• Title/Summary/Keyword: Sea-breeze

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Intercomparison of Wind and Air Temperature Fields of Meteorological Model for Forecasting Air Quality in Seoul Metropolitan Area (수도권지역 대기질 예측을 위한 기상장 모델의 바람장과 온도장 비교 연구)

  • Jeong, Ju-Hee;Kim, Yoo-Keun;Moon, Yun-Seob;Hwang, Mi-Kyoung
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.640-652
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    • 2007
  • The MM5, RAMS and WRF, meteorological models have provided the dynamical parameters as inputs to air quality model. A major content of this study is that significant characteristics of three models for high-ozone occurrence analyze for surface wind and air temperature fields and compare with observation data in Seoul metropolitan area. An analysis of air temperature field revealed that location of core in high temperature of MM5 and WRF differed from that of RAMS. MM5 and WRF indicated high temperature in Seoul but RAMS represented it on the outskirts of Seoul. MM5 and WRF were underestimated maximum temperature during daytime but RAMS simulated similar value with observation data. Surface wind field with three models, it was shown many differences at horizontal distribution of wind direction. RAMS indicated weak wind speed in land and strong sea breeze at coastal areas than MM5 and WRF. However wind speed simulated by three model were overestimated during both daytime and nighttime.

A study on high ozone concentration in Shiwha.Banwol industry complex using photochemical air pollution model- Analysis of meteorological characteristics - (시화.반월단지지역의 고농도 오존일에 대한 광화학모델 적용 연구 - 기상특성에 대한 분석 -)

  • An, Jae-Ho
    • Journal of the Korean Solar Energy Society
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    • v.31 no.5
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    • pp.47-59
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    • 2011
  • The purpose of this paper is to simulate the high ozone concentration in Shiwha Banwol indusrial complex. High pollution episodes (ozone alert) of this area are the results of geographical location and its air pollutants emission. This research has used meteorological model (RAMS) and photochemical air pollution Model (CIT model). As first step of the evaluate of this combined model system simulations are done in terms of meteorological characteristics like wind fields, PBL-height, etc.. Numerical simulations are carried out with real meteorological synoptic data on June. 24-25, 2010. In comparison with real measurement and another research the model reflects well local meteorological phenomena and shows the possibility to be utilized to analyse the pollutant dispersion over irregular terrain region. The high ozone concentration is deeply correlated to the ambient air temperature, wind speed and solar radiation. Local meteorological phenomena like sea-land breeze impact on horizontal dispersion of ozone. This analysis of meteorological characteristics can, in turn, help to predict their influences on air quality and to manage the high ozone episodes.

Geomorphological Properties and Changes of Goreabul Sand Beach in Yeongdeok (영덕 고래불 모래해안의 지형 특성과 변화)

  • Bang, Hyun Ju;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.3
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    • pp.83-92
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    • 2011
  • The properties and changes of geomorphic relief and coastal deposits were analyzed at Goreabul sand beach in Yeongdeok-gun, the largest that in east coast of Kyungsangbuk-do Province. As the result of grain size analysis, in almost season except summer, the sands mainly deposited in Goraebul sand beach because longshore current drift northward contrary to Gangwon-do east coast, and summer longshore current is weak or change direction to south ward. Sand beach mostly came form erosion owing to typoon and storm and was deposit more coarse sand in the summer, and was produced deposition actively in the fall and winter. Front side of sand dune came from deposition on sand every season by sea breeze, especially in the winter.

Analysis of Turbulence at the K-UAM Grand Challenge Site in Goheung (고흥 K-UAM 그랜드 챌린지 실증지역에서의 난류 분석)

  • Min-seong Kim;Hee-Wook Choi;Seong-hwa Park;Geun-Hoi Kim;Sang-Sam Lee;Yong Hee Lee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.32 no.3
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    • pp.114-123
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    • 2024
  • Recently, urban population congestion has caused significant traffic and air pollution problems in city centers. To address these issues, Urban Air Mobility (UAM) has been proposed, with commercialization targeted for 2025 in Korea. The Korea Meteorological Administration (KMA) has been conducting the K-UAM Grand Challenge in Goheung since 2022 to develop operational standards and relevant technologies. This study uses a ultrasonic anemometer at a height of 10 meters to analyze turbulence around the vertiport. Data was collected from November 2022 to November 2023. For turbulence analysis, the Eddy Dissipation Rate (EDR = ε1/3), defined by the International Civil Aviation Organization (ICAO), was used. EDR was calculated using Kolmogorov's theory and derived from the energy spectrum. EDR values were classified into None, Light, Moderate, and Severe, and analyzed by season, day, and wind direction. The results showed strong daytime turbulence in summer, especially with southerly winds in spring and summer, due to sea breeze fronts. This study provides essential data for planning safe UAM operations considering weather conditions.

On Surface Ozone Observed in the Seoul Metropolitan Area during 1989 and 1990 (서울 수도권 지역의 광화학오존에 관한 연구)

  • 정용승;정재섭
    • Journal of Korean Society for Atmospheric Environment
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    • v.7 no.3
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    • pp.169-179
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    • 1991
  • Atmospheric $O_3$ in the biosphere is formed under the favourable meteorological condition, when the primary pollutants, such as $NO_2, HC, CO, CH_4$, etc., react with over constituents. Observed annual average concentrations for 1989 and 1990 were 11.8 and 10.4 ppb, respectively. THe number of days measured ozone over 80 ppb in Seoul were 36 in 1989 and 39 in 1990. In general, monthly maximum values occurred in May and August. In comparison with 1 $\sim$ 2 maxima of $O_3$ distribution in large cities in other countries, it was found that there were 3 $\sim$ 4 maxima in Seoul and its suburbs. Topographic effects, resulted by wind channelling in the Han River valley and by the blocking of air pollutants in the mountain, appeared to produce multiple centres of $O_3$ maxima in Seoul. Surface $O_3$ values were low with decreasing solar radiation, when the cloudiness increased and precipitation occurred. According to 12 cases examined, 2 cases shown here, $O_3$ values exceeding 80 ppb were occurred when the Korean peninsular was under the influence of the backside airflows with high intensity of solar radiation. Occasionally, sea breezes were observed to occur in warm seasons, and the chanelling effect of the Han River valley appeared to increase the general wind (speed) to the east side of Seoul. In this meso-scale situation $O_3$ in downwind is highly correlated with precursors. The sea breeze of 2 $\sim$ 4 m $s^{-1}$ will take 3 $\sim$ 5 hours to transport photochemical precursors for 20 $\sim$ 50 km. In turn the areas of maximum $O_3$ occurrence in Seoul are in the range of meso-scale transport of air pollutants.

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A Study on the Users' Awareness of Waterfront in Japan - Focusing on Yokohama Minatomirai21 area - (일본 워터프런트 공간에 있어서 수변공간의식에 대한 연구 ~요코하마 미나토미라이21지구를 대상으로~)

  • Kon, Masayuki;Lee, Myung-Kwon;Yang, Dong-Cheon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.06a
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    • pp.7-8
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    • 2012
  • Using a questionnaire, this study examined the users' consciousness through the human five senses on the waterside space in the district of Minato Mirai 21, Yokohama located in the east of Kanagawa prefecture, which is well known for its waterfront in Japan. Among the users, the results of the questionnaire showed 52.2% of male, and 29.6% accounted for people in their twenties as the dominant groups. Out of the nineteen questions regarding the consciousness on the waterside space, 'feel the sea breeze' accounted for 237(78.7%) while 'the sea is visible' accounted for 217(72.1%). Then, the contents of the nineteen questions were re-classified into such seven items as the human five senses(sight, hearing, touch, taste, and smell), activities, and the existence of facilities, discovering the consciousness of the users. The results demonstrated that touch(22.9%) and sight(20.8%) respectively were the most influential items.

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A Study on the Users' Awareness of Waterfront in Busan Area - Focusing on Haeundae & Jagalchi (부산지역 수변공간에서의 수변공간의식에 관한 연구 - 해운대와 자갈치를 대상으로 -)

  • Yang, Dong-Cheon;Kon, Masayuki;Lee, Myung-Kwon
    • Journal of Navigation and Port Research
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    • v.37 no.5
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    • pp.543-549
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    • 2013
  • In this study, as waterfront space to represent the Busan, to elect (Haeundae, Minrak park, Gwangalli, APEC Naru Park, Dadaepo, Jagalchi, Taejongdae) the seven high degree of recognition, we conducted a pre-sample survey. We investigated the awareness of waterfront space to re-conducted a questionnaire survey (Haeundae, Jagalchi) the two places the property was most apparent on the basis of the result, visitors feel about waterside space. As a result, the Haeundae, has been answered ". Feels the breeze of the sea" (163 people) 81.5% of users, Jagalchi is the fruits of the sea "(111 people) 55.8% it is answered. "that can be eaten. In addition, the center of consciousness of waterfront space, we conducted an analysis of the overall satisfaction of waterfront space age group of each, depending on the desired behavior.

Evaluation of Internal through Analysis of Airflow and Ventilation of Coal Storage Shed (옥내저탄장 기류 흐름 및 환기량 분석을 통한 내부 유동 평가)

  • Jo, Hyun-Joung;Lee, Jin-Hong
    • Journal of Environmental Impact Assessment
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    • v.31 no.5
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    • pp.334-342
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    • 2022
  • The stringent air environment conservation act forced to build an indoor dome for coal storage. However, it causes some problems due to accumulation of fly ash and harmful substances inside. To solve this problem, this study analyzed the pattern of internal airflow and the amount of ventilation for an indoor coal yard. Overall, the airflow inside the indoor coal yard tended to move to the southwest facing the mountain. In addition, sea-breeze was blowing from the northern louver window facing the sea, where airflow was flowing in. The total flow rate flowing into the indoor coal yard was 918,691 m3/h, and the number of natural ventilation per hour was 0.6 times. Therefore, it is proposed to install a forced ventilation device at the location where internal air flow is concentrated.

Inhibitory Factors of Robinia pseudoacacia Distribution in a Pinus thunbergii Forest at the Coast (해안 곰솔림 내 아까시나무의 분포확대 억제요인)

  • Jung, Sung-Cheol;Koo, Kyo-Sang;Kim, Kyong-Ha
    • Korean Journal of Environment and Ecology
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    • v.25 no.5
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    • pp.717-724
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    • 2011
  • The objectives of this study were to analyze environment in the forest and growth characteristics for investigating the characteristics of Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast. As a result of analyzing inhibitory factors of Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast, it is considered that the salt level included in a sea wind is supposed to be the primary factor of the slow growth for Robinia pseudoacacia since brown leaves, wilting and early leaf fall have appeared in the 0m spot from the artificial dune which has the high salt level. However, the soil properties and light environment hardly have a effect on the growth of Robinia pseudoacacia because there is no difference among planting places. Also, the growth ring of the horizontal root in 2year individuals 0.1~0.2m away from the dune have been formed for 1 year only as a consequence of analyzing growth rings of Robinia pseudoacacia growing on the coast. It can be infered that the nourishment of the horizontal root from individuals growing on the coast have been provided for the first 1 year only. It is estimated that, in case of the nearby areas on the coast, it is not enough to provided nourishment to the horizontal root due to obstructing the growth of new individuals by a sea wind, so the growth of the horizontal root would be hampered. Therefore, it is considered that impedient Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast is caused by making no growth of new horizontal roots and newborn individuals.

A study on the comparative awareness survey of waterfront areas in Haeundae, Jagalchi and Yokohama (해운대, 자갈치, 요코하마의 워터프런트 지역에 있어서 수변공간의식구조에 관한 연구)

  • Kon, Masayuki;Lee, Myung-Kwon;Yang, Dong-Cheon;Ahn, Chang-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.10a
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    • pp.37-38
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    • 2012
  • This study intended for Yokohama Minato Mirai21 district in Japan as waterfront, and Korea did an object again in Haeundae on high ground beach, a Jagalchi market. I carried out questionary survey in an object with the three places and investigated human waterside space consciousness to keep that I came and went. I analyzed the waterside space consciousness of the user to see a questionnaire result. It was 78.7% of 237 people, and there was much 'which felt the' sea breeze for the waterside space consciousness most, and 'that' which the 'sea was seen next saw 217 72.1%,' ship appeared by 203 67.4% order. I carried out reclassification for human five senses (sight, hearing, the sense of touch, taste, sense of smell) and activity, seven items such as the existence of the institution by the question contents of 19 about the waterside space consciousness each and grasped the consciousness of the waterfront user. As a result, Haeundae sense of smell was 32.3%, and a Jagalchi market was that sense of smell (26.1%) had an influence on the waterside space consciousness in 32.3% of taste, 21, Minato Mirai, Yokohama district, and sea building on high ground beach appeared.

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