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        검색결과 63

        41.
        2002.07 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the characteristics of role of transport on aerosol concentration at Crate Lake, Oregon USA for 1988.3~1999. 5. The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from USA federal and regional-state organizations. Also IMPROVE sampler is designed to obtain a complete signature of the composition of the airborne particles affecting visibility. According to 10-day backward isentropic trajectory analysis, the frequency of local, marine and Asian trajectory showed 33.1%(335 cases), 47%(478 cases), 5.2%(53 cases) respectively. The monthly variation of nss SO42-, nss S, NO3-, K and C showed the double peak pattern, high in April~May and August~September and showed the lowest concentration in Winter. The other constituents concentration except for Cl-, Na, Mg was high in local trajectory than marine trajectory. A ratio nss SO42- to SO42- was 90.5% in marine trajectory and 98% in local trajectory. It suggest that the aerosol in Crater Lake was effected by salt. The annual mean concentration of nss SO42- and nss S decreased but the the springtime concentration increased.
        42.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        Cheeka Peak is a unique site for monitoring the background chemistry and aerosol contents of pristine marine air at mid-latitude. During long-range onshore winds that occur frequently throughout the year, it is predicted to have the cleanest air in the northern hemisphere. Measurements of CO and O3 were conducted at Cheeka Peak Observatory(CPO) on the northwestern tip of Washington state, USA during March 6 ~May 29, 2001. The data have been segregated to quantify the mixing ratio of these species in the Pacific marine atmosphere. Also the marine air masses were further classified into four categories based on 10-day backward isentropic trajectories; high, mid, and low latitude and those which had crossed over the Asian industrial region. The diurnal variation of CO and O3 at CPO showed a similar to tendency of background measurement site. When marine air mass flowed to CPO, CO concentration was lower and O3 was similar or higher than those of total data. The westerly flow from ocean, not easterly from continent occurred the high concentration of CO and O3 at CPO. Using the trajectory segregation of marine air mass, the comparison of concentration according to latitude calculated. the CO concentration of Asian trajectory was lower than other latitudes, O3 concentration was higher.
        43.
        2002.04 KCI 등재 서비스 종료(열람 제한)
        This study was carried out for reading the change of local meteorological environment according to dam construction of Nakdong-river using numerical model. The study used PSU/NCAR Mesoscale Model version5(MM5) for inquiring effect of formation of artificial lake after dam construction. The colleague simulated temperature mixing ratio, latent heat flux and sensible heat flux in two cause of existing lake and not. Temperature and mixing ratio in southwest of Andong lake increased because of the air that was warm and moist above the lake moved to southwest due to the northeasterly wind. In the case of existing lake around Andong, latent heat flux increased much in the daytime after sunrise. However, sensible heat flux decreased but it didn't change distinctly in southwest of Andong like the other values.
        44.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        This study was carried out for reading the change of local meteorological environment according to dam construction of Nakdong-river using meteorological data analysis, and modeling. The meteorological data analysised are mean temperature, foggy day, precipittion day and sunshine time. As the result of analyzing meteorological data of before and after the construction of dam in Andong and Hapchon, some discrepancy were observed by month because the lakes have different effect on the region as wind field. The common phenomenons that are revealed after dam construction are increase of foggy day and decrease of sunshine time.
        45.
        2001.12 KCI 등재 서비스 종료(열람 제한)
        The vertical structure of atmosphere was observed to investigate the variation of surface ozone concentration by vertical downward mixing of residual ozone in the atmospheric boundary layer at the Busan coastal area. Airsonde and pilot balloon measurements were made at Gamcheondong and the Kimhae airport for April 26∼27, 1996. The vertical profile of potential temperature showed a residual layer between 510m and 1800m from 2100LST April 26 to 0900LST April 27. The downward mixing of ozone in the residual layer of the atmospheric boundary layer was confirmed from vertical profile of mixing ratio near 600m in the morning. The thickness of the sea breeze layer was 900m at 1500LST April 26. Thereafter, it become to be lowered with time. A low level jet was measured near 900m at 0300LST on April 27 from a pibal measurement. Early morning sharp increase of surface ozone concentration at the Busan coastal area was caused by vertical downward mixing of ozone concentration rather than by photochemical reaction in the atmospheric boundary layer.
        46.
        2000.08 KCI 등재 서비스 종료(열람 제한)
        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.lppb) 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.
        47.
        1999.10 KCI 등재 서비스 종료(열람 제한)
        A series of meteorological observation using automation weather station(AWS) carried out to investigate characteristics of nocturnal meteorological parameters for 16∼17 June 1998 at Buljeongdong mountain slope, Kyungbuk. Dry temperature at valley was lower than mountain because of high lapse rate at valley, so the strong inversion layer occurrenced at mountain slope for nighttime. Contrary of dry temperature, relative humidity of valley was higher than mountain for nighttime. Wind speed at valley from sunset to next day morning was lower than mountain, but that of valley after sunrise was higher than mountain. Wind direction at valley for all observation time were southeasterlies(SE), that of mountain for nighttime were northeasterlies(NE) or northnorthwesterlies(NNW), and that of mountain after sunrise were irregular. Vapor pressure at valley for all observation time was higher mountain, particularly the difference was high for nighttime.
        48.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the characteristics of nocturnal maximum ozone occurrence and the meteorological relevance using to hourly ozone data and meteorological data for 1995∼1996 in Pusan coastal area. Kwangbokdong showed the highest occurrence of nocturnal maximum ozone as 36.9%, and Deokcheondong showed the lowest occurrence(9.2%) for research period in Pusan. The occurrence rates of nocturnal maximum ozone concentration were decreased toward land area. The low maximum temperature, high minimum temperature, low diurnal range, high relative humidity, high wind speed, high cloud amount, low sunshine and low radiation were closely related to the main meteorological characteristics occurring the nocturnal maximum concentration of ozone. It was shown that normal daily variation of ozone concentration by strong photochemical reaction at the before day of nocturnal maximum ozone. The concentration of nocturnal maximum ozone were occured by entrainment of ozone from the upper layer of developed mixing layer. There are no ozone sources near the ground at night, so that the nighttime ozone should be entrained from the upper layer by forced convection.
        49.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to examine the monthly and seasonal variation of SO2, TSP, O3 concentration in Dongsamdong, Pusan coastal area. And the characteristics of air pollution of this area was compared to Kwangbokdong in Pusan and Taehadong in Ullungdo. Monthly mean concentration of SO2 and TSP showed lower than Kwangbokdong, O3 was higher than Kwangbokdong. In case of SO2, seasonal variation of Dongsamdong was remarkabler than Kwangbokdong and the concentration difference of early morning and daytime was higher than Kwangbokdong, Taehadong showed very lower concentration as background area. In case of TSP, Dongsamdong was lower concentration and smaller diurnal change than Kwangbokdong, Taehadong showed very lower concentration as background area. In case of O3, Dongsamdong was l0ppb higher than Kwangbokdong at daytime maximum concentration, diurnal change of concentration was higher, too. In case of frequency distribution of concentration, SO2 and TSP at Dongsamdong showed higher frequency in low concentration class and O3 showed in high concentration class as compared with Kwangbokdong.
        50.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        The two-stage numerical model was used to study the relation between three-dimensional local wind model, advection/diffusion model of random walk method and second moment method in western coastal area for Korean peninsula. The first stage is three dimensional time-dependent local wind model which gives the wind field and vertical diffusion coefficient. The second stage is advection/diffusion model which uses the results of the first stage as input data. First, wind fields on Korean peninsula for none synoptic scale wind showed typical land and sea breeze circulation, and the emitted particles were transported by sea breeze for daytime, emissions return to sea by land breeze for nighttime.
        51.
        1998.04 KCI 등재 서비스 종료(열람 제한)
        The low level atmospheric observation carried out to investigate magnitude, formation and dissipation of nocturnal surface inversion layer, also to survey relation to each meterological parameter in inversion layer at Pusan power plant for Oct. 13, 1996. As coastal area, the surface inversion layer height was relatively high(186m), and after sunset unstable layer formated from surface to around 40m, and the inversion layer was left still in the upper layer. The surface inversion layer dissipated at 0920LST perfectly. The layer that strong inversion layer was formated, showed steep variation of potential temperature and wind speed and relative humidity.
        52.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        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 distribution 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.
        53.
        1997.08 KCI 등재 서비스 종료(열람 제한)
        Numerical simulations of photochemical air pollution (CBM: Carbon-Bond Mechanism) under a theoretical three-dimensional local wind system are carried to clarify the fundamental characteristics of the effects of local wind on photochemical air pollution. According to the AWS data of Pusan coastal area and KMA, the surface wind of Pusan during summertime showed a very remarkable land and sea breeze circulation. The ozone concentration distribution using local wind model showed that high ozone concentration zone near coastal area moved toward inland in the afternoon. This change implies a sea breeze increases the ozone concentration, but a land breeze decreases it in Pusan coastal area
        54.
        1996.12 KCI 등재 서비스 종료(열람 제한)
        For the efficient control of atmospheric quality, it is so important to predict the influence accurately of which the air pollutant emitted into the atmosphere. Atmospheric dispersion model enables to simulate and grasp the atmospheric condition occurred due to the emission of pollutants. The result of model is largely affected by the amount of emission, the characteristics of physical and chemical process, meteorological input data, and the receptor which the concentration is calculated. The aim of this research, therefore, is to suggest more suitable model in Pusan area than other areas by performing TCM2, CDM2.0 and ISCLT2 models. As the basic work for executing the model, we computed the amount of emission of air pollutants in Pusan at 1992 and analyzed the occurrence frequency of atmospheric stability for recent decade(1985∼1994). CDM2.0 showed the similar result relatively with observed value in the case of full year(1992), fall and winter, and ISCLT2 brought more suitable result in spring for Pusan area. As the result of this research, in future, it is necessary for us to develop the numerical model considering the topographical characteristics, to select the proper observation site and to increase the observation site for Pusan.
        55.
        1996.08 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate the level of atmospheric heavy metals and the relationship of that concentration with weather conditions. This research monitored the concentration of Total Suspended Particulates (TSP) at every three hours by using High Volume Air Sampler from December 24th, of 1995 to Febuary 20th, 1996 in Kimhae area, which recently became a rapidly growing residential and industrial sitc. The items such as air-temperature, relative humidity, radition, wind speed, and wind direction were monitored by using Atmospheric Weather System at the same time. From the collected TSP, the concentration of heavy metals were analyzed by using the Atomic Absorption Spcetrophotometry. The mean concentration of TSP was 110.4 ㎍/㎥, and the mean concentration of lead (Pb), copper (Cu), chromium (Cr), manganese (Mn), cadmium (Cd), were 0.837 ㎍/㎥, 0.486 ㎍/㎥, 0.264 ㎍/㎥, 0.157 ㎍/㎥, 0.054 ㎍/㎥, respectively. Regarding daily variations, the concentration of TSP was highest in the morning (158.1 ㎍/㎥) followed by evening (119.4 ㎍/㎥) and afternoon (111.1 ㎍/㎥). The concentration of Pb and Mn was higher in the morning, and that of Cu, Cr and Cd was higher in the afternoon and the evening. Regarding the relationship between the concentration of pollutants and weather condition, the concentration TSP revealed positive correlation with temperature, humidity, wind speed, but negative correlation with radition (p<0.01). The concentration of Mn revealed positive correlation with temperature and humidity, but negative correlation with wind speed (p<0.01). And the the concentration of pollutants and weather condition revealed higher correlation within the same time period. In summary, the paralleled mornitoring of air conditions and weather condition should be recommended to get the correct informations concerning the pollution and to prevent the deterioration of air conditions.
        56.
        1996.08 KCI 등재 서비스 종료(열람 제한)
        The surface meteorological and upper layer meteorological observation carried out to investigate influences of sea breeze effect on lower layer atmosphere at Gori nuclear power plant for 29∼30 July, 1996. According to surface meteorological data, the inflow of sea breeze was occurred 11:30 on 29 July, 10:30 on 30 July, respectively at observation site. And the meteorological tower data showed that wind direction of sea breeze was identified as south-westerly, and wind speed of 58 m was 2 times stronger than that of 10 m. It is notworthy that surface inversion layer which built from the night time to daybreak of next day was not broken off by seab reeze`s inflow for daytime, and strong inversion layer observed at 47∼243 m with moderately stable class (F) by URC. It was found that strong stable layer of potential temperature appeared at that layer, maximum relative humidity observed at the bottom of inversion layer and maximum mixing ratio observed in the low of inversion layer.
        57.
        1996.08 KCI 등재 서비스 종료(열람 제한)
        Pusan is the largest coastal city with a population of about four million in Korea. Because of increased and confused traffic, photochemical air pollution become a major urban environmental problem recently. The photo-chemical air pollution weather forecasting method preciser than existing air pollution forecast method has been developed to forecast ozone episode days with meteorological conditions using the data measured at 7 air quality continuous monitoring stations from June to September using 2 years (1994, 1995). The method developed in present study showed higher percentage correct and skill score than existing air pollution forecasting in KMA (Korea Meteorological Administration).
        58.
        1996.06 KCI 등재 서비스 종료(열람 제한)
        Air pollution characteristics and the influence of sea breeze on surface ozone concentration were studied using the data measured at 7 air quality continuous monitoring stations from June to September using 3 years (1990, 1993, 1994) in Pusan coastal area. Among the 246 sea breeze days for research period, there were approximately 89 sea breeze days (36%) from June to September. And there were 120 the episode days (68%) of ozone greater than or equal to 60 ppb in summer season. In 89 sea breeze days, the episode day was highly marked as 56 days (63%). So, we knew that the sea breeze greatly affects the occurence of ozone episode day. the ozone concentration under the condition of the sea breeze increase about 40% in the daytime. Frequencies distribution of O3 concentration for sea breeze moved toward high concentration class. The characteristics of ozone concentration in relation to meteorological conditions of sea breeze is significant because we can discover major weather factors for eastablishing an air pollutionweather forecast system. For further study about meterological approach method for photochemical air pollution, it is necessary to explain the characteristics of atmosphere below 1,000 m, especially concerning the formation mechanism of inversion layers. And finally, we will study the relationships to synoptic weather conditions and vertical structure and diurnal variation of local wind systems including sea breeze, and the vertical movements of atmosphere in the city.
        59.
        1994.12 KCI 등재 서비스 종료(열람 제한)
        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 SO_2, 31.5% for TSP, 80% for 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.
        60.
        1994.03 KCI 등재 서비스 종료(열람 제한)
        The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Crout method be used for numerical calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed are, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.
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