• 제목/요약/키워드: sea wind

검색결과 1,275건 처리시간 0.032초

부산 연안역의 바람 특성에 관한 고찰 (On the Characteristic of Wind over Pusan Coastal Area, Korea)

  • 전병일;김유근;이화운
    • 한국환경과학회지
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    • 제3권1호
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    • pp.1-9
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    • 1994
  • We have Studied the characteristics of wind over Pusan coastal area in order to precisely predict surface wind having an important effect on oil spill fate using the data on surface observation of Pusan, Kimhae and Gadeogdo island which are collected during the 3 years from 1988 to 1990. We also investigated the correlation of the surface wind between Pusan, Kimhae and Gadeogdo island. In both Pusan areas and Kimhae, the land and sea breeze occurs during. the whole season except for winter. The occurrence frequency of land and sea breeze is significantly high from April to August. The correlation of surface wind between Pusan, Kimhae and Gadeogdo island surface wind is high in the daytime. The occurrence frequency of sea breeze in the Kimhae areas is higher than that in Pusan on the basis of the present criteria. For monthly occurrence, Pusan has the highest occurrence frequency of the sea breeze in August and Kimhae has in May.

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EVALUATION OF MARINE SURFACE WINDS OBSERVED BY ACTIVE AND PASSIVE MICROWAVE SENSORS ON ADEOS-II

  • Ebuchi, Naoto
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.146-149
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    • 2006
  • Marine surface winds observed by two microwave sensors, SeaWinds and Advanced Microwave Scanning Radiometer (AMSR), on the Advanced Earth Observing Satellite-II (ADEOS-II) are evaluated by comparison with off-shore moored buoy observations. The wind speed and direction observed by SeaWinds are in good agreement with buoy data with root-mean-squared (rms) differences of approximately 1 m $s^{-1}$ and $20^{\circ}$, respectively. No systematic biases depending on wind speed or cross-track wind vector cell location are discernible. The effects of oceanographic and atmospheric environments on the scatterometry are negligible. The wind speed observed by AMSR also exhibited reasonable agreement with the buoy data in general with rms difference of 1.2 m $s^{-1}$. Systematic bias which was observed in earlier versions of the AMSR winds has been removed by algorithm refinements. Intercomparison of wind speeds globally observed by SeaWinds and AMSR on the same orbits also shows good agreements. Global wind speed histograms of the SeaWinds data and European Centre for Medium-range Weather Forecasts (ECMWF) analyses agree precisely with each other, while that of the AMSR wind shows slight deviation from them.

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복잡 해안지역 해상풍 모의의 정확도 개선-II: LAPS를 사용한 자료동화 (Improvements in the Simulation of Sea Surface Wind Over the Complex Coastal Area-II: Data Assimilation Using LAPS)

  • 배주현;김유근;정주희;권지혜;서장원;김용상
    • 한국환경과학회지
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    • 제15권8호
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    • pp.745-757
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    • 2006
  • We focus on the improvement of accuracy of sea surface wind over complex coastal area doling the warm season. Local Analysis Prediction System (LAPS) was used to improve the initial values in Mesoscale Meteorological model (MM5). During the clear summer days with weak wind speed, sea surface wind simulated with LAPS was compared with the case without LAPS. The results of modeling with LAPS has a good agreement mesoscale circulation such as mountain and valley winds on land and in case of modeling without LAPS, wind speed overestimated over the sea in the daytime. And the results of simulation with LAPS indicated similar wind speed values to observational data over the sea under influence of data assimilation using BUOY, QuikSCAT, and AMEBAS. The present study suggests that MM5 modelling with LAPS showed more improved results than that of without LAPS to simulate sea surface wind over the complex coastal area.

Ocean Response to Typhoon Rusa in the South Sea of Korea and in the East China Sea

  • Lee, Dong-Kyu;Niiler, Peter
    • Journal of the korean society of oceanography
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    • 제38권2호
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    • pp.60-67
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    • 2003
  • Typhoon Rusa passed over the East China Sea and crossed over the Korea Peninsula on August 31, 2002. The core of the typhoon passed directly over a data buoy mooring site at ($127^{\circ}45'E,\;34^{\circ}25'\;N$) and several ARGOS-tracked drifters capable of measuring salinity. Peak hourly mean wind speed reached 28 m/s at the mooring site and wind pattern in the East China Sea changed from southerly wind to northwesterly wind after the typhoon passage. Two or three days before the typhoon tile drifter displacement changed significantly and the region-wide circulation pattern changed from a northeastward current to a westward current one week after the typhoon had passed. The surface water in the East China Sea was cooled to about $4^{\circ}C$ under the typhoon core and a general cooling occurred in most of the East China Sea with the exception of the Chinese coast. The salinity as observed by the drifters in the East China Sea increased about 2 psu but the near-shore water along the Korean coast observed by the mooring was freshened about 3 psu. The freshening of near-shore water was caused by an intrusion of off-shore water rather than local freshening by typhoon precipitation.

해양 표면취송류(skin drift)의 라그랑쥐 측류 및 모델링 (Lagrangian observation and modelling of sea surface wind-induced drift(skin drift))

  • 이문진;강용균
    • 한국해양환경ㆍ에너지학회지
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    • 제3권2호
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    • pp.11-17
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    • 2000
  • 해양에서 해수보다 비중이 낮은 유류의 이동.확산은 해면 (0m) 유동에 따라 좌우된다. 해양에서의 유류확산에 대한 현실에 부합되는 모델 개발의 일환으로 한반도 연안역 4개 해역에서 해양 표면 취송류 (skin drift) 추정에 대한 연구를 수행하였다. 본 연구에서는 해면과 수면하 1.5m의 유동을 동시 관측하여 둘간의 차이로서 바람에 의한 해양표면 취송류를 추정하였다. 표면취송류 유속의 평균 크기는 바람의 2.9% 였으며, 풍향에 대한 표면취송류 편향의 평균치는 바람의 오른쪽 18.6° 였다. 관측 결과는 표면취송류의 모델링에 활용하였다. 모델링에서는 바람에 따른 표면 취송류의 공간적 변동을 재현하였으며, 관측된 결과와 비교하여 검증하였다.

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씨마진 산정법의 개선에 관한 연구(I) (An Improved Method for Determining Sea Margin (I))

  • 권영중
    • 한국해양공학회지
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    • 제18권3호
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    • pp.40-43
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    • 2004
  • A rational method is presented for estimating the power increase of a ship at sea. A probabilistic approach is applied to determine the weather condition at sea, A comparison is made between some full-scale data and the result of Swift's method. A comparison is also made to find differences among the results of eight kind methods for the wind added resistance of a VLCC in head wind. The mean difference between the results is 7%, in general, for a given relative wind speed.

4차원 자료동화 기법을 이용한 해안가 대기 순환의 수치 실험 (Numerical Simulations of the local circulation in coastal area using Four-Dimensional Data Assimilation Technique)

  • 김철희;송창근
    • 환경영향평가
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    • 제11권2호
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    • pp.79-91
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    • 2002
  • Four dimensional data assimilation (FDDA) technique was considered for 3 dimensional wind field in coastal area and a set of 3 numerical experiments including control experiments has been tested for the case of the synoptic weather pattern of the weak northerly geostrophic wind with the cloud amount of less than 5/10 in autumn. A three dimensional land and sea breeze model with the sea surface temperature (SST) of 290K was performed without nudging the observed wind field and surface temperature of AWS (Automatic Weather System) for the control experiment. The results of the control experiment showed that the horizontal temperature gradient across the coastline was weakly simulated so that the strength of the sea breeze in the model was much weaker than that of observed one. The experiment with only observed horizontal wind field showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated. However, the horizontal wind speed and vertical motion in the convergence zone were weakly simulated. The experiment with nudgings of both the surface temperature and wind speed showed that both the pattern of local change of wind direction and the times of starting and ending of the land-sea breeze were fairly well simulated even though the ending time of the sea breeze was delayed due to oversimulated temperature gradient along the shoreline.

인공위성자료를 이용한 2004년 겨울철 황해 연안 해역 이상 수온 해석 (Analysis of Abnormal Sea Surface Temperature in the Coastal Waters of the Yellow Sea Using Satellite Data for the Winter Season of 2004)

  • 문정언;양찬수
    • 대한원격탐사학회지
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    • 제25권1호
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    • pp.1-10
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    • 2009
  • 각종 위성자료와 현장 관측자료를 이용하여 2004년 겨울철 황해 연안해역 이상수온 상승 현상과 외해의 해양 변동과의 연관성에 대하여 연구하였다. 위성자료에 의하면, 2003년 황해의 평균 해수면온도는 $10^{\circ}C$ 정도였고, 2004년의 평균 해수면온도는 $13^{\circ}C$ 정도로 약 $3^{\circ}C$ 정도 높았다. 현장관측 자료에서는 2003년 황해의 평균 표층수온은 $9.85^{\circ}C$ 정도였고, 2004년의 평균 표층수온은 $12.17^{\circ}C$ 정도로 위성자료와 마찬가지로 약 $3^{\circ}C$ 정도 높았다. T-S diagram 분석에 의하면, 2003년은 황해 수괴와 동중국해 수괴를 아주 명확하게 구분되었지만, 2004년에는 양 수괴의 구분이 명확하지 않았다. 2003년의 평균 기온과 풍속은 각각 $5.23^{\circ}C$, 4.81 m/s 이고, 9004년의 평균 기온과 풍속은 각각 $5.61^{\circ}C$, 4.52 m/s 로 유사하였다. 그러나 2003년에는 북서풍이 우세하였으나, 2004년에는 다양한 북풍 계열의 바람이 불어서 풍향이 달랐다. 2004년 겨울철 황해 연안해역의 이상수온 상승은 대기의 영향보다 외해 해양 변동과 깊은 연관성이 있는 것으로 판단되었고, 이에 대해서는 추후 연구가 이루어질 것이다.

Tropical Night (Nocturnal Thermal High) in the Mountainous Coastal City

  • Choi, Hyo
    • 한국환경과학회지
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    • 제13권11호
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    • pp.965-985
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    • 2004
  • The investigation of driving mechanism for the formation of tropical night in the coastal region, defined as persistent high air temperature over than 25$^{\circ}C$ at night was carried out from August 14 through 15, 1995. Convective boundary layer (CBL) of a 1 km depth with big turbulent vertical diffusion coefficients is developed over the ground surface of the inland basin in the west of the mountain and near the top of the mountain, while a depth of thermal internal boundary layer (TIBL) like CBL shrunken by relatively cool sea breeze starting at 100 km off the eastern sea is less than 150 m from the coast along the eastern slope of the mountain. The TIBL extends up to the height of 1500 m parallel to upslope wind combined with valley wind and easterly sea breeze from the sea. As sensible heat flux convergences between the surface and lower atmosphere both at the top of mountain and the inland coast are much greater than on the coastal sea, sensible heat flux should be accumulated inside both the TIBL and the CBL near the mountain top and then, accumulated sensible heat flux under the influence of sea breeze circulation combined with easterly sea breeze from sea to inland and uplifted valley wind from inland to the mountain top returning down toward the eastern coastal sea surface should be transported into the coast, resulting in high air temperatures near the coastal inland. Under nighttime cooling of ground surface after sunset, mountain wind causes the daytime existed westerly wind to be an intensified westerly downslope wind and land breeze further induces it to be strong offshore wind. No sensible heat flux divergence or very small flux divergence occurs in the coast, but the flux divergences are much greater on the top of the mountain and along its eastern slope than on the coastal inland and sea surfaces. Thus, less cooling down of the coastal surface than the mountain surface and sensible heat transfer from warm pool over the coast into the coastal surface produce nocturnal high air temperature on the coastal inland surfaces, which is not much changed from daytime ones, resulting in the persistence of tropical night (nocturnal thermal high) until the early in the morning.

CORRECTION OF THE EFFECT OF RELATIVE WIND DIRECTION ON WIND SPEED DERIVED BY ADVANCED MICROWAVE SCANNING RADIOMETER

  • Konda, Masanori;Shibata, Akira
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.386-389
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    • 2006
  • The sea surface wind speed (SSWS) derived by microwave radiometer can be contaminated by change of microwave brightness temperature owing to the angle between the sensor azimuth and the wind direction (Relative Wind Direction). We attempt to correct the contamination to the SSWS derived by Advanced Microwave Scanning Radiometer (AMSR) on Advanced Earth Observing Satellite II (ADEOS-II), by applying the method proposed by Konda and Shibata (2004). The improvement of accuracy of the SSWS estimation amounts to roughly 60% of the error caused by the RWD effect.

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