• 대기
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• 제28권1호
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• pp.37-51
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• 2018

In this study, we investigate the performance of Global Seasonal Forecasting System version 5 (GloSea5) in Korea Meteorological Administration on the relationship between El $Ni{\tilde{n}}o$ and East Asian climate for the period of 1991~2010. It is found that the GloSea5 has a great prediction skill of El $Ni{\tilde{n}}o$ whose anomaly correlation coefficients of $Ni{\tilde{n}}o$ indices are over 0.96 during winter. The eastern Pacific (EP) El $Ni{\tilde{n}}o$ and the central Pacific (CP) El $Ni{\tilde{n}}o$ are considered and we analyze for EP El $Ni{\tilde{n}}o$, which is well simulated in GloSea5. The analysis period is divided into the developing phase of El $Ni{\tilde{n}}o$ summer (JJA(0)), mature phase of El $Ni{\tilde{n}}o$ winter (D(0)JF(1)), and decaying phase of El $Ni{\tilde{n}}o$ summer (JJA(1)). The GloSea5 simulates the relationship between precipitation and temperature in East Asia and the prediction skill for the East Asian precipitation and temperature varies depending on the El $Ni{\tilde{n}}o$ phase. While the precipitation and temperature are simulated well over the equatorial western Pacific region, there are biases in mid-latitude region during the JJA(0) and JJA(1). Because the low level pressure, wind, and vertical stream function are simulated weakly toward mid-latitude region, though they are similar with observation in low-latitude region. During the D(0)JF(1), the precipitation and temperature patterns analogize with observation in most regions, but there is temperature bias in inland over East Asia. The reason is that the GloSea5 poorly predicts the weakening of Siberian high, even though the shift of Aleutian low is predicted. Overall, the predictability of precipitation and temperature related to El $Ni{\tilde{n}}o$ in the GloSea5 is considered to be better in D(0)JF(1) than JJA(0) and JJA(1) and better in ocean than in inland region.

• 한국해양학회지
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• 제23권3호
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• pp.110-122
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• 1988

해양연구소는 한국 해양학사상 처음으로 1983년 12월 북태평양의 클라리온-클리퍼톤균열대 (Clarion and Clipperton Fracture Zones) 사이에서 망간단괴와 망간각을 채취하였으며, 이때 사용된 해양조사선은 하와이대학의 KANA KEOKI호였다. 본 연구는 KONOD-1 지역에서 채취된 망간단괴와 망간각의 광물조성과 유용금속성분을 분석, 경호하였으며, 태평양 심해저 평원에서 보고된 망간만괴와 비교하였다. 한편 광물 및 금속함량을 기초하여 금속원소의 공급원과 망간단괴가 형성되는 원리를 해석하였다. 연구지역 망간단괴는 망간산화물로 토도로카이트(todorokite)와 ${\delta}$-$MnO_2$로 그리고 망간각은 ${\delta}$-$MnO_2$로 조성되어 있다. 주요 금속성분의 평균함량은 Mn 21.4%, Fe 6.2%, Ni 0.9%, Cu 0.7%, 그리고 Co 0.2% 이며, 이 값은 클라리온과 클리퍼톤 균열대 지역에서 규질연니를 표층퇴적물로 하고 있는 심해저평원 망간만괴에서 보고된 값보다 적다. 그러나 망간단괴중 높은 Mn/Fe비 (평균 3.9, 최고 5.9)와 높은 Cu/Ni비 (평균 0.8, 최고 1.0)는 북태평양에서 속성작용으로 형성된 망간단괴와 일치한다. KONOD-1 지역 망간단괴의 화학적 특징은 두 종류로 대분되며, 각각의 특성은 망간단괴가 형성된 퇴적환경을 암시한다. 강한 속성작용의 망간단괴는 심해저평원지역 규질연니의 현생 퇴적층위에서 형성되고 있으며 약한 속성작용의 망간단괴는 심해저 구릉이 분포하는 지형, 즉 퇴적층이 균일하지 못한 환경에 주로 분포되어 있다.

• Ocean and Polar Research
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• 제29권4호
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• pp.283-295
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• 2007

We investigated the longitudinal variations in zooplankton abundances and their related physicochemical properties at nine stations located between $136^{\circ}W$ and $128^{\circ}W$ at $10.5^{\circ}N$ in the northeastern Pacific in summer 2004. Temperature, salinity, inorganic nutrients, chlorophyll-a (hereafter chl-a) and zooplankton ($>200\;{\mu}m$) were sampled within the depth from the surface to 200 m depth at $1^{\circ}$ longitude intervals. Zooplankton($>200\;{\mu}m$) samples were vertically collected at two depth intervals from surface to 200 m, consisting of surface mixed and lower layers (thermocline$\sim$200 m). Longitudinal distributional pattern of hydrological parameters (especially salinity) was physically influenced by the intensity of westward geostrophic current passage relating to the NEC (North Equatorial Current). Data from the longitudinal survey showed clear zonal distributions in the hydrological parameters(temperature, salinity and nutrients). However, spatial patterns of the chl-a concentrations and zooplankton abundances were mostly independent of the zonal distributions of hydrological parameters. The two peaks of zooplankton abundance in the surface mixed layer were characterized by different controlling factors such as bottom-up control from nutrients to zooplankton ($129^{\circ}W$) and accumulation by increment of friction force and taxonomic interrelationship ($133^{\circ}$ and $134^{\circ}W$). Divergence-related upwelling caused introduction of nutrients into surface waters leading to the increment of chl-a concentration and zooplankton abundances ($129^{\circ}W$). Increased friction force in relation to reduced flow rates of geostrophic currents caused accumulation of zooplankton drifting from eastern stations of study area($133^{\circ}$ and $134^{\circ}W$). Besides, high correlation between immature copepods and carnivorous groups such as chaetognaths and cyclopoids also possibly contributed to the enhanced total abundance of zooplankton in the surface mixed layer (p<0.05). Zooplankton community was divided into three groups (A, B, C) which consecutively included the eastern peak of zooplankton($129^{\circ}W$), the western peak($133^{\circ}$ and $134^{\circ}W$) and high nutrient but low chl-a concentration and zooplankton abundance ($136^{\circ}W$). Moreover, Group B corresponded to the westward movement of low saline waters(<33.6 psu) from 128 to $132^{\circ}W$. In summary, longitudinal distributions of zooplankton community was characterized by three different controlling factors: bottom-up control ($129^{\circ}W$), accumulation by increased friction force and relationships among zooplankton groups ($133^{\circ}$ and $134^{\circ}W$), and mismatch between hydrological parameters and zooplankton in the high nutrient low chlorophyll area ($136^{\circ}W$) during the study period.

• 한국환경과학회지
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• 제17권4호
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• pp.461-468
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• 2008

Competitive power of pelagic fishery in Korea has been weakened by the domestic and international problems such as wage increase and exclusive economic zone. To make it worse, fishing fleet spends more than 80% of fishing time on searching fishing grounds. Real-time information on oceanographic data, temperature in particular, are likely to contribute to raise efficiency of fishing. However, available data obtained by satellite remote sensing, fixed buoy and drifting buoy, limited to sea surface or fixed positions. ARGO (Array for Real-time Geostrophic Oceanography), an international program, has delivered vertical profiles of temperature and salinity in the upper 2000m of the world ocean every 10 days using freely moving floats. We have developed real-time oceanographic information system for pelagic fishery based on the Argo data which has the contents of vertical profile, horizontal distribution and vertical section of temperature around fishing grounds and searched data can be download unrestrictedly. Comparison of skipjack catch with sea surface temperature and depth of $20^{\circ}C$ derived from Argo data in the West Equatorial Pacific revealed that Argo data are able to help fishing fleet to find fishing grounds and to increase catch.

• Ocean and Polar Research
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• 제26권2호
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• pp.219-230
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• 2004

The aims of this study are to construct database using geostatistics and Geographic Information System (GIS), and to derive the spatial relationships between manganese nodule abundance and each factor affecting nodule abundance, such as metal grade, slope, aspect, water depth, topography, and acoustic characteristics of the subbottom using the GIS and probability methods. The greater is the copper and nickel grade, the higher is the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than $3^{\circ}$, excluding seamounts and cliff areas. There is no increment in the rating with increasing slope. The rating is highest for slopes between 2.5 and $3.5^{\circ}$ in block B2 and between 3 and $6^{\circ}$ in block C1. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The ratings prove lowest for seamount and hill crest. The results of the study show a decrease in the rating with an increase in water depth in the study area. There was a poor relationship between manganese nodule abundance and the thickness of the upper transparent layer in block C1. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권3호
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• pp.139-148
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• 2000

A mass balance/photochemical modeling approach was used to evaluate the sea-to-air dimethyl sulfide (DMS) fluxes in tropical regions and part of the Southern Ocean. The flux determinations were based on 10 airborne observations by ACE 1 transit flights (i.e., Flights 4-9 and 29-32). The DMS flux values for the tropical regions ranged from 1.0 to 7.4 $\mu$mole/$m^2$/day with an average estimate of 4.2$\pm$2.3 $\mu$mole/$m^2$/day. The seasonal variations in the DMS flux predicted for the equatorial Pacific Ocean based on atmospheric DMS measurements were not entirely consistent with those derived from seawater DMS measurements were not entirely consistent with those derived from seawater DMS measurements reported in previous literature. Inhomogeneities in the DMS flux field were found to cause significant shifts in the atmospheric DMS levels even in the same sampling location. Accordingly, no definitive statement can be made at this stage regarding systematic differences or agreements in the DMS flux estimates from the two approaches. Moreover, this study strongly suggests that DMS oxidation is the most likely dominant source of SO$_2$in tropical regions, which is also supported by another set of compiled observations. Finally, these SO$_2$observations indicate that, when significant data was available for both the boundary and buffer layers, the vertical SO$_2$gradient between these two zones was primarily negative.

• 한국지구과학회지
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• 제34권2호
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• pp.136-147
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• 2013

이 연구는 6월 남극진동이 한국 6월 강우량에 영향을 주는지 알아보기 위해 두 변수 사이에 상관분석이 이루어졌고 높은 양의 상관관계가 있음이 밝혀졌다. 이는 한국 6월 강우량이 같은 시기에 남반구에서 강화되는 머스커렌 고기압과 호주 고기압의 영향을 받음을 의미하는 것이다. 이 두 고기압이 발달할 때 호주 주위지역으로부터 적도방향으로 적도 횡단류가 강화되며, 이 적도 횡단류의 강화는 북태평양고기압의 북쪽으로의 강화로 이어진다. 이는 결국 장마전선을 한국으로 북상시키는 역할을 한다. 더욱이 북태평양 고기압의 북쪽으로의 강화는 한국에 상륙하거나 영향을 주는 태풍의 빈도를 증가시켜 6월 강우량의 증가에 중요한 역할을 한다.

• 지구물리
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• 제9권4호
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• pp.311-320
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• 2006

웨이브렛(wavelet) 이론을 이용한 디지털 필터를 심해저 광물자원 개발광구 중 KR5 지역의 실제 수심자료에 적용하였다. 이 연구에서는 Linear B-spline 웨이브렛 필터와 Cubic B-spline 함수의 미분 웨이브렛 필터를 사용하였으며, 적절한 변수를 결정하여 필터를 적용하여 선형으로 발달된 해저구릉과 해저곡의 위치 및 해저구릉의 경사면의 방향을 추출하였다. 2-D 행렬의 필터에서 해저구릉의 너비와 길이를 결정하는 필터의 길이와 수를 시행착오를 거쳐 추정하였다. 필터의 적용으로 추출한 특징들은 실제 지형도상 해저구릉과 해저곡과 일치하였다. 필터 적용으로 해저구릉과 해저곡의 형태를 분리하여 추출함으로써 지형분석에 더 많은 정보를 제공하고, 해저구릉의 경사면의 방향과 위치를 도면상에 도시하여 지형 자료 분석에 유용하게 사용된다. 이러한 지형 특성의 분석은 망간단괴의 분포 특성과의 비교를 통하여 심해저 광물자원 채광지역 선정에 유용한 자료가 될 것으로 사료된다.

• Ocean and Polar Research
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• 제31권4호
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• pp.339-347
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• 2009

It is possible to obtain accurate temperature and salinity profiles of the oceans using a SBE 911plus CTD and accompanying data conversion packages. To obtain highly accurate results, CTD data needs to be carefully processed in addition to proper and regular maintenance of the CTD itself. Since the manufacturer of the CTD provides tools that are necessary for post processing, it is possible to conduct proper processing without too much effort. Some users, however, are not familiar with all of the processes and inadvertently ignore some of these processes at the expense of data quality. To draw attention to these and other similar issues, we show how it is possible to improve data quality by utilizing a few extra processes to the standard or default data process procedures with CTD data obtained from the equatorial Eastern Pacific between 2001 and 2005, and 2007. One easy step that is often ignored in the standard data process procedure is "wild edit", which removes abnormal values from the raw data. If those abnormal values are not removed, the abnormality could spread vertically during subsequent processes and produce abnormal salinity in a range much wider than that of the raw data. To remove spikes in salinity profiles the "align CTD" procedure must be carried out not with the default values included in the data processing software but with a proper time constant. Only when "cell thermal mass" correction is conducted with optimal parameters, we can reduce the difference between upcast and downcast, and obtain results that can satisfy the nominal accuracy of the CTD.

• 한국수산과학회지
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• 제20권4호
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• pp.355-359
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• 1987

(Type A, B 및 C)으로 분류되며, 이들 미끼구조들은 단일 단괴에서도 혼합구조로서 흔히 산출된다. 각 유형은 상이한 화학성분과 구성광물 및 결정도를 나타내며 이 중 A형은 조립질 조직을 갖고있고 다른 유형에 비해 결정도가 높은 Todorokite로 주로 구성되고 Mn의 함량도 놀은 반면에 B와 C형은 중간 내지는 세립질 조직을 갖고 있다$(Mn=30.6\%)$. 또한 A형은 상대적으로 빠른 성장속도를 나타내며, 보트리오이드 사이의 공극에서 Smectite와 규질화석이 나타난다. 이러한 특징은 A형 구조를 갖는 미세한 층(microlayer)의 성인이 해저에서의 열수작용과 관련된 것으로 생각되며, 열수용액은 주변 단열대와 해저확장대로부터 공급된 것으로 추정된다.