해색위성 GOCI을 이용한 녹조(green algae bloom)의 탐지 및 이상 분포 추적

손영백,유주형,박영제,유정미,한희정,민지은,이보람,박영규 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.5

남해와 동중국해에서 위성으로 추정된 표층수온 및 클로로필의 장기 변화

손영백,유주형,노재훈,주세종,김상현 한국해양과학기술원 2012 Ocean and Polar Research Vol.34 No.2

The purpose of this study is to investigate climatological variations from the sea surface temperature (SST), chlorophyll-a concentration (Chl-a), and phytoplankton size class (PSC), using NOAA AVHRR, SeaWiFS, and MODIS data in the South Sea of Korea (SSK) and East China Sea (ECS). 26-year monthly SST and 13-year monthly Chl-a and PSC data, separated by whole and nine-different areas, were used to understand seasonal and inter-annual variations. SST and Chl-a clearly showed seasonal variations: higher SST and Chl-a were observed during the summer and spring, and lower values occurred during the winter and summer. The annual and monthly SST over 26 years increased by 0.2~1.0oC. The annual and monthly Chl-a concentration over 13 years decreased by 0.2~1.1 mg/m3. To determine more detailed spatial and temporal variations, we used the combined data with monthly SST, Chl-a, and PSC. Between 1998 and 2010, the inter-annual trend of Chl-a decreased, with decreasing micro- and nano-size plankton, and increasing pico-size plankton. In regional analysis, the west region of the study area was spatially and temporally correlated with the area dominated by decreasing micro-size plankton; while the east region was less sensitive to coastal and land effects, and was dominated by increasing pico-size plankton. This phenomenon is better related to one or more forcing factors: the increased stratification of ocean driven by changes occurring in spatial variations of the SST caused limited contributions of nutrients and changed marine ecosystems in the study area.

Detecting Massive Green Algae (Ulva prolifera) Blooms in the Yellow Sea and East China Sea using Geostationary Ocean Color Imager (GOCI) Data

손영백,민지은,류주형 한국해양과학기술원 2012 Ocean science journal Vol.47 No.3

The historically massive bloom of the green macroalgae Ulva prolifera reported in June-August 2008 around the Qingdao, Yellow Sea, East China Sea and Japan coasts has recurred in a similar season and region. On June 13, 2011,around Qingdao, China, the world’s first Geostationary Ocean Color Imager (GOCI) detected an enormous bloom of floating green algae, which originated from the nearshore Subei Bank, China. The large floating green algae patches were observed along and across the Yellow Sea and in the East China Sea during 2011 summer by various oceanic cruises. To detect the massive macroalgae blooms from space, we analyzed their spectral characteristics from in situ optical measurements and satellite-derived green algae spectra. An “Index of floating Green Algae for GOCI” (IGAG) was developed from the multiple spectral band ratios using three wavelengths (555, 660, 745 nm), which the spectral response of green algae reflected at 555, 745, and 865 nm and absorbed at 660 and 680 nm. The results were compared with those obtained by the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and Korea Ocean Satellite Center (KOSC) approaches. An advantage of the IGAG method was that muted or subtle signals of floating green algae were enhanced and separated from surrounding complex water signals. Although maps of floating green algae derived by the other approaches delineated dense green algae, they were less sensitive to subtle (less dense) features and in cases of nearby cloudy or complex water conditions. The floating green algae maps from IGAG provided a more robust estimate of wide floating green algae blooms than those derived using NDVI, EVI, or KOSC approaches. The IGAG approach should be useful for tracing and monitoring changes in green algae blooms on regional and global scales.

해색위성 GOCI을 이용한 녹조(green algae bloom)의 탐지 및 이상 분포 추적

손영백,유주형,박영제,유정미,한희정,민지은,이보람,박영규 대한조선학회 2012 대한조선학회 학술대회자료집 Vol.2012 No.5

저궤도 원격탐사 활용 제주연안 해조류 탐지 및 변화 분석

손영백,민승환,권순열,박광섭,이태희 한국환경생물학회 2020 한국환경생물학회 학술대회 Vol.2020 No.11

GOCI에서 관측된 일본 센다이 지진해일(tsunami) 효과

손영백,유주형,박영제,최종국,문정언,안재현,안유환,한희정,이순주,조성익 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.6

기후변화가 주는 제주 바다의 변화

손영백 제주학회 2021 제주학회 학술발표논문집 Vol.2021 No.2

동중국해에서 위성에서 추정된 10년 동안의 표층 입자성 유기 탄소의 시/공간적 변화

손영백,이태희,최동림,장성태,김철호,안유환,유주형,김문구,정섬규,Son, Young-Baek,Lee, Tae-Hee,Choi, Dong-Lim,Jang, Sung-Tae,Kim, Cheol-Ho,Ahn, Yu-Hwan,Ryu, Joo-Hyung,Kim, Moon-Koo,Jung, Seom-Kyu,Ishizaka, Joji 대한원격탐사학회 2010 대한원격탐사학회지 Vol.26 No.4

Surface particulate organic carbon (POC) concentration estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data is used to determine spatial and temporal variations of the Changjiang Diluted Water (CDW) in the East China Sea. 10-year monthly POC concentrations (1997-2007) show clearly seasonal variations. Inter-annual variation of POC in whole and three different areas separated by standard deviation is not linearly correlated with the Changjiang River discharge that has decreased after 1998. To determine more detailed spatial and temporal POC variations, we used empirical orthogonal function (EOF) analysis in summer (Jun.-Sep.) from 2000 to 2007. First mode is spatially and temporally correlated with the area influenced by the Changjiang River discharge. Second mode is temporally less sensitive with the Changjiang River discharge but spatially correlated with north-south patterns. Relatively higher POC variations during 2000 and 2003 were shown in the southern East China Sea. These patterns during 2004 and 2007 moved to the northern East China Sea. This phenomenon is better related to spatial variations of wind-direction than the amount of Changjiang River discharge, which is verified from in-situ measurement.

위성 해색자료에서 추정한 동중국해 클로로필 선형경향의 계절별 차이

손영백,장찬주,김상현 한국해양과학기술원 2013 Ocean and Polar Research Vol.35 No.2

The purpose of this study is to investigate seasonal difference in linear trends in satellite-derived chlorophyll-a concentration (Chl-a) and their related environmental changes in the South Sea of Korea (SSK) and East China Sea (ECS) for recent 15 years (Jan. 1998~Dec. 2012) by analyzing climatological data of Chl-a, Rrs(555), sea surface wind (SSW) and nutrient. A linear trend analysis of Chl-a data reveals that, during recent 15 years, the spring bloom was enhanced in most of the ECS, while summer and fall blooms were weakened. The increased spring (Mar. - May) Chl-a was associated with strengthened winter (Dec. - Feb.) wind that probably provided more nutrient into the upper ocean from the deep. The causes of decreased summer (Jun. - Aug.) Chl-a in the northern ECS were uncertain, but seemed to be related with the nutrient limitation. Recently (after 2006), low-salinity Changjiang diluted water in the south of Jeju and the SSK had lower phosphate that caused increase in N/P ratio with Chl-a decrease. The decreased fall (Sep. - Nov.) Chl-a was associated with weakened wind that tends to entrain less nutrient into the upper ocean from the deep. This study suggests that phytoplankton in the ECS differently changes in response to environmental changes depending on season and region.

현장관측 및 원격탐사 자료를 이용한 북동 멕시코 만에서 El $Ni\tilde{n}o$와 La $Ni\tilde{n}a$ 기간 동안 표층 입자성 유기탄소의 시/공간적 변화 연구

손영백,Son, Young-Baek,Gardner, Wilford D. 한국해양학회 2010 바다 Vol.15 No.2

북동 멕시코 만에서 particulate organic carbon(POC)의 시/공간적 변화를 조사하기 위하여, 1997년 11월부터 2000년 8월까지 총 9번의 관측이 이루어 졌으며, 같은 기간 동안 위성자료(해색, 표층수온, 해면고도이상, 표층바람)와 주요 강들 의 유출량이 조사되었다. POC 농도는 내 대륙붕과 미시시피 하구 역에서 높은 값을 (>100 $mg/m^3$) 나타내고 대륙붕과 대륙사면으로 가면서 감소된다. POC의 경년 변화는 상대적으로 1997과 1998년(El $Ni\tilde{n}o$)이 1999과 2000년(La $Ni\tilde{n}a$) 보다 상대적으로 증가되어 나타난다. 이런 현상은 미시시피강 및 다른 주요 강들에 영향을 주는 강우량 변화에 따른 담수 유 입의 변화와 직접적으로 연관되어 있으며, 강우량 변화는 ENSO 현상과 같은 세계 기후변화와 관련이 있는 것으로 사료 된다. 북동 멕시코 만 연안으로 유입되는 주요 강들의 방류량은 초봄에 증가되어 여름과 가을에 감소되지만, 공간적으로 확장된 높은 농도의 POC 분포는 여름 조사기간에서 관측되고, 낮은 농도 및 제한된 확산은 가을과 초 봄 관측에서 나타 난다. 여름철 동안 상대적인 강의 유출량은 봄에 비하여 현저하게 감소하지만, 증가된 표층수온은 수층을 강하게 성층화 시키고 표층에서 부력을 증가시킨다. 이런 조건에서 고농도의 POC를 함유하는 저염수는 상부 대륙사면까지 확장되고 이 는 Loop Current와 Loop Current Eddies의해서 조절된다. 봄과 가을 동안 유출량은 보통이거나 이상을 보이지만, 증가된 바람과 낮은 표층수온으로 인하여 수직적 혼합을 유발하고 이는 높은 농도의 POC를 내 대륙붕에 제한 시키는 것으로 사료된다. Surface particulate organic carbon (POC) concentration was measured in the Northeastern Gulf of Mexico on 9 cruises from November 1997 to August 2000 to investigate the seasonal and spatial variability related to synchronous remote sensing data (Sea-viewing Wide Field-of-view Sensor (SeaWiFS), sea surface temperature (SST), sea surface height anomaly (SSHA), and sea surface wind (SSW)) and recorded river discharge data. Surface POC concentrations have higher values (>100 $mg/m^3$) on the inner shelf and near the Mississippi Delta, and decrease across the shelf and slope. The inter-annual variations of surface POC concentrations are relatively higher during 1997 and 1998 (El Nino) than during 1999 and 2000 (La Nina) in the study area. This phenomenon is directly related to the output of Mississippi River and other major rivers, which associated with global climate change such as ENSO events. Although highest river runoff into the northern Gulf of Mexico Coast occurs in early spring and lowest flow in late summer and fall, wide-range POC plumes are observed during the summer cruises and lower concentrations and narrow dispersion of POC during the spring and fall cruises. During the summer seasons, the river discharge remarkably decreases compared to the spring, but increasing temperature causes strong stratification of the water column and increasing buoyancy in near-surface waters. Low-density plumes containing higher POC concentrations extend out over the shelf and slope with spatial patterns and controlled by the Loop Current and eddies, which dominate offshore circulation. Although river discharge is normal or abnormal during the spring and fall seasons, increasing wind stress and decreasing temperature cause vertical mixing, with higher surface POC concentrations confined to the inner shelf.