• Ocean and Polar Research
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• 제27권1호
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• pp.15-24
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• 2005

In order to investigate the structures and dynamics of phytoplankton communities, each physicochemical environmental factor, species composition, standing crop, and dominant species were examined in the marine ranching ground of Tongyeong coastal waters from April to October, 2000. During the studies, mean water temperature and salinity were $18.8^{\circ}C$ and 33.1 psu, respectively. DO, SS and transparency varied from 5.43 to 11.39 mg/l, 14.6 to 32.4mg/l and 3.5 to 9.0m, respectively. Light intensities varied from 0.02 to $966{\mu}E/m^2/s$, which decreased with depth. $NH_4-N,\;NO_3-N,\;NO_2-N,\;PO_4-P,\;and\;SiO_2-Si$ were fluctuated from 0.059 to 0.332 mg/l, 0.040 to 0.800 mg/l, 0.001 to 0.468 mg/l, 2.3 to $143.0{\mu}g/l$, and 0.007 to 0.600 mg/l, respectively. chlorophyll a concentrations were fluctuated from 0.7 to $8.9{\mu}g/l$. Among 130 taxa of phytoplankton communities observed. diatoms occupied more than 81.54% of the total species, and the others were dinoflagellates and silicoflagellates. Phytoplankton standing crops ranged from $4.6{\times}10^4\;to\;2.6{\times}10^6cells/l$. In October, the standing crops were at bloom level showing more than $10^6cells/lat$ all stations. Dominant species changed by month and station. Leptocylindrus danicus occupied 59.84% in April and 22.03% in June. Pseudo-nitzschia pungens in August and Chaetoceros socialis and Skeletonema costatum in October were predominant species. In order to investigate factors influencing the total phytoplankton standing crops the correlations between the standing crops of diatoms, dinoflagellates, all phytoplanktons occurred and environmental factors were calculated using a multiple regression analysis. The coefficient of determination $(R^2)$ for total standing crops was 0.63 which explained 63% of variance and that of $R^2$ for diatom was 0.82. In statistical analysis, the results showed that the environmental factors influencing the size of the communities were predominantly water temperature, salinity and silicate.

• Ocean and Polar Research
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• 제26권3호
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• pp.439-451
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• 2004

Total solar irradiance (750), total UV irradiunce (TUV) and erythemal UV irradiance (EUV) measured at King Sejong station $(62.22^{\circ}S,\;58.78^{\circ}W)$ in west Antarctica have been used together with total ozone, cloud amount and snow cover to examine the effects of ozone, cloud and snow surface on these surface solar inadiunce over the period of 1998-2003. The data of three solar components for each scan were grouped by cloud amount, n in oktas $(0{\leq}n<3,\;3{\leq}n<4,\;4{\leq}n<5,\;5{\leq}n<6,\;6{\leq}n<7\;and\;7{\leq}n<8)$ and plotted against solar zenith angle (SZA) over the range of $45^{\circ}\;to\;75^{\circ}$. The radiation amplification factor (RAE) is used to quantify ozone effect on EUV. RAF of EUV decreases from 1.51 to 0.94 under clear skies but increases from 0.94 to 1.85 under cloudy skies as SZA increases, and decreases from 1.51 to 1.01 as cloud amount increases. The effects of cloud amount and snow surface on EUV are estimated as a function of SZA and cloud amount after normalization of the data to the reference total ozone of 300 DU. In order to analyse the transmission of solar radiation by cloud, regression analyses have been performed for the maximum values of solar irradiance on clear sky conditions $(0{\leq}n<3)$ and the mean values on cloudy conditions, respectively. The maximum regression values for the clear sky cases were taken to represent minimum aerosol conditions fur the site and thus appropriate for use as a normalization (reference) factor for the other regressions. The overall features for the transmission of the three solar components show a relatively high values around SZAs of $55^{\circ}\;and\;60^{\circ}$ under all sky conditions and cloud amounts $4{\leq}n<5$ and $5{\leq}n<6$. The transmission is, in general, the largest in TUV and the smallest in EUV among the three components of the solar irradiance. If the ground is covered with snow on partly cloudy days $(6{\leq}n<7)$, EUV increases by 20 to 26% compared to snow-free surface around SZA $60^{\circ}-65^{\circ}$, due to multiple reflections and scattering between the surface and the clouds. The relative difference between snow surface and snow-free surface slowly increases from 9% to 20% as total ozone increases from 100 DU to 400 DU under partly cloud conditions $(3{\leq}n<6)$ at SZA $60^{\circ}$. The snow effects on TUV and TSO are relatively high with 32% and 34%, respectively, under clear sky conditions, while the effects changes to 36% and 20% for TUV and TSO, respectively, as cloud amount increases.

• 한국해양학회지:바다
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• 제4권3호
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• pp.188-197
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• 1999

해수에서 퇴적층으로 향하는 우라늄 제거 과정과 플럭스를 연구하기 위해 1996년 10월 16일과 1997년 8월 25일에 천수만 입구지역에서 공극수와 해저상자(benthic chamber, BC) 내부시료를 채취하였다. 공극수로부터 추정된 우라늄 플럭스는 해수~퇴적물 경계면에서 0.112~0.566 mg/$m^2yr$ 이었으며, 해수에서 퇴적물로 제거되는 양상을 보였다. 황해 전체로는 $4.3{\sim}21.5{\times}10^7$ g/yr의 우라늄이 제거되며 이는 전지구적 제거 플럭스의 0.4~2.2%에 달하는 값이다. 같은 방법으로 추정된 영양영 플럭스는 암모니아성 질소 135.6 mmol/$m^2yr$, 질산성 질소 228.2 mmol/$m^2yr$, 인산염 36.8 mmol/$m^2yr$, 그리고 규산염 23.9 mmol/$m^2yr$로 공극수에서 저층 해수로 용출되고 있다. 공극수중 질산성 질소와 퇴적물 망간의 수직 분포도로부터 산화환원 경계층이 퇴적물 표충하 3~5 cm 깊이에 존재함을 추정할 수 있었다. BC를 이용한 인산염 플럭스는 28.5 mmol/$m^2yr$로서 공극수를 통한 추정값과 비슷하였다. 반면에 BC를 이용한 우라늄과 규산염 플럭스 추정치는 공극수에 의한 값보다 두 자릿수 정도로 큰 값을 나타내었다. 공극수내 농도 분포로부터 추정된 우라늄과 영양염의 플럭스 추정치가 BC를 통한 추정치보다 더욱 신뢰도가 높다고 판단된다.

• Ocean and Polar Research
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• 제31권1호
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• pp.31-50
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• 2009

The demarcation of Maritime Boundary is directly related to the expansion of jurisdiction and the securing of resources. Resource diplomacies of the three countries Korea, China and Japan represent a major task for the national administrations : to secure resources as well as to stablize and sustain resources for future national economies. At the sea area around Korea as well, countries are fiercely competing to secure resources and to expand jurisdiction. This is evidenced by the fact that various principles and logics which are beneficial to each own country are presented through international precedents, agreement between countries and the theories of the international law scholars. They say that the conclusion of demarcation of maritime boundary for the Yellow Sea would be easy from the point that there is no dispute related to island dominion in the waters of the Korean Peninsula especially the Yellow Sea, but still we need to have a strategic approach to this issue from the point that the factors used for claiming maritime boundaries may expand the waters of a country over much. For example, the continental shelf boundary in consideration of the distribution of sedimentary deposits in the Yellow Sea which is being raised by China began from the hypothesis that the inflow of sedimentary deposits to the Yellow Sea through the rivers of China represents absolute majority, but the results of the latest studies raised questions on the hypothesis. Especially, the studies done by Martin and Yang revealed that the inflow of sedimentary deposits to the Yellow Sea from the Yellow River is approximately less than 1% of total sedimentary deposits in the Yellow Sea, and also the result of analysis on the causes and counter policy measures on the environment of Bohai, China supports the reliability of the results of such studies. From a legal aspect, the sedimentary deposits of rivers which are claimed by China represent extremely weak ground for the claim for the title of the continental shelf. The siltline claimed by China seems to be based on the Article 76-4-(a)(i) of UNCLOS. This is, however, not the definition on the title of the continental shelf but it is only a technical formula to utilize in a case where a country desires to expand the continental shelf to over 200 nautical miles. Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf also confirm this point through the Article 2.1.2 of the Guideline. The only case in which sedimentary deposits of rivers were referred to as concrete demarcation of maritime boundary was in the which was concluded in 1986 between India and Myanmar at the Andaman Sea. In the said case, India acknowledged the boundary up to the isobath of 200m which Myanmar claimed based on the sedimentary deposits of the Irrawaddy River. It has limits as a case for acknowledging the sedimentary deposits, however, because in fact India's acknowledgment was made in exchange for the condition that Myanmar gave up the dominion of two islands which they had been claiming from India up until that time.

• 한국항해항만학회지
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• 제31권5호
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• pp.409-414
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• 2007

GPS 환경에서 다중경로 신호는 의사거리 측정 정확도의 성능을 감소시키므로 GPS에 기반한 응용에서 위치 성능 감소로 나타나며, 이는 특히 고층 건물이 많은 도심환경 및 수면에 의한 반사가 많은 해양에서 문제가 된다. 다중경로 신호는 GPS 수신기 내부 상관기에서 상관 함수의 Early-Late 간 비대칭을 유발하므로, 본 논문에서는 Late 상관 값의 비대칭 정도를 보상하여 다중경로 오차를 제거하기 위한 가중 상관기 구조를 소프트웨어 GPS 수신기를 이용하여 구현하고, 그 성능을 평가하였다. 가중 상관기는 2개의 상관 암으로 이루어진 다중 상관기를 사용하여 상관함수의 비대칭 여부를 판단하고, 비대칭성을 감소시키기 위한 보정치를 생성한다. 이 구조는 다중 상관기에 비하여 연산 처리량 부하는 감소시키는 반면, 비슷한 다중경로 오차 제거 성능을 제공한다. 본 논문에서는 다중경로 신호 생성 블록을 포함한 GPS 신호 발생기와 가중 상관기 구조를 포함한 소프트웨어 GPS 수신기를 이용하여 다중경로 오차 제거 성능을 검증하였다. 실험을 통하여 가중 상관기가 일반 상관기와 협대역 상관기보다 더 나은 오차 제거 성능을 보임을 확인하였다.

• 대한원격탐사학회지
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• 제27권3호
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• pp.235-258
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• 2011

The purpose of this study is to investigate climatological variations from the temporal and spatial surface particulate organic carbon (POC) estimates based on SeaWiFS spectral radiance, and to determine the physical mechanisms that affect the distribution of pac in the Gulf of Mexico. 7-year monthly mean values of surface pac concentration (Sept. 1997 - Dec. 2004) were estimated from Maximum Normalized Difference Carbon Index (MNDCI) algorithm using SeaWiFS data. Synchronous 7-year monthly mean values of remote sensing data (sea surface temperature (SST), sea surface wind (SSW), sea surface height anomaly (SSHA), precipitation rate (PR)) and recorded river discharge data were used to determine physical forcing factors. The spatial pattern of POC was related to one or more factors such as river runoff, wind-derived current, and stratification of the water column, the energetic Loop Current/Eddies, and buoyancy forcing. The observed seasonal change in the POC plume's response to wind speed in the western delta region resulted from seasonal changes in the upper ocean stratification. During late spring and summer, the low-density river water is heated rapidly at the surface by incoming solar radiation. This lowers the density of the fresh-water plume and increases the near-surface stratification of the water column. In the absence of significant wind forcing, the plume undergoes buoyant spreading and the sediment is maintained at the surface by the shallow pycnocline. However, when the wind speed increases substantially, wind-wave action increases vertical motion, reducing stratification, and the sediment were mixed downward rather than spreading laterally. Maximum particle concentrations over the outer shelf and the upper slope during lower runoff seasons were related to the Loop Current/eddies and buoyancy forcing. Inter-annual differences of POC concentration were related to ENSO cycles. During the El Nino events (1997-1998 and 2002-2004), the higher pac concentrations existed and were related to high runoffs in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico. During La Nina conditions (1999-2001), low Poe concentration was related to normal or low river discharge, and low PM/nutrient waters in the eastern Gulf of Mexico, but the opposite conditions in the western Gulf of Mexico.

• 환경생물
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• 제26권2호
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• pp.94-101
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• 2008

공장 폐수로 인한 오염이 심한 경기 시화호에서 오염정도가 다른 두 지역으로부터 풀망둑을 채집하여 이들의 해독효소계 또는 항산화효소계의 반응을 비교하였다. 해독효소계에서 I상효소로는 CYP, P450R, b5R, EROD를, II상효소로는 GST를 조사하였다. 그리고 항산화효소계로는 CAT, GR, CPx의 활성 그리고 GSH및 CSSG농도를 조사하였다. 그 결과, 오염정도가 심한 지역에서 잡은 어류가 간장 중 P450R, b5R, GST의 활성이 높았으나 EROD활성은 오히려 낮았고 CYP농도는 차이가 없었다. 그리고 이지역에서 잡은 어류는 CAT와 GR의 활성, 비효소적인 항산화계인 CSH와 GSSC농도도 더 높았으나 GTx활성은 오히려 낮았다. 이들 결과는 시화호의 오염된 곳에서 서식하는 풀망둑 Acanthogobius hasta은 상당히 해독효소계가 항진되어 있으며 산화 스트레스도 크게 받고 있음을 보여준다.

• 한국수산과학회지
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• 제24권5호
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• pp.315-326
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• 1991

본 조사는 노래미(Agrammus agrmmus)의 위만복도의 일주변화에 관한 수리적 접근을 시도한 것이다. 표본은 삼천포 신수도 연안에서 1984년 9월부터 1985년 8월사이에 낚시와 삼중자강으로 채집된 것이다. 하루 중 위만복도는 이른 아침과 늦은 오후에 각각 한차례씩 증가하였고, 늦은 오전과 정오무렵 및 야간에는 감소하였다. 즉, 노래미의 섭식활동은 해뜰무렵과 해질무렵에 강하였다. 본 종의 하루 중 일주섭식활동은 위배출만 일어나는 시간대와 섭식과 위배출이 동시에 일어나는 시간대로 구분할 수 있었다. 위배출 시간대에서 시간의 경과에 따른 위만복도는 지수 함수적으로 감소하였고, 섭식과 위배출이 동시에 일어나는 시간대에서 시간의 경과에 따른 위만복도는 단위시간당 위배출률과 섭식률, 위의 최대만복도 등에 영향을 받았다. 위배출률은 위배출 시간대에서 시간 t와 t시점에서의 위만복도 $F_t$, 간, 또는 $F_t$와 $t+\Delta t$시점에서의 위만복도 $F+_{\Delta t}$, 간의 회귀관계식으로분터 회귀계수를 추정하는 방법으로써 구할 수 있었다. 섭식률과 위의 최대만복도는 섭식과 위배출이 동시에 일어나는 시간대에서 $F_t$와 $t+\Delta t$간의 회귀관계식으로부터 추정할 수 있었다. 섭식률과 위배출률은 봄에 높았고 겨울에 낮았다. 본 종의 일주섭식활동에 관한 가설들로부터 추논된 위배출 시간대와 섭식과 위배출이 동시에 일어나는 시간대에서 시간 t와 t시점에서의 위만복도 $F_t$, 간의 관계식은 각각 아래와 같다. $$F_t=F_{to}e^{-r(t-to)}$$, $$F_t=F\infty-(F\infty-F_{to})e^{-(p+r)(t-{to})}$$

• 대기
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• 제21권1호
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• pp.1-16
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• 2011

Numerical prediction capability has been improved over the decades, but progress of prediction for high-impact weather (HIW) was unsatisfactory. One reason of low predictability for HIW is lack of observation data. The National Institute of Meteorological Research (NIMR) has been performed observation program for improvement of predictability, and reduction in social and economical cost for HIW. As part of this observation program, summer intensive observation program (ProbeX-2009) was performed at the observation-gap areas from 25 August to 6 September 2009. Sounding observations using radiosonde were conducted in the Gisang2000 research vessel (R/V) from the Korea Meteorological Administration (KMA) over the West Sea and the Eardo R/V from the Korea Ocean Research and Development Institute (KORDI) over the South Sea. Observation System Experiment (OSE) is carried out to examine the effect of ProbeX-2009 data. OSEs using Korea Local Analysis and Prediction System (KLAPS) and Weather Research and Forecasting (WRF) Model are conducted to investigate the predictability for a short time forecast. And, OSEs using WRF/3DVAR system and WRF forecast model are conducted to study the predictability for an extended time. Control experiment (K_CTL and CNTL) used only GTS observation and experiment (K_EXP and SWEXP) used ProbeX-2009 data from two system are performed. ETS for 3hr accumulated rainfall simulated by KLAPS-WRF shows that K_EXP is higher than K_CTL. Also, ETS for 12hr accumulated rainfall of SWEXP from 3DVAR-WRF is higher than CNTL. The results indicate that observation over the ocean has positive impact on HIW prediction.

• 한국항해항만학회지
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• 제36권5호
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• pp.339-347
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• 2012

예인줄을 여러 개의 유한요소로 분할 한 뒤 각 요소들에 Newton의 운동 제 2법칙을 적용하고 각각에 작용하는 외력은 성분별로 장력, 항력, Coriolis 힘, 중력, 부력, 입수 충격력 등으로 구분하여 예선과 부선을 연결하는 예인줄의 동역학 모델을 정립하였다. 일반적으로 예인줄 요소의 병진 운동만을 고려하는 이전의 연구들과는 달리 본 논문에서는 예인줄 요소의 운동을 횡동요를 제외한 5자유도로 확장하고 외력 고려가 용이한 물체고정좌표계에서 기술하였다. 예인줄 요소들 간에는 연결점에서 인장만 되는 스프링과 감쇠기로 연결하고, 스프링의 강성계수는 실제 적용되는 예인줄의 강성계수와 등가가 되도록 설정하였다. 정립된 예인줄 모델의 검증을 위하여 예인줄의 공기중 및 수면 바로 위에서의 자유낙하, 예인선의 가속운동, 예인선의 조화운동 시나리오에 대하여 시뮬레이션을 수행하였다. 시뮬레이션 결과, 예인선, 부선, 예인줄 요소들의 운동 시계열 값들은 실제 예상치와 유사한 경향을 보이는 것을 확인하였다.