• 한국대기환경학회지
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• 제10권4호
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• pp.252-259
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• 1994

A ground station has been established at Kosan, Cheju Island, since January of 1992 for the monitoring of background air Pollutant levels in Korea. Anthropogenic pollutant sources and meteorological conditions of Kosan were surveyed. Concentrations of SO$_2$, NO, NO$_{y}$ and $O_3$, were measured and analyzed for the period of February through December, 1992. The annual means of NO and SO$_2$, levels were very low in comparison to other urban's levels and similiar to other country's background levels. The annual mean of $O_3$, level was higher than urban's but comparable to other coastal region's. The NO concentration showed a distinct seasonal and diurnal variations. Summer peak was detected in the monthly means of NO and smooth peak around noon was found in the annual means of hourly data. Diurnal variation of the SO$_2$ concentration was barely detected but a slice increase in winter was detected. The $O_3$, concentration data, however, showed seasonal and diurnal variations similar to the urban's.an's.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E3호
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• pp.129-142
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• 2002

This paper provides a long-term perspective for ozone concentrations at 20 national air quality monitoring sites in Seoul from 1989 to 1998, which were managed by the Korean Ministry of Environment. Ozone episodes occurred more frequently in the east areas (Bangi, Guui, Seongsu, and Ssangmun) than in the west area (Guro and Oryu). When an ozone episode happened, hourly ozone concentrations over 80 ppb continued for an average of 4.0 hours at all sites. Annual variations in daily mean and maximum oBone concentrations showed broadly consistent upward trends at Ssangmun and Gwanaksan. Monthly mean ozone concentrations were the highest from May to June and the 99$^{th}$ and 95$^{th}$ percentile levels appeared higher during June, July, and August. The diurnal patterns of hourly mean ozone levels in urban areas showed typical photochemical formation and destruction, while the flat diurnal shape before 1996 at Gwanaksan indicated few significant photochemical reactions due to a lack of precursors of ozone. The occurrence of ozone over 80 ppb was ascribed to meteorological conditions such as high temperature, strong solar radiation, low relative humidity, and low wind speed with winds most frequently in a westerly direction.

• 한국대기환경학회지
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• 제18권1호
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• pp.11-23
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• 2002

The concentrations of aldehydes were measured in downtown area of Buchun and Kwanghwamoon of Seoul from October 1997 to August 1998 using 2-series impingers. The data have been analysed to identify the seasonal pattern of aldehyde sources in metropolitan areas. The measured concentration (in ppbv) of aldehydes were 8.86 $\pm$ 7.28 HCHO (formaldehyde) and 7.79$\pm$7.29 $CH_3$CHO (acetaldehyde) in Buchun, while recording 10.13$\pm$8.58 (HCHO) and 7.64$\pm$6.65 ($CH_3$CHO) in Kwanghwamoon. Their diurnal variation patterns showed significant increase of HCHO and $CH_3$CHO concentration in early afternoon, indicating an increase in secondary sources. Their concentrations however decreased in the nighttime, regardless of seasons. The strength of correlations between certain pairs such as (1) HCHO and CO and (2) $CH_3$CHO and CO were generally high during the winter months (0.64< r < 0.84), suggesting the possibility of similar source processes for HCHO, $CH_3$CHO and CO. On the other hand during the summer months, their correlations are frequently lower than winter months. We suggested that the complexity of source/sink processes during the summer period may reduce the correlations between aldehyde and CO.

• 한국환경복원기술학회지
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• 제13권1호
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• pp.32-39
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• 2010

The air temperature-reducing effects by irrigation reservoir in urban area was investigated at Ilwol Pond (IWP). Air temperature and humidity data were observed at 10minute interval from September 1th, 2008 to August 31th, 2009. Air temperature of IWP and Sumsung Apartment (SAT) were analyzed to examine air temperature-reducing effects by IWP in terms of diurnal and seasonal variation. As a result, the average air temperature difference between IWP and SAT was $0.6^{\circ}C$ and the nighttime shows more air temperature-reducing effects. The dominant air temperature-reducing effects by IWP occurred at fall night and summer daytime. However, the air temperature-reducing effects by IWP is lower to that by Arboretum (ARB).

• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.304-307
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• 1997

Rectal temperature (Tr), skin surface temperatures (Ts), and heart rate (HR) were measured continuously from birth (day 1) till day 7, while resting heat production (HP) was measured in a chamber on days 1, 3, 5 and 7, in order to study the characteristic variation of Tr in newborn calves by heat balance methods. Despite constant levels of milk being given to the newborn calves each day, daily mean resting HP was lowest on the day of birth, then increased to peak on day 3 and then decreased slightly thereafter. Daily mean HR was higher on days 2, 3 and 4, than on other days. Tr exhibited diurnal rhythms and daily mean Tr was low on day 1, high on day 3, and then decreased slightly after day 3. Daily average mean skin temperature (mTs) was similar on all days. Mean body temperature (Tb) exhibited diurnal rhythms and had a similar range between days, suggesting that heat balance and thermoregulation were carried out effectively on each day. The variation of Tb appeared to be synchronized with that of HP and suggested that newborn calves might use variations in the levels of Tb to facilitate the body's required levels of heart loss.

• 한국환경과학회지
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• 제29권7호
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• pp.749-760
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• 2020

This study investigates the characteristics of diurnal, seasonal, and weekly roadside and residential concentrations of PM₁₀ and PM_2.5 in Busan, as well as relationship with meteorological phenomenon. Annual mean PM₁₀ and PM_2.5 concentrations in Busan were 44.2 ㎍/㎥ and 25.3 ㎍/㎥, respectively. The PM_2.5/PM₁₀ concentration ratio was 0.58. Diurnal variations of PM₁₀ and PM_2.5 concentrations in Busan were categorized into three types, depending on the number of peaks and times at which the peaks occurred. Roadside PM₁₀ concentration was highest on Saturday and lowest on Friday. Residential PM₁₀ concentration was highest on Monday and lowest on Friday. Residential PM_2.5 concentration was highest on Monday and Tuesday and lowest on Friday. PM₁₀ and PM_2.5 concentrations were highest on Asian dust and haze, respectively. The results indicate that understanding the spaciotemporal variation of fine particles could provide insights into establishing a strategy to control urban air quality.

• 한국대기환경학회지
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• 제13권2호
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• pp.115-122
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• 1997

Diurnal variation of $PM_{10}$ concentration was investigated for 24 sites in library including reading room, bookstock room, lobby, office and so on, and 9 sites in student building at Kangwon National University using scattering light integrated type digital dust indicator. The dimensional conversion factors for mass concentrations (K) were determined by comparing between the $PM_{10}$ concentrations collected by $PM_{10}$ hig volume air sampler and the digital dust indicator. The dimensional conversion factor (K) was 3.33 for indoor air in this experiment. The highest concentrations were 649 $\mug/m^3$/day for smoking room in the library and 242 $\mug/m^3$/day for circle room in the student building. Most of spaces in the library except a office and bookstock rooms were over 150 $\mug/m^3$/day of $PM_{10}$ concentrations and 6 indoor spaces were over the guideline for indoor air quality in student building except a health center and two restaurants. Therefore, it should be required to make an improvement on the indoor air quaility for public facilities in the university buildings.

• 한국환경과학회지
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• 제9권4호
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• pp.295-302
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• 2000

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone, nitrogen dioxide and meteorological data for 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was the highest at Dongsamdong in Spring(35.4ppb), at Kwangbokdong in Fall(25.1ppb) and the lowest Dongsamdong(22.2ppb) and Kwangbokdong(16.0ppb) in Winter. Relative standard deviation indicating clearness of observation site was 0.42 at Dongsamdong and 0.49 at Kwangbokdong that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong and Kwangbokdong showed maximum at 1500~1600LST and minimum 0700~0800LST that typical pattern of ozone concentration. In ozone episode period(Sept. 10~15, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface. During the episode days peak ozone concentrations are much higher than the normal values, wind speeds are always lower, and solar radiation is high with the exception of the September episode.

• 환경영향평가
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• 제8권2호
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• pp.21-29
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• 1999

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone and meteorological data of 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was highest in Spring(35.4ppb) and lowest in Winter(22.2ppb). Relative standard deviation indicating clearness of observation site was 0.42 that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong showed maximum at 15~16LST and minimum 07~08LST that typical pattern of ozone concentration. In ozone episode period(May 18~23, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface.

• 한국해양학회지
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• 제19권2호
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• pp.210-216
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• 1984

5년간의 시간별 풍속 자료를 이용하여 연안 표층풍의 일변화가 분석되었다. 특히 내륙으로 부는 바람 (onshore flow)이 지배적인 계절에는 야간 최대풍의 최대 출현 빈도가 자정에 나타났다. 연평균 남풍 계열을 갖는 야간 최대풍은 북풍 계열 보다 약 3배이상의 출현을 보여준다. 중림의 대기 안정도가 연안에 지배적이므로 바람이 해양에서 내륙으로 불 경우는 (offshore flow) 상승된 전선역전층과 지표역전층에 의해 형성된 전단력(shear flow)이 연안경계층으로 전이되어 야간 연안 최대표층풍이 형성된다.