• 제목/요약/키워드: Sea surface winds

검색결과 130건 처리시간 0.031초

중규모 기상모델(MM5/KMA)과 3세대 파랑모델(WAVEWATCH-III)로 계산된 한반도 주변해역의 2002년 월평균 해상풍과 파랑 분포 특성 (Characteristics of the Monthly Mean Sea Surface Winds and Wind Waves near the Korean Marginal Seas in the 2002 Year Computed Using MM5/KMA and WAVEWATHC-III model)

  • 서장원;장유순
    • 한국해양학회지:바다
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    • 제8권3호
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    • pp.262-273
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    • 2003
  • 기상청에서 현업 예보용으로 사용되는 중규모 기상 모델(MM5/KMA)의 해상풍 예측 결과와 이를 입력 자료로 제 3세대 파랑 모델(WAVEWATCH-III)을 적용하여 2002년 1년 동안의 한반도 주변해역의 해상풍과 파랑 특성을 분석하였다. 모델 결과의 검증을 위해서 해양기상 관측 부이의 관측 자료와 TOPEX/POSEIDON위성의 유의 파고 자료를 이용한 통계 비교 분석을 실시하였다. 관측 값과 모델 결과 사이에 약 60-80%의 상관성을 나타내었고, 연안에 가장 근접해 위치한 칠발도의 풍향을 제외하면, 연안 지역까지의 해상풍과 파고를 본 모델에서 잘 재현하고 있다고 분석되었다. 위의 검증 결과를 토대로 2002년 한반도를 포함한 동아시아 해역의 월평균 해상풍 및 유의파고, 파장, 파주기의 분포도를 제시하였다.

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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MERITS OF COMBINATION OF ACTIVE AND PASSIVE MICROWAVE SENSORS FOR DEVELOPING ALGORITHMS OF SST AND SURFACE WIND SPEED

  • Shibata, Akira;Murakami, Hiroshi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.138-141
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    • 2006
  • In developing algorithms to retrieve the sea surface temperature (SST) and sea surface wind speed from the Advanced Microwave Scanning Radiometer (AMSR) aboard the AQUA and the Advanced Earth Observation Satellite-II (ADEOS-II), data from the SeaWinds aboard ADEOS-II were helpful. Since features of the ocean microwave emission (Tb) related with ocean wind are not well understood, in case of using only AMSR data, combination of AMSR and SeaWinds revealed pronounced features about the ocean Tb. Two results from combinations of the two sensors were shown in this paper. One result was obtained at wind speeds over about 6m/s, in which the ocean Tb varies with the air-sea temperature difference, even though the SeaWinds wind speed is fixed at the same values. The ocean Tb increases as the air-sea temperature difference becomes negative, i.e., the boundary condition becomes unstable. This result indicates that the air temperature should be included in AMSR SST algorithm. The second result was obtained from comparison of two wind speeds between AMSR and SeaWinds. There is a small difference of two wind speeds, which might be related with several mechanisms, such as evaporation and plankton.

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한반도 주변해역의 기상부이와 등표에서 관측된 계절별 해상풍과 유의파고 특성 (Seasonal Characteristics of Sea Surface Winds and Significant Wave Heights Observed Marine Meterological Buoys and Lighthouse AWSs near the Korean Peninsula)

  • 강윤희;석현배;방진희;김유근
    • 한국환경과학회지
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    • 제24권3호
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    • pp.291-302
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    • 2015
  • The seasonal variations of sea surface winds and significant wave heights were investigated using the data observed from the marine meteorological buoys (nine stations) and Automatic Weather Stations (AWSs) in lighthouse (nine stations) around the Korean Peninsula during 2010~2012. In summer, the prevailing sea surface winds over the East/West Sea and the South Sea were northerly/southerly and easterly/westerly winds due to both of southeast monsoon and the shape of Korean Peninsula. On the other hand, the strong northerly winds has been observed at most stations near Korean marginal seas under northwest monsoon in winter. However, the sea surface winds at some stations (e.g. Galmaeyeo, Haesuseo in the West Sea) have different characteristics due to topographic effects such as island or coastal line. The significant wave heights are the highest in winter and the lowest in summer at most stations. In case of some lighthouse AWSs surrounded by islands (e.g. Haesuseo, Seosudo) or close to coast (e.g. Gangan, Jigwido), very low significant wave heights (below 0.5 m) with low correlations between sea surface wind speeds and significant wave heights were observed.

Can we obtain sea-surface flow information from satellite scatterometer winds\ulcorner

  • Park, Kyung-Ae;Cornillon, Peter;Chung, Jong-Yul;Kim, Kuh
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.621-626
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    • 2002
  • A satellite scatterometer is a microwave radar sensor used to measure the backscattering at a sea surface. This instrument transmits radar pulses to the sea surface and measure the radar energy reflected back towards the source. Changes in wind velocity make sea surface roughness change and then affect on backscattered power. This gives us information of sea surface wind speed. Directions of wind vectors are acquired by multiple, collocated, and nearly simultaneous measurements. It should be noted that the scatterometer observes not the wind directly but the wind stress vector relative to the surface current. This suggests the possibility that the satellite scatterometer winds can include the effect of the surface current. This study shows the evidence that scatterometer measure surface wind stress, not surface winds and presents the velocity structure of oceanic warm and cold eddies.

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The Modulation of Currents and Waves near the Korean Marginal seas computed by using MM5/KMA and WAVEWATHC-III model

  • Seo, Jang-Won;Chang, You-Soon
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.37-42
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    • 2003
  • We have analyzed the characteristics of the sea surface winds and wind waves near the Korean marginal seas on the basis of prediction results of the sea surface winds from MM5/KMA model, which is being used for the operation system at the Korea Meteorological observation buoy data to verify the model results during Typhoon events. The correlation coefficients between the models and observation data reach up to about 95%, supporting that these models satisfactorily simulate the sea surface winds and wave heights even at the coastal regions. Based on these verification results, we have carried out numerical experiments about the wave modulation. When there exist an opposite strong current for the propagation direction of the waves or wind direction, wave height and length gets higher and shorter, and vice versa. It is proved that these modulations of wave parameters are well generated when wind speed is relatively week.

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Mixed Layer Variability in Northern Arabian Sea as Detected by an Argo Float

  • Bhaskar, T.V.S. Udaya;Swain, D.;Ravichandran, M.
    • Ocean Science Journal
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    • 제42권4호
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    • pp.241-246
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    • 2007
  • Northern Arabian Sea (NAS) between $17^{\circ}N-20.5^{\circ}N$ and $59^{\circ}E-69^{\circ}E$ was observed by using Argo float daily data fur about 9 months, from April 2002 through December 2002. Results showed that during April - May mixed layer shoaled due to light winds, clear sky and intense solar insolation. Sea surface temperature (SST) rose by $2.3^{\circ}C$ and ocean gained an average of 99.8 $Wm^{-2}$. Mixed layer reached maximum depth of about 71 m during June - September owing to strong winds and cloudy skies. Ocean gained abnormally low $\sim18Wm^{-2}$ and SST dropped by $3.4^{\circ}C$. During the inter monsoon period, October, mixed layer shoaled and maintained a depth of 20 to 30 m. November - December was accompanied by moderate winds, dropping of SST by $1.5^{\circ}C$ and ocean lost an average of 52.5 $Wm^{-2}$. Mixed layer deepened gradually reaching a maximum of 62 m in December. Analysis of surface fluxes and winds suggested that winds and fluxes are the dominating factors causing deepening of mixed layer during summer and winter monsoon periods respectively. Relatively big]h correlation between MLD, net heat flux and wind speed revealed that short term variability of MLD coincided well with short term variability of surface forcing.

해상풍 관측자료에 근거한 태풍 해상풍 모형간의 상호비교 (A Comparison of Typhoon Wind Models with Observed Winds)

  • 강시환;전기천;박광순;방경훈
    • 한국해양학회지:바다
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    • 제7권3호
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    • pp.100-107
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    • 2002
  • 지난 20년 기간 동안에 한반도와 그 주변해상을 통과했던 64개의 태풍에 대해 태풍 파라미터 모형(TPM)과 원시 소용돌이 모형(PVM)의 모의를 통해서 해상풍을 산출하였다. 그 결과를 동중국해, 남해 그리고 동해상에서 관측된 일본 기상청(JMA)의 해상풍 자료와 비교하였으며, 오차 분석을 통해서 두 모형의 신뢰도와 민감도에 대해 고찰하였다. 원해상의 해양부이 관측자료와의 비교에서는 두 모형 모두 관측치보다 낮게 모의되었으며, rms오차와 상대오차는 PVM이 TPM보다 훨씬 낮게 나타났다. 그러나, 큐슈 연안의 해상풍 자료에 대해서는 PVM은 약간 높게 TPM은 낮게 모의되었으며, PVM이 TPM보다 오차가 작은 것으로 나타났다. 태풍중심위치와 해상풍 관측지점 간의 거리에 따른 상대오차의 분석결과, 태풍 중심권에 근접한 거리에서는 두 모형 모두 상대오차가 작았으나, 200km이상의 먼 거리에 대해서는 TPM의 상대오차는 거리에 비례해서 약 70%까지 크게 증가하는 반면. PVM의 상대오차는 약 20%정도로 나타났다.

한국근해의 월평균 해상풍 (Monthly-mean sea surface winds over the adjacent seas of the Korea Peninsular)

  • 나정열;서장원
    • 한국해양학회지
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    • 제27권1호
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    • pp.1-10
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    • 1992
  • 10년간(1978~1987) 매일 2회 발행된 전기도를 근거로 Cardone Model을 이용한 한 국근해에서의 해상풍을 구하고 이를 근거로 월평균 wind-stress와 wind-stress curl의 분포를 계산하였다. 계산된 해상풍과 실측자료와의 비교를 위해 일본기상청 관측부 표 (Buoy 6) 자료와 비교한 결과 풍향 및 풍속이 매우 일치함을 보였다. 특히 계산된 wind-stress의 평균값은 기존의 값들에 비해서 동해의 경우 약 2배 정도로 나타나고 있다. Wind-stress의 분포특성은 서행의 경우는 $120^{\circ}{\;}~{\;}125^{\circ}{\;}E$를 중심으로 동.서로 부호가 서로 반대인 값을 가지며 특히 중국연안은 여름철을 제외한 전월에 음의 값을 나타낸다. 한편 동해(일본해)는 북부해역의 양의 값과 남부해역의 음의 값으로 그 특 징을 보이나 북부해역의 경우 동해의 최북단 및 원산만 부근에서 최대의 양의 값이 나 타나고 있다.

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Diurnal Variation of Atomospheric Pollutant Concentrations Affected by Development of Windstorms along the Lee Side of Coastal Mountain Area

  • Choi, Hyo
    • International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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    • 제24권1호
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    • pp.29-45
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    • 1996
  • Before (March 26, 1994) or after the occurrence of a downslope windstorm (March 29), the NO, $NO_2$, and $SO_2$ at the ground level of Kangnung city were monitored with high concentrations in the afternoon, due to a large amount of gases emitted from combustion of motor vehicle and heating apparatus, especially near 1600-1800 LST and 2000-2100 LST, but at night, they had low concentrations, resulting from small consumptions of vehicle and heating fuels. When both moderate westerly synoptic-scale winds flow over Mt. Taegwallyang and easterly meso-scale sea breeze during the day, atmospheric pollutants should be trapped by two different wind systems, resulting in higher concentration at Kangnung city in the afternoon. At night, the association of westerly synoptic wind and land breeze can produce relatively strong winds and the dissipation by the winds cause these low concentrations to lower and lower, as nightime goes on. From March 27 through 28, an enforced localized windstorm could be produced along the lee side of the mountain near Kangnung, generating westerly internal gravity waves with hydraulic jump motions. Sea breeze toward inland appartantly confines to the bottom of the eastern side of the mountain, due to the interruption of eastward violent internal gravity waves. As the windstorm moves down toward the ground, an encountering point of two opposite winds approaches Kangnung, and a great amount of NO and $NO_2$ were removed by the strong surface winds. Thus, their maximum concentrations are found to be near 18 and 20 LST, 17 and 21 LST. In the nighttime, the more developed storm should produce very strong surface winds and the NO and $NO_2$ could be easily dissipated into other place. The $SO_2$ concentration had no maximum value, that is, almost constant one all day long, due to its removal by the strong surface winds. Especially, the CO concentrations were slightly lower during the strom period than both before or after the strom, but they were nearly constant without much changes during the during the daytime and nighttime.

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