• Journal of Environmental Science International
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• v.2 no.3
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• pp.161-177
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• 1993

The Yellow Sand Events observed over the Korean peninsula during 22-24 April, 1993 were examined using the synoptic data and GMS visible image to identify the transport path of the Yellow Sand and the main factor governing the duration of the Yellow Sand phenomenon. The 850 hPa convergence chart and the 700 hPa trajectory analyses of the air mass laden with Yellow Sand particles suggested that the Yellow Sand particles observed over Korea were probably transported from the Gobi Desert and the Loess Plateau. The duration of the Yellow Sand Events was about 35-40 hours rather shorter than normal as the high pressure system centered near the Mongolia region moved rapidly toward the Yellow Sea, which drove away the Yellow Sand particles over the Korean peninsula toward the Japan Islands, furthermore the low-level stratification of the air mass over the Korean penishula showed the unstable atmospheric condition leading to atmospheric diffusion of the particles. The trajectory analyses and the GMS visible image indicated that the long-range transport of the air mass laden with the Yellow Sand particles of this case was more dependent on the 700 hPa air flow than on the 850 hPa air flow.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.76-85
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• 2003

Mass and elemental dry deposition fluxes and ambient particle size distributions were measured using dry deposition plates and a cascade impactor, from March to November 1998 in Seoul, Korea. During the spring sampling period several yellow sand events characterized by long range transport from China and Mongolia impacted the area. During these events the mass fluxes were statistically the same as during springtime non-yellow-sand events. However, most elemental fluxes were higher. In general, the flux ratios of both crustal (Al, Ca, Mn) and anthropogenic elements (Ni, Pb) to total mass measured during the daytime yellow-sand events were substantially higher than those measured in spring daytime during non-yellow-sand time periods. During all seasons the average measured daytime fluxes were about two times higher than at nighttime. The flux of primarily anthropogenic metals (Cu, Ni, Pb, Zn) and Mn was on average one to two orders of magnitude lower than the flux of the crustal metals Al and Ca. As is typically found two modes, fine (0.1∼l.0 $\mu\textrm{m}$) and coarse (1.0∼10.0 $\mu\textrm{m}$) were present in the measured size distributions (<10 $\mu\textrm{m}$). The particles in the coarse mode constitute a major portion of the measured mass size distribution during the yellow-sand events possibly due to the long-range transport of those particles from China.

• Asian Journal of Atmospheric Environment
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• v.7 no.4
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• pp.191-198
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• 2013

Cryptomeria japonica pollen is the most common pollen, which are scattering during each spring season in Japan. Japanese cedar (Cryptomeria japonica) pollinosis is one of seasonal allergic rhinitis that mainly occurs in Japan. In addition, long range transportation of Yellow Sand from the East Asian continent was also found during the pollen scattering seasons in Japan. Therefore, the interaction or impact between pollen and Yellow Sand should be concerned. In this study, our objective was to investigate the airborne behaviour of Cryptomeria japonica pollen grains and its size-segregated allergenic (Cry j 1) particles as the airborne tracer of Cryptomeria japonica pollen during the Yellow Sand events. Airborne Cryptomeria japonica pollen grains and its size-segregated allergenic particles were collected at roadside of urban residential zones of Saitama city during the pollination periods from February to March in two year investigation of 2009 and 2010. The overlap of Yellow Sand events and dispersal peak of pollen grains was observed. According to the Meteorological data, we found that the peaks of airborne pollen grains appeared under higher wind speed and temperature than the previous day. It was thought that Yellow Sand events and airborne pollen counts were related to wind speed. From the investigation of the airborne behavior of the size-segregated allergen particles by determining Cry j 1 with Surface Plasmon Resonance (SPR), the higher concentrations of the allergenic Cry j 1 were detected in particle size equal to or less than $1.1{\mu}m$($PM_{1.1}$) than other particle sizes during Yellow Sand events, especially in the rainy day. We conclude that rainwater trapping Yellow Sand is one of the important factors that affect the release of allergenic pollen species of Cry j 1. Therefore, it is very important to clarify the relationships between Cryptomeria japonica pollen allergenic species and chemical contents of the Yellow Sand particles in further studies.

• Korean Journal of Remote Sensing
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• v.14 no.3
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• pp.307-314
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• 1998

To examine the detectability of the yellow sand and/or aerosol from China crossing over the Yellow Sea within the range of OSMI wavelengths(400-900 nm), we have investigated the optical characteristics of aerosols in yellow sand events observed on April, 1998 in Seoul. The spectral reflectance(%) and aerosol optical thickness in the range of Visible(VIS) and near Infrared (NIR) wavelengths were derived from the measurements of solar radiation using the GER-2600 spectroradiometer and sunphotometer during the April, 1798. The average spectral reflectance for the yellow sand events is over 40% and higher around 14:30 than 12:00 LST, but that for clear days is about 20% both at 12:00 and 14:30 LST in the range of 500-900 nm. The aerosol optical thickness at 501 nm varied from 0.25 on very clear day to 1.01 during a so-called "yellow-sand" episode and that for 673 nm varied from 0.14 to 0.92, respectively.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.92-106
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• 2004

Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alaskan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.

• Environmental Analysis Health and Toxicology
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• v.17 no.4
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• pp.333-339
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• 2002

Yellow sand (YS) storms were observed about ten times in the Korean peninsula during March and April in 2002. Twenty four hour fine particle (PM$\_$2.5/) samples were collected onto the 47 mm Teflon - coated quartz filters over 9 days during and after the events using the MiniVol Portable Air Sampler at a flow rate of 5 liters per minute. The highest PM$\_$2.5/ concentration measured during the YS period was 289 $\mu\textrm{g}$/㎥, which is 13 times higher than the lowest of the values for the samples collected during the non-yellow sand period. The filter samples were analyzed for inorganic ions using the IC, AAS and Autoanalyzer, and for metals using the ICP-MS. The results showed that the concentrations of some inorganic ions (e.g., Ca$\^$2+/ and SO$_4$$\^$2-/) and metals (e.g., Fe, Mn) of soil origin were elevated during the yellow sand events.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.197-206
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• 2001

The long-range transport mechanisms of Asian dust were analyzed based on the synoptic weather system and numerical simulation by using NCEP/NCAR reanalysis and TOMS data during the periods of 1996-2001. We classified the whole weather types of eastern Asia during spring and created the representative weather types during the yellow sand events using cluster analysis and weather charts for the last 6 years(1996~2001). These long-range transport mechanisms were related to various pressure patterns including high and low, trough and ridge, and upper-level fronts. Case studies of the yellow sand events have performed by the simulation of MM5 with meteorological elements such as the horizontal wind of u and v component, potential temperature, potential vorticity, and vertical circulation during the episodic days(2~8 March 2001). In addition, the origin of the long-range transport was examined with the estimation of backward trajectory using HYSPLIT4 Model. In this paper, we concluded that three weather types at 1000 hPa, 850 hPa, 500 hPa, and 300 hPa levels were classified respectively. The dominant features were the extending continental outflow from China to Korea at 1000 hPa and 850 hPa levels, the deep trough passage and cold advection at 500 hPa and 300 hPa levels during the yellow sand events. And also, we confirmed the existence of pola $r_tropical jets in the upper-level, the behavior of potential vorticity over Korea, the estimation of potential vorticity through vertical cross section, and the transport of yellow sand through backward trajectories.es.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.3
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• pp.34-44
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• 1986

Particle size distribution of airborne suspended particulate concentrations according to particle size in the events of yellow sand phenomena, have been measured and analyzed by using Andersen air sampler for four years, January 1982 through December 1985. The conclusions are as follows: 1. Yellow sand phenomena, generally, occur between March and May. 2. The frequent occurrences of yellow sand were observed during March and April and airborne suspended particulate concentrations in the cases of yellow sand appeared to be 2 $\sim$ 3.4 times higher than those of normal conditions. 3. Geometric mean particle diameter and its geometric mean standard deviation by logarithmic normal distribution sheet, were quite close to each other and log-distribution curves showed similar shapes. 4. Analysis by particle size distribution curve showed bi-modal distribution. 5. Concentrations of coarse particles in normal conditions were 1.2 $\sim$ 2 times higher than those of fine particles and, similarly, coarse particle concentrations in yellow sand cases were 1.3 $\sim$ 2.5 times higher than those of fine particles. 6. Concentrations of coarse particles in yellow sand cases were 2 $\sim$ 3.6 times higher than those in normal conditions and those of fine particles were 1.7 $\sim$ 3.5 times higher.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.3
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• pp.191-208
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• 1998

Estimations of dry and wet depositions in Korea and the size distributions of yellow sand above Korea have been carried out using the Eulerian aerosol model with the simulated meteorological data from the SNU mesoscale meteorological model. The estimated particle size distribution in Korea shows a bimodal distribution with peak values at 0.6 pm and 7 pm and a minimum at 2 pm in the lower layer However, as higher up, the bimodal distribution becomes an unimodal distribution with a peak value at 4∼5mm. Among the total amount of yellow sand deflated in the source regions , the dry and wet deposition fluxes were about 92%, and about 1.3∼0.5%, repectively, and the rest(5∼6%) is suspended in the air, Most of dust lifted in the air during the clear weather is deposited in the vicinity of the source regions by dry deposition and the rest undergoes the long -range transport with a gradual removal by the wet deposition processes. Over Korean peninsula, the total amount of yellow sand suspended in the air was about 6∼8% of the emissions in the source region and the dry and wet deposition fluxes were about 0.005∼0.7% and 0.003∼0.051% of the total emitted amount, repectively. It is estimated that 2.7∼8.9 mesa-tons of yellow sand is transported annually over the Korean peninsula with the annual mean dry deposition of 2.1∼490 kilo-tons and the annual mean wet deposition of 1.5∼65 kilo-tons.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.4
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• pp.233-244
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• 1994

The phenomenon of yellow sand (dust clouds) occurred in Korea during the spring of 1993 and 1994 is studied in detail. In total 6 cases including 15 days of yellow sand were observed in 1993 and the annual number of these events was found to increased. Examinations in this study include meteorological charts satellite imagery, pilot reports (PIREP) of Korea Air Force, and air concentrations of total suspended particulates(TSP). We present on estimation of total atmospheric loadings based on the observation and theory. According to the PIREP, in general the dust clouds travelled in the lower troposphere up to the level 5km. The visibility within the clouds was in the range of 3-8km The area covered by yellow sand in an event exceeded 0.4 M $\textrm{km}^2$ . According to trajectory analyses, dust clouds invaded Korea in April and May 1993 were landed in the sink area after 2~4 days travelling for 2,000~3,000km from a source region. Estimates of total atmospheric loadings of a dust cloud for April 23~24 in 1993 were 1.5 M ton. In addition, 7 dust storms were also reported in synoptic observations in NW China and Mongolia during the spring in 1994. The yellow sand was not reported with meteorological observations in Korea, however pilots reported significant dust clouds over the Yellow Sea on 8 and 13 April and 20 May 1994.