• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.545-554
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• 1998

The diurnal variation of O3 concentration shows two peaks, the first peak at noontime and the secondary peak at night. In order to show why the secondary peak, high nocturnal O3 concentration, occurs without sunlight which is a essential factor of a photochemical response, the O3 concentration, several weather elements and synoptic weather map were used for June∼September at 1995, 1996. The mean concentration of high nocturnal O3 concentration days is higher by 5.4 ppb than that of low nocturnal O3 concentration days. The nocturnal O3 concentration is higher than that of diurnal O3 concentration during high nocturnal O3 concentration days, at July, 1995 and June, 1996. The high nocturnal O3 concentration is related to low air pressure, high cloud cover and high wind speed. The correlation coefficient, r. between nocturnal O3 concentration and wind speed, pressure and cloud cover is 0.387, -0.218, and 0.194, respeftiviely. It is interesting that the O3 concentration increases at Pusan when the typhoon passes by. The same result showed at Taegu when the typhoon FAYE passed by. According to the analysis of nocturnal O3 concentration for June∼September at 1995 and 1996, it seems that the high nocturnal O3 concentration relates to the trough and cyclones passing by Pusan.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.437-444
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• 2001

The characteristic features of surface ozone concentration and the forecasting procedure of high ozone days have been studied. The ozone concentration was continuously measured during 3 years (1997~1999) at air quality monitoring stations in five major cities in Korea. The diurnal variation of surface ozone concentration on high ozone days is characterized by low ozone concentration at night. The ozone concentration Increases continuously after sunrise, In reach a peak at 1500~1600 LST. Thereafter it decreases steadily to a low concentration at sunset. The diurnal and annual maximum of the surface ozone concentration at Seoul were observed in May and June, respectively. The favorable synoptic condition for the high ozone day is divided into 4 different synoptic weather patterns: a high-pressure system from the Sea of Okhotsk, the Pacific subtropical high extending westward, a moving high-pressure system covering the Korean peninsula. and a synoptic system In front of a typhoon. Most of high ozone days occur under the high pressure system in Korea.

• Journal of Environmental Science International
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• v.9 no.4
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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.

• KIEAE Journal
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• v.12 no.6
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• pp.93-98
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• 2012

The concerns on high ozone concentration phenomenon is significantly growing in Seoul metropolitan area including the industry complex area, like Shiwha Banwol area. The aims of this research is the analysis of relationship between high concentrations of $O_3$ and solar radiation parameters in atmosphere. The understanding of the effects of solar radiation intensity, humidity, high air temperature on ozone concentration in a day is very useful to provide a direction for reducing of the high ozone concentration to a local government or a metropolitan government. The correlation analysis between maximum ozone concentration and various meteorological parameters in 2009 - 2011 carried out using IBM's SPSS program. The results showed that the mean correlations coefficient (R) between daily Ozone maximum and solar radiation resulted R = 0.64 during 2011. May - September in 10 air pollution stations. In case of correlations between daily ozone maximum and relative humidity showed negative correlation R = -0.61. The correlation analysis with mean air temperature during 1-3 PM resulted R = 0.29. This low correlation coefficient could be corrected by using of categorized data of ozone concentration. The daily maximum ozone concentration is more dependent on peak solar radiation and high air temperature during 1-3 PM than its simple daily maximum values. The results of this research would be used to develop the high ozone alert system around Seoul metropolitan area. This correlation analysis could be partially integrated to prediction of ozone peak concentration in connection with other methods like classification and regression tree(CART).

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.215-224
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• 2004

We report the high concentration episodes for PM$_{10}$, SO$_2$, NO$_2$, and $O_3$ in many urban areas Korea during 2002. The high concentration episodes are identified based on the National Ambient Air Quality Standards and the observations obtained from the Regional Air Monitoring Network composed of approximately 160 air pollution monitoring stations located in a number of major or big cities in South Korea including Seoul, Pusan, Daegu, and Incheon cities. The results show that the twenty cases of high concentration episodes in 2002 consists of both ozone warning episodes (6 cases) and high PM$_{10}$ concentration cases (14 cases), and one half of the latter are found to occur in association with the Yellow Sand (Asian Dust) phenomena. The most outstanding characteristics of the reported episodes are the excessively high levels of maximum PM$_{10}$ concentrations during the Yellow Sand period (i.e., exceeding 3,000$\mu\textrm{g}$/㎥ in April, 2002) and their variable occurrence frequencies across seasons. The high ozone concentration episode days are mainly resulting from both the high photochemical reactions and poor ventilations. The high PM$_{10}$ concentration days during non Yellow Sand periods, however, mostly occurred under the influence of synoptic meteorological conditions such as stagnant or slowly passing high pressure centers, and consequently prevailing weak wind speeds over the Korean peninsula. The overall results of our study thus suggest the importance of both synoptic and local meteorological factors for high concentration levels in the major and/or big cities in Korea.n Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.119-128
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• 2004

The nitrate concentrations in PM$_{2.5}$ and TSP measured at Gosan, Jeju Island, Korea, between March 1998 and February 2002, are discussed. Especially, the characteristics of high nitrate concentration days were analyzed. High nitrate concentration cases in PM$_{2.5}$ were highly correlated with anthropogenic species such as NH$_4$$^{[-10]}$ , and high nitrate concentration cases in TSP were highly correlated with crustal species such as nss-Ca$^{2+}$ and nss -Mg$^{2+}$ Backward trajectory analysis results show the cases of high correlation between nitrate and anthropogenic species occurred when the air parcels moved from China, and the cases of high correlation between nitrate and crustal species occurred when the air parcels moved from Mongolia. Also, high nitrate concentration cases occurred most often in spring (65%) when the air parcels moved from Mongolia and China.ina.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.1
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• pp.41-49
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• 1997

Status of photochemical air pollution in the Greater Seoul Area (GSA) between 1990 and 1995 was assessed in terms of frequency distributions, number of days exceeding standards, average concentration and meteorological effects. In Seoul compared with other areas in Korea, daily maximum concentration was higher but average concentration was not so high due to lower daily minimum from April to October. The top 5th percentile was high especially in summer season. Average number of days exceeding 100 ppb at monitoring stations in GSA was highest in 1994, the hottest year, but it was only 4 days a year. Mean meteorological pattern of high ozone days could be summarized as low wind speeds, high temperatures, strong solar radiation, and low precipitation. Westerlies were more frequent on high ozone days and at Pangi station located in the eastside of GSA, both number of high ozone days and average concentration were high. Effect of precursor transport on the rise of ozone concentration was, however, not consistently important on the whole in GSA.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.465-471
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• 1999

The concentration of air pollution in a large city such as Pusan has been increased every years due to the increase on fuel consumption at factories and by vehicles as well as the gravitation of the population. In this study, we have analyzed $NO_2$ concentration data and various data of meteorological factors during 1994-1997 to investigate the characteristics of $NO_2$ concentration and how the high $NO_2$ concentration is generated under the meterological condition. According to the study, $NO_2$ peak concentration at most sites occured about 1h later after the rush hour. In the characteristics of emissions in sites, sinpyeong-dong was highly contributed to point source while the other sites were highly contributed to line source. The high $NO_2$ concentration had high generation probability when temperature contained typical seasonal characteristics and wind speed was low. Using the relationship between meteorological factors and the daily average $NO_2$ concentration, correlation analysis was practiced. the seasonal variation of the daily average $NO_2$ concentration was correlated with air temperature, solar radiation and wind speed, but the correlation coefficient between meteorological factors and the daily average $NO_2$ concentration was not so much high. Thus we have known that the daily average $NO_2$ concentration is partially explained by meteorological factors.

• Journal of Environmental Science International
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• v.21 no.7
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• pp.815-824
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• 2012

The purpose of this study was to analyze the meteorological characteristics of wintertime high PM10 concentration episodes in Busan. $PM_{10}$ concentration has been reduced for the past four years and recorded near or exceeded 100 ${\mu}g/m^3$ (national standard of $PM_{10}$). High concentration episodes in Busan were 6 case, $PM_{2.5}/PM_{10}$ ratio was 0.36~0.39(mean 0.55). High $PM_{10}$ concentration occurred during higher air temperature, more solar radiation and sunshine, lower relative humidity, and smaller cloud amount. Synoptically, it also occurred when Busan was in the center or the edge of anticyclone and when sea breeze intruded. An analysis of upper air sounding showed that high $PM_{10}$ concentration occurred when surface inversion layer and upper subsidence inversion layer existed, and when boundary layer depth and vertical mixing coefficient were low. An analysis of backward trajectory of air mass showed that high $PM_{10}$ concentration was largely affected by long range transport considering that it occurs when air mass is intruded from China.

• Analytical Science and Technology
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• v.12 no.4
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• pp.312-317
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• 1999

Quality control was carried out the three analytes, BOD, COD, TN, TP of high and low concentration for thirteen laboratories. Evaluation values of Quality control was determined from average value which were made by six times test, repeatedly and periodically. This value had not only error ratio of within 5% from prepared sample value but also high precision of standard deviation, 0.44 (BOD, low concentration), 2.15 (BOD, high concentration), 0.12 (COD, low concentration), 1.63 (COD, high concentration), 0.35 (TN, low concentration), 1.99 (TN, high concentration), 0.05 (TP, low concentration), 0.14 (TP, high concentration). Upper (Lower) Warning Limit (ULWL) and Upper (Lower) Acceptance Limit (ULAL) values made from quality control chart. Three (5.30, 9.70, 5.30 mg/L) and five laboratories were over ULAL value in low and high BOD concentration, respectively. Two (41.00, 30.60 mg/L) and four laboratories were over ULAL value in low and high COD concentration, respectively. while, other eleven laboratories appeared reliable data. One laboratory (0.70 mg/L) was over ULAL at low TN concentration, while other eleven laboratories had reliable values. In case of high TN concentration, eleven laboratories were over ULAL value, it should be focuced for improvement of reliability about measurement and analysis of TN. Four (1.14, 0.45, 0.64, 1.49mg/L) and seven laboratories were over ULAL in low and high TP concentration, respectively.