• Journal of Korean Society for Atmospheric Environment
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• v.13 no.6
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• pp.439-450
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• 1997

Atmospheric fine particles $(PM_{2.5})$ were collected at the background sites, Kangwha, Taean, and Kosan and characterized to understand their behaviors at the sites. Daily samples of $PM_{2.5}$ mass were measured and ionic species, carbonaceous species, and gaseous species were analyzed. Four-day backward trajectory analysis was also carried out. The mean concentrations of anthropogenic species were highest at Kangwha among three sites, while contributions from sea salts wree highest at Taean during the measurement period due to higher wind speed at Taean. Major chemical components in fine particles were sulfate, organic carbon, nitrate, and ammoniu. Most of the non-sea-salt (nss) sulfates in $PM_{2.5}$ might be present as ammonium sulfates at these sites. Most air parcels arriving at Kangwha and Taean were from northern China. Therefore, both sites were thought to be affected by the same air parcel. At Kosan, during the measurement period, air parcels were from either northern China or sourthern China. The nss sulfate concentration in the air parcels from southern China was higher, while the nss calcium, nitrate, and ammonium concentrations were higher when the air parcels were from northern China.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.4
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• pp.415-420
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• 2000

The daily mean concentrations of PM2.5 mass ionic species carbonaceous species and HNO3, HCl, and NH3 were analyzed at three background sites in Korea : Kangwha, Kosan, and Dongbaik during two intensive field studies between December 1996 and January 1997, Four-day backward trajectory analysis was also carried out. The mean concentrations of anthropogenic species were higher at Kangwha and Dongbaik than Kosan. At these two sites themean concentrations of nitrate and ammonium/ammonia were higher than those of Kosan. It was suggested that these two sites be considered as the background sites of the Seoul Metropolitan Area and Pusan respectively. Major chemical components in fine particles were sulfate organic carbon nitrate and ammonium for all the sites. More than 90% of sulfate were non-sea-salt(nss) sulfates and most of the nss sulfate in PM2.5 might be present as ammonium sulfates at all sites. Most of air parcels arriving a Kangwha and Dongbaik were from the northern China. At Kosan during the measurement period half of air parcels were from the northern China and the other half from the southern China. At Kosan the concentrations of anthropogenic air pollutants originated from the southern China were higher than those typically observed from the northern China.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.201-211
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• 2015

Acoustic propagation in shallow water with changing environments is a major concern of navy. Temporal and spatial variability of acoustic propagation in the northern East China Sea (ECS) is studied, using the 11 years hydrographic data and the Bellhop acoustic model. Acoustic propagation in the northern ECS is highly variable due to extensive interaction of various ocean currents and boundaries. Seasonal variations of transmission loss (TL) with various source depths are highly affected by sharp gradient of sound speed and bottoms interaction. Especially, various bottom sediment types lead to severely degrading a waterborne propagation with bottom loss. In particular, the highly increased TL near the ocean front depends on the source position, and the direction of sound propagation.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.51-56
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• 2008

Azuki bean has never been commercially grown in Thailand, due in part to a lack of suitable varieties. A core collection of 114 azuki bean accessions, originally from different parts of China(northern, central, southern) representing the germplasm of Chinese land races, were evaluated in the experimental field of the Institute of Vegetable Crops, Jiangsu Academy of Agricultural Sciences, China from June to October 2004. The same experiment was repeated at Kamphaeng Saen campus of Kasetsart University, Thailand from February to May 2005. Yield, yield components, and agronomic traits were recorded in all accessions in order to identify certain genotypes for further investigation. The statistical parameters that were used as indicators of phenotypic variation were mean, coefficient of variability(CV), correlation coefficient(r), range, mean difference, and phenotypic clustering of the accessions. The results indicated that the azuki bean varieties planted in Kamphaeng Saen were shorter, earlier in growing duration, and lower in plant height, seed yield per plant, 100-seed weight, and pods per plant as compared to when they were grown in China. This discrepancy was caused largely by the combined effect of temperature, rainfall, and day length. The traits that were rather stable in both locations were branches per plant and seeds per pod. Azuki bean varieties from northern China showed higher response to the changing environments compared with those from central and southern China. Some agronomic traits showed high correlation coefficient between the environments in Thailand and China. The CV of agronomic traits in both locations were ranked in descending order as follows: seed yield per plant, pods per plant, branches per plant, plant height, 100-seed weight, seeds per pod, and growing duration. The CV of seeds per pod and branches per plant were almost the same in both locations. Yield per plant in China correlated well(r=0.75) with pods per plant, but not with the other traits. Based on their response to both environments, the azuki bean accessions can be broadly divided into four groups, viz. northern 1, northern 2, central, and southern. This implied that there was more diversity, but probably less stability among the accessions originating from northern China.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.649-654
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• 2002

In summer season of 1998, a huge flood occurred around the Yangtze River in the eastern China. The low salinity water less than 28 psu from the river was detected around the southeastern part of the Jeju Island which is located in the southern part of the Korean peninsula. We studied how to detect low salinity water from the Yangtze River, which gives terrible damages to the Korean fisheries. We got the relationships between low surface salinity, turbid water from the Yangtze River and digital ocean color using remote sensing of SeaWiFS satellite in the northern East China Sea in summer seanson of 1998, 1999, 2000 and 2001. The charts of salinity in the northern East China Sea were made by the regenerating of the satellite ocean color data with the formula from the relationships between low salinity, in situ turbid water (transparency) and satellite ocean color.

• Ocean and Polar Research
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• v.31 no.2
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• pp.219-229
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• 2009

In order to establish annual variations in the marine ecosystem of the East China Sea, suspended solids (SSs) and particulate organic carbon (POC) were extensively investigated in the northern part of the East China Sea from August 2003 to April 2008. Surface SS concentrations showed large spatial variations in spring and fall, but not in summer. Surface SS concentrations in spring were lower than those in summer and fall. In summer, SSs discharged from Changjiang were mostly deposited in the coastal areas and did not reach our study area which was located about 260 km from the river mouth. High SS concentrations were observed near the bottom, which resulted from resuspension of bottom sediments by the bottom currents. Surface POC concentrations did not exhibited large seasonal variations. Phytoplankton biomass was a main factor controlling surface POC concentrations. POC/chlorophyll ratios showed large seasonal variations, with maximum numbers in summer. POC/PON ratios were higher in summer than the Redefied ratio (6.6), while they were lower in spring and fall. In summer, higher POC/chlorophyll and POC/PON ratios were probably attributed to the high phytoplankton mortality caused by nutrient depletion in surface waters.

• Korean Journal of Remote Sensing
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• v.20 no.3
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• pp.153-162
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• 2004

In the summer of 1998-2001, a huge flood occurred in the Yangtze River in the eastern China. Low salinity water less than 28 psu from the river was detected around the southwestern part of the Jeju Island, which is located in the southern part of the Korean Peninsula. We studied how to detect low salinity water from the Yangtze River, that cause a terrible damage to the Korean fisheries. We established a relationships between low salinity at surface, turbid water from the Yangtze River and digital ocean color remotely sensed data of SeaWiFS sensor in the northern East China Sea, in the summer of 1998, 1999, 2000 and 2001. The salinity charts of the northern East China Sea were created by regeneration of the satellite ocean color data using the empirical formula from the relationships between in situ low salinity, in situ measured turbid water with transparency and SeaWiFS ocean color data (normalized water leaving radiance of 490 nm/555 nm).

• Journal of the Speleological Society of Korea
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• no.95
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• pp.23-33
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• 2009

This study analyzed the distribution of China's caves and cave resources in Research. The results are as follows: First, China's melting karst caves are mainly distributed in southwest widely distributed. Recently in Beijing and other northern areas found in many caves. First, China's Karst caves are mainly distributed in karst-flung southwest. Recently in Beijing and other northern areas found in many caves. Second, although China is widespread volcanic landscapes, but most of the extinct volcano, the lava caves less so. Are mainly distributed in Hainan Island, north-east there are some distribution. Third, China's recent development and evolution of the cave, analysis of the paleo-environment records of cave stalagmites, cave biology, cave tourism development, environmental aspects of cave research more active.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.4-8
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• 2002

• Ocean and Polar Research
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• v.33 no.2
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• pp.135-147
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• 2011

Zooplankton is an important constituent in assessing ecosystem responses to global warming. The northern East China Sea is an important ecosystem for carbon cycling with a net sink of carbon dioxide. Despite their importance as a major component in carbon cycling, relatively little is known about zooplankton biomass structure and its regulating factors in the northern East China Sea. This study examined zooplankton biomass distribution pattern in the region from multiple cruises encompassing various seasons between 2004 and 2009. Results showed that zooplankton biomass exhibits less cross-shelf gradient in general with declining biomass to the eastern shelf towards the Tsushima Current Water. Size-fractionated biomass showed that the 1.0~2.0 mm size group, mostly copepods, dominated zooplankton biomass, comprising 38 to 48% of total biomass. Smaller zooplankton (0.2~1.0 mm) biomass, consisting mainly of Paracalanus spp, a particle eating herbivorous copepod, was positively related to chlorophyll-a concentration, but no relationship was established for larger zooplankton (1.0~5.0 mm). Spatially-averaged mean total zooplankton biomass was also highly related to chlorophyll-a concentration. These result suggest that the long-term trend of zooplankton biomass increase in this region is partly accounted for by the increases of phytoplankton biomass and productivity underway in the region. However, the underlying mechanisms of how sea surface warming in the study area leads to increased phytoplankton biomass and productivity remains unclear.