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        검색결과 87

        81.
        2011.11 KCI 등재 서비스 종료(열람 제한)
        Suspended and sinking particles were collected during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of carotenoids both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Fucoxanthin was the dominant carotenoid pigments both in suspended and sinking particles. The present study also indicates that 19'-hexanoyoxyfucoxanthin-containing prymesiophytes (Phaeocystis spp.) was abundant in the study area. The flux rates of carotenoids were generally highest at 50 m, and approximately double the flux rates at deeper horizons, however, at Inner Bay sites, the mean flux rates of carotenoids were greatest at 200 m, and 3 times greater than that of 50 m. Such anomalous high fluxes at 200 m imply that grazers were locally abundant between 100 m and 200 m at these sites close to land, and this hypothesis is supported by visual evidence of lots of fecal pellets in the 200 m trap. Integrates standing stocks versus sinking pigments data support that particulate material in Prydz Bay was not recycled rapidly.
        82.
        2011.06 KCI 등재 서비스 종료(열람 제한)
        Suspended and sinking particles were collected in austral summer during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of chlorophylls and their degradation products both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Chlorophylls a and c were the dominant algal pigments both in suspended and sinking particles. Because of the abundance of fecal pellets at Site 740, the mean fluxes at 200 m averaged 6 fold greater than that at 50 m. This implies that a dense swarm of zooplankters, presumably large copepods and/or salps, may "feed and excrete" mainly in between 100-200 m depths at this site, closest to land in Prydz Bay. Interestingly, The flux of phaeophorbide a was generally similar in magnitude to that of chlorophyll a throughout the study areas. This is an evidence that materials escaping from near-surface regions in austral summer derive mainly from the gazing of zooplankters. "New production" from sediment-trapped CHL pigment fluxes in Prydz Bay was estimated using f-ratio of 0.15, ranging from 520 to 1,605 μgC m-2 day-1.
        83.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        황사발생 전과 후인 2003년 10월 26일 00시부터 29일 18시까지 한국의 동쪽 연안에 있는 강릉시에서 PM10, PM2.5와 PM1 매 시각별 분포를 조사하였다. 황사가 고비사막으로부터 유입되기 전까지는 매 시각 PM10 농도가 20μg/m3 내외, PM2.5가 10μg/m3 내외, PM1가 5μg/m3 내외로 매우 낮은 농도를 나타내지만 황사가 유입된 10월 27일 09시부터 28일 05시까지는 PM10의 농도의 범위가 48.20~154.57μg/m3이며, 평상시 비해PM10의 농도가 3.8배로 높았다. 유사하게 PM2.5의 농도는 26.92~93.19μg/m3의 변화폭을 나타내며, 최대 3.4배로 높게 나타났고, PM1의 농도는 19.63~76.05μg/m3의 변화폭을 갖고, 최대 14.1배가 되었다. 황사가 나타나는 동안에는 수송된 황사먼지의 집중적인 유입과 동시에 도로 위의 차량의 밀집과 일몰 후 주거지역에서의 보일러 가동으로 출근시각인 09시와 퇴근시각인 17시에 PM의 고농도가 나타났다. 황사가 관측되기 전에는 미세입자와 극미세입자의 비율을 나타내는 (PM10-PM2.5)/PM2.5는 0.75~7.12, 극미세입자와 초극미세입자의 비율을 나타내는 (PM2.5-PM1)/PM1는 0.23~1.90로 나타났으며, 황사가 관측되는 기간에는 0.60~1.25와 0.21~0.37을 각각 나타내었다. 강릉시에 황사가 나타나기 전에는 2.5μm 큰 입자들이 2.5μm 이하의 극미세입자보다 PM10의 농도에 큰 영향을 주었으나, 황사가 관측되는 기간에는 2.5μm 이하의 극미세입자들이 PM10의 고농도 출현에 크게 기여하였다. 황사가 관측되는 기간에는 지역의 PM고농도에 2.5μm 이상의 큰 입자가 기여하는 일반적인 양상과 반대였다.
        84.
        2009.11 KCI 등재 서비스 종료(열람 제한)
        In order to measure in-situ suspended particle size, volume concentration of suspended particulate matter and current speed, mooring observation was performed at the Gwangyang Bay by using of an optical instrument, 'LISST-100' and an acoustic instrument, 'ADV'(St. S1). And the sediment flux was obtained based on the concentration of suspended particulate matter and current speeds measured at three lines of Gwangyang Bay during ebb and flood tide of August 2006. To investigate the spatial variation of suspended particulate matter, profiling observations were measured difference echo intensity and beam attenuation coefficient by using of ADCP and Transmissometer (Line A, B, C). The suspended sediment flux rate at the mouth of Gwangyang Bay was observed to be higher during asymmetrical than symmetrical of current speeds. The flux of suspended particulate matter concentration and current speeds were transported to southeastern direction of surface layer and northwestern direction of bottom layer at the western area at line A of Gwangyang Bay. Small suspended particles have been found to increase attenuation and transmission more efficiently than similar large particles using acoustic intensity (ADV/ADCP) or optical transmit coefficient (LISST-100/Transmissometer). The application and problems as using optical or acoustic instruments will be detected for use in time varying calibrations to account for non-negligible changes in complex environments in situ particle dynamics are poorly understood.
        86.
        2005.11 KCI 등재 서비스 종료(열람 제한)
        In order to investigate the distribution of suspended particulate matter of the surface water in the South Sea of Korea in early winter, the cruise results during 2 to 8 December 2004 were analyzed in relation to the hydrography. The front was formed along the line connecting between Tsushima and Cheju Islands, which divided the water into two water masses; the coastal water with low temperature and low salinity, and the Tsushima Warm Current Water with high temperature and high salinity. In the coastal water the suspended particulte matter was 5.0-6.5 mg/l, while in the oceanic water suspended particulate matter was 4.5-5.0 mg/l. The coastal water showed higher mixing effects, compared to the oceanic area where vertical stratification was clearly formed. These indicate that the distribution of suspended particulate matter was affected by the stratification or mixing of the water column. Also it is suggested that the mixing effects of sea surface cooling and wind play an important role on the distribution of suspended particulate matter in the South Sea of Korea in winter time.
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