• 대기
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• 제29권1호
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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.

• 한국환경과학회지
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• 제11권12호
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• pp.1243-1252
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• 2002

This paper aims to find the characteristics of concentration distribution of coastal urban air pollutants. For this purpose, It was used the daily meteorological data and the hourly concentration data for $O_3$and NO$_2$ in Busan metropolitan city from 1994 to 1996. It was investigated the annual and monthly distribution of ozone and nitrogen dioxide concentration at each site in Busan, and also investigated the characteristics of concentration change of air pollutants with time under the sea breeze. As a results, the concentration of nitrogen dioxide and ozone tend to be increased every year and nitrogen dioxide concentration is higher than ozone concentration at all sites in Busan. The concentration of ozone is high in summer season and low in winter season, but the concentration of nitrogen dioxide have a reversed trend. The monthly peak concentration of ozone occurred in April and September, while the monthly minimum concentration of nitrogen dioxide occurred in August. Their trend were identified by sites near the coastline than sites stands apart from the coastline. The sea breeze occurred annual mean 81 day in Busan from 1994 to 1996. The main wind direction of sea breeze was classified into southwesterly and southeasterly. In case of southwesterly, It was pronounced the south wind and southwest wind. In case of southeasterly, the occurrence frequency of east wind was high. Especially, the concentrations of urban air pollutants, such as ozone and nitrogen dioxide, were high on time which the sea breeze flow, and the areas that ozone concentration was high moved from outside part to central part of city with time. In costal urban such as Busan, the wind direction of sea breeze is influenced the change of ozone and nitrogen dioxide concentration on time which the sea breeze flow at each site and also influenced the change of air pollutants concentration of sites on the pathway of sea breeze.

• 한국지구과학회지
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• 제23권5호
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• pp.436-441
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• 2002

본 연구는 강릉 연안지역의 해풍 선정기준과 단 시간 해풍의 기후학적 특성에 관한 것이다. 강릉 연안지역에서의 해풍 선정기준은 다음과 같다. 즉, 육풍에서 해풍으로, 그리고 그 반대로의 분명한 풍향 변화가 있는 가운데 북동 기류와 같이 지형적 원인에 의한 풍향 변화는 해풍 선정에서 제외시켰다. 그리고 해풍이 1시간 또는 2시간만 지속된 경우도 포함시켰다. 이렇게 선정된 해풍 가운데 강릉 연안 지역에서의 가장 큰 특징인 단 시간 해풍에 대한 기후학적 특성을 10년동안(1988년${\sim}$1997년)의 자료를 통해 분석하였고 계절별 발생빈도, 발생시간, 풍향, 풍속, 기온으로 구성되었다. 마지막으로 본 연구는 강릉 연안지역 뿐만 아니라 동해안 지역 해풍의 기후학적 특성활용에 대해 간략히 논하였다.

• 대기
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• 제30권3호
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• pp.221-236
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• 2020

The Gangneung region has the complicated geographical characteristics being adjacent to East Sea and Taeback mountains, and thus sea breeze could play an important role in local weather in various aspects. This study aims to understand overall characteristics of sea breeze largely based on long-term (2009~2018) ground-based observation data. We also propose a selection criteria of sea breeze occurrence day; 1) daily precipitation is less than 10 mm, 2) surface wind direction is 0~110° (northerly to easterly) for more than 3 hours during the daytime, 3) wind direction is 110~360° for more than 3 hours during the nighttime, and 4) land and sea temperature difference is positive during the daytime, 5) sea and land sea-level pressure difference is more than 0.5 hPa. As a result, a total of 595 days was selected for the past 10 years. The occurrence of sea breeze is the highest in late Spring to early Summer (May to June). The passage time of sea breeze at the inland station (1.6 km farther inland) is one hour later than the coastal station. On the typical sea breeze event of April 12, 2019, the passage speed and duration of sea breeze was 15 km hr^-1 and about 9 hours, respectively, with its depth of about 500 m and its head swelling. The current results emphasize the critical role of sea breeze in forecasting surface temperature and wind, and contribute to relieve heat wave especially in summer in the Yeongdong region.

• 한국대기환경학회지
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• 제20권1호
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• pp.1-15
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• 2004

Sea/land circulation system is a representative mesoscale local circulation system in coastal area. In this study, wind fields around coastal area. Pohang, which is affected by this system was investigated and its detailed characteristic analysis was carried out. The following can be found out from the numerical simulation. Generally, at nighttime mountain winds prevail and land breeze toward the coastal area was well simulated During daytime, valley wind and sea breeze was simulated in detail. Especially, as a result of analyzing the land breeze path, it could be found along the coastline as it flows out through low land coastal area. In order to investigate the accuracy of model results. wind speed, temperature and wind direction of continuous typical sea/land breeze occurrence day was compared with observation data. Analyzing the characteristics of local circulation system was very hard because of horizontally sparse observation data but from the above result, a numerical simulation using RAMS, which satisfies the spatial high resolution, will provide more accurate results.

• 과학교육연구지
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• 제38권1호
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• pp.160-167
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• 2014

이 연구의 목적은 해륙풍에 대해 초등학생들이 어떻게 인지하고 있는지 알아보는 것이다. 연구를 위해 J시 소재 초등학생 159명을 표집하였다. 연구결과 초등학생들 중 해륙풍과 바람이 부는 이유에 대해 바르게 이해하고 있는 학생은 총 159명 중 45명(29.3%)에 불과했다. 대부분의 학생들은 실험결과를 가지고 그대로 해륙풍의 방향을 설명하였다. 즉 학생들은 실험결과를 가지고 해륙풍을 추리하지 않고 있었다. 학생들은 추론 과정을 거치지 않고 실험결과를 그대로 해륙풍의 방향으로 결론지었다. 이러한 결과는 해륙풍에 관한 바른 이해를 위해 새로운 실험 기구의 개발과 실험과 관련된 학습 과정에서 추리 과정을 강조하여 가르쳐야 한다는 점을 시사해주고 있다.

• 대기
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• 제15권4호
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• pp.191-202
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• 2005

This study was conducted to estimate how vertically high and horizontally long a sea breeze occurred around Gangneung of the Korean peninsula would be reached to an inland. Geographically, gangneung is located on the center of the east coast shaping an arc, and a coastal line around gangneung has a form extending northwestward and southeastward, respectively. Therefore, an inflow of the northerly has similar effects of the sea breeze since a deep valley of Daegwallyeong, which is one of main ridges of the Taebaek mountains, not only reaches northeastward up to this region but also plays the part of the steering gear changing a wind direction from northerly to easterly, this is, the wind from sea. First of all, the study had defined the sea breeze as a wind blown from NNE to ESE, clockwise. And then, we analyzed characteristics of the sea breeze occurred around gangneung in view of the maximum wind speed and the wind direction for October 1st, 2003 through September 30th, 2004, the upper air database for May through June of 2004, and the wind vector database of AWS (Automatic Weather System). All meteorological information is collected at the weather station of gangneung and by the AWS which is being scattered around this region. Finally, the study figures out that how horizontally long a sea breeze would be reached depends on a level of the easterly inflow. At the first step of the inflow of the sea breeze, the wind from NNW blows into this region by keeping up the speed $3m{\cdot}s^{-1}$, and effects of the northerly are dominated with time and the wind at the inland blows out southwestward cause of the surface friction at the next step. On the other hand, there is no change of wind direction in the inflow at Daegwallyeong because a surface friction of there is smaller than around gangneung, relatively. In other word, the easterly blows toward Daegwallyeong. However, the wind speed is not higher than that of the coast around gangneung.

• 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.

• 한국환경과학회지
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• 제6권6호
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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.

• 한국대기환경학회지
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• 제18권1호
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• pp.1-10
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• 2002

A three-dimensional numerical model which involved the nesting method was developed to reproduce the wind circulation of Kwangyang Bay area which comprises complicated mountains and sea topograph. The calculated results indicated geographical effects of Kwangyang Bay area, sea/land breezes and mount-valley wind which are local circular winds. We also noticed that the northern inland area of Kwangyang Bay formed the very complex wind systems under the influence of such geographic effects when a land breeze was not formed. A good agreement was found between predicted and observed values of temperature. In addition, the calculated results of the wind direction and the wind velocity are in accord with the observed values. They showed only a slight difference in between predicted and the observed values, when the sea breeze and the land breeze are changing.