CTD 교정과 불확도 평가

이정한,황근춘,김은수,이승훈 한국해양과학기술원 2014 Ocean and Polar Research Vol.36 No.1

The quality control of ocean observations data is becoming a major issue as real-time observational data and information services have increased recently. Therefore, it is necessary for oceanographic instruments to calibrate. In this paper, we first introduce the CTD calibration system and traceability. Next, CTD calibration procedures and estimation of uncertainty of measurement are described. The expanded uncertainty (k = 2) of the temperature, pressure and conductivity are 0.003oC, 6.0 × 10−5 and 0.006 mS/cm respectively. Finally, the excellence of CTD calibration and its measurement capability has been proven by comparing the inter-calibration result of KIOST and Sea-Bird Electronics (SBE). CTD calibration residuals are less than ±0.0001oC, ±0.001 MPa, ±0.0001 S/m for SBE 3plus temperature sensor, SBE 19plus pressure sensor and SBE 4C conductivity sensor respectively.

초음파 도플러 유속계 교정 시설 현황

이정한,황근춘,김은수 한국해양과학기술원 2011 Ocean and Polar Research Vol.33 No.2

Despite technological developments and application advances of Acoustic Doppler Current Profilers (ADCPs), no standard procedure has been adopted or accepted for calibration of ADCPs. Limitations of existing facilities for calibrating ADCPs, the complexity of ADCP instruments, and rapid changes in ADCP technology are some of the reasons why a standard procedure has not been adopted. However, there is increasing realization of the need for effective Quality Assurance (QA) and as part of that the importance of standardized calibration. In this study, the significance of calibration and QA plans for ADCPs is discussed and the calibration facilities for ADCPs at home and abroad are reported. Furthermore, the method for calibrating ADCPs using a towed car and its limitations are discussed. This study contributes to discussions surrounding the establishment of standard procedures for calibrating ADCPs and QA plans, and the construction of calibration facilities in the future.

질산염 첨가에 따른 중형폐쇄생태계 내 플랑크톤 군집의 변화

강정훈,김웅서,신경순,장만,황근춘 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.3

Temporal variation of the natural planktonic community in the Southern Sea of Korea was investigated by using four floating enclosed bags (3.2m deep and 2,500 liter) in order to understand the effect of enriched nitrate on the planktonic community in the spring (March-April) of 2002. Prior to beginning the incubation, the bags were placed in two different concentrations of nitrate, which consisted of control (ambient water) and experimental mesocosms (final concentration of 12M). The nitrate concentration in the experimental mesocosms remained significantly higher than those in control mesocosms throughout the study period (ANOVA, p<0.001). Following the addition of nitrate, abundance and chl-a concentration of phytoplankton peaked on Day 1, when diatoms established the peak in the experimental mesocosms. Diatoms consisted mainly of Thalassiosira decipiens, Pseudo-nitzschia pungens, Leptocylindrus danicus, Thalassionema nitzschioides, Chaetoceros pseudocrinitus and Actinoptychus senarius. However, the peak did not lead to the difference in abundance and composition of phytoplankton between control and experimental mesocosms during the study period. The dinoflagellates began to increase soon after the diatoms decreased in all mesocosms. Copepods, as a dominant group in the mesozooplankton community, showed no immediate peak in relation to the nitrate addition, but only their own developmental process from the eggs to adult stage during the study period. The bottom-up control from enriched nitrate via phytoplankton to adult copepods was not distinguished in terms of the abundance of the planktonic community. This might stem from the relatively low nitrate availability of phytoplankton at no N-limited seawater and the weak coupling between rapidly sunken diatoms and copepods through the water column.

열대 태평양에서 운영되는 TRITON 부이와 비교를 통한 KORDI 부이 시스템 개선 연구

김동국,전동철,김응,황근춘,황상철 한국해양과학기술원 2011 Ocean and Polar Research Vol.33 No.3

This study documents KORDI's experience of successfully deploying a deep ocean buoy for monitoring oceanic and atmospheric variabilities in the tropical western Pacific Ocea nsince May 2010. The primary focus of this study was to compare TRITON (big and old type) with m-TRITON (smaller and new type) buoys within the JAMSTEC's buoy management system. The objective of operating a KORDI buoy is to ascertain oceanic variability in the tropical western Pacific. We adopted a slack-line mooring type to observe water temperatures at six layers from surface to 400 m depth. However, we could not acquire satisfactory results due to lack of expertise in buoy management system. A new KORDI buoy has been developing, which has been modified from both buoys, and ARGOS-3 satellite system and a slack-type mooring line.

2001년 5월과 6월 서태평양에서의 Thermosalinograph 관측

이재학,전동철,황상철,정병철,황근춘,이하웅 한국해양과학기술원 2002 Ocean and Polar Research Vol.24 No.3

We have analyzed sea surface temperature and salinity data collected in the western Pacific Ocean by using an automated Thermosalinograph (TSG) installed on the RV Onnuri during May - June of 2001. The TSG data exhibit characteristics of water masses distributed in the near surface layer of the cruise area very well. Especially, they reveal the diurnal surface temperature cycle and the effect of rainfall on temperature and salinity in the equatorial region, showing the effectiveness of the use of TSG. Problems to be improved for the better TSG operation are the method of water sampling and calibration of TSG sensors. Installation of a pressure gauge in the TSG system and periodical sensor calibration are strongly recommended to ensure reliability of data. 및 토의2001년 5-6월 한국해양연구원에서 연구선 온누리호를 이용하여 수행된 서태평양 대양항해 중 자동 기록으로 획득된 TSG 자료를 분석하고 이의 운용상 문제점 및 개선책을 제시하였다. 관측된 TSG 값은 CTD 측정값에 비하여 수온은 약 +0.3oC, 염분은 시간에 따라 약 0.06에서 +0.04 psu 편향오류를 보여주었으며, 관측오류의 요인은 취수된 해수의 TSG까지 이동시 수온 상승과 TSG 내에서의 미세한 기포로 판단된다. TSG 운용상 제기된 문제점은 TSG 센서를 통과하는 해수의 공급의 방법(즉, 통과 유속 증가에 의한 센서 통과 해수 내 기포 생성 유무)과 자료(특히, 염분) 검정 문제였다. 관측오류를 감소시키기 위하여 TSG 상태를 쉽게 판단할 수 있도록 기포감지기와 압력계의 설치가 필요하며, TSG 센서의 사전 검·교정이 이루어졌을 경우라도 TSG 자료를 검정할 수 있는 CTD 또는 염분계에 의한 현장 측정이 필수적인 것으로 나타났다.TSG 자료는 동중국해 대륙붕, 쿠로시오 통과해역, 필리핀해 및 서태평양 적도해역 표층의 해황을 잘 나타내었다. 특히, 적도해역에서 표층수온은 약 0.4-1.3oC 변화 폭의 뚜렷한 일 변화를 보여주었고 일중 최고 및 최저 수온은 현지 시간으로 14-15시 및 5-6시경으로 나타나 수온 상승 시간이 하강 시간보다 빠른 것으로 나타났다. 기상 자료와 비교 결과 구름에 의한 태양복사 차단 영향이 약 0.5oC 정도임을 시사해주었다. 적도해역에서 특징적인 염분 변화는 수 십 분에서 수 시간 지속되는 저염의 peak로 이는 열대 소나기성 강우의 영향으로 판단되며 수온도 약 0.2-0.6oC 정도로 낮아지는 영향을 주는 것으로 관측되었다.TSG 자료로부터 여러 해양물리학적 해석이 가능하였던 점은 TSG의 유용성을 나타낸 것으로 적절한 자료 처리 과정을 거치면 TSG 자료가 항해 해역 표층의 물리적인 해황 특성을 정확하게 나타낼 수 있다는 것을 의미한다. 이는 또한 국내의 TSG 운용의 수준이 SOOP(2001)과 같은 선박을 이용한 해양 표층 해황의 모니터링 프로그램에 참가 할 수 있는 수준에 근접해 가고 있음을 나타낸 것이라 할 수 있다. 따라서 앞으로는 연구사업에 관련된 항해에서뿐만 아니라 모든 항해 기간 중 TSG 자료가 획득될 수 있도록 하여 유용한 자료의 누적을 도모하고 연구선 활용의 효율을 높여야 할 것이다. 아울러 TSG 자료를 전지구해양예보를 위한 자료동화에 이용될 수 있도록 위성통신 등을 이용한 준 실시간 자료 전달 체계의 구성이 바람직하다.

전자태그를 이용한 해양 연구 기기 및 장비 통합 관리시스템

이정한(Jung-Han Lee),황근춘(Keun-Choon Hwang),김은수(Eun-Soo Kim) 한국해양환경·에너지학회 2011 한국해양환경·에너지학회지 Vol.14 No.3

열대 태평양에서 운영되는 TRITON 부이와 비교를 통한 KORDI 부이 시스템 개선 연구

김동국,전동철,김응,황근춘,황상철,Kim, Dong-Guk,Jeon, Dong-Chull,Kim, Eung,Hwang, Keun-Choon,Hwang, Sang-Chul 한국해양과학기술원 2011 Ocean and Polar Research Vol.33 No.suppl3

This study documents KORDI's experience of successfully deploying a deep ocean buoy for monitoring oceanic and atmospheric variabilities in the tropical western Pacific Ocea nsince May 2010. The primary focus of this study was to compare TRITON (big and old type) with m-TRITON (smaller and new type) buoys within the JAMSTEC's buoy management system. The objective of operating a KORDI buoy is to ascertain oceanic variability in the tropical western Pacific. We adopted a slack-line mooring type to observe water temperatures at six layers from surface to 400 m depth. However, we could not acquire satisfactory results due to lack of expertise in buoy management system. A new KORDI buoy has been developing, which has been modified from both buoys, and ARGOS-3 satellite system and a slack-type mooring line.

광양만에서 무기 영양염의 시공간적 분포를 조절하는 요인

장풍국,이재도,장만,신경순,이원제,장민철,이우진,황근춘 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.4

In order to understand the spatial and temporal variations of nutrients and factors controlling their distribution in Gwangyang Bay, this study was carried out bimonthly from June 2001 to July 2003. Inorganic silicate and nitrate concentrations ranged from 0.04mM to 69.5mM (avg. 12.9 mM), and from 0.12 mM to 42.2 mM (avg. 7.83 mM), respectively. Silicate concentrations measured just after the typhoon were the highest with an average of 43.2 mM at the surface layer in June 2001, whereas the highest nitrate concentration (avg. 37.0 mM) was observed in the surface layer in July 2003. River runoff apparently influenced variations in silicate and nitrate concentrations (r=0.701 and 0.728, p<0.000, respectively) as well as salinity (r = -0.628, p<0.000). Phosphate concentrations ranged from 0.24 mM to 5.70 mM (avg. 1.34mM) and were highest at stations 5, 6, and 7, near a fertilizer plant with an average of 2.01 mM. On the basis of N/P and Si/N molar ratios, limiting nutrients have varied temporary and spatially. During 2001-2002, nitrogen was a limiting nutrient in the study area, and phosphate was limited when a large volume of freshwater flowed into the bay. Silicate was limited when the high standing crops of phytoplankton occurred in the whole study area throughout 2003, and in the inner bay in February and August 2002. During the study period, factors controlling the distribution of nutrients might be summarized as follows; 1) inflow of freshwater by heavy rain accompanied by typhoons and frequent rainfall in summer, showing high concentrations of silicate and nitrate, 2) release of high phosphate concentrations from the fertilizer plant located in the south of Moydo to adjacent stations, 3) release of nutrients from bottom sediment, 4) magnitude of occurrence of phytoplankton standing crops.

북동태평양 발산대 해역($7^{\circ}{\sim}10.5^{\circ}N$)의 무기영양염 분포와 재무기질화 비율

손주원,김경홍,김미진,손승규,지상범,황근춘,박용철,Son, Ju-Won,Kim, Kyeong-Hong,Kim, Mi-Jin,Son, Seung-Kyu,Chi, Sang-Bum,Hwang, Keun-Choon,Park, Yong-Chul 한국해양학회 2008 바다 Vol.13 No.3

2003년 7월, 2005년 8월 그리고 2007년 7월에 북동태평양의 발산대 해역($7^{\circ}{\sim}10.5^{\circ}N$)에서 무기영양염 분포와 재무기질화 비율 연구를 위한 조사를 수행하였다. 북적도 반류와 북적도 해류의 경계에서 형성되는 발산대는 라니냐 현상이 있었던 2007년 7월에 북위 $10^{\circ}N$에 위치하였으며, 용승 현상이 강하게 일어났다. 빈영양 환경의 특성을 갖는 표면 혼합층의 깊이는 2003년에 평균 46 m, 2005년에 평균 61 m 그리고 2007년에 평균 30 m 이었고, 표면 혼합층 이하에서는 용존산소 소모와 더불어 무기영양염 농도가 급격하게 증가하는 영양염약층이 형성됐다. 상층(수심 $0{\sim}100m$)에서 아질산염을 포함한 질산염의 총량은 2003년에 $5.51{\sim}21.71gN/m^2$(평균 $12.82gN/m^2$)의 범위를 나타냈고, 2005년에는 $5.62{\sim}8.46gN/m^2$(평균 $7.15gN/m^2$)의 범위를 그리고 2007년에는 $8.98~27.80 gN/m2$(평균 21.12 gN/m2)의 범위로 발산대가 형성된 지점에서 높은 값을 나타냈다. 인산염 총량과 규산염 총량 또한 아질산염을 포함한 질산염 총량 분포와 유사하였으며, 상층에서 파악된 아질산염을 포함한 질산염 총량에 대한 규산염 총량의 비율은 $0.87{\pm}0.11$ 이었다. 연구 해역에서 식물 플랑크톤 성장을 제한하는 무기영양염은 질소계 영양염으로(N/P ratio=14.6), 북적도 반류 지역에 비해 북적도 해류 지역에서 보다 낮은 농도를 나타냈다. 규산염 또한 낮은 농도로 존재하여 규소 제한 환경을 이루었다. 본 연구를 통해 분석된 재무기질화 비율은 $P/N/-O_2=1/14.6{\pm}1.1/100.4{\pm}8.8(23.44{\leq}Sigma-{\theta}{\leq}26.38)$로 Redfield stoichiometry($P/N/-O_2=1/16/138$) 보다는 낮았지만, 연구 해역 표층에서 재무기질화 과정을 설명하기에 충분하였다. The distribution of inorganic nutrients and their remineralization ratio in the divergence zone ($7^{\circ}{\sim}10.5^{\circ}N$) of the northeastern Pacific were investigated from July 2003 to July 2007. A divergence zone along the boundary of the North Equatorial Counter Current (NECC) and North Equatorial Current (NEC) at $10^{\circ}N$ was observed in July 2007 when the La Nina event and divergence-related upwelling was strong. The mean depth of oligotrophic surface mixed layer in the divergence zone was 46, 61, and 30 m in July 2003, August 2005, and July 2007, respectively. Below the surface mixed layer, a nutricline was clearly observed. The depth integrated value of nitrate including nitrite (DIVn) in the upper layer($0{\sim}100$ m depth) ranged from 5.51 to 21.71 $gN/m^2$(mean 12.82 $gN/m^2$) in July 2003, from 5.62 to 8.46 $gN/m^2$ (mean 7.15 $gN/m^2$) in August 2005, and from 8.98 to 27.80 $gN/m^2$(mean 21.12 $gN/m^2$) in July 2007. The maximum DIVn was observed at the divergence zone. The distributions of phosphate(DIVp) and silicate(DIVsi) were similar to that of DIVn and the DIVn/DIVsi ratio was $0.87{\pm}0.11$ in the upper layer. The limiting nutrient for phytoplankton growth in the study area was identified as nitrogen(N/P ratio=14.6). The nitrate (including nitrite) concentrations were lower in the region mainly affected by NEC than in the region affected by NECC. The study area of low silicate concentrations was also considered to be Si-limiting environment. The remineralization ratios of nutrients were $P/N/-O_2=1/14.6{\pm}1.1/100.4{\pm}8.8(23.44{\leq}Sigma-{\theta}{\leq}26.38)$ in the study area. These ratios suggested remineralization process in the surface layer of divergence zone.

남해안 반폐쇄성 해역 퇴적물의 중금속 분포와 오염역사

김경태(K.T. Kim),김은수(E.S. Kim),황근춘(K. C. Hwang),정경호(K.H. Chung),조성록(S.R. Cho),박준건(J.K. Park) 한국해양환경·에너지학회 2006 한국해양환경공학회 학술대회논문집 Vol.2006 No.-

반폐쇄성 해역인 고현만의 중금속 분포 특성과 오염 역사를 파악을 위하여 표층 및 주상 퇴적물조사를 수행하였다. 표층 퇴적물의 경우 조선소 배출구 주변에서 Cu와 ZN이 높은 농도를 나타내었으며, 만 내측에서 외측으로 가면서 급격하게 감소하는 경향을 보였다. 정점 2와 6의 주상 퇴적물에서 Cu, Zn, Cd 및 Pb 등의 중금속은 1920년부터 1970년까지 완만하게 증가하였으나 1970년부터 2000년까지는 급격한 증가 추세를 나타내었고, 이후엔 감소하였다. 고현만 해역의 높은 Cu와 Zn은 신조선 건조와 선박활동에 기인한 것으로 한 생각된다. In order to investigate spatial and temporal distribution of heavy metals in sediments of Gohyun Bay, one of the semi-enclosed bays in Korea. Highly elevated Cu and Zn contents were found in surface sediments near shipyard effluent outlet. Metal contents in the surface sediments steeply decreased towards of coast. Cu and Zn contents are Heavy metal(Cu, Zn, Cd and Pb) contents in sediment cores from St. 2 and 6 slowly increased during the period of 1920-1970, rapidly increased during 1970-2000, and followed by slight decrease after 2000. The highest value of metal(Cu, Zn, Cd and Pb) excesses among the sediment cores were found at St. 2. The hot spots for Cu and Zn in this bay are likely to result from ship building and activities.