• 한국대기환경학회지
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• 제24권5호
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• pp.501-511
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• 2008

The Objective of this study is to examine the characteristic of fine aerosol $(PM_{2.5})$ obtained at Ieodo Ocean Research Station, which lies between the eastern part of China and the south western part of Korea. The average mass concentration of $PM_{2.5}$ was $21.5{\pm}17.0{\mu}g/m^3$ during June $2004{\sim}June 2006$. The concentration was the highest in winter $(34.8{\mu}g/m^3)$ and lowest in summer $(16.5{\mu}g/m^3)$. Water soluble ions were measured for samples collected from December 2004 to September 2005. Among them, $SO_4^{2-}\;and\;NH_4^+$ were the most abundant species and accounted for 32.2% and 14.2% of the $PM_{2.5}$ mass, respectively. The mass fraction of $SO_4^{2-}$ was higher in winter (42%) than in spring (26%). Nitrate concentrations were much lower than those of sulfate due mainly to evaporation during sampling period. The cluster analysis of backward airmass trajectories showed that the high mass loadings $(26.9{\mu}g/m^3\;on\;average)$ were associated with air originating inland China. Also, the seasonal variation of $PM_{2.5}$ mass was well correlated with the frequency of westerly winds passing through the western part of China. During the ABC-EAREX2005 (March 2005), $PM_{2.5}$ mass and major ionic concentrations were higher at Ieodo, compared with $PM_{2.5}$ measurements at Gosan while they were similar in variation pattern. These results suggested that $PM_{2.5}$ mass and its ionic composition of Ieodo Ocean Research Station were greatly influenced by continental outflows from China.

• Ocean and Polar Research
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• 제26권2호
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• pp.145-154
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• 2004

Surface energy and $CO_2$ fluxes have been measured over an ocean at Ieodo Ocean Research Station of KORDI since May 2003. Eddy covariance technique, which is a direct flux measurement, is used to quantitatively understand the interaction between the ocean surface and the atmospheric boundary layer. Although fluxes were continuously measured during the period from May 2003 to February 2004, the quality control of these data yielded <20% of data retrieval. The atmospheric stability did not show any distinct dirunal patterns and remained near-neutral to stable from May to June but mostly unstable during fall and winter in 2003. Sensible heat flux showed a good correlation with the difference between the sea water temperature and the air temperature. The maximum fluxes of sensible heat and latent heat were $120Wm^{-2}$ and $350Wm^{-2}$ respectively, with an averaged Bowen ratio of 0.2. The ocean around the tower absorbed $CO_2$ from the atmosphere and the uptake rates showed seasonal variations. Based our preliminary results, the daytime $CO_2$ flux was steady with an average of $-0.1 mgCO_2m^{-2}s^{-1}$ in summer and increased in winter. The nighttime $CO_2$ uptake was greater and fluctuating, reaching up to $-0.1 mgCO_2m^{-2}s^{-1}$ but these data require further examination due to weak turbulent mixing at nighttime. The magnitude of $CO_2$ flux was positively correlated with the half hourly changes in horizontal mean wind speed. Due to the paucity of quality data, further data collection is needed for more detailed analyses and interpretation.

• 한국지구과학회지
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• 제41권4호
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• pp.323-343
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• 2020

Observation data measured at Ieodo Ocean Research Station (IORS) have been utilized in oceanographic and atmospheric studies since 2003. Sea level data observed at the IORS have not been paid attention as compared with many other variables such as aerosol, radiation, turbulent flux, wind, wave, fog, temperature, and salinity. Total sea level rises at the IORS (5.6 mm yr^-1) from both satellite and tide-gauge observations were higher than those in the northeast Asian marginal seas (5.4 mm yr^-1) and the world (4.6 mm yr^-1) from satellite observation from 2009 to 2018. The rates of thermosteric, halosteric, and steric sea level rises were 2.7-4.8, -0.7-2.6, 2.3-7.4 mm yr^-1 from four different calculating methods using observations. The rising rate of the steric sea level was higher than that of the total sea level in the case with additional data quality control. Calculating the non-steric sea level was not found to yield meaningful results, despite the ability to calculate non-steric sea level by simply subtracting the steric sea level from total sea level. This uncertainty did not arise from the data analysis but from a lack of good data, even though tide, temperature, and salinity data were quality controlled two times by Korea Hydrographic and Oceanography Agency. The status of the IORS data suggests that the maintenance management of observation systems, equipment, and data quality control should be improved to facilitate data use from the IORS.

• 한국해양학회지:바다
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• 제22권3호
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• pp.57-68
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• 2017

이어도 종합해양과학기지(IORS, Ieodo Ocean Research Station) 주변 해역은 시 공간적으로 해양 환경 변화가 심하여, 해양-대기교환 과정을 비롯하여 해양 생태계와 기후 변화 연구에 필수적인 해수면온도(SST, Sea surface temperature) 자료의 지속적인 측정이 요구되는 해역이다. 본 연구에서는 이어도 종합해양과학기지에 열적외선 센서를 이용하여 해수면온도 연속 관측이 가능한 시스템을 구축하였다. 자동 대기 보정 및 해양 조건에 따른 방사율 계산이 가능한 해수면온도 추출 알고리즘을 개발하였고, 현장측정 해수면온도 자료와의 비교 및 검증을 통해 정확도를 평가하였다. 2015년 5월 17일부터 26일, 그리고 2016년 7월 15일부터 18일까지 기지에 체류하는 동안 열적외선 관측 시스템으로 측정된 해수면온도와 기지 부착 CT (Conductivity-Temperature) 및 튜브 부착 수온 센서들을 이용하여 현장에서 측정된 해수면온도 시계열을 비교하여 상호상관계수0.72-0.85, 평균제곱근 편차 $0.37-0.90^{\circ}C$의 정확도를 얻었다. 이 시스템은 이어도 종합해양과학기지뿐만 아니라 신안 가거초 및 옹진 소청초 등의 다른 종합해양과학기지에도 쉽게 구축이 가능한 시스템으로써 향후 발사될 인공위성의 해수면온도 산출알고리즘 개발의 테스트사이트나 검보정사이트로 활용될 수 있을 것으로 기대할 수 있다.

• 대기
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• 제17권4호
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• pp.421-433
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• 2007

We have investigated the seasonal characteristics of surface turbulent fluxes observed at Ieodo Ocean Research Station from 2005 to 2006. Both 10Hz and 30 minutes flux data are quality controled, and tilt correction is performed in 10Hz data before quality control. The turbulent fluxes of open sea shows clear seasonal variations, though diurnal variations are barely shown. The seasonal ratio of stable and unstable conditions are closely related to the temperature difference between sea surface and air. In stable and semi-stable condition, latent and sensible heat fluxes have very small values without any relationship with wind speed. Though friction velocity shows slightly increasing trend with wind speed, it has many outliers. In unstable condition, turbulent fluxes increased with wind speed. Especially, latent heat flux increased rapidly during DJF. The latent heat flux at high wind speeds is more scatter.

• Ocean Science Journal
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• 제41권4호
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• pp.235-244
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• 2006

Determining 'photosynthetically active radiation' (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PAR irradiance-ratio values is appropriate in calculating phytoplankton productivity as follows: an average of $0.44\;({\pm}0.01)$ in January to an average of $0.48\;({\pm}0.01)$ in July, with average daily variabilities over these periods of about $0.016\;({\pm}0.008)$ and $0.025\;({\pm}0.008)$, respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.

• 한국환경과학회지
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• 제29권11호
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• pp.1141-1151
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• 2020

The impact of sound speed variability in the sea is the very important on acoustic propagation for the underwater acoustic systems. Understanding of the temporal and spatial variability of ocean sound speed in the sea around the Ieodo were obtained using oceanographic data (temperature, salinity). from the Korea Oceanographic Data Center, collected by season for 17 years. The vertical distributions of sound speed are mainly related to seasonal variations and various current such as Chinese coastal water, Yellow Sea Cold Water (YSCW), Kuroshio source water. The standard deviations show that great variations of sound speed exist in the upper layer and observation station between 16 and 18. In order to quantitatively explain the reason for sound speed variations, Empirical Orthogonal Function (EOF) analysis was performed on sound speed data at the Line 316 covering 68 cruises between 2002 and 2018. Three main modes of EOFs respectively revealed 55, 29, and 5% the total variance of sound speed. The first mode of the EOFs was associated with influence of surface heating. The second EOFs pattern shows that contributions of YSCW and surface heating. The first and second modes had seasonal and inter-annul variations.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2007년도 추계학술대회 논문집
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• pp.213-214
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• 2007

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2014년도 춘계학술대회
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• pp.68-69
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• 2014

우리나라 관할해역까지 확장된 해상교통 모니터링이 필요하여, 장기적으로는 전 세계 원하는 해역의 선박 모니터링이 요구되는 시점이다. 이를 통해서만 우리의 Sea Line의 확보가 가능하며, 해양 경제영토의 확장이 가능하기 때문이다. 이와 같은 목표를 위한 초기 단계로, 경기만 연안 통합모니터링 시험을 거쳐 2013년 11월에는 이어도해양과학기지에서 실험이 이루어졌으며, 이 결과를 이번 학술대회에서 소개하고자 한다.

• 한국해안해양공학회지
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• 제14권2호
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• pp.161-170
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• 2002

이어도 해양과학기지의 풍력을 검토하기 위하여 50m/s의 설계풍속에 대하여 풍동실험과 수치해석을 수행하였다. 해수면위 상부구조물의 축소모형(1/80)에 대하여 풍력 및 모멘트를 계측하고 풍력계수를 산출하여 수치해석 결과와 비교한 결과, 이들 결과들이 대체적으로 잘 일치함을 확인하였다 따라서, 본 풍동실험의 결과를 상부구조물의 내풍설계자료로 충분히 활용할 수 있을 것으로 판단된다 실험결과를 이용하여 상부구조물 전체에 작용하는 풍력 및 모멘트 값들과 그리고 불투과 부속시설(주 데크, 태양광 발전판, 헬기 이 착륙장)의 외장 설계풍압과 구조설계용 풍압을 제시하였다.