• 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.

• Asian Journal of Atmospheric Environment
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• v.9 no.1
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• pp.1-11
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• 2015

Increasing ozone concentrations are observed over Japan from year to year. One cause of high ozone concentration in the Kanto region, which includes areas inland from large coastal cities such as metropolitan Tokyo, is the transportation of precursors by sea breezes. However, high ozone concentrations are also observed in the morning, before sea breezes approach inland areas. In this point, there would be a possibility of residual ozone existing above the nocturnal boundary layer affects the ozone concentration in the following morning. In this study, we utilized the Weather Research and Forecasting model and the Community Multiscale Air Quality model to evaluate the effect of regional precursors and residual ozone on ozone concentrations over the inland Kanto region. The results show that precursors emitted from non-metropolitan areas affected inland ozone concentrations more than did precursors from metropolitan areas. Moreover, calculated results indicate downward transportation of residual ozone, resulting in increased concentration. The residual ozone was also affected by precursors emitted from non-metropolitan areas.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.13-23
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• 2003

A local wind model and a three dimensional local environmental model including advection, diffusion, deposition. and photochemical reactions were performed at Gwangyang Bay, Korea, to predict air flow and air pollutants concentrations. A large grid was used, and nesting method was employed for small grid calculation. From the meterological module simulation, we were able to reproduce local wind characteristics such as sea/land winds and mountain/valley winds simulation at Gwangyang Bay. In addition, the concentration module showed high concentration regions at Yosu industrial complex, Gwangyang steel company. and Container anchor. It was also seen that air pollutants were dispersed by sea/land winds. A comparison between the measurement and the prediction of sulfur dioxide and nitric oxide, which are relatively low-reacted pollutants, was performed. However, the measured nitrogen dioxide and ozone concentrations were higher than the simulated ones. Particularly, ozone concentration between 8 a..m. and 8 p.m. agreed well, but the measured ozone during the rest of time were generally higher.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.323-340
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• 2003

There have been persistent civil appeals in Ansan area against the odor and aerosols emitted from nearby Banwol/Sihwa industrial complex. A fundamental solution for the good air quality has not been addressed yet in spite of the continuous counterplan to reduce odor emission. A systematic and scientific study is needed to examine the reason for the odor episode and to predict the impact coverage of odor pollution. An approach by computational simulation is considered to be adequate to investigate the transportation and the dispersion processes of air pollutants blown by sea breeze toward the coastal city, Ansan. This study has employed various dispersion models to simulate the transportation and the dispersion processes of odor pollutants by a local circulation between land/sea breeze using the data set of emission rates of odorous species from the Banwol/Sihwa industrial complex.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.246-258
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• 2010

A convective circulation box was redesigned after analyzing reasons why adolescent elementary school students could not derive a convective circulation concept from the convection circulation box experiments. Even though students were in the formal operational period of Piaget, the adolescents felt difficult to understand a concept of the natural phenomena they have never seen before. Thus, we designed a method to help students increase their scientific understandings about the concept through developing a miniature convective circulation box. Findings indicated that an application of redesigned convective circulation box in the classroom experiment significantly increased the students' understanding about the convective circulations of land and sea breezes, and as well as their participation in the activities. In addition, the redesigned convective circulation box motivated students to develop their scientific thinking skills by allowing them to decide where to put visible incenses inside the box and to directly observe the smoke currents circulation formed accordingly. Redesigning and using a convective circulationbox as a miniature of natural phenomenon helps students avoid having misconceptions. The biggest merits of the box are that it is observable in all directions, it provides much clearer convective circulations comparing to the extant box, and it requires low production costs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.721-730
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• 2021

Maritime air pollutants around port cities have gained a great deal of attention due to their direct impacts on regional air quality. This study aims to determine the geographical properties of sea/land breezes in different areas to discover overall ranges of maritime emission dispersion. The HOTMAC-RAPTAD modeling program was used to simulate regional-scale air dispersion considering non-linear and unsteady states during the general summer period for the target areas of the Yellow Sea (Incheon Port and Pyeongtaek·Dangjin Ports), archipelago region (Mokpo Port), South and East Sea (Busan and Masan Ports) and East Sea with mountainous area (Donghae·Mukho Ports). The resulting dispersion lengths of vessel emissions into the onshore regions around the target ports shed light on portal air quality management, because vessel emissions from the Incheon, Mokpo, Busan, and Donghae·Mukho ports were transported 27-31km (Western Seoul), 21-24km (Southern Muan), 20-26km (Gimhae and Yangsan), and 22-25km (Taebeak Mountains), respectively. Therefore, the results of this study provide useful data for regional air quality management and marine air pollution mitigation to improve the sustainability of port cities.

• Journal of Environmental Science International
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• v.3 no.1
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• pp.39-47
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• 1994

Dispersion characteristics of air pollutants in the mountainous coastal area are investigated in considering with the mesoscale local circulations using a two dimensional numerical model with two kinds of topograpy of 500m and 300m. In the model, land-sea breezes and mountain-valley wind are mainly considered under the condition of the absence of large scale prevailing flow in the circulation analysis, and the pollutants dispersion is traced by the Lagrangian methods. According to the results, the wind velocity is affected by topography and is stronger in the case of 500m height mountain than that of 300m, the Pollutants that source is near the coast transported over the mountain and dispersed to behind inland area. It is classified that the topography change control affects the wind velocity and the circulations. The pollutants that source is different transported and concentrated to behind inland and/or diffused to the sea area by the combination of the wind system with topographic changes. The results can be applied to the air pollution control with the arrangement design of industrial area and the planning of coastal developments.

• Advances in environmental research
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• v.6 no.2
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• pp.139-146
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• 2017

The purpose of this study was to determine the present air pollutant concentrations and predicted levels for next 30 years in urban environment of Karachi city. For that, a total of fifty measurements were made for each twenty selected locations of the city. The locations were selected on the basis of land use pattern such as residential, commercial, industrial settlements, open areas, congested traffic and low traffic areas for investigation of air pollutants variability and intensity. The measurements were taken continuously for six months period using PM Meter, Model AEROCET 531 and Ambient Air Quality Meter, Model AAQ 7545. The concentration of air pollutants were found higher at Al Asif Square and Maripur Road due to higher intensity of traffic and at Korangi Crossing because of industrial areas. The level of pollutants was lower at Sea View owing to lower traffic congestion and transportation of pollutants by sea breezes.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.137-145
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• 1997

To predict the effects of air pollutant in the coastal region, we have developed the air pollutant model, the reaction model and the deposition of NO, $NO_2, and O_3$. And the numerical model of air pollutant concentration employed the nested technique to calculate with the higher resolution for the area. The nested technique used two grid systems, one for the large scale calculating region with the coarse mesh grid (CMG) and the other for the small scale region with the fine grid (FMG). In other to prove the validity of the simulation model the calculations were conducted for the present situation. The results of them reasonably agree with the observed data and proved the validity of the model.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.5
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• pp.587-598
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• 1999

In recent years emissions of pollutants from ship sources, especially NOx and SOx, is controlled by IMO(International Maritime Organization). The emissions of pollutants from ship sources in Pusan is considerably large, because the number of ship's coming and going in Pusan port is larger than that of other ports in Korea. Since Pusan is under the strong influence of land-sea breezes, pollutants emitted from ship sources will be transported into the inland. Control of emissions from ship sources is required to devise effectively the policy of air quality management in Pusan. Therefore this paper considered the present condition of total pollutant sources and emission characteristics including in coastal urban area.