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        검색결과 59

        41.
        2006.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대기-해양의 상호작용과 제주도 후면에서 발생하는 카르만소용돌이행렬의 상관관계를 수치실험을 통하여 분석하였다. 카르만 소용돌이는 한라산의 제한된 높이에서 형성되는 경향을 가지고 있다. 그리고 본 연구에서는 900 hPa고도에서 카르만 소용돌이가 뚜렷이 생성되었다. 카르만소용돌이행렬의 발생초기에는 하나의 소용돌이세포가 나타나고 시간이 경과함에 따라 소용돌이는 이류를 한다. 이때 작은 소용돌이로 분리되는 경향이 있다. 분리된 소용돌이의 강도와 지속시간은 해수면 온도 분포와 밀접한 관계를 가진다. 즉 약한 해수면의 온도경도는 카르만 소용돌이의 지속 시간을 길게 하며, 산 후면의 소용돌이도를 감소시킨다. 강한 해수면 온도경도는 혼합층과 대기하층 수증기량을 증가시키고, 강화된 하층대기 혼합은 산악에 의하여 형성되는 기계적 응력을 감소시키는 경향이 있다.
        4,300원
        42.
        2005.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        엘니뇨현상과 관련된 해양 아표층 변동성을 조사하기 위해 1980년부터 2004년까지의 적도 해역의 20도 등온선 깊이(Z20)와 난수질량(WWV) 자료를 분석하였다. 주성분 분석, 합성 분석 및 교차상관 분석 결과, 아표층 시계열 자료는 Nino3.4 SST와 유의미한 시간 지연을 가지고 강한 상관성을 보였다. 이 결과는 아표층 해양 변수가 엘니뇨현상에 유용한 예측 인자임을 시사한다. 분석된 결과를 근거로 1996년부터 2004년까지 Nino3.4 SST를 예측하기 위해 신경망 예측 모델을 구성하였다. 해상풍을 입력 자료로 사용하였을 경우 보다 WWV를 적용하였을 때 3개월 이하의 단기 예측을 제외하고 모든 예측 시간에서 더 우수한 예측력을 보였으며, 5-8개월의 예측에 있어서는 기존의 여러 통계 모델 결과보다 예측 성능이 우수함을 확인하였다.
        4,000원
        43.
        2005.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대표적인 엘니뇨 지수인 태평양 Nino 해역의 표층 수온을 예측하기 위해 비선형 통계모델 중의 하나인 신경망 기법을 적용하였다. 신경망 모델 학습 과정의 입력 자료로 1951년부터 1993년까지의 태평양 해역(120˚ E, 20˚ S-20˚ N) NCEP/NCAR의 재분석 표층 수온 편차의 경험적 직교함수 7개 주모드를 사용하였고, 그 중 1994년부터 2003년까지의 10년 결과를 분석하였다. 모든 해역에서의 9개월까지의 신경망 모델의 예측력은 비교적 우수하였으며, 특히 1997년과 1998년의 강한 엘니뇨의 발달 및 소멸도 잘 예측함을 확인할 수 있었다. 해역별로는 Nino3 지역의 예측성능이 가장 높았으며, 9개월 이후부터는 그 예측력이 급격히 감소하였다. 한편 지역적인 영향이 커 예측력이 낮은 동태평양 연안의 Nino1+2 지역은 9개월 이후에도 예측력의 감소가 관찰되지 않았다.
        4,000원
        44.
        2003.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        해수면 온도에 대한 구름복사 강제력의 지역 의존도가 조사되었다. 이 조사는 경년 변동과 계절 시간규모에 대해서 각각 조사되었다. 적도 동태평양에서 경년 변동의 경우 해수면 온도가 1˚C 증가할 때 순 구름복사 강제력은 약 3Wm-2가 증가하였으며, 계절변동이 포함된 경우 약 3.5Wm-2가 증가하는 것으로 나타났다. 반면 열대 해양전체에서 경년 변동의 경우 해수면 온도가 1˚C 증가할 때 순 구름복사 강제력은 1.5Wm-2 감소하였으나, 계절변동이 포함된 경우 약 2.9Wm-2로 증가하였다. 따라서 해수면 온도에 대한 구름복사 강제력의 의존도는 적도 동태평양에서 열대 해양으로 넓어질수록 경년 변동에 의해 영향에서 계절변동에 의한 영향이 더 지배적으로 작용한다. 계절 변동이 포함된 경우 해역에 관계없이 해수면온도가 1˚C 증가할 때, 순 구름복사 강제력은 약 2∼3Wm-2 증가하였다. 이러한 결과는 해수면 온도의 경년 변동이 뚜렷한 적도 동태평양에서는 경년 변동에 의한 구름복사 강제력이 대기를 가열하는 반면, 열대 해양 전체에서는 계절변동에 의한 구름복사 강제력이 대기를 가열한다는 것을 의미한다.
        4,000원
        45.
        1981.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라 남부해안기후의 특성과 수온과의 관계를 알아보기 위하여 해안지방인 부산, 여수, 목포를 준표준 내륙지방으로 광주와 대구, 인근 해양의 가덕도, 소리도, 홍도의 수온을 선정하여 20년 간(1960~1979)의 관측자료로서 기온, 습도, 강수량을 조사 분석한 결과는 다음과 같다. 1) 해안지방(부산, 여수, 목포)은 해양의 영향으로 내륙지방(대구, 광주)보다 기온의 연교차가 적고 기온이 수온보다 높을 때는 내륙지방이 해안지방의 기온보다 높고, 수온이 기온보다 높을 때는 내륙지방이 해안지방보다 낮다. 2) 수온과 기온의 차에 따라서 내륙지방과 해안지방의 기온차가 결정되며(상관계수 0.9이상) 그 양적 예측도 상관관계식을 활용함으로써 가능하다고 생각된다. 3) 해안지방과 내륙지방의 습도의 차이도 기온의 경우와 비슷하게 나타났으나 목포는 지형적인 영향으로 다른 해안지방과 다르게 나타났다. 4) 수온과 기온의 차이에 따라서 해안지방과 내륙지방의 습도의 차이가 결정된다(상관계수 0.9이상, 목포제외), 그러므로 그 양적 해석도 가능하다. 5) 남해안지방의 강수량은 내륙지방과 그 차이가 뚜렷하게 나타나지는 않았다.
        4,000원
        46.
        2018.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        El Niño is the largest fluctuation in the climate system, and it can lead to effects influencing humans all over the world. An El Niño 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 Niño 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 Niño 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 Niño period. However, we identified an additional warm water region in the Niño 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.
        47.
        2018.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this article is analyzing the impacts of seawater surface temperature rise on sea mustard yields of Goheung and Wando coast in Korea, with employing a panel data regression model. Our results show that there has been a negative impacts on sea mustard yields as seawater surface temperature continuously has been rising. Especially if the upward trend in seawater surface temperature since 2005 will be maintained in future, sea mustard yield is expected to decrease by 2.6% per year.
        48.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        In this study, the wind direction and the wind speed of the nearest temperature observations point of the National Weather Service was analyzed in order to investigate the rapid rise and drop of water temperature in the East Coast appeared after passing of the 2015 typhoon No. 9 and 11. Then the figures were simulated and analyzed using the WRF(weather research and forecast) model to investigate in more detailed path of the typhoon as well as the changes in the wind field. The results were as follows. A sudden drop of water temperature was confirmed due to upwelling on the East coast when ninth typhoon Chanhom is transformed from tropical cyclones into extra tropical cyclone, then kept moving eastwards from Pyongyang forming a strong southerly wind after 13th and this phenomenon lasted for two days. The high SST(sea surface temperature) is confirmed due to a strong northerly wind by 11th typhoon Nangka. This strong wind directly affected the east coast for three days causing the Ekman effect which transported high offshore surface waters to the coast. The downwelling occurred causing an accumulation of high temperature surface water. As a results, the SST of 15m and 25m rose to that of 5m.
        49.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        The COMS (Communication, Ocean and Meteorological Satellite) has been used in numerical weather prediction and meteorological monitoring over East Asia and Oceania since it has been launched in 2010. For more active utilization in climate research, the COMS level 3 products should be available in appropriate spatial and temporal resolutions. We compared different methods to generate monthly sea surface temperature (SST) products from the COMS time-series data. We employed three techniques for aggregating the time series, which are arithmetic mean, timeslot average, and moving average, and also used mean ensemble of them. Each level 3 dataset around South Korea was compared with monthly SST product from the Moderate Resolution Imaging Spectroradiometer (MODIS) of Aqua satellite during April 2011-March 2014. The timeslot average showed better root mean squared difference (RMSD) during the initial operational period of the COMS, when the retrieved values could be somewhat unstable. Daytime aggregations were derived more accurately by using the arithmetic mean or moving average, and the accuracy of nighttime aggregation was improved by the mean ensemble. Also, the timeslot average presented reasonable results particularly for coastlines where the standard deviation and missing value ratio were greater than normal. Because an optimal aggregation technique was variable depending on spatial and temporal conditions, we should be careful in selecting appropriate method for generation of the COMS level 3 products according to research objectives.
        50.
        2014.08 KCI 등재 서비스 종료(열람 제한)
        In order to understand the relation between the distribution of sea surface temperature and heavy snowfall over western coast of the Korean peninsula, several numerical assessments were carried out. Numerical model used in this study is WRF, and sea surface temperature data were FNL(National Center for Environment Prediction-Final operational global analysis), RTG(Real Time Global analysis), and OSTIA(Operational Sea Surface Temperature and Sea Ice Analysis). There were produced on the basis of remote sensing data, such as a variety of satellite and in situ observation. The analysis focused on the heavy snowfall over Honam districts for 2 days from 29 December 2010. In comparison with RTG and OSTIA SST data, sensible and latent heat fluexes estimated by numerical simulation with FNL data were higher than those with RTG and OSTIA SST data, due to higher sea surface temperature of FNL. General distribution of RTG and OSTIA SST showed similar, however, fine spatial differences appear in near western coast of the peninsula. Estimated snow fall amount with OSTIA SST was occurred far from the western coast because of higher SST over sea far from coast than that near coast. On the other hand, snowfall amount near coast is larger than that over distance sea in simulation with RTG SST. The difference of snowfall amount between numerical assessment with RTG and OSTIA is induced from the fine difference of SST spatial distributions over the Yellow sea. So, the prediction accuracy of snowfall amount is strongly associated with the SST distribution not only over near coast but also over far from the western coast of the Korean peninsula.
        51.
        2010.05 KCI 등재 서비스 종료(열람 제한)
        수문학적 물순환과정에서 강우는 여러 기상학적 인자들과 밀접한 관련을 갖으며 발생한다. 따라서 본 연구에서는 대표적인 수문기상인자인 해수면온도와 한반도에 발생하는 월강우량 사이의 관계에 대하여 분석하였다. 우리나라의 61개 지점의 월평균 강우량과 위도 및 경도 자료를 이용하여 군집분석을 수행하였다. 군집 분석 결과에서 우리나라의 월강우자료를 이용하여 크게 4개의 군집으로 구분할 수 있었다. 군집별로 구분된 강우관측소의 월강우량 자료들을 주성분을 추출하였다
        52.
        2010.02 KCI 등재 서비스 종료(열람 제한)
        Accurate simulation of the meteorological field is very important to assess the wind resources. Some researchers showed that sea surface temperature (SST) plays a leading role on the local meterological simulation. New Generation Sea Surface Temperature (NGSST), Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), and Real-Time Global Sea Surface Temperature (RTG SST) have different spatial distribution near the coast and OSTIA shows the best accuracy compared with buoy data in the southeastern coast of the Korean Peninsula. Those SST products are used to initialize the Weather Research and Forecasting (WRF) Model for November 13-23 2008. The simulation of OSTIA shows better result in comparison with NGSST and RTG SST. NGSST shows a large difference with OSTIA in horizontal and vertical wind fields during the weak synoptic condition, but wind power density shows a large difference during strong synoptic condition. RTG SST shows the similar patterns but smaller the magnitude and the extent.
        53.
        2008.02 KCI 등재 서비스 종료(열람 제한)
        In order to investigate the effect of inflow of Yangze river on the distribution of chlorophyll-a, the results of serial oceanographic observation during 2000-2005 were used. The oceanographic conditions in the northern East China Sea is influenced by the Tsushima Warm Current and low saline water derived from the Yangze river. The distributions of these water masses vary significantly by the season in the northern East China Sea. The sea surface temperature and salinity were stable and concentrations of chlorophyll-a were low in the eastern part of 126°E. On the contrary, the salinity was significantly influenced by the low saline water derived from Yangze river with the high concentrations of chlorophyll-a. It is suggested that the low saline water inflowed from the Yangze river affects high concentrations of chlorophyll-a in the northern East China Sea in summer.
        54.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        수문시계열을 분석하기 위한 방법으로 낮은 차원에서 해석이 가능한 주성분분석 방법의 문제점을 검토하고 이를 보완할 수 있는 독립성분분석의 이론과 특성을 검토하였고 수문기상자료인 Nino지역의 해수면온도에 적용하여 El -Southern Oscillation(ENSO) 사상과의 상관성을 평가하였다. 혼합자료를 사용하여 독립성분분석 방법의 주성분 분리 능력을 검토한 결과 독립성분분석이 기존 주성분분석에 비해 통계적으로 우수한 결과를 나타내었다. El 의 감시
        55.
        2001.04 KCI 등재 서비스 종료(열람 제한)
        The magnitudes of sea surface temperature (SST) anomalies at 13 coastal stations along the Korean peninsula in the summer and winter for the past 29years (1969-1997) are more larger than those in the spring and autumn. The periods of positive SST anomalies (negative SST anomalies) longer than 1℃ were 75(74.5) months in the eastern coast of Korea, 47.8(51.6) months in the southern coast of Korea and 69.5(69.8) months in the western coast of Korea during the past 348 months (1969-1997). The predominant periods of the low-pass filtered monthly SST anomalies are 3 years or 13 months, even another predominant period is 24 months. The spatial variation of SST anomalies were confined by regional seas of the Korean peninsula, such as the East Sea, the South Sea and the West Sea itself.
        56.
        2000.08 KCI 등재 서비스 종료(열람 제한)
        The relationship between air temperature and sea surface temperature are studied using the daily air temperature and sea surface temperature data for 25 years (1970∼1994) at 9 coastal stations in Korea. Seasonal variations of air temperature have larger amplitudes than those of sea surface temperature. The seasonal variations of air temperature leads those of sea surface temperature by 2 to 3 weeks. The anomalies of sea surface temperature and air temperature are positively correlated. The long term anomalies of sea surface temperature and air temperature with time scales more than 1 month are more highly correlated than those of short term, with time scales less than 1 month. Accumulated monthly anomalies of sea surface temperature and air temperature for 6 months showed higher correlation than the anomalies of each month. The magnitudes of sea surface temperature and air temperature anomalies are related with the duration of anomalies. Their magnitudes are large when the durations of anomalies are long.
        57.
        2000.06 KCI 등재 서비스 종료(열람 제한)
        The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied. The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998. The initial water temperature at C. polykrikoides bloom was about 21℃ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21℃ isothermal line in the East Sea. The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin. The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998. In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom. The SST at the red tides varied from 21℃ to 25℃ ; 21℃, 23℃, 24℃ and 24-25℃ in 1995, 1996, 1997 and 1998, respectively.
        58.
        1995.12 KCI 등재 서비스 종료(열람 제한)
        The aim of the present study is to investigate the interannual variabilities of the East Asia monsoon rainfall associated with the global sea surface temperature anomaly(SSTA). For this study, the summer rainfall(from June to August) over the twenty-eight period of 1961-1988 were analyzed with being divided by nine-subregions over East Asia including Korea, China and Japan. From the analysis of the principal modes explaining the interannual variation, the interannual variabilities of summer rainfalls in South Japan and Korea are larger than those of the other subregions of the East Asia. There is a strong negative correlation between the summer rainfalls of south China and Korea. In this study, the relationship between the summer monsoon of each subregion and SSTs of the tropical NINO regions, of western Pacific warm pool, and of the subtropical ocean were investigated. The longitudinal sections of the lagged cross correlations of the summer rainfall anomaly in (a) Korea and (b) south China, and the monthly SSTA in the equatorial (averaged from 6S to 6N) Pacific were analyzed. The negative maximum correlation pattern of Korea`s summer rainfall and SSTs over the eastern Pacific is transfered to positive maximum correlation over central Pacific region with a biennial periodicity. In South China, the significant positive correlations are found at -12 month lag over the eastern Pacific and maximum negative correlation at +6 month lag over the central Pacific with the quasi-biennial oscillation. But the correlation coefficient reverses completely to that in Korea. In order to investigate the most prevailing interannual variability of rainfall related to the favored SSTA region, the lagged cross correlations between East Asia rainfall and SSTs over the NINO regions(NINO 1+2(0-10S, 90W-80W), NINO 3(5N-5S, 150W-90W), NINO 4(5N-5S, 160E-150W) and the western Pacific warm pool (5N-5S, 120E-160E) were analyzed. Among the lagged cross-correlation cycles in NINO regions, the maximum correlations for the negative lagged months prevail in NINO 1+2 and NINO 3, and the cross correlations for the positive lagged months NINO 4. It is noteworthy that correlation between the western Pacific warm pool SSTA and the monsoon rainfall in Korea and South China have the maximum value at negative 4 month lag. The evolution of the correlation between the East Asia monsoon rainfall and SSTA is linked to the equatorial convective cluster and related to northward propagating situation, and raising the possibility that the East Asia monsoon precipitation may be more fundamentally related to the interaction of intraseasonal oscillations and the sub-regional characteristics including the surface boundary conditions and the behavior of climatological air mass.
        59.
        1994.06 KCI 등재 서비스 종료(열람 제한)
        The distributions of sea surface temperature across the Cheju Strait and the Korea Strait have been measured by using a thermometer installed on board No.1 Cheju, a ferry that operates regularly between Pusan and Seogwipo. The data from 14 October 1991 to 15 August 1992 were analyzed in this paper. A clear temperature front is formed at the adjacent sea of Geomundo, and its position is not fixed and moves north and south. The slow northward movement of the front can easily be traced, but the southward movement from March to October is obscure. The temperature contrast in the Cheju Strait and the Korea Strait is very weak in this period. Some periodical fluctuations with a period of several tens of days are observed in the region of the temperature front from November to February. This fluctuation seems to be caused by winter heat flux exchange and the strong southeastward wind force. The result shows that continous observation of the sea surface temperature distribution across the Cheju Strait and the Korea Strait yields a good method for monitoring the presence of Tsushima Warm Current and the fluctuations of South Korea Coastal Water. The formation and structure of shelf front in the Cheju Strait and the Korea Strait was analysed based on the detailed oceanographic data observed during the period of 1990-1992. The analysis shows that well-defined fronts were formed through yearly around the Chuja Island, particularly in summer. In nature, its structure and formation position can be changed easily from year to year and by season. But, in region of the Korea Strait this front is relatively weak.
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