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Dulam J.,Institute of Meteorology and Hydrology | Shinoda M.,Tottori University
Scientific Online Letters on the Atmosphere | Year: 2011

A severe dust storm occurred in Mongolia during 29-31 March 2007. Observed meteorological elements and weather situations during the dust storm period were discussed in this paper. A surface cyclone developed over the territory of Mongolia in association with the trough aloft passing through the country. The cyclone generated the severe dust storm over the Gobi Desert and steppe-desert areas. During the dust storm period, wind speed varied from 10 m s-1 to 40 m s-1 and visibilities were reduced to 2 km. Minimum visibilities were 10-50 m in the Gobi Desert areas. Estimated dust concentrations were varied from 151 μgm-1to 23847μgm-1by the Zamyn-Uud equation and 182μgm-1to 9111μgm-1by the Dalanzadgad equation. The duration of the dust storm was 1-20 hours at various sites per day. The dust storm caused death of a person and substantial economic loss.


Shinoda M.,Tottori University | Kimura R.,Tottori University | Mikami M.,Meteorological Research Institute | Tsubo M.,Tottori University | And 6 more authors.
Scientific Online Letters on the Atmosphere | Year: 2010

The joint Japan-Mongolia-USA project DUVEX (Dust-Vegetation Interaction Experiment) was designed to develop a biogeophysical model which can simulate dust emission and ecosystemprocesses over the vegetated land surface. Dust emission processes have been investigated mostly on bare land, and there is very little information about vegetated land. Thus, intensive observations were conducted of a dust event that occurred on the Mongolian steppe on 24 April 2008. Meteorological and dust elements (e.g., saltation flux, visibility,dust concentration) and land-surface parameters (e.g., roughnesslength, vegetation cover, and the ground-based normalized difference vegetation index) were measured. During the event (from 13:00 to 18:00 LST on 24 April), the threshold wind speed at 1.54 m height, which is the minimum wind speed inducing saltation of particles ranging from 30 to 667 μm in diameter, was 8. m s-1 on a land surface with 7.2% vegetation cover with dead brown leaves, a small roughness length (0.0058 m), and a very dry sandy soil at 0-5 mm depth (water content, 0.002 g g-1). For comparisonwith previous studies, the threshold wind speed value was converted to the values at the heights in each study by using the logarithmic law of wind profile. Our value is close to the SYNOP-derived values for the same area, but larger than ground-observed and SYNOP-derived values for East Asian deserts. © 2010, the Meteorological Society of Japan.


Jugder D.,Institute of Meteorology and Hydrology | Jugder D.,Tottori University | Shinoda M.,Tottori University | Sugimoto N.,Japan National Institute of Environmental Studies | And 5 more authors.
Global and Planetary Change | Year: 2011

Dust mass concentrations of PM10 and PM2.5 from four monitoring stations in the Gobi Desert region of Mongolia were analyzed for a 16-month period in 2009-2010. Annual averaged PM10 concentration ranged from 9μgm-3 to 49μgm-3 at these stations during 2009. Concentrations were high in winter owing to air pollution and in spring owing to dust storms; the monthly mean concentrations of PM10 (PM2.5) at the three stations except for Sainshand reached yearly maxima in December and January, ranging from 60 (38) μgm-3 to 120 (94) μgm-3. Diurnal variations of PM10 and PM2.5 concentrations at two sites, Dalanzadgad and Zamyn-Uud, included two maxima in the morning and evening and two minima in the afternoon and early morning. However, at Erdene PM10 maxima occurred in the afternoon and evening. Both PM10 and PM2.5 concentrations were enhanced from March to May by dust storms. Dust storms raised huge amounts of fine dust particles in the Gobi of Mongolia. Maximum daily mean PM10 (PM2.5) concentrations reached 821 (500) μgm-3 at Dalanzadgad, 308 (129) μgm-3 at Zamyn-Uud, and 1328μgm-3 at Erdene. Hourly maximum PM10 (PM2.5) concentrations were as high as 6626 (2899) μgm-3 at Dalanzadgad during a dust storm. © 2011 Elsevier B.V.


PubMed | Tokyo Institute of Technology, Sophia University, Institute of Meteorology and Hydrology, Japan National Institute for Agro - Environmental Sciences and Meteorological Research Institute
Type: Journal Article | Journal: Journal of environmental radioactivity | Year: 2016

Plutonium (


Igarashi Y.,Meteorological Research Institute | Fujiwara H.,Japan National Institute for Agro - Environmental Sciences | Jugder D.,Institute of Meteorology and Hydrology
Atmospheric Chemistry and Physics | Year: 2011

Recent climate change, especially during the 2000s, may be the primary reason for the expansion of the Asian dust source region. The change in the dust source region was investigated by examining anthropogenic radionuclides contained in surface soil samples from Mongolia. Surface soil was globally labeled by radioactive fallout from nuclear testing during the late 1950s and early 1960s, but there are no current direct sources for anthropogenic radionuclides in the air (before the Fukushima nuclear power plant accident in 2011). Radionuclides in the atmosphere are therefore carried mainly by wind-blown dust from surface soil, that is, aeolian dust. Asian dust carries traces of 90Sr, 137Cs, and other anthropogenic radionuclides; the heaviest deposition occurs in spring and has been recorded in Japan since the early 1990s. The composition of anthropogenic radionuclides in atmospheric depositions would be affected by a change in the dust source. Previous studies of atmospheric deposition at long-term monitoring sites (e.g. in Tsukuba, Japan) have detected changes in the 137Cs/90Sr ratio and in the specific activity of the radionuclides. These changes in the composition of observed atmospheric depositions are supposed to reflect changes in the climatic conditions of the dust source region. To investigate this dust source change, we conducted a field survey of radionuclides (90Sr and 137Cs) in surface soil samples in September 2007 in the eastern and southern regions of Mongolia, where dust storms have occurred more frequently since 2000. The specific activities of both radionuclides as well as the 137Cs/90Sr ratio in the surface soil were well correlated with annual average precipitation in the Mongolian desert-steppe zone. Higher specific activities and a higher 137Cs/90Sr ratio were found in grassland regions that experienced greater precipitation. These findings suggest that the increased specific activities and the activity ratio detected in atmospheric depositions in Japan during years with frequent Asian dust transport events in the 2000s are a sign of grassland degradation. © 2011 Author(s).


Jugder D.,Institute of Meteorology and Hydrology | Jugder D.,Tottori University | Sugimoto N.,Japan National Institute of Environmental Studies | Shinoda M.,Tottori University | And 3 more authors.
Atmospheric Environment | Year: 2012

Polarization-sensitive Mie-scattering lidars were installed for dust storm monitoring at Sainshand and Zamyn-Uud in the Gobi Desert and at the Mongolian capital city of Ulaanbaatar in 2007. We studied the temporal and spatial distributions and transportation of dust, elevated dust, biomass burning smoke, and anthropogenic aerosol by using lidar measurements from the end of 2007 to the first half of 2010. The study results show that the maximum height of dust layers over the Gobi Desert of Mongolia during dust event periods varied from 0.5 to 5.5 km above the ground level (AGL). The 95th percentile level of dust vertical distribution was found at 4 and 4.5 km for Zamyn-Uud and Sainshand, respectively. The averaged maximum height of dust layers during dust events was 2.0-2.2 km AGL at those Gobi sites. The lidar measurements also revealed transport of dust layers elevated in the atmosphere. Base heights of elevated dust layers varied from 0.5 to 2.5 km AGL, while maximum heights from 2.5 to 4.5 km AGL. Backward air trajectory analyses suggested source areas of the elevated dust that transported from other source regions to southeastern Mongolia. A detail study was conducted of the dust event in 19-20 May 2008. Hourly maximum dust concentrations of PM10 (PM2.5) reached 1139-1409 (384-404) μg m-3 during the dust event episode. Dust concentration of PM10 had high correlations with visibilities. Threshold winds for dust emission were determined at Sainshand and Zamyn-Uud. The lidar measurements at the three sites detected vertical profiles of biomass burning smoke and anthropogenic aerosol with top heights of 3-4 km AGL. © 2012 Elsevier Ltd.


Jersabek C.D.,University of Salzburg | Jersabek C.D.,Academy of Natural Sciences of Philadelphia | Bolortsetseg E.,Institute of Meteorology and Hydrology
Proceedings of the Academy of Natural Sciences of Philadelphia | Year: 2010

A list of monogonont rotifers that have São far been found in Mongolia has been compiled, based on recent collections and previously published records. For all species, detailed information is provided on their occurrence in Mongolia, along with notes on their world distribution and autecology. To date, 246 species and infraspecific taxa in 55 genera are known, including 16 potentially new, as yet undescribed species.


Sugimoto N.,Japan National Institute of Environmental Studies | Hara Y.,Japan National Institute of Environmental Studies | Yumimoto K.,Kyushu University | Uno I.,Kyushu University | And 2 more authors.
Scientific Online Letters on the Atmosphere | Year: 2010

Dust emission estimated with a 4D-Var data assimilation system using ground-based lidar network data was compared with vegetation growth data based on visual observations in the Gobi desert in Mongolia in the spring of 2007. The dust emission flux estimated with the data assimilation system was less than that estimated without data assimilation in the dust event of May 21-30 and was the opposite in the event of March 25-April 3. The threshold surface friction velocity estimated from the results of the data assimilation was less than 0.3 m s-1 in the dust event of March 25-April 3 and was ~0.36 m s-1 in the event of May 21-30. The difference between the two events was qualitatively explained by the vegetation growth data. The accumulated precipitation during the period was ~2 mm. The results show that vegetation growth with slight precipitation in the Gobi desert may significantly reduce dust emission. © 2010, the Meteorological Society of Japan.


Batbold A.,Hokkaido University | Sato T.,Hokkaido University | Ishikawa M.,Hokkaido University | Tsogt J.,Institute of Meteorology and Hydrology
Scientific Online Letters on the Atmosphere | Year: 2011

Global weather forecasts do not have sufficient performance to predict the local severe weather events that are accompanied with cyclones and cold fronts due to their coarse horizontal resolution. This study investigated the performance of dynamical downscaling (DD) using mesoscale model to simulate the severe windstorm in eastern Mongolia which occurred on 26-27 May 2008. Our results revealed that the DD experiments were successful in capturing the general features of the windstorm in terms of wind and temperature patterns. The timing and amplitude of drastic changes in the simulated temperature and wind speed were very similar to that observed than that obtained from the global atmospheric data, suggesting that DD is capable of predicting extreme wind storm events in Mongolia. Analyses on the nested domains indicate that the DD has crucial impact on the performance for simulating severe storm even with a moderate resolution (27 km), and further nesting (9 and 3 km) plays a role to improve it. Furthermore, the maximum wind speed approaches the observed value more closely as the horizontal resolution increases, although it still underestimates the observed wind speed even in the 3 km mesh domain. On the other hand, the abrupt temperature change is captured well even in the low-resolution domain, suggesting a difference in necessary horizontal resolution for temperature change and maximum wind speed. © 2011, the Meteorological Society of Japan.


Prakash S.,Atmospheric and Oceanic science Group | Mahesh C.,Atmospheric and Oceanic science Group | Gairola R.M.,Atmospheric and Oceanic science Group | Buyantogtokh B.,Institute of Meteorology and Hydrology
International Journal of Hydrology Science and Technology | Year: 2012

Rainfall forecast has prime importance in an agrarian country like India, wherein the agricultural production is solely dependent on monsoon rainfall. In this paper, an artificial neural network (ANN) technique is used to construct a non-linear mapping between output data from global forecast system (GFS) and rainfall from tropical rainfall measuring mission (TRMM) satellite measurements. The objective of the present study is to generate region-specific six-hourly quantitative rainfall forecast over central India using ANN and resilient propagation learning algorithm. Meteorological variables from the GFS model and precipitation product from TRMM multisatellite precipitation analysis (TMPA) are used as input data for training the network, which generate rainfall forecast for the next time step. The test was performed for central India during the summer monsoon period of 2010. In order to evaluate the potential of rainfall forecast skill over the studied region, the forecast precipitation has been intercompared with TMPA-3B42, and Kalpana-1 derived precipitation products and a statistical analysis was performed. The linear correlation between ANN forecast and TMPA-3B42 rainfall was 0.58, whereas it was 0.52 with Kalpana-1 derived precipitation estimates. The results show that the predicted precipitation by the present technique performs better than GFS model precipitation forecast, and the system indicates a potential for more accurate rainfall forecasting. Copyright © 2012 Inderscience Enterprises Ltd.

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