• Journal of the Korean earth science society
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• v.45 no.4
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• pp.327-337
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• 2024

The ocean is linked to long-term climate variability, but there are very few methods to assess the short-term performance of forecast models. This study analyzes the short-term prediction performance regarding ocean temperature and salinity of the Global Seasonal prediction system version 5 (GloSea5). GloSea5 is a historical climate re-creation (2001-2010) performed on the 1st, 9th, 17th, and 25th of each month. It comprises three ensembles. High-resolution hindcasts from the three ensembles were compared with the Array for Real-Time Geostrophic Oceanography (ARGO) float data for the period 2001-2010. The horizontal position was preprocessed to match the ARGO float data and the vertical layer to the GloSea5 data. The root mean square error (RMSE), Brier Score (BS), and Brier Skill Score (BSS) were calculated for short-term forecast periods with a lead-time of 10 days. The results show that sea surface temperature (SST) has a large RMSE in the western boundary current region in Pacific and Atlantic Oceans and Antarctic Circumpolar Current region, and sea surface salinity (SSS) has significant errors in the tropics with high precipitation, with both variables having the largest errors in the Atlantic. SST and SSS had larger errors during the fall for the NINO3.4 region and during the summer for the East Sea. Computing the BS and BSS for ocean temperature and salinity in the NINO3.4 region revealed that forecast skill decreases with increasing lead-time for SST, but not for SSS. The preprocessing of GloSea5 forecasts to match the ARGO float data applied in this study, and the evaluation methods for forecast models using the BS and BSS, could be applied to evaluate other forecast models and/or variables.

• Ocean and Polar Research
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• v.43 no.4
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• pp.335-352
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• 2021

Trace elements in the ocean have been known as essential micronutrients for the primary production of phytoplankton and the growth of marine organisms. The GEOTRACES program beginning in the mid-2000 provided a new understanding of the distribution, origin and behavior of trace elements in the ocean, together with the establishment of both clean seawater sampling and trace element analysis techniques. The Indian Ocean, one of the major oceans, is relatively the least explored area, despite playing an important role in global climate variability. Although trace element observations have recently been conducted in the Indian Ocean by Japanese-and Indian scientists, relatively not much study has been done compared to the Atlantic, Pacific and Polar Regions. Recently, together with the launch of R/V Isabu, a 5,000-ton grade large- and comprehensive research vessel, the observations of trace elements has been conducted in the Indian Ocean for the first time in Korea since 2018. In this paper, we introduce the key results of currently conducted GEOTRACES expedition in the Indian Ocean to present future trace element research directions in the Indian Ocean, and also reviewed the preliminary results in the Indian Ocean studies from Korea. In the 2020s, new Indian Ocean GEOTRACES projects are planned around European countries, and it is time for Korea to prepare for the next phase of the trace element study in the Indian Ocean in line with these international trends.

• Korean Management Science Review
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• v.27 no.2
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• pp.55-66
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• 2010

In Korea, deap-sea fishing industry plays an important role in a food industry. However, it is in a difficult situation because of the more competitive business environment. Therefore, there is a need to restructure the deap-sea fishing industry by scraping superannuated ships. This paper is designed to present scrap programs for deap-sea fishing industry of Korea. We performed ratio analysis to evaluate financial performance of fishing companies and then applied a mixed integer programming (MIP) model to identify optimal schedule for scraping. The results of the financial ratio analysis indicates that it is legible to provide governmental aid to Atlantic trawl, Northern Pacific trawl, and Indian ocean trawl with minimum required rate of return (MRR) of 3%, and the Atlantic strip fishing industry is qualified to receive the governmental aid with MRR value of 5%. Furthermore, by applying the MIP model to develop scrap planning, we demonstrate how our model can be used to restructure the deap-sea fishing industry of Korea.

• Proceedings of the KSRS Conference
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• v.1
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• pp.308-311
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• 2006

This study compared between tropospheric column ozone by applying the SAM method to TOMS and OMI data for northern summer. Tropospheric ozone from the SAM represents a peak over the tropical Atlantic, where it is related with biomass burning. This feature is also seen in the distribution of the model and CO. Additionally, enhancement of the SAM ozone over the Middle East, and South and North America agrees well with the model and CO distribution. However, the SAM results show more ozone than the model results over the northern hemisphere, especially the ocean (e.g. the North Pacific and the North Atlantic). The tropospheric ozone distribution from OMI data shows more ozone than that from TOMS data. This can be caused by different viewing angle, sampling frequency, and a-priori ozone profiles between OMI and TOMS. The correlation between the SAM tropospheric ozone and CO is better than that between the model and CO in the tropics. However, that correlation is reversed in the midlatitude.

• Journal of Species Research
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• v.8 no.4
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• pp.365-372
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• 2019

We have conducted faunistic study of sea lice collected from marine plankton samples of western and southern coasts of Korea. These specimens were identified as Caligus undulatus Shen and Li, 1959, belonging to family Caligidae and order Siphonostomatoida with worldwide distribution. The range extension of C. undulatus is reported in addition to the previously known distributional range from the Northwest Pacific (China, Japan, and Korea), India, Brazil, and Mexico. This species can be distinguished from all previous reports with characteristics such as overall body proportions of both sexes, structure details of mouth appendages, armature of legs, and some variation in body size. The distributional range of C. undulatus is now given with its northern and south hemisphere limit being 40 to $10^{\circ}N$ in the Indo-Pacific and $30^{\circ}S$ in the Southwest Atlantic. This is the first record of its female occurring in Korea.

• Development and Reproduction
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• v.8 no.1
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• pp.11-17
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• 2004

The larvae and juvenile development of haddock Melanogrammus aeglefinus which is significant commercial fish living north Atlantic Ocean are described here. Larvae were reared in laboratory and sampled periodically for developmental study until 67 days after hatching. An increase in total length(TL) of fish indicated continuous growth, described by the growth expression Y=4.07 $e^{0.037}$( $R^{2}$=0.9978). The newly hatched pre-larvae was 4.9 mm in TL with ellipsoid yolk. In 16 days after hatching, larvae attained 6.8 mm in TL, and absorbed the yolk completely to become post-larval stage, but first heterotrophic food could be in 7 days after hatching already. Post-larval stage continued during 16~52 days after hatching with development of organs attachment. In 61 days after hatching with 41.3 mm in TL, the fries became a juvenile stage respectively having small teed lateral line, and a black blotch on the flank same as adults, but chin barbel was not developed yet. It was presumed that haddock changed food and ecological behavior after metamorphosis ken this time.e.

• Journal of International Area Studies (JIAS)
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• v.14 no.2
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• pp.449-476
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• 2010

This paper focuses on the security problems in atlantic ocean involved in the USA and Latin America and the Caribbean. The ocean security matters in this region have mainly argued military concerns traditionally. However, the concept of ocean security has been changed in the 21st century and strongly debated with various dimensions: social, human and resource, environment as well. This paper traces these changed concepts currently with many empirical cases existed in many security conflicts in this ocean, especially between the USA and Latin(South) America region. Historically, security conflicts in the OAS(Organization of American States) countries have involved with many military matters, territory and oceans, and currently added up with terrorism and drug problems as well. However, the great and potential conflict emerged in the security issues is resource matter in this ocean and get a dilemma to be sorted out between military and social security matter. For example, the re-establishment of 'the 4th Fleet' in US Navy got a great conflict between the USA and the South American countries, both of them wants to achieve to resource security in this ocean to meet their energy security. Finally this paper addresses some implications and prospects in this conflict in near future and suggests a few solutions and advices for Korean's relation in this ocean.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.87-92
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• 2009

CSR for bulk carrier has been required 25 years operation life in North Atlantic condition. As the fatigue life requirement of ship structure is increased it is necessary to study to satisfy the fatigue life which is much severe. Therefore from the fatigue analysis, especially fatigue strength for double bottom & lower stool connection area is not enough. To satisfy the fatigue life, it needs to increase double bottom strength or insert thicker plate. In this study, the consideration though structure modification have been doe with 81K bulk carrier and to find the solution of fatigue problem.

• Journal of Ecology and Environment
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• v.47 no.2
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• pp.49-62
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• 2023

Background: Over the past three decades, gradual eustatic sea-level rise has been considered a primary exogenous factor in the increased frequency of flooding and biological changes in several salt marshes. Under this paradigm, the potential importance of short-term events, such as ocean storminess, in coastal hydrology and ecology is underrepresented in the literature. In this study, a simulation was developed to evaluate the influence of wind waves driven by atmospheric oscillations on sedimentary and vegetation dynamics at the Skallingen salt marsh in southwestern Denmark. The model was built based on long-term data of mean sea level, sediment accretion, and plant species composition collected at the Skallingen salt marsh from 1933-2006. In the model, the submergence frequency (number yr^-1) was estimated as a combined function of wind-driven high water level (HWL) events (> 80 cm Danish Ordnance Datum) affected by the North Atlantic Oscillation (NAO) and changes in surface elevation (cm yr^-1). Vegetation dynamics were represented as transitions between successional stages controlled by flooding effects. Two types of simulations were performed: (1) baseline modeling, which assumed no effect of wind-driven sea-level change, and (2) experimental modeling, which considered both normal tidal activity and wind-driven sea-level change. Results: Experimental modeling successfully represented the patterns of vegetation change observed in the field. It realistically simulated a retarded or retrogressive successional state dominated by early- to mid-successional species, despite a continuous increase in surface elevation at Skallingen. This situation is believed to be caused by an increase in extreme HWL events that cannot occur without meteorological ocean storms. In contrast, baseline modeling showed progressive succession towards the predominance of late-successional species, which was not the then-current state in the marsh. Conclusions: These findings support the hypothesis that variations in the NAO index toward its positive phase have increased storminess and wind tides on the North Sea surface (especially since the 1980s). This led to an increased frequency and duration of submergence and delayed ecological succession. Researchers should therefore employ a multitemporal perspective, recognizing the importance of short-term sea-level changes nested within long-term gradual trends.

• Proceedings of the Korean Quaternary Association Conference
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• 2004.06a
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• pp.51-51
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• 2004

As an important contribution to the planed drilling (IODP) in the central part of the Arctic Ocean, we are currently working on a refined chronostratigraphy for Marine Isotope Stage (MIS) 16 to MIS 2 on the exciting material from ODP Site 910A (Leg 151) which has been recovered from the marginal Eastern Arctic Ocean (the Yermak Plateau - the Atlantic/Arctic Ocean Gateway). Several stratigraphic age fix-points support the interpretation of the stable oxygen. isotope record of planktonic foraminifer N, pachyderma sin. that is punctuated by several short-term meltwater events. We believe that our new record will serve as 'the important correlating tool for establishing a basic stratigraphy for the Quaternary Arctic Ocean as well as for generating high-resolution paleoenvironmental reconstructions in the central Arctic Ocean. Furthermore, our study will provide reference stratigraphic data sets for interpreting the micropaleontological, sedimentological and organic / inorganic - geochemical proxies of the new boreholes that will be drilled on the Lomonosov Ridge(Central Arctic Ocean) in the frame of the "Arctic Coring Expedition' (ACEX, IODP) in summer 2004.