea of Japan in Japan, it was observed clear seasonal variation with high concentrations in winter and low concentrations in summer in 2005. The measured seasonal variations were also simulated well. Results with analysis by model simulation revealed that higher concentrations in winter were due to the high emission in China in winter and long-range transport from the Asian continent toward the Japanese islands. In summer, the lower concentrations result in lower emission in China and prevent of long-range transport of PAHs under the Pacific high. The geographical distributions of PAHs emission and concentration suggest that seasonal variation of PAHs concentrations observed at Wajima were strongly controlled by emission strength and meteorological conditions.
    No preview · Article · Dec 2011
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    ABSTRACT: Aerosol number concentrations were continuously measured at sites at Tsukuba and Mt. Haruna on the Kanto region of Japan by using optical particle counters (OPCs) from February to June 2007. Three specific dust events captured at the sites were analyzed by using lidar, backward trajectories, and model simulation in detail. The temporal variations in aerosol concentrations in the two Asian-dust events (K1 event: 31 March–3 April; K2 event: 25–28 May) were similar. Dust particles (≥2.0 μm in diameter) were transported in association with a synoptic-scale cold front, and they arrived at the Tsukuba site about 8 h after they were observed at the Mt. Haruna site, in association with the dissipation of a local front formed ahead of the cold front. However, the inflow patterns of dust particles differed between the K1 and K2 events. The K1 event flowed onto the Kanto Plain, detouring around the mountainous region, whereas the K2 event directly flowed across the mountains. The difference in inflow pattern was probably due to the blocking effects of the mountains and the formation of a stable layer near the surface. Preceding the dust plume arrival, an increase in the number concentration of small-aerosol particles (0.3–1.0 μm in diameter), which are considered to be spherical by lidar, was observed, but only at the Tsukuba site. This increase was possibly due to anthropogenic pollution transported over long distances from the continent and from domestic sources in the Kanto region. The third event was a local dust event, because it was observed only at the Tsukuba site (on 13 and 14 March) under dry conditions (10 m s−1).
    Full-text · Article · Aug 2011 · Atmospheric Environment
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    ABSTRACT: As a part of the effort to understand the structure of long-range transported aerosol plumes and local pollution, aerosol observations monitored the mass concentrations and number-size distributions during the period August 2006 to July 2009 near the top of Mt. Haruna (1365 m), an isolated mountain in the Kanto Plain in Japan. The mass concentrations observed at Mt. Haruna and plain sites showed a seasonal variation with a maximum in spring and summer, respectively. The spring peaks in aerosols at Mt. Haruna were probably caused by long-range transport of mineral dust and anthropogenic particles from the Asian continent. The summer peaks at the plain sites was attributed to local pollution from the Tokyo metropolitan area. Three examples of 2007 Asian dust events were investigated to show that aerosols may be dispersed in a complicated three-dimensional structure and that delayed arrivals of the dust plumes at plain sites compared to Mt. Haruna were not a rare case. Because of the boundary layer being stable at night, the dust layer was advected eastward without the vertical mixing before sunrise. This study suggests that after thermal convection activated by sunlight during daytime Asian dust transported in the free troposphere may be brought down into the atmospheric boundary layer, increasing the dust concentration there.
    Full-text · Article · Nov 2010 · Atmospheric Environment
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    ABSTRACT: Concentrations of 222Rn were observed at the summit of Mt. Fuji (35.4°N, 138.7°E; 3776 m above sea level) in Japan from October 2002 to September 2003. These observations were analyzed using a global three-dimensional model. Daily 222Rn concentrations varied from 0.2 to 2.5 Bq m−3. The variation exhibited a slight seasonal cycle with high values in winter and summer. Day-to-day variation of 222Rn concentrations in winter had a large amplitude, depending on differences in transport processes from the Asian continent. In winter, higher concentrations of 222Rn were observed in an air mass with ascending motion advected from the middle latitudes of the eastern Asian continent where the 222Rn concentration of the air mass was high. In contrast, a lower concentration was observed in the air mass in winter, with a descending motion advected from Siberia where the 222Rn amount was low. The high amplitude of temporal variation of 222Rn in summer was due to the alternation of air masses originated from the continent or the ocean. The relatively low amplitude of day-to-day variation during spring and autumn was a reflection of the vertically uniform distribution of 222Rn in the air column over the Asian continent, where uniformity was produced by vertical mixing due to turbulence and thermal convection. The seasonal variation was linked to the East Asian monsoon circulation, with the westerly jet shifted northward or southward depending on the season. The main export of 222Rn was around 25 to 55°N during the winter and into the spring, shifting northward to around 30–70°N during the summer.
    Full-text · Article · Oct 2010 · Atmospheric Environment
  • Yayoi Inomata

    No preview · Chapter · Jun 2010
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    ABSTRACT: Both wet and dry deposition fluxes of Aeolian dust were analyzed for over one year (from March 2007 to May 2008) including two dust seasons in Tsukuba, Japan. The annual wet and dry deposition fluxes of dust were 5.5 g m-2 and 3.8 g m-2, respectively. The largest wet deposition flux associated with the one heavy Asian dust event was 0.95 g m-2, which accounted for 10% to the annual total deposition. A typical feature of the deposition fluxes marked seasonal variation with higher deposition in spring. Furthermore, the wet deposition fluxes in the spring (March-May) 2007 were larger than those in 2008. The temporal variations of wet depositions were agreed well with the model simulation. Analysis of model simulation showed that the seasonal and year to year variations of the wet deposition fluxes in Tsukuba could be closely connected with the variation of dust emission over the Asian continent associated with stronger wind. For dry deposition fluxes of dust, local dust near the observation region also contributed to the deposition fluxes in addition to the Asian dust.
    Full-text · Article · Oct 2009 · Scientific online letters on the atmosphere: SOLA
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    K Hirose · Y Igarashi · M Aoyama · Y Inomata
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    ABSTRACT: Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.
    Full-text · Article · Oct 2009 · Journal of Environmental Radioactivity

Publication Stats

296 Citations
75.04 Total Impact Points

Institutions

  • 2010-2014
    • Asia Center for Air Pollution Research
      Niahi-niigata, Niigata, Japan
  • 2007-2011
    • Meteorological Research Institute, Japan Meteorological Agency
      Ibaragi, Ōsaka, Japan
  • 2006
    • Kanazawa University
      Kanazawa, Ishikawa, Japan
  • 2000-2006
    • Nagoya University
      • • Solar-Terrestrial Environment Laboratory
      • • Graduate School of Environmental Studies
      Nagoya, Aichi, Japan