• Title/Summary/Keyword: Sea wind

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Modification of Sea Water Temperature by Wind Driven Current in the Mountainous Coastal Sea

  • Choi, Hyo;Kim, Jin-Yun
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.177-184
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    • 2003
  • Numerical simulation on marine wind and sea surface elevation was carried out using both three-dimensional hydrostatic and non-hydrostatic models and a simple oceanic model from 0900 LST, August 13 to 0900 LST, August 15, 1995. As daytime easterly meso-scale sea-breeze from the eastern sea penetrates Kangnung city in the center part as basin and goes up along the slope of Mt. Taegullyang in the west, it confronts synoptic-scale westerly wind blowing over the top of the mountain at the mid of the eastern slope and then the resultant wind produces an upper level westerly return flow toward the East Sea. In a narrow band of weak surface wind within 10km of the coastal sea, wind stress is generally small, less than l${\times}$10E-2 Pa and it reaches 2 ${\times}$ 10E-2 Pa to the 35 km. Positive wind stress curl of 15 $\times$ 10E-5Pa $m^{-1}$ still exists in the same band and corresponds to the ascent of 70 em from the sea level. This is due to the generation of northerly wind driven current with a speed of 11 m $S^{-1}$ along the coast under the influence of south-easterly wind and makes an intrusion of warm waters from the southern sea into the northern coast, such as the East Korea Warm Current. On the other hand, even if nighttime downslope windstorm of 14m/s associated with both mountain wind and land-breeze produces the development of internal gravity waves with a hydraulic jump motion of air near the coastal inland surface, the surface wind in the coastal sea is relatively moderate south-westerly wind, resulting in moderate wind stress. Negative wind stress curl in the coast causes the subsidence of the sea surface of 15 em along the coast and south-westerly coastal surface wind drives alongshore south-easterly wind driven current, opposite to the daytime one. Then, it causes the intrusion of cold waters like the North Korea Cold Current in the northern coastal sea into the narrow band of the southern coastal sea. However, the band of positive wind stress curl at the distance of 30km away from the coast toward further offshore area can also cause the uprising of sea waters and the intrusion of warm waters from the southern sea toward the northern sea (northerly wind driven current), resulting in a counter-clockwise wind driven current. These clockwise and counter-clockwise currents much induce the formation of low clouds containing fog and drizzle in the coastal region.

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Characteristics of Atmospheric Circulation in Sokcho Coast (속초연안에서 대기순환의 특성)

  • Choi Hyo
    • Journal of Environmental Science International
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    • v.14 no.1
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    • pp.41-51
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    • 2005
  • Using three-dimensional non-hydrostatical numerical model with one way double nesting technique, atmo­spheric circulation in the mountainous coastal region in summer was investigated from August 13 through 15, 1995. During the day, synoptic westerly wind blows over Mt. Mishrung in the west of a coastal city, Sokcho toward the East Sea, while simultaneously, easterly upslope wind combined with both valley wind from plain (coast) toward mountain and sea-breeze from sea toward inland coast blows toward the top of the mountain. Two different directional wind systems confront each other in the mid of eastern slope of the mountain and the upslope wind goes up to the height over 2 km, becoming an easterly return flow in the upper level over the sea and making sea-breeze front with two kinds of sea-breeze circulations of a small one in the coast and a large one in the open sea. Convective boundary layer is developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west and a thickness of thermal internal boundary layer from the coast along the eastern slope of the mountain is only confined to less than 200 m. On the other hand, after sunset, no prohibition of upslope wind generated during the day and downward wind combined with mountain wind from mountain towardplain and land-breeze from land toward under nocturnal radiative cooling of the ground surfaces should intensify westerly downslope wind, resulting in the formation of wind storm. As the wind storm moving down along the eastern slop causes the development of internal gravity waves with hydraulic jump motion in the coast, bounding up toward the upper level of the coastal sea, atmospheric circulation with both onshore and offshore winds like sea-breeze circulation forms in the coastal sea within 70 km until midnight and after that, westerly wind prevails in the coast and open seas.

Evolution of Wind Storm over Coastal Complex Terrain (연안복합지형에서 바람폭풍의 진화)

  • Choi, Hyo;Seo, Jang-Won;Nam, Jae-Cheol
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.865-880
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    • 2002
  • As prevailing synoptic scale westerly wind blowing over high steep Mt. Taegulyang in the west of Kangnung coastal city toward the Sea of Japan became downslope wind and easterly upslope wind combined with both valley wind and sea breeze(valley-sea breeze) also blew from the sea toward the top of the mountain, two different kinds of wind regimes confronted each other in the mid of eastern slope of the mountain and further downward motion of downlsope wind along the eastern slope of the mountain should be prohibited by the upslope wind. Then, the upslope wind away from the eastern slope of the mountain went up to 1700m height over the ground, becoming an easterly return flow in the upper level of the sea. Two kinds of circulations were detected with a small one in the coastal sea and a large one from the coast toward the open sea. Convective boundary layer was developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west, while a thickness of thermal internal boundary layer(TIBL) form the coast along the eastern slope of the mountain was only confined to less than 200m. After sunset, under no prohibition of upslope wind, westerly downslope wind blew from the top of the mountain toward the coastal basin and the downslope wind should be intensified by both mountain wind and land breeze(mountain-land breeze) induced by nighttime radiative cooling of the ground surfaces, resulting in the formation of downslope wind storm. The wind storm caused the development of internal gravity waves with hydraulic jump motion bounding up toward the upper level of the sea in the coastal plain and relatively moderate wind on the sea.

The influence of sea surface temperature for vertical extreme wind shear change and its relation to the atmospheric stability at coastal area

  • Geonhwa Ryu;Young-Gon Kim;Dongjin Kim;Sang-Man Kim;Min Je Kim;Wonbae Jeon;Chae-Joo Moon
    • Wind and Structures
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    • v.36 no.3
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    • pp.201-213
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    • 2023
  • In this study, the effect of sea surface temperature (SST) on the distribution of vertical wind speed in the atmospheric boundary layer of coastal areas was analyzed. In general, coastal areas are known to be more susceptible to various meteorological factors than inland areas due to interannual changes in sea surface temperature. Therefore, the purpose of this study is to analyze the relationship between sea surface temperature (ERA5) and wind resource data based on the meteorological mast of Høvsøre, the test bed area of the onshore wind farm in the coastal area of Denmark. In addition, the possibility of coastal disasters caused by abnormal vertical wind shear due to changes in sea surface temperature was also analyzed. According to the analysis of the correlation between the wind resource data at met mast and the sea surface temperature by ERA5, the wind speed from the sea and the vertical wind shear are stronger than from the inland, and are vulnerable to seasonal sea surface temperature fluctuations. In particular, the abnormal vertical wind shear, in which only the lower wind speed was strengthened and appeared in the form of a nose, mainly appeared in winter when the atmosphere was near-neutral or stable, and all occurred when the wind blows from the sea. This phenomenon usually occurred when there was a sudden change in sea surface temperature within a short period of time.

Monthly Wind Stress and Wind Stress Curl Distributions in the Eastern Sea(Japan Sea) (동해상의 월별 바람응력 및 바람응력컬 분포)

  • 김철호;최병호
    • Water for future
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    • v.19 no.3
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    • pp.239-248
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    • 1986
  • Monthly wind stress, wind stress curl and volume transport stream functions are computed in the Eastern Sea(Japan Sea) based upon observed wind and atmospheric pressure data respectively. The presented two results show different distributios on locality and season but as common features the results reveal the northwesterly surface wind stress \ulcorner 새 the monsoon in winter, south to southwesterly wind stress \ulcorner 새 the southerly wind in summer and strond anticyclonic curl in the northern part on the Eastern Sea(Japan Sea) in winter. In the distributions obtained from the sea level atmospheric pressure data, the maximum value of the wind stress and of curls of small scales are shown off the southeast coast of Siberia and northeast coast of Korea. Volume transport distributions obtained from the Sverdrup relationship suggest that the strong northward boundary current can be formed along the northeast coast of Korea in winter and weak southward boundary current in summer.

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The Conceptual Study on Driving Factors for Wind based on Land and Sea Breeze in the Elementary Textbooks (초등학교 교과서 속 해륙풍에 기반한 바람이 부는 이유에 대한 개념적 고찰)

  • Lee, Gyuho
    • Journal of Korean Elementary Science Education
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    • v.34 no.4
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    • pp.486-501
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    • 2015
  • In the elementary school science curriculum, wind is one of the most important concept. In particular, land and sea breeze has been a key example to deliver how wind is driven, and thus its model experiments have been used to help students understand causes of wind. Here we compare causes and explanations for wind and land and sea breeze between textbooks in colleges and elementary schools to examine any potential improvement for the contents. In addition, we conducted survey to examine how pre-service teachers understand land and sea breeze, and convection box experiment used in elementary school textbooks is useful to understand land and sea breeze. Based on the comparison, we find that college level textbook explains the cause of wind as atmospheric pressure difference while elementary school textbooks explain them differently according to curriculums. In the textbooks, there are a difference in the way described for land and sea breeze. Analysis of questionnaire indicate that pre-service teachers understood land and sea breeze correctly, and they selected the convection box experiment in 2009 curriculum textbooks as the most suitable one. Explanations and experiments for land and sea breeze in the textbooks have been revised as the modification of elementary school curriculums. We expect this study helps to deliver more solid contents for wind and land and sea breeze in the upcoming new curriculum.

BORA IN THE ADRIATIC SEA AND BLACK SEA IMAGED BY THE ENVISAT SYNTHETIC APERTURE RADAR

  • Ivanov, Andrei Yu.;Alpers, Werner
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.964-968
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    • 2006
  • Bora events over the Adriatic Sea and Black Sea are investigated by using synthetic aperture radar (SAR) images acquired by the Advanced Synthetic Aperture Radar (ASAR) onboard the European Envisat satellite. These images show pronounced elongated patterns of increased sea surface roughness caused by bora winds. The comparison of the SAR images with wind fields derived from Quikscat data confirms that in all cases a strong northeasterly wind was blowing from the mountains onto the sea. It is shown that the SAR images reveal details of the spatial extent of the bora wind fields over the sea which cannot be obtained by other instruments. Furtheremore, also quantitative information on the wind field is extracted from the SAR images by using a wind scatterometer model.

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Marine Meteorological Characteristics in 2006-2007 : Sea Surface Wind (2006-2007년 해양기상 특성 : 해상풍)

  • You, Sung Hyup;Kwon, Ji Hye;Kim, Jeong-Sik
    • Atmosphere
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    • v.19 no.2
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    • pp.145-154
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    • 2009
  • This study compared the sea surface wind pattern between model results from KMA operational model (RDAPS) and retrieved results from QuickSCAT in the 2006-2007 year. The mean spatial distributions of sea surface wind of RDAPS and QuikSCAT show the prominent seasonal patterns of summer and winter season adjacent to Korean Peninsular. The magnitude of sea surface wind predicted by RDAPS is weaker than that of QuikSCAT in most north Pacific ocean. In summer of 2006 positive bias with the maximum of 1 m/s is appeared in broad region of north Pacific ocean, however. the positive bias region is decreased to small region in 2007. Even though the predicted sea wind by RDAPS is stronger(weaker) than observed one by QuikSCAT in summer (winter), the RDAPS model simulate well the sea surface wind adjacent to Korean peninsular.

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

  • Shibata, Akira;Murakami, Hiroshi
    • Proceedings of the KSRS Conference
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    • v.1
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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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The Estimaion of Wind Energy Resources through out the QuikSCAT Data (위성 관측 자료를 이용한 서해 해상 풍력자원 평가)

  • Jang, Jea-Kyung;Yu, Byoung-Min;Ryu, Ki-Wahn;Lee, Jun-Shin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.486-490
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    • 2009
  • In order to investigate the offshore wind resources, the "QuikSCAT Level 3" data by the QuikSCAT satellite was analyzed from Jan 2000 to Dec 2008. QuikSCAT satellite is a specialized device for a microwave scatterometer that measures near-surface wind speed and direction under all weather and cloud conditions. Wind speed measured at 10 m above from the sea surface as extrapolated to the hub height by using the power law model. It has been found that the high wind energy prevailing in the south sea and the east sea of the Korean peninsula. From the limitation of seawater depth for piling the tower and archipelagic environment around the south sea, the west and the south-west sea are favorable to construct the large scale wind farm. Wind map and monthly variation of wind speed are investigate at the positions.

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