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        검색결과 4

        1.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        황사가 식물플랑크톤에 미치는 영향을 파악하기 위해, 황사가 발생한 2006년 4월 22 ~ 26일까지 태안반도 인근해역에서 현장조사 및 생리실험을 수행하였다. 황사발생동안 식물플랑크톤 군집은 26 ~ 290 × 103 cells·L-1의 범위로 다소 낮은 현존량과 주요 분류군인 돌말류의 증가, 특히 혼합해역의 대표종인 Paralia sulcata와 같은 저서성 돌말류의 증가가 뚜렷하였다. 또한 황사발생 후의 Chl-a 농도는 황사발생 전의 조석에 따른 Chl-a 농도변화범위를 초과하였다. 황사투여실험에서는 황사투여 농도가 증가함에 따라 일차생산력은 점차 감소하였고, 최대 탄소 동화계수 역시 같은 경향을 보였다. 48시간 배양실험에서는 황사투여 초기(T0)에 실험구(test)가 대조구(control)에 비해 낮은 일차생산력을 보였으나, 48시간 후(T48)에는 실험구가 대조구보다 높은 일차생산력을 보였다. 특히 실험구는 초기보다 48시간 후의 일차생산력이 약 321%로 크게 증가하였다. 따라서 중국과 인접한 조사해역의 식물플랑크톤은 황사와 함께 수반되는 강한 물리적 환경이 발생초기에 식물플랑크톤의 성장을 일시적으로 저해시킬 수 있으나, 이후 안정적인 수괴가 지속될 경우 식물플랑크톤의 성장을 촉진시키는 잠재적인 요인으로도 파악되었다.
        4,000원
        2.
        2012.06 구독 인증기관 무료, 개인회원 유료
        Spatial and temporal variations of Yellow Dust source area and desertification in dryland regions of the Northeast Asia were evaluated based on extensive literature review on field and modeling evidences. In overall, Yellow Dust occurrence decreased since 1960s but it increased again in Mongolia and northeastern China after 2000s, the latter of which indicates eastward encroachment of major Yellow Dust source area for the last decade. The phenomena seem to coincide well with recent desertification of Mongolia, Inner Mongolia, and Manchuria. Vegetation cover is evaluated as an important biophysical variable for controlling both dust occurrence and desertification, which considerably depends on both precipitation and livestock pastoralism. Hence, dryland sustainability should consider dynamic balancing between vegetation productivity and livestock utilization under varying climate and socio-economic situations, which requires socio-ecological perspective on sustainable dryland management.
        4,000원
        3.
        2012.02 KCI 등재 서비스 종료(열람 제한)
        Hourly concentrations of PM1, PM2.5 and PM10, were investigated at Gangneung city in the Korean east coast on 0000LST October 26~1800LST October 29, 2003. Before the intrusion of Yellow dust from Gobi Desert, PM10(PM2.5, PM1) concentration was generally low, more or less than 20 (10, 5) μg/m3, and higher PM concentration was found at 0900LST at the beginning time of office hour and their maximum ones at 1700LST around its ending time. As correlation coefficient of PM10 and PM2.5(PM2.5 and PM1, and PM10 and PM1) was very high with 0.90(0.99, 0.84), and fractional ratios of (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 1.37~3.39(0.23~0.54), respectively. It implied that local PM10 concentration could be greatly affected by particulate matters of sizes larger than 2.5 μm, and PM2.5 concentration could be by particulate matters of sizes smaller than 2.5 μm. During the dust intrusion, maximum concentration of PM10(PM2.5, PM1) reached 154.57(93.19, 76.05) μg/m3 with 3.8(3.4, 14.1) times higher concentration than before the dust intrusion. As correlation coefficient of PM10 and PM2.5(vice verse, PM2.5, PM1) was almost perfect high with 0.98(1.00, 0.97) and fractional ratios of (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 0.48~1.25(0.16~0.37), local PM10 concentration could be major affected by particulates smaller than both 2.5 μm and 1 μm (fine particulate), opposite to ones before the dust intrusion. After the ending of dust intrusion, as its coefficient of 0.23(0.81, - 0.36) was very low, except the case of PM2.5 and PM1 and (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 1.13~1.91(0.29~1.90), concentrations of coarse particulates larger than 2.5 μm greatly contributed to PM10 concentration, again. For a whole period, as the correlation coefficients of PM10, PM2.5, PM1 were very high with 0.94, 1.00 and 0.92, reliable regression equations among PM concentrations were suggested.
        4.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        In order to investigate the variations and corelation among PM10, PM2.5 and PM1 concentrations, the hourly concentrations of each particle sizes of 300 ηm to 20 μm at a city, Gangneung in the eastern mountainous coast of Korean peninsula have been measured by GRIMM aerosol sampler-1107 from March 7 to 17, 2004. Before the influence of the Yellow Dust event from China toward the city, PM10, PM2.5 and PM1 concentrations near the ground of the city were very low less than 35.97 μg/m3, 22.33 μg/m3 and 16.77 μg/m3, with little variations. Under the partial influence of the dust transport from the China on March 9, they increased to 87.08 μg/m3, 56.55 μg/m3 and 51.62 μg/m3. PM10 concentration was 1.5 times higher than PM2.5 and 1.85 times higher than PM1. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 1.49 with an averaged 0.5 and one of (PM2.5-PM1)/PM1 had a maximum value of 0.4 with an averaged 0.25. PM10 and PM2.5 concentrations were largely influenced by particles smaller than 2.5 μm and 1 μm particle sizes, respectively. During the dust event from the afternoon of March 10 until 1200 LST, March 14, PM10, PM2.5 and PM1 concentrations reached 343.53 μg/m3, 105 μg/m3 and 60 μg/m3, indicating the PM10 concentration being 3.3 times higher than PM2.5 and 5.97 times higher than PM1. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 7.82 with an averaged 3.5 and one of (PM2.5-PM1)/PM1 had a maximum value of 2.8 with an averaged 1.5, showing PM10 and PM2.5 concentrations largely influenced by particles greater than 2.5 μm and 1 μm particle sizes, respectively. After the dust event, the most of PM concentrations became below 100 μg/m3, except of 0900LST, March 15, showing the gradual decrease of their concentrations. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 3.75 with an averaged 1.6 and one of (PM2.5-PM1)/PM1 had a maximum value of 1.5 with an averaged 0.8, showing the PM10 concentration largely influenced by corse particles than 2.5 μm and the PM2.5 by fine particles smaller than 1 μm, respectively. Before the dust event, correlation coefficients between PM10, PM2.5 and PM1 were 0.89, 0.99 and 0.82, respectively, and during the dust event, the coefficients were 0.71, 0.94 and 0.44. After the dust event, the coefficients were 0.90, 0.99 and 0.85. For whole period, the coefficients were 0.54, 0.95 and 0.28, respectively.