• ALGAE
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• 제30권3호
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• pp.223-232
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• 2015

More than 20 and 10 clades / ecotypes of Synechococcus and Prochlorococcus, respectively, have been identified in various oceanic regions. However, their diversity has yet to be thoroughly studied in the northwest Pacific Ocean. Further, spatial distribution of Synechococcus clades in the oligotrophic oceans has been scarcely characterized. To elucidate picocyanobacterial lineage distribution in the northwest Pacific Ocean, 16S-23S internal transcribed spacer sequences of picocyanobacteria were sequenced by barcoded amplicon pyrosequencing method. Additional pyrosequencing library using a primer specific for the Synechococcus subcluster-5.1 was constructed to thoroughly understand Synechococcus diversity in the oligotrophic oceans. In warm pool area, Prochlorococcus was predominant and showed a distinct depthpartitioning between HLII and LL ecotypes. Despite low abundances, diverse Synechococcus clades appeared in the oligotrophic open ocean, showing both vertical and horizontal niche partitioning. Clade II was the predominant Synechococcus clade, especially in upper euphotic depths. In shallow and middle euphotic depths, clades UC-A, III, and CRD1 were distributed broadly. However, a distinct shift in the horizontal distribution was found at ca. $20^{\circ}N$. Conversely, clades XVII and CRD2 dominated at deep euphotic depths and constituted a higher proportion than clade II. These niche-partitioning of Synechococcus clades seemed to be related with temperature, nutrient concentration as well as iron concentration.

• 한국항해학회지
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• 제11권2호
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• pp.1-31
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• 1987

Nowadays, the transportation of almost all cargoes depends on sea routes in international trade. In the transaction of trade, cargo transportation must be completed on the base of two contrary objectives, one of which is to protect the vessel, cargoes and crew aborad her safely through every step of the transportation and the other is to pursue profits from the transaction of the trade. In spite of the great development of the modern techniques in shipbuilding today, many sea disaters of big merchant vessels have been occurring successively in winter seasons every year on the sea routes of the North Pacific Ocean. Whenever the accident of losing a vessel in rough sea occurred , many experts of the country to which the vessel belonged had tried to take out the reason of the missing without manifesting the exact cause of the unhappy occurrence. In this paper, we calculated ocean wave status along the route of the North Pacific Ocean theoretically concluded by us as optimum on the basis of weather and sea conditions. In the calculation, we used ITTC wave spectrum formula and meteorological data of "Winds '||'&'||' Waves of the north Pacific Ocean" edited by Ship Research Institute of Japan on the basic data assembled by World Meterological Organization through past 10 years. We selected three sample vessels of most common size in the North Pacific Ocean Routes, a container, a log carrier and a bulk carrier and applied tree sample vessels to the calculated sea conditions for getting the rolling angles of the vessels and stress exerting on the hulls. Examining the calculated results, we concluded as follows; 1. Under the condition of these status7 by beaufort scale, "heave to" maneuvering is the best and safest way to steer every vessel. 2. The most dangerous part of sea area along the west bound optimum route of the North Pacific Ocean in winter season, is the southern sea area of the Kamchatka peninsula.a peninsula.

• 수산해양기술연구
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• 제46권4호
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• pp.430-440
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• 2010

To investigate the catches of jack mackerel fishery, a series of fishing experiments was conducted in the high seas of the southeastern Pacific Ocean ($30^{\circ}S-38^{\circ}S,\;82^{\circ}W-95^{\circ}W$) during the period of 9 August to 18 December, 2003 by commercial fishing vessel and research vessel. The number of 205 tows fishing was carried out in the southeastern Pacific Ocean. The total catch was 1,988 ton and CPUE was 2.4 ton/hour. CPUE showed high values in the frontal zone during the survey. Main target species caught from the experimental fishing were the jack mackerel, Trachurus murphyi (98.1%) and chub mackerel, Scomber japonicus (1.9%) as bycatch. Body length of the jack mackerel was different between female and male. The high mean catch per unit effort of jack mackerel was showed when the fishing ground of jack mackerel fishery was over the $110^{\circ}W$ in the southeastern Pacific Ocean. But the fluctuation of the catch per unit effort in the western part of fishing ground was not matched with those year. Reliable physical and oceanographical information will be useful for the efficiency of fishing activity. According to the result of monthly movement of center of fishing ground, the fishing activity of jack mackerel fishery was performed northward in the southeastern Pacific Ocean as time passes.

• 한국기후변화학회지
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• 제8권1호
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• pp.11-19
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• 2017

This study examined the relationship between the initiation timing typhoon season in the Northwestern Pacific and the tropical sea surface temperature (SST) using a numerical simulation. The initiation timing of the typhoon season is closely associated with SSTs over the Indian Ocean (IO) and the eastern Pacific (EP) in the preceding winter and early-spring. The experiment based on the Weather and Research Forecast (WRF) model showed that the start date of the typhoon season is delayed for about one month when the SSTs over the IO and the EP increase in the preceding winter. The forced tropical SST pattern induces anticyclonic anomalies in the Northwestern Pacific, which is an unfavorable condition for typhoon development, and hence it could delay the initiation of the typhoon season.

• 수산해양기술연구
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• 제7권1호
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• pp.39-43
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• 1971

Koreans have been interested in the North Pacific fisheries since the exploratory fishing was carried out by R/V Baek-Kyung of Pusan Fisheries College in 1966. Although the salmon fishing was interrupted by some countries, Korean trawlers are venturing in the North Pacific Ocean for catching demersal fishes. The trawl fishery in the region raises some problems. i. e. the conflict with the coastal or nearshore fishery, low fish price, etc. This paper concerns with the plan for the settlement of these problems..

• Ocean Science Journal
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• 제41권2호
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• pp.105-111
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• 2006

In this paper, the lines of investigation on a problem of the development of remote acoustic sensing methods in oceanology are formulated. This paper summarizes the results of investigations into the possibilities for monitoring temperature and flow fields in shallow seas. In the discussed experiments, the instrumentation being constituents of the complex for long-duration remote monitoring of marine medium climatic variability and that of the acoustic tomography of shallow sea dynamic processes is used. The acoustic instruments were located on the POI FEB RAS acousto-hydrophysical polygon (Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences) near the Gamov Peninsula. Acoustic receiving and transmitting systems operating with multiplex phase-manipulated signals (of M-codes) at frequency range 250-2500 Hz form the basis for this complex.

• Journal of Astronomy and Space Sciences
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• 제35권2호
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• pp.105-109
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• 2018

El $Ni{\tilde{n}}o$ is the largest fluctuation in the climate system, and it can lead to effects influencing humans all over the world. An El $Ni{\tilde{n}}o$ occurs when sea surface temperatures in the central and eastern tropical Pacific Ocean become substantially higher than average. We investigated the change in sea surface temperature in the Pacific Ocean during the El $Ni{\tilde{n}}o$ period of 2015 and 2016 using the advanced very-high-resolution radiometer (AVHRR) of NOAA Satellites. We calculated anomalies of the Pacific equatorial sea surface temperature for the normal period of 1981-2010 to identify the variation of the 2015 El $Ni{\tilde{n}}o$ and warm water area. Generally, the warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America during an El $Ni{\tilde{n}}o$ period. However, we identified an additional warm water region in the $Ni{\tilde{n}}o$ 1+2 and Peru coastal area. This indicates that there are other factors that increase the sea surface temperature. In the future, we will study the heat coming from the bottom of the sea to understand the origin of the heat transport of the Pacific Ocean.

• Ocean and Polar Research
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• 제45권1호
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• pp.23-31
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• 2023

The core of the foreign policy of the Yoon Suk-yeol government is the promotion of active economic and security diplomacy as indicated in Policy Tasks No. 98. To this end, economic consultative bodies such as Regional Comprehensive Economic Partnership Agreement(RCEP), Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), and Indo-Pacific Economic Framework (IPEF) are taking the initiative to respond to the formation of supply chain, human rights, environment, and digital-related norms, and actively support Korean companies' overseas expansion. Due to the nature of the Ministry of Oceans and Fisheries (MOF) as an organization established centered on the space of the ocean, the MOF faces difficulties in bringing the functions of other ministries into the space of the ocean. Considering the vision, objectives, and detailed plans of the MOF, the contribution of the MOF in the field of active economic security, one of the main foreign policies of the Yoon Suk-yeol government, is perhaps too obvious. However, since the re-launch of the MOF, the ODA budget for the oceans and fisheries sector is too small compared to other ministries, so even if new policy demands are discovered, there are many difficulties in implementing these policies in practice. Recognizing these problems, this paper examines the background and contents of foreign policies that have been promoted for the efficient promotion of RCEP, CPTPP and IPEF and introduces the areas of cooperation in the oceans and fisheries sector in these foreign policies.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.133-136
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• 2006

The mesoscale eddy field in the North Pacific Ocean, simulated by a high resolution eddy-resolving OGCM ($1/12^{\circ}C$ horizontal resolution), was analyzed, and compared with satellite altimetry data of TOPEX/Poseidon. High levels of eddy kinetic energy (EKE) appear near the Kurosho, North Equatorial Current (NEC), and Subtropical Countercurrent (STCC) in the western part of the subropical gyre. In particlure, it was found that the EKE level of the STCC has a well-defined annual cycle, but no distinct annual cycle of the EKE exists in any other zonal current of the North Pacific Ocean.

• 대기
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• 제32권1호
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• pp.71-84
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• 2022

This paper describes verification results for the ocean analysis field produced by the Nucleus for European Modelling of the Ocean (NEMO) of the Korea Meteorological Administration (KMA) against observed Argo floats and drift buoys over the western Pacific Ocean and the equatorial Pacific during 2020~2021. This is confirmed by a comparison of the verification for the newly updated version of the HYbrid Coordinate Ocean Model/Navy Coupled Ocean Data Assimilation (HYCOM/NCODA) against same observations. NEMO shows that the vertical ocean temperature is much closer to the Argo floats than HYCOM for most seasons in terms of bias and root mean square error. On the other hand, there are overall considerable cold biases for HYCOM, which may be due to the more rapid decreasing temperature at the shallow thermocline in HYCOM. Conclusion demonstrated that the NEMO analysis for ocean temperature is more reliable than the analysis produced by the latest version of HYCOM as well as by the out-of-date HYCOM applied to the precedent study. The surface ocean current produced by NEMO also shows 14% closer to the AOML (Atlantic Oceanographic and Meteorological Laboratory) in situ drift buoys observations than HYCOM over the western Pacific Ocean. Over the equatorial Pacific, however, HYCOM shows slightly closer to AOML observation than NEMO in some seasons. Overall, this study suggests that the resulting information may be used to promote more use of NEMO analysis.