• 대한원격탐사학회지
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• 제38권4호
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• pp.355-364
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• 2022

In this study a tendency of abnormal sea surface temperature (SST) occurrence in the seas around South Korea is analyzed from daily SST data from satellite and 14 buoys from August 2020 to July 2021. As thresholds 28℃ and 4℃ are used to determine marine heatwaves(MHWs) and abnormal low water temperature (ALWT), respectively, because those values are adopted by the National Institute of Fisheries Science for the breaking news of abnormal temperature. In order to calculate frequency of abnormal SST occurrence spatially by using satellite SST, research area was divided into six areas of coast and three open seas. ALWT dominantly appeared over a wide area (7,745 km²) in Gyeonggi Bay for total 94 days and it was also confirmed from buoy temperature showing an occurrence number of 47 days. MHWs tended to be high in frequency in the coastal areas of Chungcheongdo and Jeollabukdo and the south coastal areas while in case of buoy temperature Jupo was the place of high frequency (32 days). This difference was supposed to be due to the low accuracy of satellite SST at the coasts. MHWs are also dominant in offshore waters around Korean Peninsula. Although detecting abnormal SST by using satellite SST has advantage of understanding occurrence from a spatial point of view, we also need to perform detection using buoys to increase detection accuracy along the coast.

• 한국환경과학회지
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• 제14권10호
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• pp.945-953
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• 2005

Daily time series of longshore sea surface temperature (SST) data at 3 stations, sea surface SST data at 58 stations in the eastern coast of the Korean Peninsular from 2001 to 2005 were used in order to study the temporal and spatial variations of the upwelling coastal cold water occurred in summer season. When the cold water occurred, SST has been decreased more than $-5^{\circ}C$ in a day. The cold water occurred frequently in the eastern coastal areas of Korea such as Ulgi, Kampo, Jukbyun. Daily variations of cold water temperature were quantified using remote control buoy system at Kijang in the southeastern coastal water from July to August in 2004. Hourly variations of SST occurred around $\pm3^{\circ}C$ when cold water disappeared at Kijang. There were close relationship between the strength of East Korean Warm Current, North Korean Cold Water and the scale of spatio-temporal cold water variations in summer season.

• 대기
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• 제27권3호
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• pp.317-329
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• 2017

Ocean mixed layer (OML) depth affects diurnal cycle of sea surface temperature (SST) induced by change of solar radiation absorption and heat budget in ocean. The diurnal SST variation can lead to convection over the ocean, which can impact on localized precipitation both over coastal and inland. In this study, we investigate the OML characteristics affecting the diurnal cycle of SST for the Korean Peninsula and surrounding areas. To analyze OML characteristics, HYCOM oceanic mixed layer depth (MLD) and wind field at 10 m from ERA-interim during 2008~2016 are used. In the winter, MLD is deeply formed when the strong wind field is located on perpendicular to continental slope over deep seafloor areas. Besides, cooling SST-induced vertical mixing in OML is reinforced by dry cold air originated from Siberia. The OML in summer is shallowly distributed about 20 m. In order to estimate the impact of OML model in high resolution NWP model, four experimental simulations are performed. At this time, the prognostic scheme of skin SST is applied in NWP to simulate diurnal SST. The simulation results show that CNTL (off-OML) overestimates diurnal cycle of SST, while EXPs (on-OML) indicate similar results to observations. The prediction performance for precipitation of EXPs shows improvement compared with CNTL over coastal as well as inland. This results suggest that the application of the OML model in summer season can contribute to improving the prediction for performance of SST and precipitation over coastal area and inland.

• 한국해안해양공학회지
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• 제7권3호
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• pp.241-247
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• 1995

대한해협 해역에 대한 AVHRR/SST 이용하여 표층의 시간평균 유속을 추정하였다. 자료의 시간간격은 조석주기와 근사하며 조류성분이 제거될 수 있는가를 조사하였다. 유속을 추정하는 방법은 역행렬법을 사용하였으며 추정한 결과를 조류성분을 제거한 ADCP자료 및 Odamaki(1989)의 관측결과와 비교하였다. 분석결과에 의하면 조류운동이 있는 해역에 대한 AVHRR/SST 자료로부터 시간평균유속을 추정하는 경우에 조류성분을 제거할 수 있는 가능성이 있는 것으로 나타났다.

• 한국환경과학회지
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• 제11권7호
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• pp.627-636
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• 2002

While typhoons were passing by the coastal and offshore waters around the Korean peninsula, the variations of the sea surface temperature (SST) were studied. To study on the variation, the data related to the 22 typhoons among 346 typhoons which occurred in the western Pacific during 1990∼1999, daily measured field SSTs at coastal and offshore, and imageries from advanced very high resolution radiometer on NOAA satellite during 1990∼1999 were used. The average variations of the SSTs were -0.9℃ at coastal waters and -2℃ at offshore around the Korean peninsula while the typhoons were passing by. In very near coastal waters from the land, the SST was not changed because the bottom depth of the coastal waters was shallower than the depth of thermalcline, while the typhoon was passing. The temporal and spatial variation of SSTs at coastal waters in summer were depended on the various types of the typhoons＇paths which were passing through the Korean peninsula. When a typhoon passed by the western parts including the Yellow Sea of the Korean peninsula upwelling cold water occurred along the eastern coastal waters of the peninsula. The reason was estimated with the typhoon that was as very strong wind which blew from south toward north direction along the eastern shore of the peninsula, led to the Ekman transport from near the eastern coastal area toward the offshore. While cold water was occurring in the eastern coast, a typhoon passed over the coastal area, the cold water disappeared. The reason was estimated that the cold water was mixed up with the surrounding warm water by the effect of the typhoon. While a cold water was occurring in the eastern coast, a typhoon passed by the offshore of the eastern coast, there were the increasing of the SST as well as the disappearing of the cold water. While a typhoon was passing by the offshore of the eastern coast, the cold water which resulted from the strong tidal current in the western coast of the peninsula was horizontally spread from the onshore to the offshore. We think that the typhoon played the role of the very strong wind which was blowing from north toward south. Therefore, the Ekman transport occurred from the onshore toward the offshore of the western coast in the Korean peninsula.

• 대한원격탐사학회지
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• 제30권6호
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• pp.797-807
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• 2014

해수표층온도(sea surface temperature; SST)는 해양환경 변화와 해양생물의 생태활동의 특성을 파악하는데 매우 중요한 환경요소 중 하나이다. 인공위성 열적외선 영상으로는 전 세계의 해수표층온도 변화를 파악하는 데는 유용하지만, 섬들이 많고, 해안선이 복잡한 한반도 연안 해역에서는 고해상도의 해수표층온도 자료를 획득하기에는 어려운 실정이다. 하지만 인간생활에 밀접한 영향을 주고받으며 대부분의 양식장이 분포하고 있는 곳이 연안 해역이므로 상세한 해수표층온도의 변화를 파악하는 것이 매우 중요하다. 이를 위하여 본 연구는 저비용의 지상용 열적외선카메라(FLIR)를 항공기용으로 구축하여 연안 표층수온 추출 가능성을 확인하고자 하였다. 2012년 5월 23일부터 2013년 12월 7일까지 최소 8회 이상 서해 연안에 대하여 항공기 관측실험을 실시하였으며, 이때 구축된 열적외선 센서를 탑재하여 해수표층온도 추출 연구를 수행하였다. 항공기에 탑재된 열적외선 센서로부터 획득된 자료는 대기모델 및 온/습도계 센서를 이용하여 방사보정(radiometric correction)을 수행하였고, Global Positioning System (GPS) 및 Inertial Measurement Unit (IMU) 센서를 이용하여 기하보정(geometric correction)을 자동으로 수행한 후 해수 표층온도 자료를 추출하였다. 그 중 2013년 6월 25일에 관측된 항공기 해수표층온도에 대해 인공위성 및 선박 열적외선 센서를 통해 획득된 해수표층온도 자료와 비교하였으며, 선박 현장 관측 자료와는 $1^{\circ}C$ 이내 오차 범위의 해수표층온도를 획득하였다.

• 한국대기환경학회지
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• 제27권1호
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• pp.30-40
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• 2011

Numerical simulations were carried out to investigate the impact of SST spatial distribution on the result of air quality modeling. Eulerian photochemical dispersion model CAMx (Comprehensive Air quality Model with eXtensions, version 4.50) was applied in this study and meteorological fields were prepared by RAMS (Regional Atmospheric Modeling System). Three different meteorological fields, due to different SST spatial distributions were used for air quality modeling to assess the sensitivity of CAMx modeling to the different meteorological input data. The horizontal distributions of surface ozone concentrations were analyzed and compared. In each case, the simulated ozone concentrations were different due to the discrepancies of horizontal SST distributions. The discrepancies of land-sea breeze velocity caused the difference of daytime and nighttime ozone concentrations. The result of statistic analysis also showed differences for each case. Case NG, which used meteorological fields with high resolution SST data was most successfully estimated correlation coefficient, root mean squared error and index of agreement value for ground level ozone concentration. The prediction accuracy was also improved clearly for case NG. In conclusion, the results suggest that SST spatial distribution plays an important role in the results of air quality modeling on high ozone episode at coastal region.

• 해양환경안전학회지
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• 제12권1호
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• pp.23-32
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• 2006

동계 서해에서 해황과 기상인자와의 상호 관련성에 대해서 조사하였다. 수온의 수평분포는 수심이 얕은 연악역이 외해역보다 저수온으로 12월과 2월사이에 외해역에서 $3^{\circ}C$, 연안역에서는 $6^{\circ}C$ 정도의 큰 수온 하강을 보였다. 염분의 분포는 북쪽해역이 연안역과 남쪽해역보다 저농도를 보였다. 또한, 하계에 남북방향으로 형성되었던 등염선이 동계에는 북서에서 남동 방향으로 형성한다. 한국 서해연안의 기온과 연안의 표층수온 사이에는 기온이 상승하면 수온이 상승하고 기온이 하강하면 수온도 하강하는 정의 상관관계를 보인다. 서해 외해의 표층수온은 잠열속과 현열속에 의한 해양에서의 방출열량과 역의 상관관계를 보인다. 동계 서해 연안지역 기온과 연안역 표층염분과의 관계는 기온이 상승하면 연안역의 염분이 증가하고, 수온이 하강하면 염분이 낮아지는 정의 상관관계를 보인다. 또한 서해의 하계($6{\sim}9$월) 강수량은 10월과 12월보다 다음해 동계 2월의 염분분포에 크게 영향을 미치고 있다.

• 상하수도학회지
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• 제22권1호
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• pp.15-22
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• 2008

This study collected the latest 30-year (1976~2005) continuous rainfall data hourly recorded at 61 meterological observatories in Korea, and the continuous rainfall data was divided into individual rainfall events. In addition, distribution charts of average rainfall event-depth were created to facilitate the application to the overflow risk-based design of detention storage basin. This study shows that 4 hour is appropriate for SST (storm separation time) to separate individual rainfall events from the continuous rainfall data, and the one-parameter exponential distribution is suitable for the frequency distribution of rainfall event depths for the domestic rainfall data. The analysis of the domestic rainfall data using SST of 4 hour showed that the individual rainfall event was 1380 to 2031 times, the average rainfall event-depth was 19.1 to 32.4mm, and ranged between 0.877 and 0.926. Distribution charts of average rainfall event-depth were created for 4hour and 6 hour of SST, respectively. The inland Gyeongsangbuk-do, Western coastal area and inland of Jeollabuk-do had relatively lower average rainfall event-depth, whereas Southern coastal area, such as Namhae, Yeosu, and Jeju-do had relatively higher average rainfall event-depth.

• 수산해양기술연구
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• 제58권3호
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• pp.281-287
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• 2022

The distributions of common minke whales observed in the East Sea in ten surveys in May of 2003, 2005, 2006, 2007, 2009, 2010, 2012, 2015, 2016 and 2020 were investigated using satellite sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectrometer (MODIS). Most of the minke whales were observed in the waters off the Korean Peninsula at 36-38.5° N, which is expected as the highly productive coastal upwelling area. Yet, no minke whale was observed in 2006 when a relatively larger scale coastal upwelling occurred with SST at 11℃. In 2016 and 2020, the warm water higher than 17℃ extended widely in the area, and the minke whales were observed in the offshore waters, deeper than 1,000 m. 87.5% of minke whales observed in May appeared in the SST from 13 to 16℃, and they seemed to avoid relatively high temperatures. This suggests that optimum habitat water temperature of minke whales in May is 13-16℃. The SST in the area had risen 1.67℃ from 2003 to 2021, and it was remarkably higher than in other parts of the surrounding areas. The future temperature rising may change the route and timing of the migration of minke whales in the study area.