• Title/Summary/Keyword: summer environment

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Year-to- Year Variation of Cold Waters around the Korea Strait

  • Min, Hong-Sik;Kim, Young-Ho;Kim, Cheol-Ho
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.227-234
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    • 2006
  • Year-to-year variation of bottom cold waters around the Korea Strait was investigated based on bottom temperatures measured by submarine telephone cable between Pusan, Korea and Hamada, Japan from 1982 to 1992. The characteristics of bottom temperatures could be divided into three different groups: the Korean side, the middle, and the Japanese side. Temperature drops in summer appeared in all the three regions implying the intrusion of cold waters into the Korea Strait. Significant decreases in the Korean side were observed in 1983, 1986, 1990, 1991, and 1992 when bottom temperatures were high in the middle. In contrast, bottom temperatures significantly decreased in the middle in 1985, 1988, and 1989 when the temperature drops in the Korean side were relatively small. This tendency for a negative relationship was also shown in the second mode of an EOF analysis. In the years when bottom temperatures significantly decrease din the Korean side, the cold water along the east coast of Korea expanded offshore and its temperature was low. On the contrary, cold water in the southern region of the Ulleung Basin developed in the years when bottom temperatures decreased considerably in the middle.

Water Quality Assessment for Reservoirs using the Korean Trophic State Index (한국형 부영양화 지수를 이용한 저수지 수질평가)

  • Kim, Eungseok;Sim, Kuybum;Kim, Sangdan;Choi, Hyun Il
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.78-83
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    • 2012
  • Man-made reservoirs over 95% in Korea are shallower than 10 meters in depth, which is apt to cause eutrophication. This study has characterized long-term trends in water quality factors for the selected six reservoir points in the Kum River watersheds, and then estimated the seasonal trophic state index for each reservoir. The reservoir trophic state was evaluated at four trophic levels using the Korean trophic state index, TSIKO. It is observed from seasonal results for six reservoirs that the highest value of the trophic state index is estimated in summer while the trophic state index value is low in spring and winter seasons. Especially, the Boryeong Lake has a relatively lower trophic state index since this reservoir has been managed properly for water withdrawal and irrigation. It is expected that the seasonal trophic state index resulted from this study can contribute toward long-term water quality improvement plans for reservoirs.

The Characteristics and Correlation Analyses of Chlorophyll-a Data Monitored Continuously in Daecheong Reservoir (연속 측정된 대청호 Chlorophyll-a의 자료 특성 및 상관 분석)

  • Yeon, Insung;Hong, Jiyoung;Hong, Eunyoung;Lim, Byungjin
    • Journal of Korean Society on Water Environment
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    • v.26 no.6
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    • pp.994-999
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    • 2010
  • The toxin of Cyanobacteria (blue-green algae) during summer season has been a problem and early prevention should be considered. A variety of methods can be used to forecast algal blooms and this study aims at examining feasibility of chlorophyll-a. The real-time data were collected by automatic water quality monitoring system (AWQMS) in Daecheong reservoir and invalid data were sorted by experts. And then, the sorted data were filled using linear interpolation. When the concentration of chlorophyll-a increased by $15mg/m^3$, water temperature and pH exceeded $26.8^{\circ}C$ and 9.5 respectively. As a result of correlation between chlorophyll-a and other parameters(i.e. water quality items and hydrological data), temperature (r=0.502 - 0.574), pH (r=0.583 - 0.681), total organic carbon (TOC, r=0.583 - 0.681) comparably had higher values. Meanwhile, the data around a day or two showed the highest correlation. In addition, chlorophyll-a is considered to be significantly effected by precipitation and inflow.

Effect of Temporary Shading on Cut Rose Canopy in Summer (여름철 일시차광이 절화장미 군락에 미치는 영향)

  • Jeon, Hee;Kim, Jin-Young;Kim, Hyun-Hwan;Lee, Si-Young;Woo, Young-Hoi;Kim, Wan-Soon;Nam, Yoon-Il;Kim, Kyung-Je
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2001.11a
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    • pp.151-155
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    • 2001
  • 장미는 광포화점이 50,000 lux 이상으로 광요구도가 매우 큰 화훼작물이다. 따라서 유리와 같은 광투광율이 높은 자재를 피복한 온실에서 색도나 절화의 특성이 우수하여 품질이 향상된다. 그러나 온실에 유입되는 태양에너지가 매우 커서 계절에 따라서는 열집적현상이 나타나 고온과 일소현상과 같은 이유로 식물체가 스트레스를 받기도 한다. 이러한 현상은 장미를 재배하는 시설의 피복자재에 따라 차이가 매우 크다. (중략)

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Interannual Variability and Long-term Trend of Coastal Sea Surface Temperature in Korea (한국 연안 표층수온의 경년변동과 장기변화)

  • Min, Hong-Sik;Kim, Cheol-Ho
    • Ocean and Polar Research
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    • v.28 no.4
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    • pp.415-423
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    • 2006
  • Interannual variation and long-term trends of coastal sea surface temperature (SST) in Korea were investigated by analyzing 27 coastal SST time series from 1969 to 2004. Long-term linear increasing trend was remarkable with the rate over $0.02^{\circ}C/year$ at almost all the stations. The slope of long-term linear trend was larger at the stations along the eastern coast than in the western and southern regions. It was also noticeable that there was a common tendency of interannual variability with the period of 3-5 years at most of the stations. SST was lower in the 1970's and early 1980's while it was higher in the 1990's and early 2000's after the increase in the late 1980's. The pattern of the interannual variability of SST was similar to that of air temperature. Increasing trend of minimum SST in winter was obvious at most stations na it was larger along the eastern coast, while the linear trend of maximum SST in summer was less definite. Therefore, the decreasing tendency of annual amplitude was mainly due to the increasing tendency of SST in winter.

A study on a Residential Environment of Daksil in Bonghwa (봉화 닭실마을의 입지환경에 관한 연구)

  • 조영화;곽동엽
    • Journal of the Korean housing association
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    • v.13 no.3
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    • pp.55-60
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    • 2002
  • This article is to review the concepts of Confucian Utopia in Chosun Dynasty by looking into a sample of Daksil Village in Bongwha area. Here are some of the investigation. 1. The spatial composition entities of Daksil Village are both Confucian and Tao elements. 2. The whole views are made up by placing the Taoist View(gardens) into the Confucianist view(village and Seowon) and by placing the Confucianist view(summer house) into the Taoist view(Valley view of Seokcheonjeong). Two worlds are integrated into one by including each other. 3. According to the theory of geomancy(fang-shui), Daksil has the shape of ‘Geum-Gye-Po-Ran (Golden chicken embracing eggs)’, which is considered to be a land of fortune. Conclusively, Confucianists in Chosen Dynasty adopted fang-shui details when they built a residence, while they put much importance on Confucian and Tao elements. Moreover, it is found in the records that “It is a good place to start a village if there are mountains and water near the residence.” The fact that Daksil village is located at a day's distance from Seowon-Seokcheonjeongsa-Village-Jaesil-Grave proves that the residential village is set at an ideal place.

The Long-term Variation Patterns of Atmospheric Mercury in Seoul, Korea from 1997 to 2002 (서울시 대기 중 수은농도의 장기변동 특성 1997~2002)

  • 김민영;김기현
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.2
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    • pp.179-189
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    • 2003
  • The concentration of gaseous elemental mercury (Hg) was measured concurrently with relevant environmental parameters from Yang-Jae monitoring station in Seoul during Sept. 1997 to June 2002. Although data collection was disrupted for certain periods, the grand mean concentration of Hg for this five year period was found at 5.32 $\pm$ 3.53 ng m$^{-3}$ (N = 27,170). Because of short resolution of data acquisition, we were able to examine the temporal variability of Hg at varying time scale. The diurnal variability of Hg, when investigated for each of those five years, indicated consistently the dominance of nighttime over daytime. If examined at seasonal scale, Hg level was systematically higher during winter/spring than summer/fall period. The results of this short-term variability were best explained by the combined effects of such factors as meteorological conditions (formation of inversion layer and seasonal changes) and anthropogenic source processes. However, examination of long-term variation Pattern was much more complicated to explain. Thus, extension of our study is needed to diagnose the future direction in long-term trend of Hg behavior.

Exposure to PM10 and Carbon Monoxide (CO) Associated with Automobile Travels (자동차 운행과 관련한 PM10 및 일산화탄소 노출 평가)

  • 조완근;이진우
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.4
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    • pp.321-329
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    • 2001
  • This study included three experiments to evaluate in-vehicle exposures to PM10 and CO: 1) evaluation of in-passenger car exposures, 2) evaluation of in-public bus exposures, and 3) simultaneous evaluation of in-passenger car and in -university bus exposures. The tests of four factors (transportation mode, passenger-car type, commute period, and commute season were focused. A total of 40 actual passenger car commuters, 20 public bus commuters, and four university buses were recruited or surveyed. The same commuters ware participated in both the summer and winter studied. Two factory such as transportation mode and passenger-car type were found to have little effect on the in-vehicle levels of PM10 and CO. Commute period was found to have little effect on the in-vehicle CO levels. Conversely, the other factor, commuting season was found to influence on the in-vehicle levels of PM10 and CO. The present study also confirmed that under the Korean commute conditions, vehicle interiors are an important microenvironment for exposure to PM10 and CO. This was supported by finding that the in-vehicle Air levels were much higher than ambient air levels reported by several previous studies. The mean in -vehicle PM10 concentrations were 114 and 103$\mu\textrm{g}$/m$^3$for passenger cars and public buses, respectively. For CO, the mean in-vehicle concentrations were 2.9 and 2.6 ppm for passenger cars and public louses, respectively.

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Characteristics of Concentration and Size Distribution of PAHs of Total Suspended Particulates in urban air (도시대기부유분진중 다환방향족 탄화수소의 농도 및 입경분포 특성)

  • 조기철;이승일;김달호;허귀석;김희강
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.1
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    • pp.57-63
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    • 1994
  • In order to comprehension of the behaviour of PAHs in air which is known as carcinogens and/or mutagens suspended Particulates in ambient air were collected by Anderson air sampler from 1992. 6 to 1993. 5 in Seoul. Ten species of PAHs( Phen, An, Fl, R, Py, BaAn, BaP, Chry, BeP, DiB(a, h)An, I123p) were analyzed to understand monthly variations of PAHs distribution of PAHs concentration according to particle size, and correlation between PAHs and independent charactierstics of PAHs The highest concentration of TSP was 155.58$\mu\textrm{g}$/㎥ in May and the lowest was 60$\mu\textrm{g}$/㎥ in August. Concentration of TSP was more affected by coarse particles in spring, otherwise which was more affected by fine particles in winter. According to results of anaylsis of samples that were collected by Anderson air sampler, concentration of PAHs was more high in winter than that in summer. In almost samples collected by Anderson air sampler, concentration of PAHs was more high in coarse particles than in fine particles, but BaP well known as carcinogenic matter had more high concentration in fine particles(56-97.5%) than that in coarse particles(2.5-46%). Correlation between concentrations of TSP and PAHs was more high in fine Particles than in coarse Particles. Both fine particles and coarse particles have negative correaltion with radiation.

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Numerical Simulation of Ozone using UAM-V on Summer Episode in the Costal Urban Area, Busan (UAM-V를 이용한 부산지역 고농도 오존사례 수치모의)

  • 김유근;오인보;황미경
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.1
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    • pp.1-11
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    • 2003
  • Temporal and horizontal distributions of surface ozone concentrations covering the Busan metropolitan area were simulated by UAM -V (The Variable grid Urban Airshed Model) that was run with meteorological inputs taken from MM5 for ozone episode day (18 July 1999). UAM-V underestimated the daily maximum ozone con-centration about 14 ppb on average at all monitoring sites within Busan area comparing with observed value. but the correlation between observed and simulated values showed quite significant (R = 0.896, p< 0.01 on average). Higher concentrations of ozone occurred near the city center and industrial areas (western side of city) with high levels of anthropogenic source in the morning, and transport of ozone and its precursors by sea breeze developed in the afternoon contributed to elevated ozone levels in downwind rural areas. Particalarly in slightly downwind area of city center, the highest daily maximum ozone concentration ($\geq$120 ppb) was simulated by UAM-V at 1400 LST. Consequently, local environments including emission distributions and land -sea breeze circulation influenced ozone distributions in the Busan metropolitan area.