• Title/Summary/Keyword: sea-breeze

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Random Walk Simulation of Atmospheric Dispersion on Surface Urbanization over Complex Terrain (복잡지형에서 도시화에 따른 대기오염 확산에 관한 시뮬레이션)

  • 이순환;이화운;김유근
    • Journal of Korean Society for Atmospheric Environment
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    • v.18 no.2
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    • pp.67-83
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    • 2002
  • The coupled model (SMART) of dynamic meteorology model and particle dispersion model was developed. The numerical experiment on the relationship between change of land use and diffusion behavior in complex terrain was carried out using this model. It tried to investigate the change of particle diffusion behavior and local weather under the condition in which land-land breeze and sea breeze and mountain breeze intermingled. The numerical experiment results are as follows; 1) The more complicated local circulation field of the interaction of sea breeze, mountain breeze and Land -land breeze is formed. Then, the region circulation in which the urbanization is specific by location of the region is strengthened and is weakened. 2) Though in the region with dominant sea breeze, Land-land breeze does not appear directly, the progress of the sea wind to the inland is affected. 3) In the prediction of the air diffusion, emission high quality and accurate information of the emission site are important. That is to say, the dispersion predicting result which emission high quality and small error of the site perfectly vary for Land - land breeze in the effect may be brought about.

The Effect of Building Morphology on Sea Breeze Penetration over the Kanto Plain - Analysis of Mean Kinetic Energy Balance of Moving Control Volume along Sea Breeze -

  • Sato, Taiki;Ooka, Ryozo;Murakami, Shuzo
    • International Journal of High-Rise Buildings
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    • v.1 no.2
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    • pp.73-80
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    • 2012
  • In order to use sea breezes to counter the heat island phenomena, i.e. to promote urban ventilation, it is necessary to clarify the effect of building morphology and height on large-scale wind fields. In this study, the sea breeze in the vicinity of the Kanto Plain in Japan is simulated using a mesoscale meteorological model incorporating an urban canopy model, and the inland penetration of sea breezes is accurately reproduced. Additionally, a mean kinetic energy balance within a domain (Control Volume; CV) moving along the sea breeze is analysed. From the results, it is clarified that the sea breeze is interrupted by the resistance and turbulence caused by buildings at the centre of Tokyo. The interruption effect is increased in accordance with the height of these buildings. On the other hand, adverse pressure gradients interrupt in the internal region.

Characteristics of Fine Particle Concentration and Ionic Elements of PM2.5 during Sea Breeze Occurrences in Summertime in Busan (부산지역 여름철 해풍 발생 시 미세먼지와 초미세먼지 중의 이온성분 특성)

  • Jeon, Byung-Il
    • Journal of Environmental Science International
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    • v.30 no.6
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    • pp.465-474
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    • 2021
  • This research investigated the characteristics of fine particle concentration and ionic elements of PM2.5 during sea breeze occurrences during summertime in Busan. The PM10 and PM2.5 concentrations of summertime sea breeze occurrence days in Busan were 46.5 ㎍/m3 and 34.9 ㎍/m3, respectively. The PM10 and PM2.5 concentrations of summertime non-sea breeze occurrence days in Busan were 25.3 ㎍/m3 and 14.3 ㎍/m3, respectively. The PM2.5/PM10 ratios of sea breeze occurrence days and non-sea breeze occurrence days were 0.74 and 0.55, respectively. The SO42-, NH4+, and NO3- concentrations in PM2.5 of sea breeze occurrence days were 9.20 ㎍/m3, 4.26 ㎍/m3, and 3.18 ㎍/m3 respectively. The sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) of sea breeze occurrence days were 0.33 and 0.05, respectively. These results indicated that understanding the fine particle concentration and ionic elements of PM2.5 during sea breeze summertime conditions can provide insights useful for establishing a control strategy of urban air quality.

Characteristics of the Land and Sea Breeze on Cheju island , Korea (제주도 지방의 해륙풍의 특성)

  • 김유근
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.1
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    • pp.41-55
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    • 1991
  • A study was done to investigate characteristics of the land and sea breeze over Cheju island on the basis of surface meteorological data collected from 1977 to 1986. The results are summarized as follows: The frequency of the land and sea breze was highest in August followed by September, October, May and November in descending order. This indicates that the frequency of the land and sea breeze is higher in fall than in spring, and lowest in winter. The sea breeze began much earlier than any other regions of Korea all the year round, and it began about 30 minutes earlier and ended one hour later in the northern coast than in the southern coast of Cheju island. Meanwhile, the land breeze began about one hour earlier in the southern coast than in the northern coast and ended almost at the same time in both coasts. The annual mean duration of the sea breeze was about one hour longer in the northern coast than in the southern coast, but the land breeze showed an opposite trend. The duration of the sea breeze was longer in summer than in winter and again the land breeze was opposite. Transition period from the sea to the land breeze was relatively long in summer and shout in winter, but transition period from the land to the sea breeze was not different between seasons. The time for a maximum velocity of the sea breeze came earlier in the southern coast than in the northern coast, but that of the land breeze came almost at the same time in both coasts with no seasonal variations. Monthly mean maximum velocity of the sea breeze was greater than that of the land breeze.

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Impact of the Variation of Sea Breeze Penetration due to Terrain Complexity on PBL Development (해안지형의 복잡성에 따른 해풍침투 변화가 대기경계층에 미치는 영향 분석)

  • Park, Soon-Young;Lee, Hwa-Woon;Lee, Soon-Hwan;Lee, Kwi-Ok;Ji, Hyo-Eun
    • Journal of Environmental Science International
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    • v.20 no.2
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    • pp.275-289
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    • 2011
  • In order to clarify the relation between sea breeze penetration and Planetary Boundary Layer development in southeastern part of the Korean Peninsula, several numerical assessments were carried out using atmospheric numerical model WRF(Weather Research and Forecasting). Compared with onset time of sea breeze at eastern coast area(Uljin), the time at southern coast region(Masan) with complex costal line tend to delay for several hours. The penetration patterns of sea breeze between two coastal regions are some different due to the shape of their coastal line and back ground topography. Intensified valley wind due to high topography of lee side of Uljin can help penetration of sea breeze at early time. So penetration of sea breeze at early time often prevent PBL to develop at Uljin and lower PBL height last for a day time. But because of late penetration of sea breeze at Masna, PBL Height dramatically decrease after 1500LST. The distribution of front genesis function based on the heat and momentum variation are explained obviously the sea breeze penetration patterns and agreed well with the PBL height distribution.

A Study of Interrelationships between the Effect of the Upwelling Cold Water and Sea Breeze in the Southeastern Coast of the Korean Peninsula (한반도 동남연안지역의 냉수대 영향과 해풍의 상호관련성 연구)

  • Lee, Hwa-Woon;Ji, Hyo-Eun;Lee, Soon-Hwan
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.6
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    • pp.481-492
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    • 2009
  • The characteristic of cold water by upwelling in the southeast of the Korean Peninsula and the effect of sea breeze in this region are investigated. The coastal upwelling around the southeast coast of the Korea Peninsula is analyzed by using Coastal Oceanographic Data statistical analyses for 5 years were carried out. The period of an cold water event, on the average, was observed southwesterly wind events. The analysis suggests that strong and persistent southwesterly winds in period of an cold water play an important role of bring the moisture to the surface, generating persistent cyclone as jangma. In order to investigate the effect of cold water on sea breeze, we considered two case. First, Exp. 1 is not occurred coastal upwelling on sea breeze. Second, Exp. 2 is occurred cold water on sea breeze. Two experiments were completed separately to the effects of cold water by upwelling. The results show the sea breeze is stronger in Exp. 2, when the cold water occurs, and weaker in Exp. 1, when there is no cold water. In order to verify the effect of the sea breeze on the cold water by upwelling, on the intensification and change of direction of the prevailing wind, the sea breeze effectively intensify cold water condition.

Estimating the cooling effect of see breeze along canals and outdoor thermal comfort on urban heat load in summer (해풍(海風)을 이용한 하계(夏季) 도시열환경(都市熱環境)의 풍도(風道)계획과 인체의 쾌적성에 관한 연구)

  • Jeong, Chang-Won;Yoon, In;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.1
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    • pp.19-25
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    • 1999
  • A new urban design method from the viewpoint of climate is considered to be desired for urban life. The authors verified on an environmental planning based on new urban design concept which introduced the effect of sea breeze blowing along canals. The field observation of urban thermal environment were carried out to examine the cooling effects of a river through city. The observations were conducted to find the effect of a sea breeze and climate in summer along canals. Effective distance from the sea and cooling effect of the sea breeze on urban temperature was analyzed. The thermal index using outdoor environment was modified with New Effective Temperature ET*. On the basis of the observation. Human thermal comfort is relieved and affected by sea breeze blowing along canals. The canals were utilized as the trail on which sea breeze blows towards the center of city. From these results, The wind trail is one of the effective passive design method from the viewpoint of urban climate.

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Characteristics of Sea Breezes at Coastal Area in Boseong (보성 해안 지역에서의 해풍 특성)

  • Lim, Hee-Jeong;Lee, Young-Hee
    • Atmosphere
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    • v.29 no.1
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    • pp.41-51
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    • 2019
  • The characteristics of the sea breeze were investigated using the wind and temperature data collected from 300-m tower at Boseong from May 2014 to April 2018. Sea breeze day was detected using following criteria: 1) the presence of a clear change in wind direction near sunrise (between 1 hour after sunrise and 5 hours before sunset) and sunset (from 1500 LST to midnight), 2) presence of thermal forcing of sea breeze and 3) no heavy precipitation (rain < $10mm\;d^{-1}$). Sea breeze days occurred on 569 days for 4 years. The monthly distribution of sea breeze day occurrence shows maxima in May and September and minimum in December. The average onset and cessation times of the sea breeze are 0942 LST and 1802 LST, respectively. Although the 10-m wind shows clockwise rotation with time in the afternoon, the observed hodograph does not show an ideal elliptical shape and has different characteristics depending on the upper synoptic wind direction. Vertical structure of sea breeze shows local maximum of wind speed and local minimum of virtual potential temperature at 40 m in the afternoon for most synoptic conditions except for southeasterly synoptic wind ($60^{\circ}{\sim}150^{\circ}$) which is in the same direction as onshore flow. The local minimum of temperature is due to cold advection by sea breeze. During daytime, the intensity of inversion layer above 40 m is strongest in westerly synoptic wind ($240^{\circ}{\sim}330^{\circ}$) which is in the opposite direction to onshore flow.

The Influences of Sea Breeze on Air Pollution Concentration in Pusan, Korea (해풍이 부산 지역의 대기 오염 농도에 미치는 영향)

  • Jeon, Byeong-Il;Kim, Yu-Geun;Lee, Hwa-Un
    • Journal of Environmental Science International
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    • v.3 no.4
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    • pp.357-365
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    • 1994
  • Air pollution characteristics and the influence of sea breeze on air pollution concentration were studied using the data measured at 7 air quality continuous monitoring stations in Pusan, 1993. Maximum air pollution concentration in Pusan was Gamjeondong for $SO_2$, Sinpyeongdong for TSP, Daeyeondong for $O_3, Kwangbokdong for $NO_2$, Beomcheondong for CO and all substances were under annual ambient air quality standards. Increased rate of concentration for sea breeze was 24.4% for 502, 31.5% for TSP, 8.0% fort $O_3, 26.7% for $NO_2$, 15.7% for CO. Frequencies distribution of $SO_2$, TSP, $O_3$, $NO_2$, and CO concentration for sea breeze moved toward high concentration class.

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On Characteristics of Sea Breeze Front observed in Pusan Coastal Area, Korea (부산연안역에서 관측된 해풍전선의 특성)

  • 전병일
    • Journal of Environmental Science International
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    • v.6 no.6
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    • pp.629-636
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    • 1997
  • We have analyzed focusing on the characteristics, speed and width of sea breeze front in Pusan coastal area using the meteorological data observed at Kimhae air force meteorological station because the presence of the front has Important effects on the dInstributlon of air pollution. The inland penetration of sea breeze front was recognized by steep variation of meteorological parameters(wind direction, wind speed, temperature, dew point temperature, air pressure, relative humidity) before and after its passage and the variation of $SO_2$ concentration, the speed and width of the sea breeze front was 2.07m/s and 217m, respectively. The structure and inland penetration of sea breeeze front should be taken into account whenever a model is to be compared with detailed field measurements.

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