국립수산과학원은 과거 해양관측자료 복원사업을 통해 1961년 이전의 정선해양관측 및 연안정지관측 자료를 복원하여 디지털화 하였다. 먼저 한국근해 해양관측(정선해양관측) 자료 중 과거부터 현재까지 정점이 일치하는 21개 정점에 대한 지난 80년-92년간 표층 수온의 연변동을 분석한 결과 다소 차이는 있으나 상승 경향을 나타내었으며, 서해와 남해는 기존 연구와 동일하게 연안역보다 근해역에 위치한 정점에서 수온상승 경향이 높게 나타났다. 그러나 동해는 기존 연구와 달리 연안역보다 근해역에 위치한 정점에서 낮은 수온상승 경향을 나타내었다. 다음으로 복원된 연안정지관측 자료 중 각 동·서·남해를 대표할 수 있는 3개 정점에 대한 지난 89년-98년간 표층수온의 연변동을 살펴보면 동해(주문진, 1.63℃), 남해(거문도, 1.16℃). 서해(부도, 0.79℃)로 동해의 상승경향이 가장 뚜렷하였으며, 뚜렷한 주기 성은 파악하기 어려우나 대체로 3~6년을 주기로 상승과 하강을 반복함을 알 수 있었다. 특히 1980년대 이후 대부분 정점에서 양의 편차를 나타내었다. 마지막으로 해양-대기 상호작용을 이해하기 위해 연안정지관측정점의 표층수온변화에 따른 기온의 상관성을 분석한 결과 상관계수 값이 남해(거문도)는 0.76, 서해(부도)는 0.34, 동해(주문진)는 0.32로 남해가 가장 높게 나타났다.
본 연구에서는 1995년부터 2016년까지 여름철(5월~8월) 내 동해 연안역에서 발생하는 용승에 대한 지수(Upwelling age, UA)를 산출하고 수온(Surface sea temperature, SST)과의 상관성을 분석하였다. 동해 연안 근처의 6개 기상청 자동기상관측장비 Automatic weather system, AWS)와 종관기상관측장비(Automated synoptic observing system, ASOS) 지점에서 관측된 바람자료를 이용하여 용승지수를 계산하였으며, 수온은 국립수산과학원에서 제공하는 연안정지 자료(Coastal oceanographic data, COD)와 실시간 수온 관측 시스템 (Real-time information system for aquaculture environment, RISA) 자료를 이용하였다. 정량적으로 UA의 값은 낮게 산출되었지만 냉수대 발생 시기에 UA가 상승하였으며 실제와 유사하게 모사해 내었다. UA-SST와의 상관분석에서 음(-)의 상관이 우세하게 나타났다. 냉수대가 극심했던 2013년 6월~8월 UA-SST 상관 분석 결과, 6개 분석지점에서 -0.65~-0.89의 매우 높은 상관성을 보였으며 이는 UA가 강할수록 SST가 하강하여 강한 냉수대가 출현하였음을 증명하였다. 본 연구를 통해 동해연안역의 냉수대에 따른 용승발생 경향을 장기적으로 평가 할 수 있었으며, 용승의 크기와 강도에 따른 연안 양식어장의 피해를 최소화 하는데 기여할 것으로 사료된다.
Air pollution dispersion from rooftop emissions around hexahedron buildings was investigated using computational fluid dynamics (referred to hereafter as CFD). The Shear Stress Transport (referred to hereafter as SST) k-ω model in FLUENT CFD code was used to simulate the flow and pollution dispersion around the hexahedron buildings. The two buildings used in the study had the dimensions of H: L: W (where H = height, L = length, and W = width) with the ratios of 1:1:1 and 1:1:2. Experimental data from the wind tunnel obtained by a previous study was used to validate the numerical result of the hexahedron building. Five validation metrics are used to obtain an overall and quantitative evaluation of the performance of SST k-ω models: the fractional bias (FB), the geometric mean bias (MG), the normalized mean square errors (NMSE), the geometric variance (VG), and the factor of 2 of the observations (FAC2). The results of vertical concentration profile and longitudinal surface concentration of the 1:1:2 building illustrate the reasonable performance for all five metrics. However, the lateral concentration profile at X = 3H (where X is the distance from the source) shows poor performance for all of the metrics with the exception of NMSE, and the lateral concentration profile at X = 10H shows poor performance for FB and MG.
This paper presents the performance of a CFD model for the near field dispersion of odor from rooftop emissions. The FLUENT Shear-Stress Transport (SST hereinafter) k-ω turbulence model was used to simulate odor dispersion from a rooftop odor vent. The results were compared with a wind tunnel experiment and the calculated results of ASHRAE 2003 and 2007. The FLUENT SST k-ω turbulence model provided good results for making reasonable predictions about the building rooftop surface normalized dilution. It was found that increasing the vent height (from 1 m to 7 m) reduces rooftop surface normalized dilution. ASHRAE 2003 and ASHRAE 2007 performance measures are generally not as good as FLUENT SST k-ω turbulence model performance measures, with larger MG (the geometric mean bias, VG (the geometric variance), NMSE (the normalized mean square error), FB (Fractional bias), and smaller FAC2 (the fraction of predictions within a factor of two of observations).
In this study we investigated odor (hydrogen sulfide) dispersion around a cubic building by using commercial FLUENT CFD code. The FLUENT Shear-Stress Transport (hereafter SST) k-ω turbulence model was used to simulate odor dispersion from an odor source. The results were compared with a wind tunnel experiment and other simulation results. SST k-ω turbulence model provided good grounds for making reasonable predictions about the building surface concentrations and concentration profiles of selected leeward positions of the cubic building. It was found that a vent, which was positioned 7 m above the top of the square building center, decreased the plume length lower by 0.73 and increased the plume height by 1.43 compared to roof top vents. It was also found that by increasing the vent height there a corresponding decrease in the maximum dimensionless concentration around the roof surface.
본 연구는 다종 위성 자료를 활용한 해수면온도 합성 기법에 대한 연구이다. 현재 많은 연구자들이 사용하고 있는 NGSST 알고리듬은 위성에 따른 정확도를 고려하지 않고 시 공간 상관도만을 계산하여 해당 픽셀의 값을 추정한다. 본 연구에서는 위성 센서별로 가지고 있는 정확도를 추가로 고려한 해수면온도 합성기법을 제안하고 기존 알고리듬과의 비교를 수행하였다. 합성장을 산출하는데 사용된 센서는 적외 센서인 MODIS, AVHRR 그리고 마이크로파 센서인 AMSR-E를 사용하였고, 2011년 4월 4일을 기준으로 5 km의 공간해상도를 갖는 일일 해수면 온도 합성장을 비교하였다. 부이와의 비교 결과, 기존 방법(NGSST Method)과 제안 방법(New Method)에 의한 표준편차는 각각 0.15℃와 0.12℃이었다. 또한 기존 방법보다 제안 방법에 의한 해수면온도 값은 연안을 제외한 대부분의 해역에서 다소 높게 산출이 되었다. 현 단계에서 정량적인 평가는 어렵지만, 본 연구를 통하여 해수면온도 합성기법에 대한 연구 방향이 제시되었다고 판단된다.
In this research were used observation meteorological data and meteorological model to understand an influence of rising ocean temperature on climate change in Korean Peninsula. In the case of meteorological data, were examined inland ocean temperatures as mean annual temperature change during 28 years period (1980-2006) on six shore sites and four inland sites. Also, it have been used MM5 meteorological model to study climate change due to rising ocean temperature and simulate increasing ocean temperature of Korean Peninsula by 2oC. Results shows that the temperature on the shore sites were increasing two times more than temperature on the inland sites. The meteorological model shows similar result and the highest temperature appears on the south shore sites.
기후변화로 인해 전 세계적으로 태풍, 홍수, 가뭄, 한파 등으로 수많은 재산, 인명피해를 입히고 있다. 대기중으로 배출되는 온실가스 등은 지구온난화를 가속화 하고 있으며 많은 연구자들에 의해 온실가스의 증가와 함께 지표면 온도가 전 지구적으로 증가하고 있다고 받아들이는 추세이다(IPCC, 2001). IPCC(2001)에 따르면 온실가스 증가 추세가 지속된다면 해수면온도도 함께 증가할 것이며, Emanuel(2005)은 그동안 허리케인의 세기가 증가해왔으며 앞으로 더욱 강력한 허리케인이 발생할 것이라 주장하였다. 최근 2012년에는 3개의 태풍(제 14호~16호)이 연이어서 한반도로 상륙한 최초의 사례를 남겼다. 이 중 제 16호 태풍 ‘산바(SANBA)’는 올해 들어 5번째로 한반도에 영향을 준 태풍으로, 남해안 상륙 시 중심기압 965hPa을 기록하여 남해안으로 상륙한 태풍들 중 역대 5위의 강한 태풍으로 기록되었다. 태풍의 강도가 세지고 피해가 커짐에 따라 해수면 온도(Sea Surface Temperature), 연직바람시어와 대기현상 인자인 남방진동수 등 기후 인자들과 연계하여 많은 연구가 수행되고 있다. 본 연구에서는 기후인자 중 해수면온도를 사용하여 태풍 발생과 상관분석을 하고자 한다. 과거에 발생한 태풍들의 발생위치와 태풍이 발생했을 때의 그 지점의 해수면온도의 통계적 특성을 분석하였다.
In an effort to examine the Regional Atmospheric Modeling System (RAMS ver. 4.3) to the initial meteorological input data, detailed observational data of NOAA satellite SST (Sea Surface Temperature) was employed. The NOAA satellite SST which is currently provided daily as a seven-day mean value with resolution of 0.1 o grid spacing was used instead of the climatologically derived monthly mean SST using in RAMS. In addition, the RAMS SST data must be changed new one because it was constructed in 1993. For more realistic initial meteorological fields, the NOAA satellite SST was incorporated into the RAMS-preprocess package named ISentropic ANalysis package (ISAN). When the NOAA SST data was imposed to the initial condition of prognostic RAMS model, the resultant performance of near surface atmospheric fields was discussed and compared with that of default option of SST. We got the good results that the new SST data was made in a standard RAMS format and showed the detailed variation of SST. As the modeling grid became smaller, the SST differences of the NOAA SST run and the RAMS SST43 (default) run in diurnal variation were very minor but this research can apply to further study for the realistic SST situation and the development in predicting regional atmospheric field which imply the regional circulation due to differential surface heating between sea and land or climatological phenomenon.
Numerical simulation is essential to indicate the flow of the atmosphere in the region with a complicated topography which consists of many mountains in the inland while it is neighboring the seashore. Such complicated topography produces land and sea breeze as the mesoscale phenomenon of meteorology which results from the effect of the sea and inland. In the mesoscale simulation examines, the change of the temperature in relation to the one of the sea surface for the boundary condition and, in the inland, the interaction between the atmosphere and land surface reflecting the characteristic of the land surface. This research developed and simulated PNULSM to reflect both the SST and vegetation effect as a bottom boundary for detailed meteorological numerical simulation in coastal urban area. The result from four experiments performed according to this protocol revealed the change of temperature field and wind field depending on each effect. Therefore, the lower level of establishment of bottom boundary suitable for the characteristic of the region is necessary to figure out the atmospheric flow more precisely, and if the characteristic of the surface is improved to more realistic conditions, it will facilitate the simulation of regional environment.
The observed relationships between the Asian summer monsoon and the sea surface temperature (SST) anomalies in the northwestern Pacific (NW Pacific) are verified using the intermediate complexity global climate model (GCM) (Planet Simulator: PLASIM). The climate responses over Asia for the monsoon season to forcing from NW Pacific SST anomalies are simulated in the GCM with the enhanced SST anomalies in the NW Pacific for the pre-monsoon season compared to climatological SST. During the pre-monsoon season, the enhanced SST anomalies result in an increase in lower-level convection and precipitation in the NW Pacific. A significantly weakened Indian summer monsoon is simulated for the enhanced SST experiment in the NW Pacific for the pre-monsoon season (p-value<0.05). PLASIM dose a good job at representing the observed patterns of zonally averaged surface temperature, precipitation, and 850 hPa u-wind, although with some regional differences from observations (p-values of zonal correlation coefficients<0.01).
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
For the purpose of predicting air pollutants concentration in Pusan coastal urban, we used an Eulerian model of flow and dispersion/chemistry/deposition process considering SST effects which estimate through POM. The results of air quality model including emission from various sources show that the seasonal variation pattern of respective pollutants was affected by the seasonal SST fields and local circulation. Horizontal deviation of diurnal SST was 2.5∼4K, especially large gradients in coastal region. Through numerical simulation of wind fields we predicted that local circulation prevailed during daytime in summer and nighttime in winter. So high concentration distribution showed toward inland in spring and summer seasons, while high concentration distribution showed at inland near coast in autumn and winter.
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.
The atmospheric responses to a Sea Surface Temperature Anomaly(SSTA) over the equatorial eastern Pacific Ocean have been investigated using the horizontally fine resolution model based on OSU 2-layer Atmospheric General Circulation Model(AGCM). The SSTAs during the peak phase of 1982-83 El Nin∼o have been applied to the model as the boundary conditions of the experiment. The model simulates the eastward movement of the rising branch of the Walker circulation. That is, the major features associated with the El Nin∼no such as the increase of the precipitation rate over the center of the Pacific and decrease over the Indonesia, and the 500hPa geopotential height anomaly in the middle latitude are properly described in the fine resolution model experiment. The model results indicate that this horizontally fine resolution GCM can successfully simulate the ENSO anomalies and be more effectivelly used for the study of the climate and the climate changes.