Korea Institute Of Ocean Science And Technology Research Articles

Numerical Investigation of Global Ice Loads of Maneuvering Captive Motion in Ice Floe Fields

During escort and convoy operations, icebreakers are often required to maneuver to open up channels or adjust routes due to the prevalence of ice floe conditions in Arctic routes. This study aimed to investigate the global ice load characteristics of the maneuvering captive motions, including constant turning motion, pure yaw motion, and pure sway motion, of the icebreaker Xue Long, using a combination of the discrete element method (DEM) and drag model. First, the method was verified using simulating Araon model tests from the Korea Institute of Ocean Science and Technology (KIOST). In addition, the maneuvering captive motions of the Xue Long model were simulated at varying turning radii, drift angles, and sway and yaw periods, which are typical but currently poorly studied maneuvering motions. Overall, the results of the study showed that the method is able to reproduce the coupling effect of the ship–ice–water system by considering ship–ice interaction and ice resistance, where the mean deviation and maximum deviation of ice resistance are 9.45% and 13.3%, respectively. The influences of the turning radius, drift angle, and sway and yaw period on the ice resistance and transverse force characteristics were studied and analyzed via ship–ice interactions. The present study provides a prediction tool for the assessment of ship maneuvering performance to assist the hull line development and model testing of icebreakers.

Progress in the Industry-University-Institute Cooperative Use of Research Vessels

With the support of the Ministry of Oceans and Fisheries of Korea, the Korea Institute of Ocean Science and Technology (KIOST) promoted ‘The study for the industry-university-institute cooperative use of research vessels’, which was an opportunity to advance domestic ocean research to the next level, in line with the launch of the R/V Isabu in 2017. A brief history in relation to the project is described in Lee (Ocean Sci J 57(2), 2022) in this issue. Celebrating the 5th year of the project, KIOST (Marine scientists on a boat, Korea Institute of Ocean Science and Technology, Busan, 2021) has published a resource book on the progress of the project excluding scientific papers. In this special issue, some of the scientific results from the project are grouped together and introduced. The joint use of research vessels started with large research vessels and gradually expanded to small research vessels. Thus, the target area of the study also included from the open ocean to the coastal waters (KIOST, in Marine scientists on a boat, KIOST Korea Institute of Ocean Science and Technology, Busan, 2021) as shown in the papers featured in this issue.

해양로봇 성능평가에 관한 동향 분석 및 객관적 시험절차 구축에 관한 연구

Recently, the research on marine IoT (Internet of Things) has been diversified. The demand for marine robots capable of responding to advanced missions has been increasing. However, it is difficult to objectively evaluate the performance of marine robots. This is mainly because several problems hinder this evaluation, such as high-weight and large-scale marine robots, uncertainty in marine environmental conditions, and performance evaluation costs. Thus, KIOST(Korea Institute of Ocean Science and Technology) is building the Jang Yeongsil as a ship that can professionally conduct field tests and evaluations at sea. Additionally, they are conducting research activities to evaluate the objective performance of marine robots. Therefore, in this paper, performance evaluation trends of land/marine robots are analyzed, and evaluation items for test evaluation of marine robots are presented based on this analysis. Using depth keeping, the results were verified through a third-party witness verification. The third-party witness test results demonstrate the test procedure’s reasonableness.

Intelligent Buoy System (INBUS): Automatic Lifting Observation System for Macrotidal Coastal Waters

The west coast of South Korea is characterized by a wide macrotidal area with a maximum tidal range of ∼10 m. The sea surface elevation varies with the tidal phase, which leads to significant changes in the vertical structure of the physical, chemical, and biological properties of the water column, especially when the interaction by waves and/or the freshwater and sediment input from the river increases. Under such conditions, it is difficult to carry out continuous and consistent measurements of the vertical structures of the water qualities using a conventional observation system that is fixed to the seabed or sea surface because the thickness of the water column constantly changes. Based on the demand for long-term observations of the vertical structures of the water properties in macrotidal environments, the Intelligent Buoy System (INBUS) was developed by the Korea Institute of Ocean Science and Technology (KIOST). INBUS is a buoy equipped with an instrument frame, which is similar to other buoys that are fixed to the sea surface. During every measurement, INBUS detects the water depth and sends the frame down to the seabed to measure the water quality at every vertical level set up in the system. For example, if N levels are set in INBUS, the water depth of each measurement is divided by N layers and the instruments in the lifting frame measure the water properties of each of the N layers while they are descending to the bottom. Based on this procedure, the vertical structure of the water column is consistently measured in N layers regardless of changes of the water depth due to tides and waves. The lifting and measuring process is automatically controlled by INBUS once it is set up in the system. In addition, because INBUS allows bidirectional communication through code division multiple access (CDMA), the system can be controlled by stations on land. If the CDMA communication becomes inoperable owing to extreme wave conditions or the buoy is lost because of incidents such as a collision with a ship, the location of INBUS can be tracked by low-earth-orbit satellites.

Wave Observation Methods using High-frequency Ocean Radar

Shim, J.S.; Kim, J.H.; Chang, B.S.; Min, I.K.; Choi, J., and Chun, I., 2020. Wave observation methods using high-frequency ocean radar. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1273–1278. Coconut Creek (Florida), ISSN 0749-0208.The Korea Institute of Ocean Science and Technology (KIOST) has been developing high-frequency (HF) ocean radar for wave observation with SETsystem Inc., which had developed HF ocean radar for ocean currents. A Bayesian directional spectrum estimation method (BDM) algorithm was developed to extract wave information from HF ocean radar and tested using surface current and wave variability experiments (SCAWVEX) data. A circular array antenna was used, which has advantages in terms of smaller installation space and narrower beamwidth. The prototype of the HF ocean radar for wave was composed of BDM algorithm and circular array antenna for optimizing the observed waves. The prototype of the HF ocean radar was installed at the East Sea Research Institute, Uljin, in the Republic of Korea (ROK). The radar system is being checked, and a future study will compare the results with those of other observation tools.

R/V Isabu-Based First Ultraclean Seawater Sampling for Ocean Trace Elements in Korea

Trace elements (Mn, Fe, Co, Ni, Cu, Zn, etc.) are essential micronutrients for marine organisms and are thus related to major issues in the ocean, such as climate change, ecosystem change, and pollution. However, given their extremely low concentrations in seawater, contamination-free clean seawater sampling for trace elements onboard is the most crucial factor in this study. Because of the absence of both clean seawater sampling techniques and related infrastructure (e.g., a research vessel equipped with a nonmetal sampling system), the trace element community in Korea has not contributed to the global community studying trace elements in the ocean, although the associated global joint study program “GEOTRACES” has been operating for 10 years. With the newly launched research vessel (R/V) Isabu of the Korea Institute of Ocean Science and Technology (KIOST), Korea is now equipped with a large comprehensive R/V complete with a contamination-free PRISTINE ultraclean seawater sampling system for trace elements. We conducted clean seawater sampling 2 research cruises in the Indian Ocean during 2017–2018 aboard the R/V Isabu, and we successfully obtained reliable data, which agree well with previously reported trace element data at these locations. Here, we present the procedure and preliminary results of clean water sampling for trace elements based on the R/V Isabu, as the first Korean open ocean trace element study. From this study, we expect that R/V Isabu will play an important role in research on oceanic trace elements and isotopes in the future.

Optimization of Chemical Oxygen Demand Determination in Seawater Samples Using the Alkaline Potassium Permanganate Method

Chemical oxygen demand (COD) is a practical parameter that is used to estimate the amount of organic pollutants in aqueous systems. It is generally used as a guideline to control the quality of waste treatment effluent globally and is a management tool to evaluate the total pollution load in the highly developed coastal regions of Korea. It is a preferred method because of the speed and simplicity of the analysis and because there are fewer instrumentation requirements. The Ministry of Oceans and Fisheries (MOF) of the Republic of Korea developed a standard procedure for the measurement of COD. It has been revised several times, and the most recent revision was made in 2013 (MOF 2013–230). In this study, we modified the standard COD measurement procedure (MOF 2013–230), especially the sample digestion apparatus, to enhance analytical efficiency for a large sample number (batch), which is called a Korea Institute of Ocean Science and Technology (KIOST) modified MOF 2013–230. We examined uncertainty related to each experimental step and optimized laboratory conditions to reduce such uncertainties. The detection limit and estimated expanded uncertainty related to the KIOST modified MOF 2013–230 was 0.18 and 0.11 mg O2/L at a 95% confidence level (k = 2), respectively. This study also provides several tips to maintain consistent COD measurements in seawater using the alkaline potassium permanganate method.

Simulation of Vertical Water Temperature Structure Variation in the Yellow Sea Typhoon MEARI

ABSTRACT Kwon, Y.-Y.; Jeong, J.-Y.; Choi, J.-Y.; Shim, J.-S., and Kwon, J.-I., 2018. The simulation of vertical water temperature structure variation in the Yellow Sea typhoon MEARI. In: Shim, J.S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1016–1020. Coconut Creek (Florida), ISSN 0749-0208. Typhoon MEARI developed on June 22, 2011 in the eastern Philippines and passed through the central part of Yellow Sea for the first time in the history of meteorological observations. The Korea Institute of Ocean Science and Technology (KIOST) observed surface water temperature, salinity, flow velocity, and the vertical profile of temperature and salinity at a buoy located near the Eocheong Island off the west coast of the Korean Peninsula during Typhoon MEARI (1105). The purpose of this study is to analyze the change of water temperature and velocity characteristics of the typhoon p...

2014년 JCOMM 해수 염분 측정 국제 상호비교실험 결과 보고

The inter-comparison project for seawater salinity measurements, in which 25 laboratories from 16 countries took part, was conducted by JCOMM (Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology) for the first time in 2014. Two seawater samples of different salinity values ranging from 30-35 and 20-25 for Sample A and Sample B respectively and which had sufficient homogeneity and stability were distributed to all participants. Participants measured the salinity in their own laboratories at least 3 times and reported the results. Statistical treatments were applied to the results to assess discrepancies among laboratories. 20 out of the 25 laboratories used laboratory salinometers and statistics for this group were denoted as belonging to group <TEX>${\alpha}$</TEX>; while 5 out of the 25 laboratories used hand-held measuring instruments and statistics for this group were denoted as belonging to group <TEX>${\beta}$</TEX>. Bias described as discrepancy among laboratories in group <TEX>${\alpha}$</TEX> was within <TEX>${\pm}0.001$</TEX> and expanded uncertainty (k = 2) was in the vicinity of 0.002. The bias and the uncertainty of Korea Institute of Ocean Science and Technology (KIOST), in group <TEX>${\alpha}$</TEX>, were 0.000 and 0.002, respectively. The biases of group <TEX>${\beta}$</TEX> were greater than group <TEX>${\alpha}$</TEX> because of constraints related to instrument accuracy. Biases from 3 laboratories in group <TEX>${\beta}$</TEX> exceed the accuracy specification of the corresponding instruments. Considering that the uncertainty of Standard Seawater (SSW) is of the order 0.001 to 0.002, the inter-comparison results show that 16 laboratories among the 25 laboratories made high quality measurements, largely indistinguishable from one another.

은 나노 입자가 코팅된 인공경량골재의 생물오손 방지 특성

본 연구는 해상 양식장 내에 유해 조류로 인해 발생하는 수산 동, 식물의 폐사를 막고, 양식장을 주기적으로 정화하는 폰툰 시스템 내의 멤브레인 층(Membrane Layer)의 생물오손(Biofouling)을 막고자, ML에 적용되는 인공경량골재 및 골재의 구조에 따른 미생물 흡착을 비교하고자 지오폴리머에 은 나노 입자를 코팅하여 생물오손 정도를 확인하고 그 능력을 평가하였다. 이후 코팅에 따른 미생물 기능 억제 능력을 확인하고자 항균 테스트를 실시하였으며, 한국해양과학기술원 남해연구소 앞바다에 설치하여 생물오손 정도와 무게변화율을 관찰하였다. 항균 테스트 결과 은 나노 입자를 코팅한 인공경량골재에서 99.99 %의 세균 감소율을 확인하였으며, 생물오손 정도를 관찰한 결과 2개월부터 은 나노 입자의 효과에 의해 생물오손 정도가 억제되는 것을 확인하였다. 은 나노 입자 코팅에 의한 생물오손 억제기간은 인공경량골재에서 5개월, 지오폴리머에서 3개월 미만으로 나타났으며, 따라서 은 나노 입자가 코팅된 인공경량골재가 효과적으로 생물오손을 감소시킬 수 있는 친환경적이며 효과적인 방법임을 알 수 있었다. Ships and marine structures have a lot of problems in their high maintenance and operating cost by biofouling. A biofouling occurrs by the adhesion of marine microorganism, algae and bacteria. In this study, the aim is to prevent or to reduce the biofouling phenomena through silver nano-particle coating on artificial light-weight aggregates and geopolymer. The antibacterial activity on them is tested according to ASTM E2149-2013a. The test results showed, it is estimated that silver nano-particles removed 99.99 % of bacteria. Specimens were set up in the sea side of field test area in Korea Institute of Ocean Science and Technology (KIOST) and have been observed for five months. The anti-biofouling effect and difference in weight change rate have been detected two months later after the installation. Because silver nanoparticles inhibit bacterial growth and kill the cells by destroying bacterial membranes, silver nano-particle coating on artificial lightweight aggregates is a well-suited and eco-friendly method for preventing biofouling in the sea up to 5 months.

Wave Simulation for Submarine Cable Route of Southwest Sea Offshore Wind Farm Using the SWAN Model

Submarine cable installation is essentials for grid connection between existing power grid and newly produced electricity which will be from offshore wind farm in Southwest sea area of Korea. Especially, submarine cable route and protection method is designed in order to ensure the economical efficiency, workability and stability of submarine cable installation. On this paper, we will give the basic information about the submarine cable route and protection method of offshore wind farm which will be built in Southwest sea area of Korea. For this, we have a numerical simulation at high and low tide based on the third-generation wave model SWAN(Simulating WAves Nearshore) using the long term wave data from Korea Institute of Ocean Science and Technology(KIOST). The results of the study, year mean Hs is 1.03m, Tz is 4.47s and dominant wave direction is NW and SSW When the incident wave direction is NW(Hs: 7.0 m, Tp: 11.76s), the distribution of shallow water design wave height Hs was calculated about 4.0~5.0m at high tide and 2.0~3.0m at low tide. When the incident wave direction is SSW(Hs: 5.84 m, Tp: 11.15s), the distribution of shallow water design wave height Hs was calculated about 3.5~4.5m at high tide and 1.5~2.5m at low tide. The wave direction on a dominant influence in the section of longitude UTM 249749~251349(about 1.6 km) and UTM 251549~267749(about 16.2 km) in the submarine cable route are each NW and SSW. Prominently, wave focusing phenomenon appears between Wi-do and Hawangdeung-do, in this sea area is showing a relatively high wave hight than the surrounding sea areas.

Rates of total oxygen uptake of sediments and benthic nutrient fluxes measured using an in situ autonomous benthic chamber in the sediment of the slope off the southwestern part of Ulleung Basin, East Sea

We have developed a new autonomous benthic lander for deep-sea research, the Korea Institute of Ocean Science and Technology (KIOST) BelcII and BelpII. The benthic lander was successfully tested at 950 and 1450 m water depths on the slope off the southwestern part of the Ulleung Basin in the East Sea of Korea. The ex situ measurements of the total oxygen uptake (TOU) rates at all the stations exceeded the in situ measurement values, and may indicate artificial effects from onboard incubation. The TOU rates were estimated to be 5.80 mmol m–2 d–1 and 3.77 mmol m–2 d–1 at water depths of 950 m and 1450 m, respectively. The benthic nutrient fluxes were also higher at water depths of 950 m, which indicates a partitioning of organic degradation with water depth. In addition, the negative phosphate and nitrogen benthic flux ratios and the higher nitrate removal flux via the sediment–water interface at the slope imply that the nitrogen in the bottom water may be preferentially removed via microbial respiration processes in the sediments, and may be coupled with the low nitrogen-to-phosphate ratio found in the deep water. Although our measurements comprised just two experiments in the slope sediment, the robust in situ measurement of the benthic fluxes in the slope sediment is a forerunner for new research into the biogeochemical cycles across the shelf edge–slope–basin system in the East Sea.

Generation of high resolution sea surface temperature using multi-satellite data for operational oceanography

In the present article, we introduce a high resolution sea surface temperature (SST) product generated daily by Korea Institute of Ocean Science and Technology (KIOST). The SST product is comprised of four sets of data including eight-hour and daily average SST data of 1 km resolution, and is based on the four infrared (IR) satellite SST data acquired by advanced very high resolution radiometer (AVHRR), Moderate Resolution Imaging Spectroradiometer (MODIS), Multifunctional Transport Satellites-2 (MTSAT-2) Imager and Meteorological Imager (MI), two microwave radiometer SSTs acquired by Advanced Microwave Scanning Radiometer 2 (AMSR2), and WindSAT with in-situ temperature data. These input satellite and in-situ SST data are merged by using the optimal interpolation (OI) algorithm. The root-mean-square-errors (RMSEs) of satellite and in-situ data are used as a weighting value in the OI algorithm. As a pilot product, four SST data sets were generated daily from January to December 2013. In the comparison between the SSTs measured by moored buoys and the daily mean KIOST SSTs, the estimated RMSE was 0.71°C and the bias value was–0.08°C. The largest RMSE and bias were 0.86 and–0.26°C respectively, observed at a buoy site in the boundary region of warm and cold waters with increased physical variability in the Sea of Japan/East Sea. Other site near the coasts shows a lower RMSE value of 0.60°C than those at the open waters. To investigate the spatial distributions of SST, the Group for High Resolution Sea Surface Temperature (GHRSST) product was used in the comparison of temperature gradients, and it was shown that the KIOST SST product represents well the water mass structures around the Korean Peninsula. The KIOST SST product generated from both satellite and buoy data is expected to make substantial contribution to the Korea Operational Oceanographic System (KOOS) as an input parameter for data assimilation.

Development of the Operational Oceanographic System of Korea

The Korea Operational Oceanographic System (KOOS) was developed at the Korea Institute of Ocean Science and Technology (KIOST) to produce real-time forecasting and simulation of interdisciplinary multi-scale oceanic fields. This offers valuable information to better mitigate coastal disasters, such as oil spills and other marine accidents, and provides the necessary ocean predictions to support the marine activities of government agencies, marine industries, and public users. The KOOS became operational in March 2012, and consists of several operational modules and realtime observations, including satellite remote sensing, coastal remote monitoring stations using high-frequency radar, and ocean observatories. The basic forecasting system includes weather, regional and high-resolution coastal circulation and wave prediction models; the practical application system includes storm surges, oil spills, and search and rescue prediction models. An integrated maritime port prediction system and data information and skill assessment systems are also part of the KOOS. In this work, the performance of the numerical models was evaluated by the skill assessment systems. From the monthly and yearly skill assessments, the models showed reasonable skill in predicting atmospheric and oceanic states except for the regional ocean circulation models. The ongoing development and improvement of the KOOS includes improvement of the model skills through the upgrade of the satellite-based sea surface temperature algorithm, the enhancement of the ocean monitoring ability, the upgrade of the forecasting models for higher spatial resolutions and the application of data assimilation techniques improved with the feedback from the skill assessment report.

An assessment of ocean climate reanalysis by the data assimilation system of KIOST from 1947 to 2012

A data assimilation system has been developed to apply to a fully coupled climate model, CM2.1, in the Korea Institute of Ocean Science and Technology (KIOST). While the ocean observation data are assimilated into the ocean component model through the data assimilation system of the KIOST (DASK), the other component models are freely integrated. Here, we evaluated the variability of the ocean climate in the climate reanalysis by the DASK from 1947 to 2012. To assess oceanic processes and ocean climate variability as modeled by the DASK, we examined the North Pacific Intermediate Water, El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Indian Ocean Dipole (IOD), upper 300m heat content (HC300), Sea Surface Height (SSH), meridional heat transport, mean global temperature and salinity, and temperature and zonal velocity in the tropical Pacific. Furthermore, we compared these modeled features with various in-situ observations and with various other global reanalyses, such as the Simple Ocean Data Assimilation (SODA) and the GFDL Ensemble Coupled Data Assimilation systems (ECDA). The DASK represents global temperature and salinity well, not only at the surface but also at intermediate depths in the ocean. In addition, the DASK closely models the features of North Pacific Intermediate Water, a typical water mass in the North Pacific characterized by the salinity minimum layer. The DASK’s ocean climate variability also matches well with observations of the ENSO, PDO and IOD. The HC300 of the DASK shows as good or better correlations with real-world observations compared to other reanalyses systems except in the tropics. In addition, the SSH variability of the DASK shows lower correlation in the tropics and north Atlantic rather than its HC300 correlation. It is suggested that the poor performance of the DASK in the tropics and north Atlantic is resulted from the bias of its low-resolution atmospheric model. Nevertheless, it is noteworthy that the DASK performs better or comparable particularly in the North Pacific and North Atlantic even though the DASK applies the Ensemble Optimal Interpolation, which is numerically more efficient than the ensemble Kalman filter applied by the ECDA, and a lower horizontal model resolution than that of the SODA. The validation suggests the high performance of the DASK in terms of ocean climate estimation and variability at a lower computational cost than the other two reanalyses systems we studied.

Ocean color products from the Korean Geostationary Ocean Color Imager (GOCI)

The first geostationary ocean color satellite sensor, Geostationary Ocean Color Imager (GOCI), which is onboard South Korean Communication, Ocean, and Meteorological Satellite (COMS), was successfully launched in June of 2010. GOCI has a local area coverage of the western Pacific region centered at around 36°N and 130°E and covers ~2500 × 2500 km(2). GOCI has eight spectral bands from 412 to 865 nm with an hourly measurement during daytime from 9:00 to 16:00 local time, i.e., eight images per day. In a collaboration between NOAA Center for Satellite Applications and Research (STAR) and Korea Institute of Ocean Science and Technology (KIOST), we have been working on deriving and improving GOCI ocean color products, e.g., normalized water-leaving radiance spectra (nLw(λ)), chlorophyll-a concentration, diffuse attenuation coefficient at the wavelength of 490 nm (Kd(490)), etc. The GOCI-covered ocean region includes one of the world's most turbid and optically complex waters. To improve the GOCI-derived nLw(λ) spectra, a new atmospheric correction algorithm was developed and implemented in the GOCI ocean color data processing. The new algorithm was developed specifically for GOCI-like ocean color data processing for this highly turbid western Pacific region. In this paper, we show GOCI ocean color results from our collaboration effort. From in situ validation analyses, ocean color products derived from the new GOCI ocean color data processing have been significantly improved. Generally, the new GOCI ocean color products have a comparable data quality as those from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua. We show that GOCI-derived ocean color data can provide an effective tool to monitor ocean phenomenon in the region such as tide-induced re-suspension of sediments, diurnal variation of ocean optical and biogeochemical properties, and horizontal advection of river discharge. In particular, we show some examples of ocean diurnal variations in the region, which can be provided effectively from satellite geostationary measurements.

수중유영로봇 Crabster의 최적 유영 구현

Recently, development of underwater robot has actively been in progress in the world as ROV(Remotely Operator Vehicle) and AUV(Autonomous Unmmanded Vehicle) style. But KIOST(Korea Institute of Ocean Science and Technology), beginning in 2010, launched the R&D project to develop the robot, dubbed CRABSTER(Crab + (Lob)ster) in a bid to enhance the safety and efficiency of resource exploration. CRABSTER has been designed to be able to walk and swim with its own legs without screws. Among many research subjects regarding CRABSTER, optimal swimming patterns are handled in this paper. In previous studies, drag forces during one period with different values for angle of each joint were derived. However kinematics of real-robot and fluid-dynamics are not considered. We conducted simulations with an optimization algorithm for swimming by considering simplified fluid dynamics in this paper. Drag-coefficients applied to the simulation were approximated values calculated by CFD(Computational Fluid Dynamics : Tecplot 360, ANSYS). In addition, optimized swimming patterns were applied to a real robot. The experiments with the real robot were conducted in circumstances in the water. As a result, when the experiments were carried out in the water, a regular pattern of drag force output came out depending on the movement of the robot. We confirmed the fact that the drag forces from the simulation and the experiment has a high similarity.

GOCI data processing and ocean applications

GOCI, the world’s first geostationary ocean color sensor, has been developed with the purpose of monitoring the marine environment and providing a quick and timely warning of marine dangers. It takes eight times a day the images of the Northeast Asian region while the polar orbiters have only a 2-3 day revisit occasion. This unprecedented capability allows a breakthrough into a new field of ocean color observation. The hourly shot images of the GOCI permit the observations of sub-diurnal movements of suspended sediment, chlorophyll a concentration, floating derivations of green algae patches and evolutions of red tides. It is recognized that GOCI images provide also clearer views of sea fog, sea ice, yellow dust, wild fires, the effects of storms and even tsunamis than ever. Since April, 2011, after the in-orbit-test of the satellite, the Korea Ocean Satellite Center (KOSC) of the Korea Institute of Ocean Science and Technology (KIOST), has taken charge of managing the GOCI data, implementing the reception, processing, Cal/Val and their distribution to the users with a exclusive ownership. The GOCI data can be accessed through the KOSC’s new website (http://kosc.kiost.ac) for non-commercial scientific and educational purposes. The GOCI Data Processing System (GDPS), developed by the KOSC, is software dedicated to perform the atmospheric correction and to generate the GOCI products including the images of the water color properties. This special edition dedicated to the GOCI includes 13 articles which report the results of studies on overviews of the GOCI and the GDPS, sensitivity of the GOCI, comparison with other ocean color sensors, atmospheric correction, validation, and applications of GOCI data carried out by scientists from various countries. Lastly, we would like to thank OSJ for generously accepting the issue of this special edition as well as the Ministry of Land, Transport and Maritime Affairs for all the support in development and utilization of the GOCI. We sincerely hope that this special edition may foster further scientific researches and proper applications of new observation tools.