Toyama Prefectural Environmental Science Research Center

Imizu, Japan

Toyama Prefectural Environmental Science Research Center

Imizu, Japan

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Kemmei T.,Toyama Institute of Health | Kodama S.,Toyama Institute of Health | Fujishima H.,Toyama Prefectural Environmental Science Research Center | Yamamoto A.,Chubu University | And 2 more authors.
Analytica Chimica Acta | Year: 2012

The chelating agent EDTA is widely used, and as a result is showing up widely in the aquatic environment. Here we describe a preconcentration procedure for measuring EDTA concentration in sea water samples by HPLC. The procedure consists of forming an Fe(III) complex followed by solid-phase extraction using an activated carbon cartridge. After the preconcentration, EDTA was quantified by HPLC with ultraviolet detection (260. nm). The enrichment permitted the determination of EDTA at concentrations as low as 1. nM. Good recoveries were obtained for both brackish and full-strength sea water with high repeatability (RSD < 6%). The method was applied to sea water samples taken from near the mouth of the Oyabe River in Japan. © 2011 Elsevier B.V.


Osada K.,Nagoya University | Shido Y.,Nagoya University | Iida H.,Tateyama Caldera SABO Museum | Kido M.,Toyama Prefectural Environmental Science Research Center
Atmospheric Environment | Year: 2010

Atmospheric deposition is an important removal process of aerosol particles and gases from the atmosphere. To elucidate the relative contributions of wet and dry processes and in-cloud and below-cloud scavenging based on deposition amounts in winter at Mt. Tateyama, central Japan, we obtained daily samples (December, 2006-March, 2007) of size-segregated aerosol particles and precipitation at Senjyugahara (SJ; 475 m a.s.l.) and vertical samples of spring snow cover at Murododaira (MR, 2450 m a.s.l., 13 km distance from SJ) on the western flank of Mt. Tateyama. The NH 4 + and nssSO 4 2- in aerosols were mostly found in the fine fraction (<2 μm), although Na +, NO 3 -, and nssCa 2+ were mainly detected in the coarse fraction (>2 μm). Average ionic concentrations (μg g -1) in precipitation at SJ were higher about 3.8 for Na + and nssCa 2+, 3.4 for NO 3 -, 3.7 for NH 4 +, 2.5 for nssSO 4 2- than those at MR, whereas cumulative precipitation amounts at SJ and MR were, respectively, 84 and 175 cm of water equivalent. Wet and dry deposition amounts during the study period were estimated for sites using size-segregated aerosol data, winter averages of HNO 3, NH 3, and SO 2 concentrations, and dry deposition velocities. Particle-dry deposition comprised about 3% (Na +) to 11% (NH 4 +) of the total deposition at MR. The maximum amounts of gas dry deposition were estimated, respectively, as 4, 13, and 3% of the total deposition at MR for NH 4 +, NO 3 -, and nssSO 4 2-. The relative contributions of below-cloud scavenging (BCS) between MR and SJ were estimated as considering the wet only deposition amount at MR. Higher contributions of BCS were obtained for Na + (56%) and nssCa 2+ (45%), whereas BCSs for NH 4 +, NO 3 -, and nssSO 4 2- were lower than 28%. Ionic constituents existing predominantly in the coarse fraction showed a large contribution of BCS. © 2009 Elsevier Ltd. All rights reserved.


Yamashita Y.,University of Toyama | Kawamura R.,University of Toyama | Iizuka S.,Japan National Research Institute for Earth Science and Disaster Prevention | Hatsushika H.,Toyama Prefectural Environmental Science Research Center
Journal of the Meteorological Society of Japan | Year: 2012

The activity of explosively developing extratropical cyclones in the vicinity of Japan in intimate association with the occurrence of heavy snowfall on the Japan Sea side of central Japan is examined using Japanese long-term reanalysis projected data (JRA-25), with additional data from the Japan Meteorological Agency climate data assimilation system (JCDAS). On a monthly basis, the explosive extratropical cyclone tracks tend to concentrate around the Kuroshio Current off the Pacific coast of Japan and the Japan Sea at the heavy snowfall phase, whereas the tracks disperse over the broader areas in the light snowfall phase. The heavy and light snowfall phases correspond well to the strong and weak phases of the East Asian winter monsoon circulation respectively, and the monsoon variability influences the local monthly snowfall on the Japan Sea side of central Japan through change in the explosive cyclone activity. On a daily basis, stationary Rossby wave packets propagating eastward along the northern Eurasian and South Asian waveguides, i.e., subpolar and subtropical teleconnection types, contribute to the occurrence of extraordinarily heavy snowfall events through the development of explosive cyclones. The subpolar teleconnection type facilitates not only the intensification and southward migration of a cold continental high in East Asia, but also the rapid growth of an explosive cyclone around Japan by inducing the equatorward advection of higher potential vorticity from high latitudes. Both developments lead to the reinforcement of an east-west gradient in sea level pressure (SLP) across Japan, thereby providing a favorable condition for the heavy snowfall events. For the subtropical teleconnection type, the explosive cyclone system is primarily responsible for the occurrence of extremely heavy snowfall events through enhanced zonal SLP gradient. It is also found that the explosive cyclone activity differs in terms of geographical location and track between the subpolar and subtropical teleconnection types. © 2012, Meteorological Society of Japan.


Shiota M.,University of Toyama | Kawamura R.,University of Toyama | Hatsushika H.,Toyama Prefectural Environmental Science Research Center | Iizuka S.,Japan National Research Institute for Earth Science and Disaster Prevention
Scientific Online Letters on the Atmosphere | Year: 2011

Using data from the Japanese long-term Re-Analysis project (JRA-25) and the Japan Meteorological Agency Climate Data Assimilation System (JCDAS), we examined how the East Asian winter monsoon variability regulates the surface cyclogenesis in the vicinity of the East China Sea and the Kuroshio Current in late winter. On a monthly basis, the surface cyclone occurrence has a tendency to concentrate over the East China Sea at the strong phase of the East Asian winter monsoon activity, while it disperses zonally along the Kuroshio Current to the south of Japan in the weak monsoon phase. The scatteredness of the surface cyclogenesis are mainly attributed to the change in the lowertropospheric baroclinicity between the strong and weak monsoon phases. It is also suggested that, when the monsoon is strong, the enhanced baroclinic zone along the Kuroshio Current south of Japan provides a favorable condition for the rapid development of the surface cyclones that originate over the East China Sea and migrate northeastward. © 2011, the Meteorological Society of Japan.


Iizuka S.,Japan National Research Institute for Earth Science and Disaster Prevention | Shiota M.,Japan Meteorological Agency | Kawamura R.,Kyushu University | Hatsushika H.,Toyama Prefectural Environmental Science Research Center
Scientific Online Letters on the Atmosphere | Year: 2013

The possible impact of the winter monsoon intensity and sea surface temperature (SST) gradient on the activity of explosively developing extratropical cyclones around Japan is investigated using the Weather Research Forecasting model. Two independent long-term integrations over 18 winters from 1993/94 to 2010/2011 are conducted using prescribed observed SST data (OS run) and spatially smoothed data (SS run). The OS run is successful in reproducing the spatial distributions of the explosive cyclone activity in the vicinity of Japan under both strong and weak winter monsoon conditions. Under strong monsoon conditions, the Kuroshio, the Kuroshio Extension, and the Japan Sea subpolar fronts give rise to enhanced near-surface baroclinicity through the increase in heat and moisture fluxes from the ocean surface, resulting in frequent occurrence of the explosive cyclone activity along those fronts. © 2013, the Meteorological Society of Japan.


Shimizu A.,Japan National Institute of Environmental Studies | Sugimoto N.,Japan National Institute of Environmental Studies | Matsui I.,Japan National Institute of Environmental Studies | Mori I.,Japan National Institute of Environmental Studies | And 2 more authors.
Scientific Online Letters on the Atmosphere | Year: 2011

Dust extinction coefficients near the ground surface, based on National Institute for Environmental Studies lidar network measurements, were directly compared with mass densities measured simultaneously by filter sampling during several heavy dust events in Japan. The ratio between them varied from 0.5 to 2 g m -1, and depended more on the observatory, than on the dust event being observed. This variation could not be accounted for by the change in particle size distribution during long-distance transport from the source region to Japan, but internal mixing of dust with spherical particles might explain the observed results. © 2011, the Meteorological Society of Japan.


Kawase H.,Japan Agency for Marine - Earth Science and Technology | Yoshikane T.,Japan Agency for Marine - Earth Science and Technology | Hara M.,Japan Agency for Marine - Earth Science and Technology | Fujita M.,Japan Agency for Marine - Earth Science and Technology | And 3 more authors.
Scientific Online Letters on the Atmosphere | Year: 2012

We focus on the dramatic decrease in the snow cover on the Japan Sea side of Central Japan in the late 20th century. Using a regional climate model, a control experiment (CTL) was conducted, and it accurately simulated the dramatic decrease in maximum snow depth (SNDmax) between the 1980s and the 1990s. We then conducted a pseudo climate simulation (PCS) in the 1990s, which assumes the mean atmospheric fields in the 1990s and the perturbation from the mean atmospheric fields in the 1980s. The PCS method is expected to evaluate only the impacts of changes in the mean atmospheric fields on the snow cover changes. The PCS simulates the decreases in SNDmax over the coastal area, which are comparable to the changes simulated by the CTL. On the other hand, changes in SNDmax are negligible in the PCS over the mountainous area, where the slight increases in SNDmax are simulated by the CTL. Therefore, the changes in the mean atmospheric fields, especially, the mean temperature rise, are main factors of the snow cover decrease over the coastal area, while changes in both the mean atmospheric fields and the perturbation contribute to the snow cover changes over the mountainous area. © 2012, the Meteorological Society of Japan.


Kawase H.,Japan Agency for Marine - Earth Science and Technology | Hara M.,Japan Agency for Marine - Earth Science and Technology | Yoshikane T.,Japan Agency for Marine - Earth Science and Technology | Ishizaki N.N.,Japan Agency for Marine - Earth Science and Technology | And 3 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2013

The Sea of Japan side of Central Japan is one of the heaviest snowfall areas in the world. We investigate near-future snow cover changes on the Sea of Japan side using a regional climate model. We perform the pseudo global warming (PGW) downscaling based on the five global climate models (GCMs). The changes in snow cover strongly depend on the elevation; decrease in the ratios of snow cover is larger in the lower elevations. The decrease ratios of the maximum accumulated snowfall in the short term, such as 1 day, are smaller than those in the long term, such as 1 week. We conduct the PGW experiments focusing on specific periods when a 2 K warming at 850 hPa is projected by the individual GCMs (PGW-2K85). The PGW-2K85 experiments show different changes in precipitation, resulting in snow cover changes in spite of similar warming conditions. Simplified sensitivity experiments that assume homogenous warming of the atmosphere (2 K) and the sea surface show that the altitude dependency of snow cover changes is similar to that in the PGW-2K85 experiments, while the uncertainty of changes in the sea surface temperature influences the snow cover changes both in the lower and higher elevations. The decrease in snowfall is, however, underestimated in the simplified sensitivity experiments as compared with the PGW experiments. Most GCMs project an increase in dry static stability and some GCMs project an anticyclonic anomaly over Central Japan, indicating the inhibition of precipitation, including snowfall, in the PGW experiments. Key Points Dynamical downscaling of snow cover changes using a regional climate model Snow cover changes around the complex terrain on the Sea of Japan side Impact of sea surface temperature and atmospheric circulation changes on snow ©2013. American Geophysical Union. All Rights Reserved.


Shibata Y.,University of Toyama | Kawamura R.,University of Toyama | Hatsushika H.,Toyama Prefectural Environmental Science Research Center
Journal of the Meteorological Society of Japan | Year: 2010

The relationships between large-scale circulation and foehns observed during midsummer in Hokuriku district, located on the Japan Sea side of central Japan, are examined using Japanese long-term reanalysis project data, with additional data from the Japan Meteorological Agency climate data assimilation system. All foehn events are classified into two types: a tropical cyclone (TC)-induced foehn and an extratropical cyclone (EC)- induced foehn. The occurrence of the TC type is attributed to a combination of a typhoon and its induced teleconnection pattern, the Pacific-Japan (PJ) pattern, in the lower troposphere. Local intensification of the North Pacific high just east of Japan, accompanied by the dominance of the PJ pattern, can in turn force a typhoon track to shift westward. The northward migration of the typhoon along the western periphery of the locally enhanced high strengthens a zonal pressure gradient across central Japan, thus producing a foehn. In contrast, an upper-level teleconnection along the Asian jet serves as a prominent trigger of the occurrence of an EC-type foehn. Stationary Rossby wave packets propagating eastward along the upper-level Asian waveguide facilitate not only the westward development of the North Pacific high but also the development of an extratropical cyclone in the vicinity of the Japan Sea by leading to the equatorward advection of higher potential vorticity from high latitudes. Both developments are crucial for the reinforcement of a northwest-southeast pressure gradient in the lower troposphere around Japan, thus providing a favorable condition for a foehn event. © 2010,Meteorological Society of Japan.


Yoshikane T.,Japan Agency for Marine - Earth Science and Technology | Hatsushika H.,Toyama Prefectural Environmental Science Research Center | Kawase H.,Japan Agency for Marine - Earth Science and Technology | Suzuki C.,Japan Agency for Marine - Earth Science and Technology | And 2 more authors.
Scientific Online Letters on the Atmosphere | Year: 2014

The peaks of the appearance frequency of the surface air temperature during precipitation are clearly observed near the melting point of water on the Toyama Plain during the winter monsoon. The peaks could be explained by the hypothesis that the melting of snowfall is the primary cause of the cooling on the Toyama Plain. To verify this hypothesis, we investigated the relation of temperature between the inland and the coast using observed data in January from 1990 to 2009 and applied a simple estimation method of the cooling due to the melting of snowfall. The temperature on the Toyama Plain tends to remain around the melting point when the surface air temperature on the coast is higher than 273.15 K and lower than 277.15 K, which almost corresponds to the changeover from snowfall to rainfall. The relation is unclear when hardly any precipitation is observed. The simply estimated cooling by the melting of snowfall using the observed precipitation can also represents the cooling on the Toyama Plain. Accordingly, the local climatic temperature could be greatly influenced by advection of the air mass cooled by the melting of snowfall until the air mass reaches the Toyama Plain during the winter monsoon. © 2014, the Meteorological Society of Japan.

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