북동태평양에서 형광 기법을 이용한 용존유기물의 기원 및 분포

손주원,손승규,주세종,김경홍,김웅서,박용철 한국해양과학기술원 2007 Ocean and Polar Research Vol.29 No.2

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at 0o, 6oN, and 10.5oN along 131.5oW in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to 171.93 mM-C. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At 6oN, depth-integrated (from surface to 200 m depth) TOC was 337.1 gC/m2, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.

북동태평양 KODOS 해역의 유기탄소 및 겉보기산소량 특성

손주원,손승규,박용철,김기현,김경홍,김동화,김태하 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.1

The samples for organic carbon analysis were collected between 5o and 17oN along 131.5oW in the northeast Pacific KODOS (Korea Deep Ocean Study) area. The mean concentration of total organic carbon (TOC) in the surface mixed layer (~50 m) was 100.13 2.05 mM-C, while the mean concentration of TOC in the lower 500 m of the water column was 50.19 4.23 mM-C. A strong linear regression between TOC and temperature (r2 = 0.70) showed that TOC distribution was controlled by physical process. Results from the linear regression between chlorophyll-a and TOC, and between chlorophyll-a and particulate organic carbon (POC), decreasing of dissolved organic carbon (DOC) in the surface layer caused by non-biological photo-oxidation process. Below the surface layer, biological production and consumption occurred. DOC accumulation dominated in the depth range of 30~50 m and DOC consumption occurred in the depth range of 50~200 m. TOC was inversely correlated with apparent oxygen utilization (AOU) and TOC/AOU molar ratios ranged from -0.077 to -0.21. These ratios indicated that TOC oxidation was responsible for 10.9~30.1% (mean 20.2%) of oxygen consumption in the NE Pacific KODOS area. In the euphotic zone, distributions of dissolved and particulate organic matter were controlled by photo-chemical, chemical, biological and physical processes.

‘쿠키닷컴’게시글의 장소성 분석

손주원 대한지리학회 2015 대한지리학회 학술대회논문집 Vol.2015 No.11

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.

북동태평양 한국 망간단괴 광구해역에서 환경충격 시험지역과 보존지역간의 수층환경 및 침강입자 플럭스 유사성 비교

손주원,김경홍,김형직,주세종,유찬민 한국해양과학기술원 2014 Ocean and Polar Research Vol.36 No.4

Verifying the similarity of environmental characteristics between an artificial impact site and a preserved or reference site is necessary to quantitatively and qualitatively evaluate the environmental impact of mining activity. Although an impact site (BIS station) and a preserved site (called KOMO station) that have been selected in the Korea manganese nodule contract area may share similar environmental characteristics, similarities in terms of the water column environment between both sites has not been investigated. In this study, we compared the chemical properties of the water columns and sinking particle fluxes between BIS and KOMO stations through two observations (August 2011 and September 2012). Additionally, we observed particle fluxes at the KOMO station for five years (July 2003~July 2008) to understand long-term natural variability. Vertical distributions of water column properties such as dissolved oxygen, inorganic nutrients (N, P, Si), total organic carbon below surface layer (within the depth range of 200 m) were not considerably different between the two sites. Especially, values of water column parameters in the abyssopelagic zone from 4000 m to bottom layer (~5000 m) were very similar between the BIS and KOMO sites. Sinking particle fluxes from the two sites also showed similar seasonality. However, natural variation of particle flux at the KOMO site varied from 3.5 to 129.9 mg m−2 day−1, with a distinct temporal variation originating from ENSO events (almost forty times higher than a minimum value). These results could provide valuable information to more exactly evaluate the environmental impact of mining activity on water columns.

열수 플룸 검출을 위한 CTD Cast와 CTD Tow-yo 방법 비교

손주원,주종민,함동진,양승진,김종욱 한국해양과학기술원 2014 Ocean and Polar Research Vol.36 No.2

Directly searching for undiscovered hydrothermal vent sites is inefficient due to the practical difficulty of comprehensively imaging vent fields. Thus, most searches for hydrothermal vent sites rely on the detection of hydrothermal plumes from water column observation. Detecting and measuring the hydrothermal plumes are the most efficient way to infer the presence and distribution of hydrothermal vents. Both the array of vertical casting and lateral towing are the most common methods to discover hydrothermal plumes. In this study, we compared results of cast and tow-yo operations along the same section of a spreading center with a distance of 20.5 km in the North Fiji Basin for mapping hydrothermal plumes. Operation of CTD tow-yo provides a detailed pattern of plumes which enable us to locate the hydrothermal vents. On the other hand, identification of hydrothermal activity can be determined effectively by CTD cast with additional analysis of geochemical tracers. Reduction in the operating time is another advantage of CTD cast operation, especially for regional-scale survey. Our results show that the combination of CTD cast and tow-yo would improve the efficiency of the hydrothermal plume survey to locate new hydrothermal vent sites.

인도양 중앙 해령의 열수 plume 추적

손주원,유옥례,주종민,양승진,손승규 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.5

북동태평양 적도 Thermocline Ridge 해역에서 영양염(질소, 인, 규소)과 유기탄소(용존 및 입자)의 분포 특성 및 연간 변화

손주원,김경홍,김미진,손승규,지상범 한국해양과학기술원 2011 Ocean and Polar Research Vol.33 No.1

The distribution and inter-annual variation of nutrients (N, P, Si) and dissolved/particulate organic carbon were investigated in the equatorial thermocline ridge (7o~11.5oN, 131.5oW) of the northeast Pacific. From the Oceanic Nino Index and Multivariate ENSO Index provided by NOAA, normal condition was observed in July 2003 and August 2005 on the aspect of global climate/ocean change. However, La Niña and El Niño episodes occurred in July 2007 and August 2009, respectively. Thermocline ridge in the study area was located at 9oN in July 2003, 8oN in August 2005, 10oN in July 2007, and 10.5oN in August 2009 under the influence of global climate/ocean change and surface current system (North Equatorial Counter Current and North Equatorial Current) of the northeast Pacific. Maximum depth integrated values (DIV) of nutrients in the upper layer (0~100 m depth range) were shown in July 2007 (mean 21.12 gN/m2, 4.27 gP/m2, 33.72 gSi/m2) and higher variability of DIV in the equatorial thermocline ridge was observed at 10oN during the study periods. Also, maximum concentration of dissolved organic carbon (DOC) in the upper 50 m depth layer was observed in July 2007 (mean 107.48±14.58 μM), and particulate organic carbon (POC, mean 9.42±3.02 μM) was similar to that of DOC. Nutrient concentration in the surface layer increased with effect of upwelling phenomenon in the equatorial thermocline ridge and La Niña episode, which had formed in the central Pacific. This process also resulted in the increasing of organic carbon concentration (DOC and POC) in the surface layer. From these results, it is suggested that spatial and temporal variation of chemical and biological factors were generated by physical processes in the equatorial thermocline ridge.

한국 연안수에서 총유기탄소 및 화학적 산소요구량 분포 특성

손주원,박용철,이효진 한국해양학회 2003 바다 Vol.8 No.3

연안수에서 유기 화합물의 정량적인 특성을 파악하기 위하여 인천 연안 지역, 포항의 영일만을 포함한 형산강 지역 그리고 부산 연안 지역에서 시료를 채취하였다. 또한 강화도와 세어도에서 고정관측도 하였다. 연안수의 총유기탄소(TOC)와 염분과의 상관 관계 및 화학적 산소요구량(COD)과 염분과의 상관 관계를 이용하여 추정한 하천에서 연안역으로 유입되는 총유기탄소의 riverine end-member 값은 5.32 mg C/l, 화학적 산소요구량의 riverine end-member 값은 8.87 mg $O_2$/1로 나타났다 고온 촉매 산화(HTCO)방법을 이용하여 측정한 총유기탄소와 화학적 산소요구량을 비교한 결과 화학적 산소요구량은 총유기탄소의 약 47%를 반영하는 것으로 나타났다. 총유기탄소와 화학적 산소요구량에 대한 상관 관계식은 COD(mgO$_2$,/1)=0.61$\times$TOC(mg C/l)-0.03,($R^2$=0.66)으로 이 관계식을 이용하면 기존에 보고된 화학적 산소요구량으로 총유기탄소를 추정하는데 활용할 수 있을 것으로 판단된다. In order to improve our knowledge of the characteristics of organic compounds in coastal waters, water samples were collected from the Incheon coastal region, the Hyungsan River in Youngil Bay and the Busan coastal region. Also, mooring was carried out near the Kanghwa Island and Seo Island. In this study, the relationship between the total organic carbon (TOC) and salinity, chemical oxygen demand (COD) and salinity were evaluated and determined. Riverine end-member of TOC into the Korean coastal area and its COD estimated from these relationships were 5.32 mg C/l and 8.87 mg O$_2$/l, respectively. The oxidation efficiency of COD to TOC estimated using the high-temperature catalytic oxidation method was about 47%. The linear relationship between TOC and COD was derived as COD (mg O$_2$/l)=0.61${\times}$TOC (mg C/l) -0.03, (R$^2$=0.66). Therefore, it is possible to estimate total organic carbon using this equation from previously reported chemical oxygen demand.

인도양 중앙 해령의 열수 plume 추적 : 탁도 아노말리 및 메탄 분포

손주원,유옥례,주종민,양승진,손승규 대한조선학회 2012 대한조선학회 학술대회자료집 Vol.2012 No.5